EEG frequency and cognitive dysfunction in patients with Parkinson's disease

Numerous studies showed EEG changes in patients with Parkinson's disease, in comparison with healthy subjects of same age. The most often presented change is generalised (or localised) slowing of frequency.

To show the correlation of EEG frequency and Mini Mental Status (MMS) in patients with Parkinson's disease.

32 patients with Parkinsons disease were analysed. An average age was 64.63 +/- 10.01 years, and most of them were men (24 or 75%). On the basis of MMS score, two groups were selected: with and without signs of dementia. For both groups, EEG frequency values were determined.

There were 11 patients without dementia (MMS score = 23-30) with average age of 64.63 +/- 9.54 years; and with dementia (MMS score < 24) 21 patients (average age was 62.71 +/- 10.04 years). In patients without dementia, diffuse slowing down of frequency was found in one patient (9.1%); localised in three (90.9%). In dementia patients, four patients (19.04%) had diffuse slowing of EEG and seven (80.96%) had localised. A positive correlation of EEG frequency and MMS score was found (r = 0.46), and Parkinson's disease patients with dementia had more frequently EEG with slowing frequency than non-dementia patients.

EEG slowing frequency is more frequent in Parkinson's disease patients with than without dementia.