Effects of Acupuncture with a Combination of GV20 and EX-HN1 Acupoints on CO₂ Reactivity in the Anterior and Middle Cerebral Arteries during Hypercapnia in Normal Subjects: A Randomized Crossover Trial

Abstract

Objectives: To investigate the effects of acupuncture at GV20 and EX-HN1 on cerebral blood flow (CBF) velocity and cerebrovascular reactivity (CVR) in the middle cerebral arteries (MCA) and anterior cerebral arteries (ACA) and to compare the effects to acupuncture at GV20.Methods: The study was a randomized, crossover trial that included 10 healthy men aged 20 to 29 years who underwent acupuncture treatment four times with a washout period of one week. The CBF velocity and CVR were measured by transcranial Doppler sonography (TCD) on both MCAs at the first and second visits, and both ACAs at the third and fourth visits. Participants were randomly assigned to one of two groups (A and B) before the first and third visits. Group A received two phases of acupuncture intervention at a single GV20 point and a combination of GV20 and EX-HN1 acupoints. Group B received the same interventions, but in the reverse order.Results: The increase in CO₂ reactivity was significantly higher for the combination acupoints of GV20 and EX-HN1 than for the GV20 single acupoint in both MCAs (Right: 136 to 178, p=0.017; Left: 127 to 191, p=0.017) and ACAs (Right: 133 to 158, p=0.013; Left: 122 to 168, p=0.025). No significant change was noted in the corrected velocity at PETCO₂ 40 mmHg, blood pressure, or heart rate.Conclusions: The findings suggest that improvement of the CBF in the MCA and ACA after GV20 acupuncture increases when acupuncture is also performed at EX-HN1. These results clinically support the combined use of EX-HN1 and GV20 to treat disorders of MCA and ACA circulation.