Pathophysiology and psychopharmacology of dementia--a new study design. I. Diagnosis comprising subjective and objective criteria.
In a double-blind placebo-controlled psychopharmacological study 263 patients with cognitive impairment were screened and 137 of them were selected (following defined inclusion and exclusion criteria) to participate in a clinical trial (for results of treatment phase see part II, in preparation). The pretreatment state was evaluated twice using quantitative-topological EEG (qEEG) and psychopathological rating scales. There is a significant correlation between total score values of nearly all dementia-specific neuropsychological rating scales and absolute spectral power in the lower frequency ranges (delta, theta, alpha 1) at rest. In order to increase the diagnostic power, qEEG was recorded simultaneously with the performance in four different psychometric tests. It was found that the worse the psychopathological rating of a patient, the higher the absolute theta power at rest and the smaller the test- and demand-dependent further increase in theta power. The percentage of task-induced power increase in delta and theta frequency range appeared to be an efficient indicator for a reliable discrimination between healthy elderly individuals and demented patients (rank correlation coefficient for theta in F7: r = +0.55), which will also serve for evaluation of treatment.
D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000188:drug therapy* / Q000503:physiopathology* / Q000523:psychology; D004311:Double-Blind Method; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics; D011597:Psychomotor Performance; D012107:Research Design