Introduction
Dissection of a cervico-cerebral artery (CAD) occurs by a rupture within the arterial wall leading to an intramural hematoma. A possible consequence is an acute obstruction of the vessel inducing a high risk for local thrombus formation and cerebral embolism. The clinical spectrum of CAD varies considerably from local pain in the neck or unusual unilateral headaches and a Horner's syndrome to life-threatening complete hemispheric or brainstem infarction. Symptomatic dissections of the carotid and vertebral arteries have been diagnosed more frequently since the introduction of Doppler sonography and magnetic resonance imaging (MRI) (Saver et al., 1992; Rother et al., 1993; Steinke et al., 1994; Sturzenegger, 1995). Among young and middle-aged patients, CADs are now recognized as an important cause of stroke (Bogousslavsky et al., 1987; Caplan & Tettenborn, 1992; Saver et al., 1992; Kristensen et al., 1997; Brandt et al., 1998). Bogousslavsky found an incidence of 2.5% in 1200 consecutive first stroke patients (Bogousslavsky et al., 1987). Under the age of 45 years the incidence of CAD is much higher at 10–20% and CAD are the second leading cause of stroke in the younger age group (Bogousslavsky & Pierre, 1992; Gautier et al., 1989; Livosky & Rousseau, P., 1991). The mean age of the patients with CAD is 40 to 45 years (Gautier et al., 1989; Schievink et al., 1994b; Brandt et al., 1998).
The true incidence of CAD is unknown: an estimation for ICA dissection on the basis of a community study has been 2.6 per 100000 per year (Schievink et al., 1993b).