The method of volume summation (V = T(A1 + A2 ... An) was used to measure the size of extradural hematomas. The accuracy was tested on six different artificial silicone hematomas and the mean difference was -2.7 ml, SD 3.7 ml. The reproducibility was tested on CT scans of clinical hematomas, SD was 2.1 ml. An empirical formula for volume estimation then found: 0.5 X height X length X depth was moderately reliable, while midline shift and "vesselfree space" were poor indicators of size. In conclusion, the volume summation with manual outlining was found to be highly accurate, but the problems of CT smoothing, spectral shift artifact, partial volume effect and separation of the hematoma from other structures must be considered.

Specific antagonists to the influx of calcium, necessary for the excitation-contraction coupling process in arterial smooth muscle, are potentially useful in the treatment of cerebral vasospasm but systemic hypotension might limit their clinical applicability. We studied the effect of the calcium antagonist nimodipine (BAY e 9736) on cerebral arterial spasm, intraventricular pressure and blood pressure (BP), when administered into the cerebral ventricles of the dog. Cerebral vasospasm was produced by the injection of autologous blood into the cisterna magna. In a group of 8 dogs, 100 micrograms of nimodipine was injected into the lateral ventricle. The effect of the drug on the basilar artery was monitored angiographically. Nimodipine always relieved spasm, and often the relaxation surpassed the resting vessel diameter. In a control group, the injection of placebo did not relax the spastic arteries. Determinations using gas chromatography of nimodipine in CSF and blood demonstrated that a concentration of 1 microgram/ml in cisternal CSF was sufficient to reduce spasm while concomitant plasma concentrations of 0.004 micrograms/ml did not result in significant BP reduction.

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During a fifteen-year period 1,106 patients with symptoms and signs of cervical disc disease underwent Cloward's operation. Plain x-rays were performed in 94%, but the severity and extension of degenerative changes had no prognostic value. In 91% of the patients myelography was performed and in recent years mainly metrizamide was used as it was found to be more accurate. The findings on the myelograms were correlated according to age, severity and number of affected disc levels, but were independent of the duration of symptoms. Patients with medullary symptoms were found more often than not to have an anterior indentation into the spinal canal whereas most patients with radicular symptoms had wide cervical root sleeves or lateral compression. The best outcome was found among patients with monosegmental symptoms and signs and one affected disc level on the myelogram underlining that the indication for surgery in cervical disc disease should be based on both clinical and radiological findings.