Intra- and extracranial circulatory changes in cigarette smokers assessed by ultrasound: transcranial Doppler (TCD) and duplex scanning investigation.

The group of 98 "healthy smokers" was analyzed in order to evaluate potential influence of cigarette smoking on intracranial blood flow disturbances and extracranial carotid intimal changes, performing transcranial Doppler (TCD) and Duplex scanning of the carotid arteries. Almost 70% of smokers analyzed in our study had some intracranial circulatory changes, predominantly in the vertebral arteries (35%). Half of smokers analyzed had some pathological intimal changes in the carotid arteries. The most frequent finding was wall thickening (23%) and then calcified (13%) and soft plaques (10%). Dose response relationship between smoking and atherosclerosis is also introduced. More than 30 cigarettes smoked per day can significantly influence plaque development and already 20 cigarettes smoked per day can cause significant intracranial blood flow disturbances. The majority of our investigated smokers were in high risk category for development of cerebrovascular disease and 5% were in a very high risk category. Cessation of cigarette smoking will eliminate it as a risk factor. A low dose-response relation and the development of tolerance produced by exposure to nicotine were also introduced.