Twenty adult patients, (13 males and 7 females) aged from 20 to 57 years, suffering from chronic brain blood supply impairment verified by different techniques (CBF measurement, ophthalmoangioscopic study; CAT, Carotid angiogram) have been submitted to REG and various EEG investigations (Standard and spectral EEG analysis, VEP and SEP studies) prior and during a chronic treatment with eburnamonine intramuscularly given for 60 days and after drug withdrawal. A significant reduction in prominent EEG frequency during the first 30 days treatment has been observed whereas a significant increase in mean EEG amplitude during 60 days treatment could be recorded. A significant and progressive increase in mean REG sphygmic amplitude after 60 days treatment and 30 days after the withdrawal, together with a significant increase in rise time and a significant reduction in culmination time of REG, could be observed. A reduction in VEP latencies of P1 either over the occipital or over the centrofrontal regions with increase in total VEP duration and significant improvement in postero-anterior transmission of evoked response have been observed. A reduction in SEP latencies of P1 either on contralateral or on ipsilateral somatosensory cortex has been observed. A significant decrease in delta content over all brain regions and in theta content over parieto-occipital regions with significant increase in alpha content during the whole treatment and after the suspension with a transient increase in beta frequency during the first 30 days treatment have been revealed by spectral EEG analysis. Bearing in mind the different and frequently antithetic trends in EEG amplitude and frequency changes observed in patients suffering from partial blood supply impairment versus the total blood supply impairment the antihypoxic effects of (--) eburnamonine have been confirmed, with increase in blood flow, specially of cortical grey matter, revealed by REG changes.