Incidence of asymptomatic extracranial arterial disease.

Investigations of the incidence and the extent of the asymptomatic early stages of extracranial arterial disease (EAD) have been restricted for methodical reasons. Direct Continuous Wave-Doppler examination has given highly accurate results in the location and correct estimation of the degree of EAD both for the carotid (97%) and the vertebral arteries (90%), as shown from a detailed comparison with carotid (n = 604) and vertebral (n = 426) angiograms. Compared with this degree of reliability, the validity of normal auscultation for the diagnosis of EAD is shown to be poor: if bruits are taken as the only signs of associated EAD in patients with systemic atherosclerosis, only 27.6% in a group of 123 patients would have been correctly diagnosed. This parallels the number of false-positives (22.6%) in patients with normal results. The frequency and degree of EAD was studied by the use of direct Doppler examination in 2009 neurologically asymptomatic patients admitted either with severe vascular (n = 375) or coronary atherosclerosis (n = 262) or with high-risk factors (n = 1370). The frequency was significantly higher (32.8%) in patients with peripheral vascular disease than in those with coronary artery disease (6.8%) and in risk-factor patients (5.9%). The combination and degree of vessel involvement are presented in detail and their possible prognostic significance discussed.