Effect of ST36 Acupuncture on Hyperventilation-Induced CO2 Reactivity of the Basilar and Middle Cerebral Arteries and Heart Rate Variability in Normal Subjects

This study was conducted to verify the effect of acupuncture on cerebral haemodynamics to provide evidence for the use of acupuncture treatment as a complementary therapy for the high-risk stroke population. The effect of ST36 acupuncture treatment on the hyperventilation-induced CO2 reactivity of the basilar and middle cerebral arteries was studied in 10 healthy male volunteers (mean age, 25.2 ± 1.5 years) using a transcranial Doppler sonography with an interval of 1 week between measurements, and a portable ECG monitoring system was used to obtain ECG data simultaneously. The CO2 reactivity of the basilar and middle cerebral arteries increased significantly after ST36 acupuncture treatment, whereas the mean arterial blood pressure and pulse rate did not change significantly. The high-frequency power significantly increased after ST36 acupuncture treatment, and the percentage increase of high-frequency power correlated significantly with the percentage increase in the CO2 reactivity of the contralateral middle cerebral artery. These data suggest that ST36 acupuncture treatment increases CO2 reactivity, indicating improvement of vasodilatory potential of the cerebral vasculature to compensate for fluctuations caused by changes in external conditions. The increase in parasympathetic tone by ST36 acupuncture treatment is responsible for this therapeutic effect.