The cognitive profile of prion disease: a prospective clinical and imaging study

2015

Objectives Prion diseases are dementing illnesses with poorly defined neuropsychological features. This is probably because the most common form, sporadic Creutzfeldt-Jakob disease, is often rapidly progressive with pervasive cognitive decline making detailed neuropsychological investigation difficult. This study, which includes patients with inherited, acquired (iatrogenic and variant) and sporadic forms of the disease, is the only large-scale neuropsychological investigation of this patient group ever undertaken and aimed to define a neuropsychological profile of human prion diseases. Methods A tailored short cognitive examination of all of the patients (n = 81), with detailed neuropsycho…

Verbal suppression and strategy use: a role for the right lateral prefrontal cortex?

2015

Verbal initiation, suppression and strategy generation/use are cognitive processes widely held to be supported by the frontal cortex. The Hayling Test was designed to tap these cognitive processes within the same sentence completion task. There are few studies specifically investigating the neural correlates of the Hayling Test but it has been primarily used to detect frontal lobe damage. This study investigates the components of the Hayling Test in a large sample of patients with unselected focal frontal (n = 60) and posterior (n = 30) lesions. Patients and controls (n = 40) matched for education, age and sex were administered the Hayling Test as well as background cognitive tests. The sta…

Structural brain correlates of IQ changes in bipolar disorder

2006

Background. There is increasing evidence that cognitive deficits are present in bipolar disorder (BP), but their neural correlates have not been fully explored. The aim of this study is to correlate structural brain abnormalities with cognitive performance in BP and to explore differences between clinical subtypes. Method. Thirty-six BP patients (13 men, 23 women) with a mean age of 39 years (range 21–63 years) underwent neuropsychological testing and imaging. Twenty-five patients had bipolar disorder I (BP I) and 11 had bipolar disorder II (BP II). Patients with co-morbid psychiatric diagnosis, drug and alcohol abuse or systemic illness were excluded. Correlations between cognitive perform…

The neuropsychology of acquired calculation disorders

2010

Numbers and time doubly dissociate

2011

The magnitude dimensions of number, time and space have been suggested to share some common magnitude processing, which may imply symmetric interaction among dimensions. Here we challenge these suggestions by presenting a double dissociation between two neuropsychological patients with left (JT) and right (CB) parietal lesions and selective impairment of number and time processing respectively. Both patients showed an influence of task-irrelevant number stimuli on time but not space processing. In JT otherwise preserved time processing was severely impaired in the mere presence of task-irrelevant numbers, which themselves could not be processed accurately. In CB, impaired temporal estimatio…

Do aetiology, age and cogntive reserve affect executive performance?

2017

Background: The behavioral effect of frontal lesions may be influenced by confounding factors such as aetiology, age and cogntive reserve. Yet no studies have investigated their effects on patients with focal lesions. Objective: Is the grouping of patients with frontal lesions caused by stroke or tumours methodologically appropriate; does age affect cognitive performance, can cognitive reserve protect against cognitive impairment? Patients and Methods/Material and Methods: Cognitive performance was compared across a large sample of frontal patients with stroke, high or low grade tumour, or meningioma. The effect of age, education and NART IQ on the cognitive performance of patients with foc…

Monitoring cognitive changes: Psychometric properties of six cognitive tests

2004

Objectives. Repeated neuropsychological assessments are often used to monitor change in cognitive functioning over time. Thus, knowledge about the reliability and stability of neuropsychological tests and the effects of age and IQ is of paramount importance. In this study we document, for six cognitive tests: test-retest reliabilities, practice effects, reliable change (RC) indices corrected for practice, and the impact of premorbid IQ and age. Design. A sample of 188 normal adults (aged 40-70 years) were administered, on two occasions, one or more of the following tests: the Graded Naming Test (GNT), the Silhouettes Test, two tests of verbal fluency, the Modified Wisconsin Card Sorting Tes…

Underestimation of cognitive impairments by the Montreal Cognitive Assessment (MoCA) in an acute stroke unit population

2013

Abstract Background and purpose The Montreal Cognitive Assessment (MoCA) is an increasingly popular clinical screening tool for detecting cognitive impairment in stroke, but few studies have directly compared performance on the MoCA with neuropsychological assessment. Our retrospective study examined the extent to which intact performance on the MoCA reflects intact cognition as determined by neuropsychological assessment. Methods In this retrospective study, cognitive profiles for 136 acute stroke patients admitted to the Acute Stroke Unit who had available MoCA and neuropsychological assessment data were examined. Results 22% of our patients were deemed cognitively intact on the MoCA. Of …

Social and motivational functioning is not critically dependent on feedback of autonomic responses: neuropsychological evidence from patients with pu…

2004

Social, emotional and motivational behaviours are associated with production of automatic bodily responses. Re-representation in the brain through feedback of autonomic and skeletomuscular arousal is proposed to underlie "feeling states". These influence emotional judgments and bias motivational decision-making and guide social interactions. Consistent with this hypothesis, dissocial behaviour and deficits on emotional and motivation tasks are associated with blunted bodily responses in patients with orbitofrontal brain lesions or developmental psychopathy. To determine the critical dependence of social and emotional behaviours on bodily responses mediated by the autonomic nervous system, w…

Attributional style in a case of Cotard delusion.

2007

Young and colleagues (e.g. Young, A. W., & Leafhead, K. M. (1996). Betwixt life and death: case studies of the Cotard delusion. In P. W. Halligan & J. C. Marshall (Eds.), Method in madness: Case studies in cognitive neuropsychiatry. Mahway, NJ: Lawrence Erlbaum Associates.) have suggested that cases of the Cotard delusion (the belief that one is dead) result when a particular perceptual anomaly (caused by a disruption to the affective component of visual recognition) occurs in the context of an internalising attributional style. This hypothesis has not previously been tested directly. We report here an investigation of attributional style in a 24-year-old woman with Cotard delusion ("LU"). …

Changing associations between cognitive impairment and imaging in multiple sclerosis as the disease progresses.

2013

The authors explored cross-sectional associations between MRI parameters (lesion metrics, brain volumes, magnetization transfer ratio histograms, and metabolite concentrations) and cognition in 61 patients who experienced clinically-isolated syndromes (CIS) 7 years earlier. IQ decline and poorer overall cognition were associated with T2 white-matter lesions, and slow information-processing with both T2 lesions and gray-matter atrophy. In a previous study of the same cohort, gray-matter atrophy measured shortly after CIS failed to predict development of cognitive impairment years later. Our findings suggest that gray-matter pathology, reflected by atrophy measurements, becomes increasingly i…

A second family with familial AD and the V717L APP mutation has a later age at onset

2006

Four mutations have been reported at the 717 codon of the amyloid precursor protein (APP), with valine substituted by isoleucine, glycine, phenylalanine, and leucine. While several families with the isoleucine substitution have been described, the other substitutions have been reported in only one family each worldwide. A family with the V717L APP mutation has been previously reported,1 with a mean age at onset of 38 years (range 35 to 39), based on four affected family members, and a mean age at death of 46 years (range 40 to 50). We have identified a second family with a later mean age at onset of 50 years (range 48 to 57) and mean age at death of 61 years (range 57 to 68). Family 171 is …

Modulating memory performance in healthy subjects with Trancranial Direct Current Stimulation over the right dorsolateral prefrontal cortex

2015

Objective: The role of the Dorsolateral Prefrontal Cortex (DLPFC) in recognition memory has been well documented in lesion, neuroimaging and repetitive Transcranial Magnetic Stimulation (rTMS) studies. The aim of the present study was to investigate the effects of transcranial Direct Current Stimulation (tDCS) over the left and the right DLPFC during the delay interval of a non-verbal recognition memory task. Method: 36 right-handed young healthy subjects participated in the study. The experimental task was an Italian version of Recognition Memory Test for unknown faces. Study included two experiments: in a first experiment, each subject underwent one session of sham tDCS and one session of…

Auditory temporal processing deficits in patients with insular stroke

2006

OBJECTIVE: To assess central auditory function in a series of patients with stroke of the insula and adjacent areas. METHODS: The authors recruited eight patients with stroke affecting the insula and adjacent areas and eight neurologically normal controls (matched to the patients for age, sex, handedness, and hearing thresholds). The lesion spared the adjacent auditory areas in three patients and included other auditory structures in five cases. The authors conducted pure-tone audiometry and tympanometry and a central auditory test battery, which included the dichotic digits, and three temporal tests, the duration pattern, frequency pattern, and gaps in noise tests. They collected informati…

Verbal Fluency in Mild Alzheimer's Disease: Transcranial Direct Current Stimulation over the Dorsolateral Prefrontal Cortex

2021

Background: Recent studies showed that in healthy controls and in aphasic patients, inhibitory trains of repetitive transcranial magnetic stimulation (rTMS) over the right prefrontal cortex can improve phonemic fluency performance, while anodal transcranial direct current stimulation (tDCS) over the left prefrontal cortex can improve performance in naming and semantic fluency tasks. Objective: This study aimed at investigating the effects of cathodal tDCS over the left or the right dorsolateral prefrontal cortex (DLPFC) on verbal fluency tasks (VFT) in patients with mild Alzheimer’s disease (AD). Methods: Forty mild AD patients participated in the study (mean age 73.17±5.61 years). All part…

Recollection and familiarity in dense hippocampal amnesia: A case study

2004

In the amnesia literature, disagreement exists over whether anterograde amnesia involves recollective-based recognition processes and/or familiarity-based ones depending on whether the anatomical damage is restricted to the hippocampus or also involves adjacent areas, particularly the entorhinal and perirhinal cortices. So far, few patients with well documented anatomical lesions and detailed assessment of recollective and recognition performance have been described. We report a comprehensive neuroanatomical assessment and detailed investigation of the anterograde memory functions of a previously described severe amnesic patient (VC). The results of four previously published neuroradiologic…

Standardization and validation of a parallel form of the verbal and non-verbal recognition memory test in an Italian population sample.

