Ihre Suche
Ergebnisse 2 Einträge
-
Cerebral reorganization may limit the effects of central nervous system tissue damage on cognition in patients with multiple sclerosis (MS). This study investigated fMRI activation patterns in patients with relapsing-remitting MS and healthy control subjects during performance of a delayed recognition task. As intended, fMRI task performance was similar in the MS and the control group, whereas neuropsychological testing revealed reduced performance in the patient group on the Paced Serial Addition Test, a reference task for the assessment of cognitive function in MS. Patients overall showed more activation in left posterior parietal cortex than healthy control subjects. Global gray matter atrophy in the patient group was associated with low PASAT scores. In a multiple regression analysis including white matter lesion load and gray matter atrophy as covariates, PASAT performance correlated with activation in left posterior parietal cortex and right anterior midfrontal gyrus, indicating a reallocation of neuronal resources to help preserve function. Global gray matter atrophy correlated with activation in bilateral prefrontal cortex, dorsal ACC and left posterior parietal cortex and, furthermore, was associated with a low degree of deactivation in rostral ACC, suggesting neural inefficiency and consistent with a reduced capacity to modulate between frontoparietal task-associated activation and 'default network' activity. The current study provides evidence that altered brain activation in MS patients has two distinct components, one related to compensatory processes and one to neural inefficiency associated with tissue damage.
-
Cognitive deficits affecting memory, attention and speed of information processing are common in multiple sclerosis (MS). The mechanisms of cognitive impairment remain unclear. Here, we examined the association between neuropsychological test performance and brain atrophy in a group of mildly disabled patients with relapsing-remitting MS. We applied voxel-based morphometry (SPM2) to investigate the distribution of brain atrophy in relation to cognitive performance. Patients had lower scores than control subjects on tests of memory and executive function, including the PASAT, Digit Span Backward and a test of short-term verbal memory (Memo). Among patients, but not healthy controls, performance on the PASAT, a comprehensive measure of cognitive function and reference task for the cognitive evaluation of MS-patients, correlated with global grey matter volume as well as with grey matter volume in regions associated with working memory and executive function, including bilateral prefrontal cortex, precentral gyrus and superior parietal cortex as well as right cerebellum. Compared to healthy subjects, patients showed a volume reduction in left temporal and prefrontal cortex, recently identified as areas predominantly affected by diffuse brain atrophy in MS. A comparison of low performers in the patient group with their matched control subjects showed more extensive and bilateral temporal and frontal volume reductions as well as bilateral parietal volume loss, compatible with the progression of atrophy found in more advanced MS-patients. These findings indicate that MS-related deficits in cognition are closely associated with cortical atrophy.
Erkunden
Team
- Vaitl (2)
Eintragsart
Sprache
Thema
- Adaptation, Physiological (1)
- Adult (2)
- Atrophy/etiology (1)
- Brain (1)
- Brain Mapping/methods (1)
- Cerebral Cortex/*pathology (1)
- Cerebral Cortex/*physiopathology (1)
- *Cognition (1)
- Cognition Disorders/*etiology (1)
- Cognition Disorders/etiology/*physiopathology (1)
- *Evoked Potentials (1)
- Female (2)
- Humans (2)
- *Magnetic Resonance Imaging (1)
- Magnetic Resonance Imaging/*methods (1)
- Male (2)
- Middle Aged (1)
- Multiple Sclerosis/complications/*physiopathology (1)
- Multiple Sclerosis, Relapsing-Remitting/*complications (1)
- Organ Size (1)
- *Task Performance and Analysis (1)