Search

This study investigated event-related oscillations associated with a Simon task in 11 Parkinson's disease patients, 11 age-matched, and 11 young participants. During this task, participants respond faster when the relative spatial positions of stimulus and response match (no response conflict exists) than when they do not match (response conflict exists). An increased response conflict (increase in reaction times known as Simon effect) was found in elderly control and Parkinson's patients compared with young participants. Group and condition differences were found in the delta and theta frequency range, which may reflect that Parkinson's patients and matched controls use different cognitive strategies for stimulus-response processing than young controls and neurophysiological correlates of such strategy are deficient in patients compared with age-matched controls.

Objective To assess whole brain and central brain atrophy as well as their differential relation to memory, cognitive performance, fatigue, depression and quality of life in patients with relapsingremitting multiple sclerosis (RRMS). Methods A 3D flow compensated gradient recalled T1-weighted MRI was acquired in 45 RRMS patients. An automated analysis tool was used to calculate brain parenchymal fraction (BPF) and ventricular brain fraction (VF). All patients were assessed with neuropsychological tests focusing on memory and self-rating scales for depression, fatigue and quality of life. Age corrected partial correlations between brain atrophy, motor performance, psychological scales and test scores were calculated. Results BPF correlated moderately (0.3 ≤ r < 0.5) with duration of symptoms and disease, the Expanded Disability Status Scale (EDSS), the upper extremity motor performance, and with mental aspects of quality of life. VF correlated moderately with EDSS, upper and lower extremity motor performance and memory functions. Neither BPF nor VF correlated with fatigue and depression. Results of several cognitive tests correlated moderately with depression and fatigue, the Paced Auditory Serial Addition Test (PASAT) showing the largest correlation. Conclusions Memory performance shows a correlation with relative ventricular size in RRMS patients, indicating the strategic location of the ventricle system along the structures of the limbic system and its vulnerability in MS. The PASAT and several other cognitive tests show moderate correlations with depression and fatigue, arguing for an inter relation between the cognitive functioning and the emotional state of patients. However, this relation is independent of measurable brain atrophy. [ABSTRACT FROM AUTHOR]