Search results for "Brain Mapping"
showing 10 items of 396 documents
Finger movements induced by transcranial magnetic stimulation change with hand posture, but not with coil position
1998
We attempted to map the representations of movements in 2 normal subjects by delivering five transcranial magnetic stimuli (TMS) with a focal coil to each of a grid of positions over the primary motor area (M1). Isometric forces were recorded from the contralateral index finger. Maps were made with the hand in a semiflexed “neutral” position, and with the thumb and index finger opposed in a “pincer” grip. The electromyogram (EMG) was monitored to ensure relaxation. The wrist was immobilized. In the neutral position, TMS at almost all positions produced abduction. Flexion was produced in the pincer position. Thus, while sensitive to changes in posture, TMS mapping may not be sensitive to the…
Correlation between fatigue and brain atrophy and lesion load in multiple sclerosis patients independent of disability.
2007
Abstract Background Fatigue is a major problem in multiple sclerosis (MS), and its association with MRI features is debated. Objective To study the correlation between fatigue and lesion load, white matter (WM), and grey matter (GM), in MS patients independent of disability. Methods We studied 222 relapsing remitting MS patients with low disability (scores ≤ 2 at the Kurtzke Expanded Disability Status Scale). Lesion load, WM and GM were measured by fully automated, operator-independent, multi-parametric segmentation method. T1 and T2 lesion volume were also measured by a semi-automated method. Fatigue was assessed by the Fatigue Severity Scale (FSS), and patients divided in high-fatigue (FS…
Differential association of default mode network connectivity and rumination in healthy individuals and remitted MDD patients
2016
Rumination is associated with increased default-mode network (DMN) activity and functional connectivity (FC) in depressed and healthy individuals. In this study, we sought to examine the relationship between self-reported rumination and resting-state FC in the DMN and cognitive control networks in 25 remitted depressed patients and 25 matched healthy controls using independent component and seed-based analyses. We also explored potential group differences in the global pattern of resting-state FC. Healthy subjects with increased levels of rumination exhibited increased anterior DMN connectivity with the posterior DMN and the dorsal attention network and low connectivity within the anterior …
Intraoperative brain mapping during awake surgery in symptomatic supratentorial cavernomas.
2021
Abstract Background Complete resection of symptomatic supratentorial cavernoma (SCA) and removal of the surrounding gliotic area is recommended to minimize the risk of persistent seizures or (re)bleeding. Surgery of SCA located in an eloquent area, can carry out severe postoperative neurological morbidity. We report a study aimed to assess feasibility, extent of resection and outcome after surgical removal of CA by cortico-subcortical intraoperative brain stimulation (ioBS) in the awake patient. Methods Six patients diagnosed of symptomatic SCA located on an eloquent area and operated on while awake under local anaesthesia ioBS, were included. Preoperative planning included neuropsychologic…
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…
Brain lateralization of metrical accenting in musicians.
2009
The perception of meter, or the alternation of strong and weak beats, was assessed in musically trained listeners through magnetoencephalography. Metrical accents were examined with no temporal disruption of the serial grouping of tones. Results showed an effect of metrical processing among identical standard tones in the left hemisphere, with larger responses on strong than on weak beats. Moreover, processing of occasional increases in intensity (phenomenal accents) varied as a function of metrical position in the left hemisphere, but not in the right. Our findings support the view of a relatively early, left-hemispheric effect of metrical processing in musicians.
Left-hemispheric dominance for articulation: a prospective study on acute ischaemic dysarthria at different localizations.
2006
Dysarthria is a frequent symptom in cerebral ischaemia. However, speech characteristics of these patients have not previously been investigated in relation to lesion site in a prospective study. We investigated the auditory perceptual features in 62 consecutive patients with dysarthria due to a single, non-space-occupying cerebral infarction confirmed by MRI. Standardized speech samples of all patients were stored within 72 h after stroke onset using a digital tape recorder. Speech samples were assessed independently by two experienced speech therapists, who were unaware of the clinical and neuroradiological findings, using an interval scale ranging from 0 to 6. Separately assessed were fea…
Interest of targeting either cortical area Brodmann 9 or 46 in rTMS treatment for depression: a preliminary randomized study.
2013
Abstract Objective To assess the interest of specifically targeting Brodmann Areas (BA) 9 or 46 for rTMS treatment of depression. Methods Patients with Treatment-Resistant Depression were randomly assigned to two treatment groups to receive either rTMS on BA 9 or on BA 46. Each patient underwent 10 sessions of 1Hz-rTMS for 2weeks. The Hamilton and Montgomery–Asberg Depression Rating Scales (HDRS, MADRS) were used under blind conditions to assess the therapeutic response (50% improvement). A Wilcoxon signed-rank test was used to compare the depression rating scales scores obtained before and after the 10 rTMS sessions for each of the two groups. The therapeutic results in the two groups were…
Inter-hemispheric remapping between arm proprioception and vision of the hand is disrupted by single pulse TMS on the left parietal cortex.
2013
International audience; Parietal cortical areas are involved in sensori-motor transformations for their respective contralateral hemifield/body. When arms of the subjects are crossed while their gaze is fixed straight ahead, vision of the hand is processed by the hemisphere ipsilateral to the arm position and proprioception of the arm by the contralateral hemisphere. It induces interhemispheric transfer and remapping. Our objective was to investigate whether a single pulse TMS applied to the left parietal cortical area would disturb interhemispheric remapping in a similar case, and would increase a simple reaction time (RT) with respect to a control single pulse TMS applied to the frontal c…
Neural correlates of disturbed perception of verticality.
2012
Objective: Perception of verticality can be perturbed after cortical stroke. However, a relationship between lesion location and pathologic perception of verticality is still a matter of debate since previous studies revealed contradictory results. Thus, the aim of the current study was to test whether specific cortical lesions were associated with tilts of subjective visual vertical (SVV) and to determine the critical brain areas that cause such tilts in the case of a lesion. Methods: SVV was systematically studied in 54 patients (22 patients with left-sided and 32 patients with right-sided lesions) with acute unilateral strokes, analyzed by modern voxel-wise lesion-behavior mapping techni…