2017

In the neuropsychological assessment of several neurological conditions, recognition memory evaluation is requested. Recognition seems to be more appropriate than recall to study verbal and nonverbal memory, because interferences of psychological and emotional disorders are less relevant in the recognition than they are in recall memory paradigms. In many neurological disorders, longitudinal repeated assessments are needed to monitor the effectiveness of rehabilitation programs or pharmacological treatments on the recovery of memory. In order to contain the practice effect in repeated neuropsychological evaluations, it is necessary the use of parallel forms of the tests. Having two parallel…

The test accuracy of the Montreal Cognitive Assessment (MoCA) by stroke lateralisation

2017

Abstract Background The Montreal Cognitive Assessment (MoCA) is an increasingly popular screening tool for detecting cognitive impairment post-stroke. However its' test accuracy by stroke lateralisation is as yet unknown. Aim Our aim was to investigate whether the test accuracy of the MoCA differs by stroke lateralisation across different cognitive domains. Methods We retrospectively examined the cognitive profiles of 228 subacute stroke patients (86 Left, 142 Right), comparing MoCA-total and domain-specific scores with performance on detailed neuropsychological assessment. Results The prevalence of cognitive impairment detected on neuropsychological assessment was high and relatively compa…

The middle house or the middle floor: Bisecting horizontal and vertical mental number lines in neglect

2007

Abstract This study explores the processing of mental number lines and physical lines in five patients with left unilateral neglect. Three tasks were used: mental number bisection (‘report the middle number between two numbers’), physical line bisection (‘mark the middle of a line’), and a landmark task (‘is the mark on the line to the left/right or higher/lower than the middle of the line?’). We manipulated the number line orientation purely by task instruction: neglect patients were told that the number-pairs represented either houses on a street (horizontal condition) or floors in a building (vertical condition). We also manipulated physical line orientation for comparison. All five negl…

Bringing the Cognitive Estimation Task into the 21st Century: Normative Data on Two New Parallel Forms

2014

The Cognitive Estimation Test (CET) is widely used by clinicians and researchers to assess the ability to produce reasonable cognitive estimates. Although several studies have published normative data for versions of the CET, many of the items are now outdated and parallel forms of the test do not exist to allow cognitive estimation abilities to be assessed on more than one occasion. In the present study, we devised two new 9-item parallel forms of the CET. These versions were administered to 184 healthy male and female participants aged 18–79 years with 9–22 years of education. Increasing age and years of education were found to be associated with successful CET performance as well as gend…

The role of right and left posterior parietal cortex in the modulation of spatial attentional biases by self and non-self face stimuli

2012

In the present research we investigated whether the direction of the attentional bias in line bisection judgment displayed by healthy subjects is influenced by the evaluation of the social distance between self and other. We used inhibitory repetitive transcranial magnetic stimulation (rTMS) trains over the right and left parietal cortex to investigate the role of these regions in the task. Following right parietal rTMS, the self face is perceived as closer when it is located at the right line endpoint; following left parietal rTMS, the self face is perceived as closer when it is located at the left line endpoint. In both cases, the side of space ipsilateral to the rTMS is underestimated fr…

Impairments in proverb interpretation following focal frontal lobe lesions.

2012

The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal “executive” dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven’s Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients w…

Cerebral Microbleeds and Long-Term Cognitive Outcome: Longitudinal Cohort Study of Stroke Clinic Patients

2012

<i>Background:</i> Vascular cognitive impairment causes significant disability in the elderly and is common following ischaemic stroke. Although the underlying mechanisms and prognostic factors remain unclear, small vessel diseases are known to contribute. Cerebral microbleeds (CMBs) are a magnetic resonance imaging (MRI) manifestation of small vessel diseases and may contribute to vascular cognitive impairment, particularly frontal-executive functions. We hypothesized that baseline CMBs would predict long-term cognitive outcome, specifically frontal-executive function. <i>Methods:</i> A cohort of consecutive patients found to have CMBs when first referred to a strok…

"I Know that You Know that I Know": Neural Substrates Associated with Social Cognition Deficits in DM1 Patients.

2016

Myotonic dystrophy type-1 (DM1) is a genetic multi-systemic disorder involving several organs including the brain. Despite the heterogeneity of this condition, some patients with non-congenital DM1 can present with minimal cognitive impairment on formal testing but with severe difficulties in daily-living activities including social interactions. One explanation for this paradoxical mismatch can be found in patients' dysfunctional social cognition, which can be assessed in the framework of the Theory of Mind (ToM). We hypothesize here that specific disease driven abnormalities in DM1 brains may result in ToM impairments. We recruited 20 DM1 patients who underwent the "Reading the Mind in th…

Bipolar I and Bipolar II Disorder: Cognition and Emotion Processing

2006

Background. Cognitive impairment may be part of the endophenotype of bipolar disorder (BP), but little is known about patterns and severity of impairment in BP subgroups and their relation to depression. The same applies to deficits in emotion processing known to be present in BP.Method. To explore the relationship between depression and impairment in cognition and emotion processing and the differences between BP subgroups, we assessed 36 (25 BP I and 11 BP II) patients using a cognitive battery and a facial emotion recognition task.Results. BP patients were impaired compared to published norms on memory, naming and executive measures (Binomial Single Proportion tests, p<0·05). Cognitiv…

Repetitive transcranial magnetic stimulation over the left parietal cortex facilitates visual search for a letter among its mirror images

2015

Interference by task irrelevant information is seen in visual search paradigms using letters. Thus, it is harder to find the letter 'N' among its mirror reversals 'Icyrillic' than vice versa. This observation, termed the reversed letter effect, involves both a linguistic association and an interference of task irrelevant information - the shape of 'N' or 'Icyrillic' is irrelevant, the search requires merely distinguishing the tilts of oblique bars. We adapted the repetitive transcranial magnetic stimulation (rTMS) methods that we previously used, and conducted three rTMS experiments using healthy subjects. The first experiment investigated the effects of rTMS on the left and right posterior…

Facilitation of bottom-up feature detection following rTMS-interference of the right parietal cortex

2010

In visual search tasks the optimal strategy should utilize relevant information ignoring irrelevant one. When the information at the feature and object levels are in conflict, un-necessary processing at higher level of object shape can interfere with detection of lower level orientation feature. We explored the effects of inhibitory trains of transcranial magnetic stimulation (rTMS) on the right and left parietal cortex in healthy subjects performing two visual search tasks. One task (Task A) was characterised by an object-to-feature interference. The other task (Task B) was without such interference. We found that rTMS of the right parietal cortex significantly reduced reaction times (RTs)…

Low-Frequency Repetitive Transcranial Magnetic Stimulation of the Right Dorsolateral Prefrontal Cortex Enhances Recognition Memory in Alzheimer’s Dis…

2019

Background: The lack of effective pharmacological or behavioral interventions for memory impairments associated with Alzheimer’s disease (AD) emphasizes the need for the investigation of approaches based on neuromodulation. Objective: This study examined the effects of inhibitory repetitive transcranial magnetic stimulation (rTMS) of prefrontal cortex on recognition memory in AD patients. Methods: In a first experiment, 24 mild AD patients received sham and real 1Hz rTMS over the left and right dorsolateral prefrontal cortex (DLPFC), in different sessions, between encoding and retrieval phases of a non-verbal recognition memory task. In a second experiment, another group of 14 AD patients u…

Exploring the neural correlates of the reversed letter effect: Evidence from left and right parietal patients.

