Author/Editor		Barrett, Geoff; Pirtošek, Zvezdan; Jahanshahi, Marjan; Towell, Tony; Lees, Andrew
Title		Cognitive evoked potentials in Parkinson's disease and related disorders
Type		članek
Source		In: Kimura J, Shibasaki H, editors. Recent advances in clinical neurophysiology. Proceedings of the 10th international congress of EMG and clinical neurophysiology; 1995 Oct 15-19; Kyoto. Amsterdam: Elsevier science,
Publication year		1996
Volume		str. 585-9
Language		eng
Abstract		Background. The success of levodopa as a treatment for Parkinson's disease (PD) has focused attention on the need for accurate differential diagnosis between this and other akineto-rigid disorders, such as multiple system atrophy (MSA), Stele-Richardson-Olszewski syndrome (SRO) and corticobasal degeneration (CBD). These disorders show differing degrees of cognitive dysfunction at various stages during their progression which might be detected using cognitive electrophysiology (event-related potentials, ERPs). Methods. ERPs were recorded from patients with CBD, PD, DRO and MSA, and from two groups of age-matched controls (young and old). ERP tests involved a three-stimulus auditory oddball task and auditory and visual selective attention tasks. All patient groups underwent psychometric testing. Results. Reaction times of CBD and SRO patient groups were longer than those of the other groups in all three tasks. Diagnosis also affected P3 amplitude to rare nontargets and N2 latency to targets in the oddball task. Unattended stimulus conditions produced differences between patient groups from 195 ms onwards in the auditory selective attention task, whereas all conditions in the visual selective attention task produced differences related to diagnosis during the period 195-435 ms poststimulus. There was also an indication of reduced activity frontocentrally in this task for patients compared with controls. Psychometry was generally normal for CBD patients but not for the other patient groups. Conclusions. The selective attention tasks appear to be particularly good at distinguishing between patient groups and in identifying a reduction in frontocentral activity in patients compared with controls. There was a major discrepancy between the normal psychometry and clearly abnormal electrophysiology for the CBD patients.
Descriptors		PARKINSON DISEASE SUPRANUCLEAR PALSY, PROGRESSIVE EVOKED POTENTIALS COGNITION PSYCHOMETRICS