Acupuncture Effects on Cerebral Blood Flow during Normoxia and Normobaric Hypoxia: Results from a Prospective Crossover Pilot Study

Cerebral blood flow (CBF) is significantly influenced by exposure to hypoxia, both hypobaric and normobaric. Alterations in cerebral blood flow can play a crucial role in the pathogenesis of acute mountain sickness (AMS) and its symptoms, especially headache, dizziness, and nausea. Acupuncture has been proven to be effective in treating some cerebrovascular disorders and PC6 Nei Guan stimulation seems to enhance cerebral blood flow. Therefore, we have hypothesized that PC6 Nei Guan stimulation could affect CBF in acute hypoxia and could be used to contrast AMS symptoms. We evaluated blood flow in the middle cerebral artery (MCA) in normoxia, after 15 min in normobaric hypoxia (fraction of inspired oxygen (FiO(2)) 14%, corresponding to 3600 m a.s.l.) in basal conditions, and after PC6 Nei Guan stimulation, both by needle and by pressure. No comparisons with other acupuncture points and sham acupuncture were done. PC6 stimulation seemed to counteract the effects of acute normobaric hypoxia on end-diastolic velocity (EDV) in MCA, especially after acupuncture, and significantly reduced systolic and diastolic blood pressure. A rebalance of CBF could control some AMS symptoms, but further studies are necessary.