2019

To investigate the hemispheric lateralization of attentional processes during visual search tasks depending on the stimulus material embedding the target, twelve patients with unilateral left (n = 7) or right (n = 5) parietal lesions and 20 age and education matched healthy controls (HC) were recruited. We used a visual search task for a uniquely tilted oblique bar embedded in an object shape 'N' or in its mirror reversal 'И'. The accuracy and the averaged reaction times (RTs) in each stimulus type ('N' or 'И') were analysed.\ud \ud HC presented significantly longer RTs when the target bar was embedded in 'N' among its mirror reversed 'И' (p < .05). This “reversed letter effect” was also…

The differing roles of the frontal cortex in fluency tests

2012

Fluency tasks have been widely used to tap the voluntary generation of responses. The anatomical correlates of fluency tasks and their sensitivity and specificity have been hotly debated. However, investigation of the cognitive processes involved in voluntary generation of responses and whether generation is supported by a common, general process (e.g. fluid intelligence) or specific cognitive processes underpinned by particular frontal regions has rarely been addressed. This study investigates a range of verbal and non-verbal fluency tasks in patients with unselected focal frontal ( n  = 47) and posterior ( n  = 20) lesions. Patients and controls ( n  = 35) matched for education, age and s…

Qualitative different memory impairments across frontal lobe subgroups

2006

Recall impairments in patients with lesions to the prefrontal cortex (PFC) have variously been attributed to problems with organisation at encoding, organisation at retrieval and monitoring at retrieval. Neuroimaging and recent theoretical work has associated the left lateral PFC with organisation and strategy production at encoding, and the right lateral PFC with organisation, error detection and monitoring at retrieval. However few lesion studies have been anatomically specific enough to test the direct predictions made by this work. Proactive interference, response to prompting, monitoring and organisational strategies were examined in 34 patients with frontal lobe lesions and 50 healthy…

Dissociations and interactions between time, numerosity and space processing

2009

AbstractThis study investigated time, numerosity and space processing in a patient (CB) with a right hemisphere lesion. We tested whether these magnitude dimensions share a common magnitude system or whether they are processed by dimension-specific magnitude systems. Five experimental tasks were used: Tasks 1–3 assessed time and numerosity independently and time and numerosity jointly. Tasks 4 and 5 investigated space processing independently and space and numbers jointly. Patient CB was impaired at estimating time and at discriminating between temporal intervals, his errors being underestimations. In contrast, his ability to process numbers and space was normal. A unidirectional interactio…

Cognitive and social impairments in patients with superficial siderosis

2005

Superficial siderosis of the CNS is a rare condition, caused by deposition of haemosiderin in the superficial layers of the CNS due to repeated chronic subarachnoid or intraventricular haemorrhage. Typically, the hindbrain structures, especially the cerebellum, are most affected. There is a surprising lack of studies investigating in detail the behavioural functioning of patients with such a condition. In this study, we document for the first time the cognitive, social and emotional processing of six patients with a confirmed clinical diagnosis of superficial siderosis. They were aged between 40 and 62 years, with a mean age of 50.2 years; four were male. We administered a comprehensive bat…

Fluency and rule breaking behaviour in the frontal cortex

2020

Design (DF) and phonemic fluency tests (FAS; D-KEFS, 2001) are commonly used to investigate voluntary generation. Despite this, several important issues remain poorly investigated. In a sizeable sample of patients with focal left or right frontal lesion we established that voluntary generation performance cannot be accounted for by fluid intelligence. For DF we found patients performed significantly worse than healthy controls (HC) only on the switch condition. However, no significant difference between left and right frontal patients was found. In contrast, left frontal patients were significantly impaired when compared with HC and right frontal patients on FAS. These lateralization findin…

Exploring the relationship between semantics and space

2009

The asymmetric distribution of human spatial attention has been repeatedly documented in both patients and healthy controls. Biases in the distribution of attention and/or in the mental representation of space may also affect some aspects of language processing. We investigated whether biases in attention and/or mental representation of space affect semantic representations. In particular, we investigated whether semantic judgments could be modulated by the location in space where the semantic information was presented and the role of the left and right parietal cortices in this task. Healthy subjects were presented with three pictures arranged horizontally (one middle and two outer picture…

Cognitive estimation: Performance of patients with focal frontal and posterior lesions

2018

The Cognitive Estimation Test (CET) is a widely used test to investigate estimation abilities requiring complex processes such as reasoning, the development and application of appropriate strategies, response plausibility checking as well as general knowledge and numeracy (e.g., Shallice and Evans, 1978; MacPherson et al., 2014). Thus far, it remains unknown whether the CET is both sensitive and specific to frontal lobe dysfunction. Neuroimaging techniques may not represent a useful methodology for answering this question since the complex processes involved are likely to be associated with a large network of brain regions, some of which are not functionally necessary to successfully carry …

Distinct neuropsychological profiles correspond to distribution of cortical thinning in inherited prion disease caused by insertional mutation

2012

Background The human prion diseases are a group of universally fatal neurodegenerative disorders associated with the auto-catalytic misfolding of the normal cell surface prion protein (PrP). Mutations causative of inherited human prion disease (IPD) include an insertion of six additional octapeptide repeats (6-OPRI) and a missense mutation (P102L) with large families segregating for each mutation residing in southern England. Here we report for the first time the neuropsychological and clinical assessments in these two groups. Method The cognitive profiles addressing all major domains were obtained for 26 patients (18 6-OPRI, 8 P102L) and the cortical thickness determined using 1.5T MRI in …

Early detection of memory impairments in older adults: standardization of a short version of the verbal and nonverbal Recognition Memory Test

2018

In several neurological conditions, in elderly and cognitively impaired subjects, memory functioning must be evaluated to early detect the cognitive deterioration processes. In particular, recognition memory assessment is an essential step in the clinical and neuropsychological evaluation of early memory impairments. The Recognition Memory Test (RMT) developed by Smirni et al. (G Ital Psicol XXXVII(1):325-343, 2010) is an effective instrument to assess verbal and nonverbal recognition memory in the Italian population. The current study provides a new, brief, and reliable RMT format to evaluate recognition memory on elderly subjects and it reports normative data in an older adult Italian pop…

The hippocampus is required for short-term topographical memory in humans.

2007

The hippocampus plays a crucial role within the neural systems for long-term memory, but little if any role in the short-term retention of some types of stimuli. Nonetheless, the hippocampus may be specialized for allocentric topographical processing, which impacts on short-term memory or even perception. To investigate this we developed performance-matched tests of perception (match-to-sample) and short-term memory (2 s delayed-match-to-sample) for the topography and for the nonspatial aspects of visual scenes. Four patients with focal hippocampal damage and one with more extensive damage, including right parahippocampal gyrus, were tested. All five patients showed impaired topographical m…

S.5.4 - ENHANCING RECOGNITION MEMORY PERFORMANCE WITH RTMS IN HEALTHY SUBJECTS AND NEUROLOGICAL PATIENTS

2013

Frontal subregions mediating Elevator Counting task performance.

2010

Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired…

Grey matter damage and overall cognitive impairment in primary progressive multiple sclerosis

2011

Objectives: To identify associations between cognitive impairment and imaging measures in a cross-sectional study of patients with primary progressive multiple sclerosis (PPMS). Methods: Neuropsychological tests were administered to 27 patients with PPMS and 31 controls. Patients underwent brain conventional magnetic resonance imaging (MRI) sequences, volumetric scans and magnetization transfer (MT) imaging; MT ratio (MTR) parameters, grey matter (GM) and normal-appearing white matter (NAWM) volumes, and WM T2 lesion load (T2LL) were obtained. In patients, multiple linear regression models identified the imaging measure associated with the abnormal cognitive tests independently from the ot…

Cognitive and social cognitive functioning in spinocerebellar ataxia : a preliminary characterization

2006

INTRODUCTION : The spinocerebellar ataxias (SCAs), are rare neurodegenerative disorders caused by distinct genetic mutations. Clinically, the SCAs are characterised by progressive ataxia and a variety of other features, including cognitive dysfunction. The latter is consistent with a growing body of evidence supporting a cognitive as well as motor role for the cerebellum. Recent suggestions of cerebellar involvement in social cognition have not been extensively explored in these conditions. The availability of definitive molecular diagnosis allows genetically defined subgroups of SCA patients, with distinct patterns of cerebellar and extracerebellar involvement, to be tested comparatively u…

Apathy in Parkinson's Disease: A Retrospective Study of Its Prevalence and Relationship With Mood, Anxiety, and Cognitive Function.

2021

Apathy is thought to be an important clinical feature of Parkinson’s disease (PD). However, its prevalence ranges greatly across studies because of differing definitions, assessment tools, and patient inclusion criteria. Furthermore, it remains unclear how the presentation of apathy in PD is related to mood disorder and/or cognitive impairment. This study sought to examine the prevalence of a pure apathy syndrome in PD, distinct from both depression and anxiety, and reveal its associated cognitive profile. A retrospective study was performed on 177 PD patients who had completed measures of apathy [Apathy Evaluation Scale (AES)] and mood functioning [Hospital Anxiety and Depression Scale (HA…

Cognitive impairment in multiple sclerosis can be predicted by imaging early in the disease.

