Treatment of cerebral vasospasm by control of cyclic adenosine monophosphate

Twelve patients with cerebral vasospasm following subarachnoid hemorrhage were treated with intravenous aminophylline and isoproterenol. After angiographic demonstration of spasm, all patients were begun on a continuous intravenous infusion of isoproterenol, 125 μg/hr, and aminophylline, 125 mg/hr, for a period of up to two weeks. The infusion was continued until there was clinical or angiographic evidence that spasm had diminished. Nine patients improved on this regimen and three remained unchanged. The use of isoproterenol and aminophylline is based on their effect on the enzymes responsible for the formation and degradation of cyclic adenosine monophosphate (cyclic AMP). An increase in cyclic AMP has been noted to produce relaxation of vascular smooth muscle. It is proposed that manipulation of these biochemical pathways may provide a method for influencing blood flow through cerebral vessels.