Quantitative pharmaco-EEG study of nootropics].

T Kinoshita

Department of Psychiatry, Kansai Medical University.

Seishin shinkeigaku zasshi = Psychiatria et neurologia Japonica 1990

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A treatment of geriatric disorders is one of the current major problems socially as well as medically. Thus nootropics have become one of the biggest topics in drug developments. Unfortunately, it is still very difficult to assess brain dysfunctions and therapeutic efficacies of these drugs objectively. Giurgea has proposed a new drug category, "nootropic", as those substances which possess an anti-dementia action, yet the general concept remains obscure. The present author expand the concept that those substances which improve the vigilance level to be included. The author has been engaged with computer assisted pharmaco-electroencephalography and research of nootropics for last several years. Based on the own experiences, the author presented the CNS effects of five different substances such as meclofenoxate, amantadine, piracetam, teniloxazine and WEB-1881, which were regarded as nootropics from various reasons. Single dose of each substances was administered in healthy young volunteers, and teniloxazine was given to geriatric patients. EEG changes induced by these substances in normal subjects were an increase of alpha activity, particularly in higher frequency range above 9.5 Hz, and an associated decrease of slow activity and of fast activity, which are different from those of the other psychotropic drugs. Multivariate analysis of variance (MANOVA) of EEG parameters has confirmed that the response of WEB-1881 was most manifest in frontal area. This suggests that WEB-1881 might activate linguistic learning and memory process. In the patient study, the induced EEG changes were an increase of alpha activity associated with a decrease of slow activity, while fast activity did not show any changes. However, the EEG changes in the patient study were quite similar to those of normal volunteer study for the most part. It is relevant to infer the efficacy of nootropics in geriatric patients from acute normal volunteer study. In physiological aging process, alpha activity gradually decreases. The EEG changes induced by nootropics are the reverse of this process, suggesting the antagonistic efficacy in the geriatric changes. Therefore, quantitative pharmaco-EEG is one of the best tools in the screening for the CNS efficacy of nootropic or anti-dementia substance in the meantime.