2008

Background: Cognitive impairment is common in multiple sclerosis (MS) and adds significantly to the burden of the disease. The ability to predict future cognitive impairment from imaging obtained at disease onset has not been investigated. Methods: 62 patients imaged within 3 months of a clinically isolated syndrome were assessed neuropsychologically 7 years later. Baseline and periodic MRI measures of lesions, atrophy and normal-appearing white and grey matter were regressed against neuropsychological scores to explore the best predictors of cognitive outcome. Results: 28 patients had developed clinically definite MS at follow-up and a further nine met revised McDonald criteria for MS. Def…

Cognitive, biochemical, and imaging profile of patients suffering from idiopathic normal pressure hydrocephalus

2011

Abstract Introduction It has still not been clearly established whether the cognitive deficits of idiopathic normal pressure hydrocephalus (iNPH) are caused by a disturbance in cerebrospinal fluid (CSF) dynamics or an underlying metabolic disturbance. Objective To identify the possible associations between biochemical markers, the neuroimaging characteristics, and cognitive deficits of patients undergoing investigations for possible iNPH. Methods A CSF sample obtained during a lumbar puncture from 10 patients with iNPH was analyzed for several biochemical markers (lactate, 8-isoprostane, vascular endothelial growth factor [VEGF], neurofilament heavy protein, glial fibrillary acidic protein,…

IMPAIRED DECISION-MAKING AND DIFFUSION ORIENTATIONAL COMPLEXITY IN PEOPLE WITH MULTIPLE SCLEROSIS

2013

Objective Difficulties with decision-making have been reported in people with multiple sclerosis (MS). It is however unclear what aspect of decision making is impaired, for example whether they are more impulsive, and how any impairments relate to grey matter pathology. In this study we assess grey matter microstructure using a novel measure of the number of diffusion orientations on diffusion MRI “diffusion orientation complexity (DOC)”. We studied DOC in cortical areas known to be associated with decision making and looked at its associations with performance on the Cambridge Gambling Task (CGT). Method One hundred and five patients with MS (61 RR, 26 SP, 18 PP; mean age: 45.9 years) and …

Unconscious processing of Arabic numerals in unilateral neglect

2005

This study explores the processing of Arabic numerals in three patients with dense left unilateral neglect. Three tasks have been used: a test of visual awareness (is the stimulus on the left, on the right or on both sides?), a number comparison task (is the number larger or smaller than 5?), a number parity judgment task (is the number odd or even?). The test of visual awareness indicated that all three patients were completely unaware of the stimuli presented in the left hemifield. Despite this, the number comparison and number parity judgment tasks clearly indicated that Arabic numerals were unconsciously processed at semantic level (i.e. quantity). These results show that patients with …

The role of the prefrontal cortex in familiarity and recollection processes during verbal and non verbal recognition memory: a rTMS study.

2010

Neuroimaging and lesion studies have documented the involvement of the frontal lobes in recognition memory. However, the precise nature of prefrontal contributions to verbal and non-verbal memory and to familiarity and recollection processes remains unclear. The aim of the current rTMS study was to investigate for the first time the role of the DLPFC in encoding and retrieval of non-verbal and verbal memoranda and its contribution to recollection and familiarity processes. Recollection and familiarity processes were studied using the ROC and unequal variance signal detection methodologies. We found that rTMS delivered over left and right DLPFC at encoding resulted in material specific later…

Spontaneous confabulation, temporal context confusion and reality monitoring: a study of three patients with anterior communicating artery aneurysms.

2010

AbstractSpontaneous confabulation involves the production of false or distorted memories, and is commonly associated with ventromedial prefrontal damage. One influential theory proposes that the critical deficit is a failure to suppress currently irrelevant memory traces that intrude into ongoing thinking (Schnider & Ptak, 1999). In this study, we report experimental investigations with three spontaneously confabulating patients aimed at exploring this account. Using Schnider and Ptak’s (1999) continuous recognition paradigm, we replicated their experimental results with our patients. However, our data suggest that the critical impairment might be more generalized than a failure to supp…

Presence phenomena in parkinsonian disorders: Phenomenology and neuropsychological correlates.

2020

Introduction The feeling of a presence that occurs in the absence of objectively identifiable stimuli is common in parkinsonian disorders. Although previously considered benign and insignificant, recent evidence suggests that presence phenomena may act as the gateway to more severe hallucinations and dementia. Despite this, we still know relatively little about these phenomena. Objective To examine parkinsonian disorder patients' subjective experience of presence phenomena, and retrospectively analyse their cognitive correlates, in order to elucidate the emergence of information processing deficits in parkinsonian disorders. Methods/design 25 patients who endorsed presence phenomena were as…

Characteristics of frontal and temporal cortex in relation to cognitive dysfunction in Bipolar Disorders

2011

Effect of frontal lobe lesions on the recollection and familiarity components of recognition memory

2008

Single-process theories assume that familiarity is the sole influence on recognition memory with decisions being made as a continuous process. Dual-process theories claim that recognition involves both recollection and familiarity processes with recollection as a threshold process. Although, the frontal lobes of the brain play an important role in recognition memory, few studies have examined the effect of frontal lobe lesions on recollection and familiarity. In the current study, the nonverbal recognition memory of 24 patients with focal frontal lesions due to turnout or stroke was examined. Recollection and familiarity were estimated using the receiver operating characteristic (ROC) metho…

Limitations of the trail making test part-B in assessing frontal executive dysfunction.

2015

AbstractPart B of the Trail Making Test (TMT-B) is one of the most widely used neuropsychological tests of “executive” function. A commonly held assumption is that the TMT-B can be used to detect frontal executive dysfunction. However, so far, research evidence has been limited and somewhat inconclusive. In this retrospective study, performance on the TMT-B of 55 patients with known focal frontal lesions, 27 patients with focal non-frontal lesions and 70 healthy controls was compared. Completion time and the number of errors made were examined. Patients with frontal and non-frontal lesions performed significantly worse than healthy controls for both completion time and the number of errors.…

Taking both sides: do unilateral anterior temporal lobe lesions disrupt semantic memory?

2010

The most selective disorder of central conceptual knowledge arises in semantic dementia, a degenerative condition associated with bilateral atrophy of the inferior and polar regions of the temporal lobes. Likewise, semantic impairment in both herpes simplex virus encephalitis and Alzheimer's disease is typically associated with bilateral, anterior temporal pathology. These findings suggest that conceptual representations are supported via an interconnected, bilateral, anterior temporal network and that it may take damage to both sides to produce an unequivocal deficit of central semantic memory. We tested and supported this hypothesis by investigating a case series of 20 patients with unila…

The neuropsychological profile of Othello syndrome in Parkinson's disease.

2017

Mapping the onset and progression of atrophy in familial frontotemporal lobar degeneration

2005

Background: Frontotemporal lobar degeneration (FTLD) may be inherited as an autosomal dominant disease. Studying patients "at risk" for developing FTLD can provide insights into the earliest onset and evolution of the disease. Method: We carried out approximately annual clinical, MRI, and neuropsychological assessments on an asymptomatic 51 year old "at risk" family member from a family with FTLD associated with ubiquitin-positive and tau-negative inclusion bodies. We used non-linear (fluid) registration of serial MRI to determine areas undergoing significant regional atrophy at different stages of the disease. Results: Over the first 26 months of the study, the patient remained asymptomati…

Inhibition processes are dissociable and lateralized in human prefrontal cortex

2016

The prefrontal cortex (PFC) is known to make fundamental contributions to executive functions. However, the precise nature of these contributions is incompletely understood. We focused on a specific executive function, inhibition, the ability to suppress a pre-potent response. Functional imaging and animal studies have studied inhibition. However, there are only few lesion studies, typically reporting discrepant findings. For the first time, we conducted cognitive and neuroimaging investigations on patients with focal unilateral PFC lesions across two widely used inhibitory tasks requiring a verbal response: The Hayling Part 2 and Stroop Colour-Word Tests. We systematically explored the rel…

Amnesia and the hippocampus

2006

PURPOSE OF REVIEW: Long-term memory impairments have great medical significance and a considerable health and economic burden. Understanding their cognitive and neuroanatomical underpinnings is of crucial importance. Severe amnesia is usually observed following bilateral hippocampal pathology. This review addresses the precise role of the hippocampus and related medial temporal lobe structures in amnesia. RECENT FINDINGS: Disagreements exist over whether, following selective hippocampal damage: retrograde amnesia for episodic memories is temporally limited or extensive and ungraded; anterograde amnesia involves both recollective and familiarity processes. It is accepted that material specif…

Towards a unified process model for graphemic buffer disorder and deep dysgraphia

2006

Models based on the competitive queuing (CQ) approach can explain many of the effects on dysgraphic patients’ spelling attributed to disruption of the “graphemic output buffer”. Situating such a model in the wider spelling system, however, raises the question of what happens when input to the buffer (e.g., from a semantic system) is degraded while the buffer remains intact. We present a preliminary exploration of predictions following from the CQ approach. We show that the CQ account of the graphemic buffer predicts and explains the finding that deep dysgraphic patients generally show features of graphemic buffer disorder, as disrupted input from a damaged semantic system has an inevitable …

Cognitive Reserve Proxies Do Not Differentially Account for Cognitive Performance in Patients with Focal Frontal and Non-Frontal Lesions

2020

AbstractObjective:Cognitive reserve (CR) suggests that premorbid efficacy, aptitude, and flexibility of cognitive processing can aid the brain’s ability to cope with change or damage. Our previous work has shown that age and literacy attainment predict the cognitive performance of frontal patients on frontal-executive tests. However, it remains unknown whether CR also predicts the cognitive performance of non-frontal patients.Method:We investigated the independent effect of a CR proxy, National Adult Reading Test (NART) IQ, as well as age and lesion group (frontal vs. non-frontal) on measures of executive function, intelligence, processing speed, and naming in 166 patients with focal, unila…

The hippocampus and remote autobiographical memory.

