Search results for "Cuneus"
showing 10 items of 15 documents
Dominance for Vestibular Cortical Function in the Non-dominant Hemisphere
2003
The aim of this (15)O-labelled H(2)O bolus positron emission tomography (PET) study was to analyse the hemispheric dominance of the vestibular cortical system. Therefore, the differential effects of caloric vestibular stimulation (right or left ear irrigation with warm water at 44 degrees C) on cortical and subcortical activation were studied in 12 right-handed and 12 left-handed healthy volunteers. Caloric irrigation induces a direction-specific sensation of rotation and nystagmus. Significant regional cerebral blood flow increases were found in a network within both hemispheres, including the superior frontal gyrus/sulcus, the precentral gyrus and the inferior parietal lobule with the sup…
Precuneus and insular hypoactivation during cognitive processing in first-episode psychosis: Systematic review and meta-analysis of fMRI studies
2020
Abstract Introduction The neural correlates of the cognitive dysfunction in first-episode psychosis (FEP) are still unclear. The present review and meta-analysis provide an update of the location of the abnormalities in the fMRI-measured brain response to cognitive processes in individuals with FEP. Methods Systematic review and voxel-based meta-analysis of cross-sectional fMRI studies comparing neural responses to cognitive tasks between individuals with FEP and healthy controls (HC) according to PRISMA guidelines. Results Twenty-six studies were included, comprising 598 individuals with FEP and 567 HC. Individual studies reported statistically significant hypoactivation in the dorsolatera…
79. Amyloid-PET analysis based on tissue probability maps
2018
Purpose The regional quantification of amyloid burden is crucial for the clinical diagnosis of Alzheimer’s disease [1]. The best method to evaluate regional amyloid deposition in PET is through the use MR imaging for brain space normalization. However, since MR imaging is not always available in the clinical practice, a MR-less methodology is needed in order to compute semi-quantitative and analyze regional amyloid burden. Methods Forty-four patients with clinical evidence of dementia, underwent 18F-Florbetaben PET (FBB-PET), FDG-PET, neuropsychological assessment and cerebrospinal fluid analysis. We implemented a methodology that uses SPM12 to import and normalize the FBB-PET images in Mon…
Neuroimaging correlates of insight in non-affective psychosis: A systematic review and meta-analysis.
2022
Abstract Objective Neurological correlates of impaired insight in non-affective psychosis remain unclear. This study aimed to review and meta-analyze the studies assessing the grey matter volumetric correlates of impaired insight in non-affective psychosis. Methods This study consisted of a systematic review of 23 studies, and a meta-analysis with SDM-PSI of the 11 studies that were whole-brain and reported maps or peaks of correlation of studies investigating the grey matter volumetric correlates of insight assessments of non-affective psychosis, PubMed and OVID datasets were independently reviewed for articles reporting neuroimaging correlates of insight in non-affective psychosis. Qualit…
Cognitive benefits of exercise interventions: an fMRI activation likelihood estimation meta-analysis.
2021
Despite a growing number of functional MRI studies reporting exercise-induced changes during cognitive processing, a systematic determination of the underlying neurobiological pathways is currently lacking. To this end, our neuroimaging meta-analysis included 20 studies and investigated the influence of physical exercise on cognition-related functional brain activation. The overall meta-analysis encompassing all experiments revealed physical exercise-induced changes in the left parietal lobe during cognitive processing. Subgroup analysis further revealed that in the younger-age group (< 35 years old) physical exercise induced more widespread changes in the right hemisphere, whereas in th…
Combined Behavioral and Mismatch Negativity Evidence for the Effects of Long-Lasting High-Definition tDCS in Disorders of Consciousness: A Pilot Study
2020
Objective: To evaluate the effects of long-term High-definition transcranial direct current stimulation (HD-tDCS) over precuneus on the level of consciousness (LOC) and the relationship between Mismatch negativity (MMN) and the LOC over the therapy period in patients with Disorders of consciousness (DOCs). Methods: We employed a with-in group repeated measures design with an anode HD-tDCS protocol (2 mA, 20 min, the precuneus) on 11 (2 vegetative state and nine minimally conscious state) patients with DOCs. MMN and Coma Recovery Scale-Revised (CRS-R) scores were measured at four time points: before the treatment of HD-tDCS (T0), after a single session of HD-tDCS (T1), after the treatment of…
Focal cortical damage parallels cognitive impairment in minimal hepatic encephalopathy
2012
Little attention has been paid to cortical integrity in patients with minimal hepatic encephalopathy (MHE), although cognitive functions affected in early stages of liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 31 magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood ammonia levels accounte…
Neural correlates of working memory dysfunction in first-episode schizophrenia patients: an fMRI multi-center study.
2005
Working memory dysfunction is a prominent impairment in patients with schizophrenia. Our aim was to determine cerebral dysfunctions by means of functional magnetic resonance imaging (fMRI) in a large sample of first-episode schizophrenia patients during a working memory task. 75 first-episode schizophrenia patients and 81 control subjects, recruited within a multi-center study, performed 2- and 0-back tasks while brain activation was measured with fMRI. In order to guarantee comparability between data quality from different scanners, we developed and adopted a standardized, fully automated quality assurance of scanner hard- and software as well as a measure for in vivo data quality. After t…
Observer independent analysis of cerebral glucose metabolism in patients with chronic fatigue syndrome.
2003
Objectives: To evaluate cerebral glucose metabolism, assessed by 18-fluorodeoxyglucose positron emission tomography (FDG-PET), in patients with chronic fatigue syndrome (CFS), using an observer independent analytical approach; and to characterise any observed alterations by correlating them with neuropsychological deficits. Methods: 26 patients (13 female, 13 male) were examined. They all fulfilled the CDC diagnostic criteria for CFS. Their ages ranged from 26 to 61 years (mean (SD) age, 43 (9.3) years). They underwent extensive psychometric testing including the hospital anxiety and depression scale (HADS) and the short form 36 item health questionnaire (SF-36). Brain FDG-PET was done in a…
Precuneus Dysfunction in Parkinson's Disease With Mild Cognitive Impairment.
2018
Background: Mild cognitive impairment (MCI) frequently occurs in Parkinson's disease (PD). Neurovascular changes interact with neurodegenerative processes in PD. However, the deficits of cerebral blood flow (CBF) perfusion and the associated functional connectivity (FC) in PD patients with MCI (PD-MCI) remain unclear. Purpose: This study aimed to explore the specific neurovascular perfusion alterations in PD-MCI compared to PD with normal cognition (PD-NC) and healthy controls (HCs), and to further examine the resultant whole brain FC changes in the abnormal perfusion regions. Methods: Relative CBF (rCBF) was calculated using arterial spin labeling (ASL) in 54 patients with PD (27 patients …