Unilateral stenosis of the vertebral artery--secondary finding with no prognostic relevance?

The outcome of 142 patients suffering from ischemic cerebral circulation disorders was followed up over a period of 33 months on average. The spontaneous course of 25 patients with unilateral, hemodynamically ineffective stenoses of the vertebral artery was compared with that of 107 patients without vertebral artery stenoses. Within the first 12 months, novel clinically manifest cerebrovascular events were observed in 16.0% of patients without vertebral artery stenosis (deaths 5.0%), but in only 4.3% of the patients with vertebral artery stenosis (no deaths). Within 30 months, only 2 of the 13 patients with vertebral artery stenosis had suffered a new cerebrovascular attack. At the end of the observation period, 39.3% of the patients without vertebral artery stenosis and 48.0% of the patients with vertebral artery stenosis were significantly disabled in their social life or had died. An additional unilateral hemodynamically irrelevant vertebral artery stenosis did not influence the rate of reinfarction or the remission of neurological deficits, independently of age, the degree of the circulatory disorder, the vascular territory involved, the presence of an organic psychosyndrome, or of additional stenoses in the carotid arteries. Consequently, a vertebral artery stenosis narrowing the vessel diameter to less than 1/3 is without prognostic relevance.