2005

In Newsdesk (August, 2005),1 new evidence for the neuroanatomy of remote memory was reported. On the basis of the findings of the US team lead by Larry Squire,2 remote autobiographical memory was suggested to be independent of the medial temporal lobe but dependent on the neocortex. By contrast with previous hypotheses, this new proposal predicts that after damage to the medial temporal lobe only recent autobiographical memories should be impaired in neurological patients, whereas loss of both recent and old autobiographical memories implies additional damage in the neocortex. However, there is evidence not included in the Newsdesk article, that is problematic for this new prediction. Two p…

Fractionation of memory in medial temporal lobe amnesia

2006

We report a comprehensive investigation of the anterograde memory functions of two patients with memory impairments (RH and JC). RH had neuroradiological evidence of apparently selective right-sided hippocampal damage and an intact cognitive profile apart from selective memory impairments. JC, had neuroradiological evidence of bilateral hippocampal damage following anoxia due to cardiac arrest. He had anomic and "executive" difficulties in addition to a global amnesia, suggesting atrophy extending beyond hippocampal regions. Their performance is compared with that of a previously reported hippocampal amnesic patient who showed preserved recollection and familiarity for faces in the context …

MRS SHOWS ABNORMALITIES BEFORE SYMPTOMS IN FAMILIAL ALZHEIMER DISEASE

2006

Background: Pathologic change in Alzheimer disease (AD) begins some years before symptoms. MRS has the potential to detect metabolic abnormalities reflecting this early pathologic change. Presenilin 1 (PS1) and amyloid precursor protein (APP) mutation carriers have a nearly 100% risk of developing AD and may be studied prior to symptom onset. Methods: Short echo time proton MR spectra were acquired from a midline posterior cingulate voxel in presymptomatic carriers of PS1 or APP mutations (“presymptomatic mutation carriers” [PMCs]; n = 7) and age- and sex-matched control subjects (n = 6). Ratios of N-acetyl aspartate (NAA), myo-inositol (MI), and choline-containing compounds (Cho) to creati…

Cognitive impairment in relapsing-remitting multiple sclerosis can be predicted by imaging performed several years earlier.

2007

Cognitive deficits in multiple sclerosis (MS) are common and correlate with contemporary MRI brain abnormalities, particularly atrophy, but the ability of imaging early in the disease to predict later cognitive impairment remains to be determined. Thirty relapsing—remitting MS patients recruited within three years of the onset of the disease, and in whom MRI had been performed at baseline and a year later, were assessed neuropsychologically five years later. Imaging parameters accounting for significant variance in cognitive performance were identified using multiple regressions, once confounding variables were controlled. Patients performed significantly worse than expected on tests of at…

Impairments in top down attentional processes in right parietal patients: Paradoxical functional facilitation in visual search

2014

AbstractIt is well known that the right posterior parietal cortex (PPC) is involved in attentional processes, including binding features. It remains unclear whether PPC is implicated in top-down and/or bottom-up components of attention. We aim to clarify this by comparing performance of seven PPC patients and healthy controls (HC) in a visual search task involving a conflict between top-down and bottom-up processes. This task requires essentially a bottom-up feature search. However, top-down attention triggers feature binding for object recognition, designed to be irrelevant but interfering to the task. This results in top-down interference, prolonging the search reaction time. This interfe…

Cerebral microbleeds and vascular cognitive impairment

2010

Abstract MRI manifestations of small vessel diseases including white matter hyperintensities and lacunes have been recognized as potential substrates of vascular cognitive impairment for many years. Cerebral microbleeds (CMBs) – small, perviascular haemorrhages seen as small, well-demarcated, hypointense, rounded lesions on MRI sequences sensitive to magnetic susceptibility effects – are also now recognized as an imaging marker for small vessel pathology, but their clinical impact on cognition remains uncertain. CMBs are present in about a third of patients with ischaemic stroke, and in a high proportion of patients with Alzheimer's disease, cerebral amyloid angiopathy, and vascular dementi…

PATH56 MRI correlates of vascular cognitive impairment: contribution of microbleeds, white matter changes and infarcts in a large hospital-based cros…

2010

Background The mechanisms underlying vascular cognitive impairment remain poorly understood. Brain microbleeds may contribute, particularly to executive dysfunction. We investigated the cognitive effects of microbleeds and other neuroimaging markers for cerebrovascular disease in a large, hospital-based study. Methods Consecutive, unselected patients referred to the stroke unit or clinic underwent clinical assessment, detailed neuropsychological testing and vascular MRI. Microbleeds, white matter changes (WMC) and brain infarcts were identified and their effects on cognition assessed. Results 242 patients were included (N=60 with, N=182 without microbleeds). Executive impairment was more pr…

Confabulation: damage to a specific inferior medial prefrontal system

2008

Confabulation, the pathological production of false memories, occurs following a variety of aetiologies involving the frontal lobes, and is frequently held to be underpinned by combined memory and executive deficits. However, the critical frontal regions and specific cognitive deficits involved are unclear. Studies in amnesic patients have associated confabulation with damage to the orbital and ventromedial prefrontal cortices. However, neuroimaging studies have associated memory-control processes which are assumed to underlie confabulation with the right lateral prefrontal cortex. We used a confabulation battery to investigate the occurrence and localisation of confabulation in an unselect…

Prevalence and Cognitive Impact of Medial Temporal Atrophy in a Hospital Stroke Service: Retrospective Cohort Study

2015

Background Cerebrovascular disease and neurodegeneration cause cognitive impairment and frequently coexist. Aims Our objectives were to investigate the prevalence and cognitive impact of medial temporal lobe atrophy – a radiological marker often associated with Alzheimer's disease – in a hospital stroke service. Methods Retrospective cohort study of patients from a hospital stroke service. Patients assessed for suspected ischemic stroke or transient ischemic attack, irrespective of final diagnosis, underwent neuropsychological testing and magnetic resonance imaging. medial temporal lobe atrophy, white matter hyperintensities, lacunes, and cerebral microbleeds were rated using established cr…

Enhancing memory performance with rTMS in healthy subjects and individuals with Mild Cognitive Impairment: the role of the right dorsolateral prefron…

2012

A debated question in the literature is the degree of anatomical and functional lateralization of the executive control processes subserved by the dorsolateral prefrontal cortex (DLPFC) during recognition memory retrieval. We investigated if transient inhibition and excitation of the left and right DLPFC at retrieval by means of repetitive transcranial magnetic stimulation (rTMS) modulate recognition memory performance in 100 healthy controls (HCs) and in 8 patients with Mild Cognitive Impairment (MCI). Recognition memory tasks of faces, buildings and words were used in different experiments. rTMS-inhibition of the right DLPFC enhanced recognition memory of verbal and non verbal material in…

Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.

2017

Abstract A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS…

Dynamic aphasia and the generation of language

2004

Severely reduced propositional speech in the context of intact nominal language skills (i.e., repetition, naming, comprehension, and reading) is the hallmark of dynamic aphasia (Luria, 1970). Recent evidence suggests there may be different types of dynamic aphasia as some patients do not produce any response on verbal generation tasks, whilst others are able to perform normally on verbal genera- tion tasks. For example, Robinson and colleagues (Robinson, Blair, & Cipolotti, 1998; Robinson, Shallice, & Cipolotti, 2004) reported two dynamic aphasics who failed to produce a verbal response when many verbal response options were activated by a stimulus, but not when a dominant response was avai…

Does the left inferior parietal lobule contribute to multiplication facts?

2005

We report a single case, who presents with a selective and severe impairment for multiplication and division facts. His ability to retrieve subtraction and addition facts was entirely normal. His brain lesion affected the left superior temporal and to lesser extent in the left middle temporal gyri and the left precentral gyrus extending inferiorly to the pars opercularis of the left frontal lobe. Interestingly, the left supramarginal and angular gyri (SMG/AG) were spared. This finding realised a double dissociation with a previously reported patient, who despite lesions in the SMG/AG did not have a multiplication impairment (van Harskamp et al., 2002). The previously suggested crucial role …

Social and emotional functions in three patients with medial frontal lobe damage including the anterior cingulate cortex

2006

INTRODUCTION: The aim of this study was to explore social and emotional functions in patients with medial frontal damage including the anterior cingulate cortex (ACC). METHODS: Three patients with medial frontal lobe lesions primarily involving the ACC performed tasks on motivational decision making, emotional facial expression recognition, and social cognition, including theory of mind (ToM). Their performance on these tasks was compared with age and education matched healthy controls. RESULTS: Patient performance on the motivational decision making and social situations tasks did not differ from controls. Selective emotional facial expression recognition impairment for fear was evident in…

Cognitive functioning after medial frontal lobe damage including the anterior cingulate cortex: A preliminary investigation

2006

Two patients with medial frontal lobe damage involving the anterior cingulate cortex (ACC) performed a range of cognitive tasks, including tests of executive function and anterior attention. Both patients lesions extended beyond the ACC, therefore caution needs to be exerted in ascribing observed deficits to the ACC alone. Patient performance was compared with age and education matched healthy controls. Both patients showed intact intellectual, memory, and language abilities. No clear-cut abnormalities were noted in visuoperceptual functions. Speed of information processing was mildly reduced only in Patient 2 (bilateral ACC lesion). The patients demonstrated weak or impaired performance on…

Early imaging predicts later cognitive impairment in primary progressive multiple sclerosis

2010

Background: Cognitive impairment in primary progressive multiple sclerosis (PPMS) is common and correlates modestly with contemporary lesion burden and brain volume. Using a cohort/case control methodology, we explore the ability of MRI abnormalities, including those in the normal-appearing brain tissue, to predict future cognitive dysfunction in PPMS. Methods: Thirty-one patients recruited into a longitudinal study within 5 years of onset of PPMS were assessed neuropsychologically on average 5.5 years later along with 31 matched healthy controls. MRI data obtained at entry into the study (lesion metrics, brain volumes, magnetization transfer ratio histogram metrics, and magnetic resonance …

The Prefrontal Cortex and Neurological Impairments of Active Thought

2018

This article reviews the effects of lesions to the frontal cortex on the ability to carry out active thought, namely, to reason, think flexibly, produce strategies, and formulate and realize plans. We discuss how and why relevant neuropsychological studies should be carried out. The relationships between active thought and both intelligence and language are considered. The following basic processes necessary for effective active thought are reviewed: concentration, set switching, inhibiting potentiated responses, and monitoring and checking. Different forms of active thought are then addressed: abstraction, deduction, reasoning in well-structured and ill-structured problem spaces, novel st…

The neuropsychology of variant CJD: a comparative study with inherited and sporadic forms of prion disease.

