✓ Intraventricular pressure was followed continuously after operation for intracranial arterial aneurysm in 20 patients. Ventricular cerebrospinal fluid (CSF), homovanillic acid (HVA), tryptophan, and 5-hydroxyindole acetic acid (5-HIAA) were analyzed daily for 5 days, beginning before the clipping of the aneurysm. Postoperatively, seven patients had spasm, verified clinically and angiographically. Seven other patients with no clinical or angiographic signs of spasm, hydrocephalus, or increased intracranial pressure (ICP) served as controls. Nine of the 20 patients were hydrocephalic.
The mean ± SE values of HVA, tryptophan, and 5-HIAA in the controls were 264 ± 40, 1116 ± 85, and 88 ± 8 ng/ml, respectively, in the controls, and 182 ± 20, 982 ± 89, and 78 ± 3 ng/ml, respectively, in the patients with spasm. The differences are not statistically significant. However, the low values of HVA may have been produced by ischemic changes caused by the spasm. In hydrocephalic patients ventricular CSF tryptophan levels were statistically significantly higher, and 5-HIAA levels lower than in controls. In patients with increased ICP, neither alterations nor intercorrelations of monoamine metabolites and tryptophan were found. The results do not give direct support to prophylactic neuropharmacological treatment of postoperative arterial cerebral spasm. However, ventricular HVA, tryptophan, and 5-HIAA measurements can be used for prognostic purposes during the first few days after the operation.