[Blood flow velocity of calcarine artery during visual stimulation and its developmental change]

The relationship among the occipital brain activity, EEG, and cerebral blood flow was investigated, measuring the blood flow velocity (BFV) of the calcarine artery using transcranial Doppler blood flowmeter (TCD). Eighty-six healthy subjects from 3 to 30 years of age were investigated during various visual stimulations. The results were as follows. 1) Calcarine BFV increased by 28.8 +/- 10.9% in response to opening eyes, in the adult group over 15 years of age. Calcarine BFV increase by opening eyes was the highest in the group 3 to 6 years of age (46.2 +/- 9.8%). The rate of BFV increase reduced with age, reaching the adult rate 12 years of age. 2) By a reading task, calcarine BFV increased by 13.3 +/- 6.2% from that of the eyes-opening state. 3) Hemifield pattern-reversal stimulation elicited a significant increase in contralateral calcarine BFV. The BFV measurement of calcarine artery by TCD contributed to the elucidation of the relation between regional cerebral activity and blood flow in the visual cortex.