Cerebral Blood Flow and Cessation of Cigarette Smoking in Healthy Volunteers.

OBJECTIVE: The mechanisms by which cessation of cigarette smoking may improve regional cerebral blood flow (rCBF) and the details of the possible relationship remain unclear. Xenon-133 inhalation was used to determine rCBF in six smokers at baseline (during smoking) and again 6 and 9 years after they had quit smoking (quitter group). A control group of eight nonsmokers (nonsmokers group) underwent similar serial determinations. RESULTS: Regional CBF in quitters had decreased significantly after the 6 years, but improved significantly after 9 years, when abstinence had been maintained from 4 to 6 years. In the nonsmokers group rCBF did not change significantly over 9 years. CONCLUSION: Cessation of cigarette smoking improves cerebral circulation, but this effect requires several years.