EEG mapping and psychopharmacological studies with denbufylline in SDAT and MID

Computed tomography (CT), electroencephalograms (EEG), clinical and psychometric data were obtained in 96 mildly to moderately demented patients (72 women, 24 men), aged 61-96 years (mean 82), diagnosed according to DSM-III criteria. Patients were off drugs for at least 2 weeks and subdiagnosed according to the modified Marshall-Hachinski ischemic score and CT in 45 senile dementia of the Alzheimer type (SDAT) and 51 multiinfarct dementia (MID) patients. Evaluations were carried out before and 12 weeks after treatment with either 100 mg denbufylline BID or placebo and included EEG mapping, the Sandoz Clinical Assessment Geriatric (SCAG) score/factors, the Clinical Global Impression (CGI), the Digit Symbol Substitution Test (DSST), the Trail-Making Test (TMT) and the Digit Span Test (DS). Descriptive data analysis including confirmatory statements found delta/theta activity enhanced, alpha and beta activity reduced, total power augmented, and the centroid slowed down over various brain regions in patients as compared with controls. The two subtypes of dementia could be differentiated in some conventional EEG variables but mostly by means of power asymmetry indices. Denbufylline induced a statistically significant and clinically relevant improvement in both SDAT and MID patients, whereas after placebo this was not the case in CGI, the TMT, and the DS, with interdrug differences being significant in all primary target variables such as the CGI, MMS, SCAG, and DSST. Thus, both the degenerative and vascular type of dementia exhibited a therapeutic benefit that could be objectified at the neurophysiological level by EEG mapping in an improvement of vigilance.