2005

Objective: To assess cognitive function in variant Creutzfeldt-Jakob disease (vCJD). We describe the neuropsychological profiles of 10 cases and compare these data with cross sectional data obtained from patients with histologically confirmed sporadic CJD and cases with inherited prion disease with confirmed mutations in the prion protein gene. Methods: Patients referred to the Specialist Cognitive Disorders Clinic at the National Hospital for Neurology and Neurosurgery and the National Prion Clinic at St Mary's Hospital, London for further investigation of suspected CJD were recruited into the study. The neuropsychological test battery evaluated general intelligence, visual and verbal memo…

A failure of high level verbal response selection in progressive dynamic aphasia.

2005

Different theoretical interpretations have been offered in order to account for a specific language impairment termed dynamic aphasia. We report a patient (CH) who presented with a dynamic aphasia in the context of nonfluent progressive aphasia. CH had the hallmark of reduced spontaneous speech in the context of preserved naming, reading, and single word repetition and comprehension. Articulatory and grammatical difficulties were also present. CH had a very severe verbal generation impairment despite being able to describe pictorial scenes and action sequences well. In the experimental investigations CH was severely impaired in word, phrase, and sentence generation tasks when many competing…

IQ and the fronto-temporal cortex in bipolar disorder.

2012

AbstractCognitive changes are documented in bipolar disorder (BP). Cortical volume loss, especially in prefrontal regions, has also been reported, but associations between cognition and cortical abnormalities have not been fully documented. This study explores associations between cognitive performance and cortical parameters (area, thickness and volume) of the fronto-temporal cortex in 36 BP patients (25 BPI and 11 BPII). T1-weighted volumetric MRI images were obtained using a 1.5 Tesla scanner. Cortical parameters were measured using surface-based morphometry and their associations with estimated premorbid, current IQ, visual memory, and executive function explored. Premorbid IQ was assoc…

Cognitive dysfunction and depression in Fabry disease: a systematic review.

2013

Background Fabry disease, an X-linked lysosomal storage disorder, leads to multi-organ dysfunction, including cerebrovascular disease and psychological disorders. However, the prevalence and pattern of associated cognitive dysfunction is not well understood. Objectives To investigate whether there is reliable evidence for neuropsychological impairment in patients with Fabry disease and which cognitive domains are affected. To estimate the prevalence of and factors associated with depression in patients with Fabry disease. Method Qualitative systematic review of the literature of studies conducting neuropsychological assessment or measuring the prevalence of depression in adults with Fabry d…

Domain-specific trends in cognitive impairment after acute ischaemic stroke.

2012

Little is known about the pattern of subacute cognitive domain impairments after ischaemic stroke, nor the temporal evolution of such impairments. Our objective was to investigate the pattern of cognitive impairment in different neuropsychological domains up to a year after ischaemic stroke. We included prospectively collected data from an observational database of stroke patients at the National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. Patients were categorised into temporal groups according to the time between the index stroke and neuropsychological profiling. The prevalence of impairment in different cognitive domains was then compared between these categories. …

Pure Progressive Amnesia and the APPV717G Mutation

2009

We report an isolated, slowly progressive, pure amnestic phenotype in a 59-year-old member of a family affected by autosomal dominant familial Alzheimer disease. Early-onset Alzheimer disease in this family was associated with a V717G mutation in the amyloid precursor protein gene (APP). Subjective impairment of episodic memory began in our subject at the age of 44 years and subsequent, longitudinal neuropsychologic assessment confirmed progressive, severe, global impairment of memory functions over a period of 14 years with preservation of other cognitive domains. The mean annual hippocampal atrophy rate, determined by volumetric magnetic resonance imaging was intermediate between values p…

Conceptual proposition selection and the LIFG: neuropsychological evidence from a focal frontal group.

2010

Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterio…

The role of the thalamus in amnesia: a tractography, high-resolution MRI and neuropsychological study.

2008

Although it is well established that thalamic lesions may lead to profound amnesia, the precise contribution of thalamic sub-regions to memory remains unclear. In an influential article Aggleton and Brown proposed that recognition memory depends on two processes supported by distinct thalamic and cortical structures. Familiarity is mediated by the mediodorsal (MD) thalamic nucleus and the entorhinal/ perirhinal cortex. Recollection ismediated by the anterior thalamic nucleus (AN), the mamillothalamic tract (MTT) and the hippocampus. The authors also suggested that the lateral dorsal nucleus (LD) may contribute to the thalamic/hippocampus system, thereby implying that the LD may play a role …

“My Mind Is Doing It All”

2015

Objective: To study whether pressure of speech in jargon aphasia arises out of disturbances to core language or executive processes, or at the intersection of conceptual preparation. Background: Conceptual preparation mechanisms for speech have not been well studied. Several mechanisms have been proposed for jargon aphasia, a fluent, well-articulated, logorrheic propositional speech that is almost incomprehensible. Methods: We studied the vast quantity of jargon speech produced by patient J.A., who had suffered an infarct after the clipping of a middle cerebral artery aneurysm. We gave J.A. baseline cognitive tests and experimental word-and sentencegeneration tasks that we had designed for …

Diagnosis, treatment, and analysis of long-term outcomes in idiopathic normal-pressure hydrocephalus

2007

To the Editor:We read with interest the article by McGirt et al. (9) entitled“Diagnosis, Treatment, and Analysis of Long-term Outcomes inIdiopathic Normal Pressure Hydrocephalus.” The authors con-clude that gait impairment is the primary symptom that inde-pendently predicted improvement after shunting. The studyincluded 132 patients, 129 (98%) of whom had gait impairmentas a feature. We would like to comment on this particular selec-tion criterion, as well as improvements in the Mini Mental StateExamination (MMSE) as the sole measure of postoperative cog-nitive improvement.One of the inclusion criteria for this study was presentationwith two or more features of the classic triad. Thus, the …

MRI-visible perivascular spaces: relationship to cognition and small vessel disease MRI markers in ischaemic stroke and TIA.

2013

Background MRI-visible perivascular spaces (PVS) are potential neuroimaging markers of cerebral small vessel disease, but their functional significance and mechanisms remain uncertain. We investigated the association between PVS and cognitive impairment, and other MRI markers of small vessel disease, in a patient cohort of ischaemic stroke/transient ischaemic attack (TIA) referrals. Methods Data were collected from a prospective observational database. Standardised detailed neuropsychological testing was performed. A validated visual rating scale on T-2-weighted MRI was used to categorise PVS severity; validated scales were used to assess white matter hyperintensities (WMH), cerebral microb…

Cognitive functioning in orthostatic hypotension due to pure autonomic failure.

2004

Psychophysiological science proposes close interactions between cognitive processes and autonomic responses, yet the consequences of autonomic failure on cognitive functioning have not been documented. This pilot study investigates, for the first time, the cognitive profile of 14 patients with Pure Autonomic Failure (PAF). Each patient was administered a comprehensive battery of neuropsychological tests and neuroimaging investigation. A number of patients (n = 6) presented with cognitive impairment. The two most frequent types of impairment were: deficits of speed and attention, and executive functioning. Impairments of free recall memory, intellectual functioning, nominal and calculation f…

Domain-specific characterisation of early cognitive impairment following spontaneous intracerebral haemorrhage.

2018

Cognitive deficits after spontaneous intracerebral haemorrhage (ICH) are common and result in functional impairment, but few studies have examined deficits across cognitive domains in the subacute phase. This study aims to describe the cognitive profile following acute ICH and explore how cerebral amyloid angiopathy (CAA) may impact performance. We retrospectively reviewed 187 consecutive patients with ICH (mean age 58.9 years, 55.6% male) with available imaging and neuropsychological data (median 12 days after stroke). In our cohort, 84% (n = 158) were impaired in at least one cognitive domain and 65% (n = 122) in two or more domains. Deficits in non-verbal IQ (76.6%), information processi…

The utility of the recognition memory test and the graded naming test in monitoring neurological patients

2007

Objectives. Repeated neuropsychological assessments are often used to monitor cognitive changes in neurological patients. In this study we document: test-retest reliability (TRR), group changes in performance and measures of intra-subject variability for two commonly used cognitive tests. Design. A large sample of neurological patients with either acute or degenerative neurological damage, and relatively static cognitive profiles, were retrospectively selected if they had been administered twice either the Recognition Memory Test (RMT) and/or the Graded Naming Test (GNT) within a 2-year interval. Results. Overall, the TRR of the RMT was reasonable in both patient groups, although slightly b…

Cognitive and behavioural disorders associated to space-occupying lesions

2008

Dynamic aphasia in PSP: A deficit in generating a fluent sequence of novel thought

2006

We report a patient (KAS) who presented with pure dynamic aphasia in the context of progressive supranuclear palsy (PSP). KAS had the hallmark propositional language impairment in the context of preserved naming, reading, repetition and comprehension skills. The severity of KAS's propositional language deficit was demonstrated to be comparable to other dynamic aphasic patients. Remarkably, despite virtually abolished propositional speech, KAS was unimpaired on word and sentence level generation tasks that required a single response. This dissociation was further investigated on two discourse level generation tasks that required the generation of multiple connected sentences. Quantitative pr…

Diffusion MRI-based cortical complexity alterations associated with executive function in multiple sclerosis.

