[Spontaneous dissection of the internal carotid artery].

Spontaneous dissection of the internal carotid artery is supposed to be a rare condition, but seems to be increasingly diagnosed. The symptoms are protean from unilateral headache, Horners syndrome, tinnitus, to cerebral ischemia and hemipareses. The condition is of unknown incidence and usually affects previously healthy persons. It is nearly always unilateral. The diagnosis is ascertained by characteristic angiographical findings. The prognosis depends on the exhibited symptoms. Three patients seen during the last year at the Department of Neurology at the National Hospital (Rikshospitalet) are presented, together with a brief survey of symptomatology, diagnosis, prognosis and treatment.