Investigation and Comparison of the Neurophysiological and Neuropsychological Assessments in Alzheimer Dementia and Parkinson's Dementias

The aim of this study is to evaluate cognitive functions in dementia and to evaluate electroencephalography (EEG) and event related potentials (ERP-P 300) findings, to correlate any relationship between cognitive functions and neurophysiological values in demented patients. The various cognitive and mental state tests were assessed in 30 patients with Parkinson's disease and 20 patients with dementia of the Alzheimer's type, 20 control group. Interaction between electrophysiological and neuropsychological measures have been studied in patients with dementia. EEG changes were detected in 9 (45%) patients with AD in the form of deceleration in diffuse or bitemporal backgroundactivity, increase in delta and theta frequency, decrease in rapid activity . Prolongation in P300 latency was observed in 16 (80%) patients, amplitute depression in 15(75%) patients. These electrophysiological changes were found to be significant when compared with control in the same age (p<0.001). All of the electrophysiological abnormalities werein the patients with a important degree of impairment of memory, orientation, naming, writing and calculation functions. Mild EEG changes was observed in PD and normal electrophsiological findings were found in nondemen ted PD. P3 values were according to dementia symptoms. It is concluded that EEG was not an occurate means of demonstrating the degree and type of cognitive change; that auditory event related potential was correlated with impairment of cognitive functions and finally that they could contribute to the diagnosis of dementia.