2013

Purpose: To report a novel magnetic resonance imaging measure (diffusion orientational complexity [DOC]) in a study of people with multiple sclerosis (MS) and healthy controls and to determine patterns of abnormality, correlations with conventional diffusion measures, and associations with cognitive function. Materials and Methods: We performed high angular resolution diffusion imaging (HARDI) and measured DOC, mean diffusivity (MD), and fractional anisotropy (FA) in 51 MS patients and 28 healthy controls. All subjects had a 2-mm isotropic HARDI scan on a 3 T scanner using a 32-channel head receiver coil. DOC, MD, and FA were measured in three regions of interest (ROIs) in frontal cortex li…

Clinical-anatomical correlation in a selective phonemic speech production impairment

2004

Although phonemic paraphasias are common in aphasic disorders, including Broca's aphasia, conduction aphasia and transcortical motor aphasia, selective phonemic speech production impairment, or phonemic disintegration, is unusual. A patient with a selective phonemic speech production disorder underwent clinical, neuropsychological and structural neuroradiological assessment over a period of 6 years. The disorder was characterised by phonemic paraphasias (phonemic disintegration) with preserved comprehension and naming. Imaging showed a focal lesion in the white matter of the left precentral gyrus and, to a lesser extent, the posterior part of the left middle frontal gyrus, with overlying co…

Memory function after resolution of post traumatic amnesia

2005

Primary objectives: The aims of this pilot study were (1) to examine neuropsychological, particularly memory functions immediately after post-traumatic amnesia (PTA) resolution according to the Galveston Orientation and Amnesia Test (GOAT), and (2) to provide a preliminary exploration of pattern of performance on GOAT items across PTA duration. Methods and procedures: Thirty-seven head injured patients were administered the Recognition Memory Tests on the day that PTA resolved. Formal neuropsychological assessment was conducted on average 10 days after PTA resolution. Main outcomes and results: All the patients in the series showed memory impairment which varied in severity but was typicall…

The grey matter correlates of impaired decision-making in multiple sclerosis.

2014

Objective: People with multiple sclerosis (MS) have difficulties with decision-making but it is unclear if this is due to changes in impulsivity, risk taking, deliberation or risk adjustment, and how this relates to brain pathology. \ud \ud Methods: We assessed these aspects of decision-making in 105 people with MS and 43 healthy controls. We used a novel diffusion MRI method, diffusion orientational complexity (DOC), as an index of grey matter pathology in regions associated with decision-making and also measured grey matter tissue volumes and white matter lesion volumes. \ud \ud Results: People with MS showed less adjustment to risk and slower decision-making than controls. Moreover, impa…

Interferenza tra il livello dell’oggetto e attributi di base in stimuli visivi: studio su pazienti con lesione cerebrale.

2011

Introduzione. In compiti di ricerca visiva i processi top-down coinvolti nel riconoscimento della forma dell’oggetto possono interferire nella elaborazione bottom-up degli attributi elementari che compongono l’oggetto. La performance in tali compiti può essere facilitata dopo inibizione selettiva della corteccia parietale destra tramite r-TMS. In questo studio abbiamo indagato il ruolo di lesioni cerebrali nei compiti di ricerca visiva per singole caratteristiche caratterizzati da interferenza tra il livello dell’oggetto e degli attributi elementari. Pazienti con lesione focale del lobo parietale potrebbero paradossalmente non risentire dell’effetto interferente esercitato dal riconosciment…

The Doors and People Test: The Effect of Frontal Lobe Lesions on Recall and Recognition Memory Performance

2016

Objective: Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance. Other studies that do compare recall and recognition in the same frontal group do not consider recall or recognition tests that are comparable for difficulty. Recognition memory imp…

Troubles du calcul et du traitement des nombres: les travaux fondateurs.

2004

Mild cognitive impairment associated with focal right temporal lobe atrophy.

2005

Tracking progression from pre-MCI to dementia: a decade of pre-diagnostic assessment in a case of Familial Alzheimer's disease

2005

Standardizzazione di tre nuovi test di memoria di riconoscimento verbale e non verbale: uno studio preliminare.

2010

Il lavoro presenta la costruzione e standardizzazione di una nuova batteria di test neuropsicologici per la valutazione della memoria di riconoscimento verbale e non verbale. La batteria è composta da tre subtest: parole, volti non familiari ed edifici sconosciuti. I test sono stati standardizzati su un campione italiano di 308 soggetti normali di entrambi i sessi, di età compresa tra 20 e 80 anni e scolarità da 5 a 19 anni. I punteggi ai tre test risultano normalmente distribuiti. Le tre prove risultano di difficoltà uguale e graduata e sono confrontabili tra loro. La batteria consente di differenziare sia deficit globali che selettivi.

Sporadic and familial dementia with Ubiqitin Positive Tau negative inclusions: Clinical features of one histopathological abnormality underlying fron…

2005

BACKGROUND: Frontotemporal lobar degeneration comprises a group of diseases with clinical presentations and underlying histopathologies that overlap. Familial disease occurs in up to 50% of frontotemporal lobar degeneration cases. One of several underlying histopathological abnormalities is of ubiquitin-positive tau-negative inclusions, similar to those in motor neuron disease. OBJECTIVE: To compare clinical features of familial and sporadic cases in this pathological subgroup. DESIGN AND PATIENTS: Case note review of dementia patients with ubiquitin-positive tau-negative inclusion pathological abnormalities proven by autopsy. SETTING: United Kingdom tertiary referral center. MAIN OUTCOME M…

Alzheimer patients engage an alternative cortical network during a memory task.

2005

We conducted an event-related functional magnetic resonance imaging experiment to better understand the potentially compensatory alternative brain networks activated by a clinically relevant face-name association task in Alzheimer’s disease (AD) patients and matched control subjects. We recruited 17 healthy subjects and 12 AD patients at an early stage of the disease. They underwent functional magnetic resonance imaging scanning in four sessions. Each of the sessions combined a “study” phase and a “test” phase. Face/name pairs were presented in each study phase, and subjects were asked to associate faces with names. In the test phase, a recognition task, faces seen in the study phase were p…

Una nuova batteria di test di memoria di riconoscimento verbale e non verbale: uno studio preliminare.

2010

IMPAIRED ALLOCENTRIC SPATIAL MEMORY UNDERLYNG TOPOGRAPHICAL DISORIENTATION

2006

The cognitive processes supporting spatial navigation are considered in the context of a patient (CF) with possible very early Alzheimer's disease who presents with topographical disorientation. Her verbal memory and her recognition memory for unknown buildings, landmarks and outdoor scenes was intact, although she showed an impairment in face processing. By contrast, her navigational ability, quantitatively assessed within a small virtual reality (VR) town, was significantly impaired. Interestingly, she showed a selective impairment in a VR object-location memory test whenever her viewpoint was shifted between presentation and test, but not when tested from the same viewpoint. We suggest t…

Preserved knowledge maps of countries: Implications for the organisation of semantic memory

2004

We describe two patients with selectively preserved knowledge of the category of countries. Following a series of cerebra infarcts, patient DB presented with severe perceptual impairment, including dense apperceptive agnosia, prosopagnosia, an topographical agnosia. Despite these deficits, he could effortlessly name countries from their outline maps. Patient WH, who suffered from semantic dementia, had severe naming and comprehension difficulties, with extremely sparse residual semantic knowledge. Remarkably, the category of countries was preserved. First, we argue that, for both patients, this category preservation occurs at a semantic level. Second, we discuss our findings in the context …

Cognitive dysfunction in patients with cerebral microbleeds on T2*-weighted gradient-echo MRI

2004

Gradient echo T2*-weighted MRI has high sensitivity in detecting cerebral microbleeds, which appear as small dot-like hypointense lesions. Microbleeds are strongly associated with intracerebral haemorrhage, hypertension, lacunar stroke and ischaemic small vessel disease, and have generated interest as a marker of bleeding-prone microangiopathy. Microbleeds have generally been considered to be clinically silent; however, since they are located in widespread cortical and basal ganglia regions and are histologically characterized by tissue damage, we hypothesized that they would cause cognitive dysfunction. We therefore studied patients with microbleeds (n = 25) and a non-microbleed control gr…

A preliminary characterisation of cognition and social cognition in spinocerebellar ataxia types 2, 1, and 7.

