EEG REGIONAL CHANGES DURING LONG-TERM TREATMENT WITH TETRAHYDROAMINOACRIDINE (THA) IN ALZHEIMERS-DISEASE

Three patients with Alzheimer's disease of mild type received long-ter m treatment with THA at doses between 40 mg to 160 mg daily. This stud y describes the effects of THA on EEG, seen during long-term and high dose treatments. After short-term treatment, the changes of the mean f requency in the temporal and parieto-occipital regions varied between patients, but in the frontal region a significant increase of the mean frequency was seen in all patients. The EEG improvement seen in the f rontal region was more significant than that for the other regions at low dose of THA (80 mg). During long-term treatment, we observed diffe rent types of EEG changes. The early improvement seen in two patients was temporary and reverted to the pre-treatment value. In a third pati ent who did not show marked improvement after short-term treatment, an improvement was seen in all regions after longer treatment. Treatment with high doses of THA (120 mg or 160 mg) induced a marked increase i n the mean frequency not only in the frontal region but also in the te mporal and parieto-occipital regions. Higher doses of THA seem to affe ct larger areas of the brain than lower doses of THA.