The Doppler ultrasonic technique is useful for the examination of cerebral circulation as well as for the evaluation of cerebral circulation-improving drugs. This study deals with a correlation of cerebral circulation with intellectual impairment in subjects with aging brain syndrome and with measuring the effect of vinpocetine on cerebral circulation, using the Doppler technique.
The correlatiion between cerebral circulation and intellectual impairment was first studied in 48 patients with aging brain and intellectual impairment. As a parameter for cerebral ciruclation, the Continuous Index (CI), as calculated from the blood flow pattern recorded at the internal carotid artery, was used together with Hasegawa's Dementia Scale (HDS) for intellectual impairment.
Second, blood flow change of the internal carotid and vertebral artery was measured after a single oral dose of 5 mg vinpocetine and after multiple oral doses of 5 mg vinpocetine three times daily for 7 days in six patients with aging brain.
The mean correlation coefficient (r) between CI and HDS was 0.391 (P < 0.01) in 48 patients. It was 0.612 (P < 0.01) in 27 patients with moderate to severe intellectual impairment, 0.735 (P < 0.01) in 14 patients with vascular type impairment, and 0.443 (not significant) in 10 patients with the Alzheimer type. The results suggest some correlation between cerebral circulation and intellectual impairment in the aging brain, especially in patients with the vascular type.
An increase of blood flow was recognizable after a single oral dose of 5 mg vinpocetine and was more conspicuous after multiple oral doses. Thus, the effect of vinpocetine in improving cerebral circulation was evident, suggesting its clinical efficacy in improving intellectual impairment in patients with aging brain.