2010

Over the last decade, studies have implicated the cerebellum not only in motor functioning, but also in cognition and social cognition. Although some aspects of cognition have been explored in the five most common forms of Spinocerebellar Ataxia (SCA), social cognition in these patients has rarely been examined. The present study provides a preliminary characterisation of the severity of cognitive and social cognitive impairments in patients with SCA2, SCA1 and SCA7 using an identical battery to the one previously used in SCA3 and SCA6 patients for comparison. The cognitive profiles of SCA1 and SCA7 patients were comparable to that of SCA6 patients; SCA1 patients had relatively intact profi…

The impact of different aetiologies on the cognitive performance of frontal patients

2014

Neuropsychological group study methodology is considered one of the primary methods to further understanding of the organisation of frontal ‘executive’ functions. Typically, patients with frontal lesions caused by stroke or tumours have been grouped together to obtain sufficient power. However, it has been debated whether it is methodologically appropriate to group together patients with neurological lesions of different aetiologies. Despite this debate, very few studies have directly compared the performance of patients with different neurological aetiologies on neuropsychological measures. The few that did included patients with both anterior and posterior lesions. We present the first co…

Strictly lobar microbleeds are associated with executive impairment in patients with ischemic stroke or transient ischemic attack.

2013

The natural history of Alzheimer disease: a longitudinal presymptomatic and symptomatic study of a familial cohort

2004

BACKGROUND: Knowledge of the evolution of cognitive deficits in Alzheimer disease is important for our understanding of disease progression. Previous reports, however, have either lacked detail or have not covered the presymptomatic stages. OBJECTIVE: To delineate the onset and progression of clinical and neuropsychological abnormalities in familial Alzheimer disease. METHODS: Nineteen subjects with familial Alzheimer disease underwent serial clinical and neuropsychological assessments. Eight of these had undergone presymptomatic assessments. The follow-up period was 1 to 10 years (mean, 5 years). The relative timing of the occurrence of 3 markers of disease onset and progression (onset of …

A decade of prediagnostic assessment in a case of Familial Alzheimer's disease: tracking progression from asymptomatic to MCI and dementia

2005

The differing roles of the frontal cortex in fluency tests.

2012

Coiling versus clipping of treatment of aneurismal subarachnoid haemorrhage: A longitudinal investigation into cognitive outcome.

2007

The impact of deep dysgraphia on graphemic output buffer disorders

2004

This article describes an investigation into the residual writing skills of a severely dysgraphic patient (DA). We found that they were powerfully influenced by a number of lexical variables (lexicality, frequency, imageability, length and geminates). His error pattern was characterized by semantic, lexical, substitution, deletion errors and fragment responses that preserved the first letter. Thus, DA's written spelling was characterized by both deep dysgraphic and graphemic output buffer effects. It is proposed that this pattern of performance represents a new "putative functional syndrome."

Apathy and Reduced Speed of Processing Underlie Decline in Verbal Fluency following DBS

2017

Objective. Reduced verbal fluency is a strikingly uniform finding following deep brain stimulation (DBS) for Parkinson's disease (PD). The precise cognitive mechanism underlying this reduction remains unclear, but theories have suggested reduced motivation, linguistic skill, and/or executive function. It is of note, however, that previous reports have failed to consider the potential role of any changes in speed of processing. Thus, the aim of this study was to examine verbal fluency changes with a particular focus on the role of cognitive speed. Method. In this study, 28 patients with PD completed measures of verbal fluency, motivation, language, executive functioning, and speed of process…

Ruolo dei processitop-down e bottom-up in compiti di ricerca visiva: studi con r-TMS

2009

A longitudinal investigation into cognition and disease progression in spinocerebellar ataxia types 1, 2, 3, 6, and 7

2016

Background The natural history of clinical symptoms in the spinocerebellar ataxias (SCA)s has been well characterised. However there is little longitudinal data comparing cognitive changes in the most common SCA subtypes over time. The present study provides a preliminary longitudinal characterisation of the clinical and cognitive profiles in patients with SCA1, SCA2, SCA3, SCA6 and SCA7, with the aim of elucidating the role of the cerebellum in cognition. Methods 13 patients with different SCAs all caused by CAG repeat expansion (SCA1, n = 2; SCA2, n = 2; SCA3, n = 2; SCA6, n = 4; and SCA7, n = 3) completed a comprehensive battery of cognitive and mood assessments at two time points, a mea…

Relazioni fra semantica e stima temporale

2007

The effect of adult-acquired hippocampal damage on memory retrieval: an fMRI study.

2005

Bilateral hippocampal pathology typically results in significant memory problems. Despite apparently similar structural damage, patients with such lesions can differ in the pattern of impairment and preservation of memory functions. Previously, an fMRI study of a developmental amnesic patient whose anoxic hippocampal damage was incurred perinatally revealed his residual hippocampal tissue to be active during memory retrieval. This hippocampal activity was apparent during the retrieval of personal and general facts relative to a control task. In this study, we used a similar fMRI paradigm to investigate whether residual hippocampal activation was present also in patient VC with adult-acquire…

The role of the prefrontal cortex in familiarity and recollection processes during verbal and non verbal recognition memory: a rTMS study

Neuroimaging and lesion studies have documented the involvement of the frontal lobes in recognition memory. However, the precise nature of prefrontal contributions to verbal and non verbal memory and to familiarity and recollection processes remains unclear. The aim of the current rTMS study was to investigate for the first time the role of the DLPFC in encoding and retrieval of non verbal and verbal memoranda and its contribution to recollection and familiarity processes. Recollection and familiarity processes were studied using the ROC and unequal variance signal detection methodologies. We found that rTMS delivered over left and right DLPFC at encoding resulted in material specific later…

Low frequency rTMS over the right parietal cortex at retrieval increases recognition memory in healthy subjects

2013

Neuroimaging and lesion studies have led to contrasting findings regarding the potential role of the parietal lobe in episodic memory. Imaging studies strongly suggest an important participation of the posterior parietal cortex (PPC) in episodic memory, whereas lesion studies are not conclusive at this regard. Using off-line 1 Hz rTMS paradigm, we conducted 2 experiments to investigate the role of PPCs in recognition memory. Real or sham rTMS were applied over the left or the right PPC (P3 and P4 of the 10–20 EEG system) of healthy subjects before encoding (Experiment 1) and just before retrieval (Experiment 2) of forced-choice non verbal recognition memory tasks. rTMS over the left and the…

Knight's move thinking? Mild cognitive impairment in a chess player

2005

Standardised Neuropsychological Assessment for the Selection of Patients Undergoing DBS for Parkinson’s Disease

2017

DBS is an increasingly offered advanced treatment for Parkinson’s disease (PD). Neuropsychological assessment is considered to be an important part of the screening for selection of candidates for this treatment. However, no standardised screening procedure currently exists. In this study, we examined the use of our standardised neuropsychological assessment for the evaluation of surgical candidates and to identify risk factors for subsequent decline in cognition and mood. A total of 40 patients were assessed before and after DBS. Evaluation of mood and case notes review was also undertaken. Before DBS, patients with PD demonstrated frequent impairments in intellectual functioning, memory, …

Facilitation in Visual Search for Reversed Letters Following r-TMS of the Left Parietal Cortex

2014

Survival in Alzheimer disease

2005

We thank Dr Lesser for his comments. We agree that deaths in older populations with AD are often from comorbid conditions, and we would not wish to overinterpret the limited survival data from this study. We also accept that determining symptom onset is an inexact science. However, we would suggest that in this small cohort the disease course of about a decade cannot be considered an aggressive one. Since publication of our study, 2 additional subjects have died 8.9 and 16.8 years after onset thereby increasing the mean time from onset to death to 9.4 years. We agree, however, that further study is required to resolve these issues and in particular to assess genetic factors that may influen…

Facilitazioni paradossali in compiti di ricerca visiva in pazienti con lesione parietale destra.

2012

Introduzione. In compiti di ricerca visiva i processi top-down coinvolti nel riconoscimento della forma dell’oggetto possono interferire nella elaborazione bottom-up degli attributi elementari che compongono l’oggetto. Precedenti studi r-TMS hanno documentato che la performance in tali compiti può essere facilitata dopo inibizione selettiva della corteccia parietale destra. L’ipotesi alla base del presente studio è che pazienti con lesione focale parietale destra potrebbero non risentire dell’effetto interferente esercitato dal riconoscimento della forma dell’oggetto in compiti di ricerca visiva di singole caratteristiche. Metodo. Hanno partecipato allo studio sette pazienti (2 femmine e 5 …

The effect of age on cognitive performance of frontal patients

2015

Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanc…

Impairment in Theory of Mind in Parkinson's Disease Is Explained by Deficits in Inhibition

2019

Objective: Several studies have reported that people with Parkinson's disease (PD) perform poorly on tests of Theory of Mind' (ToM), suggesting impairment in the ability to understand and infer other people's thoughts and feelings. However, few studies have sought to separate the processes involved in social reasoning from those involved in managing the inhibitory demands on these tests. In this study, we investigated the contribution of inhibition to ToM performance in PD. Methods. 18 PD patients and 22 age-matched healthy controls performed a ToM test that separates the ability to infer someone else's perspective from the ability to inhibit one's own. Participants also completed a battery…

Evaluating the role of dorsolateral prefrontal cortex on recognition memory with rTMS: evidence from healthy subjects and neurological patients

2010

Converging evidence from functional imaging and lesion studies suggested that a distributed neural network comprising the hippocampal formation, medial and lateral parietal regions as well as the prefrontal cortex is involved in episodic memory. Some findings suggested that successful memory formation requires the coordinated modulation of neural activity among these different cortical areas. It appears particularly important to understand the functional interactions between these regions during memory processes. My talk will be focused on the prefrontal contribution to verbal and non-verbal recognition memory and to familiarity and recollection processes. New evidence will be provided and …