Atraumatic rCBF measurement: an aid in the timing of surgery and the management of spasm following SAH.

We tested the ability of a non-invasive regional cerebral blood flow (rCBF) measurement to show vasospasm. The correlations between the flow values, the clinical condition, the CT scan and angiography were also studied. During none of the measurements were there any negative side effects on the patients. A bad clinical condition was usually accompanied by low flow data during the rCBF investigation. In accordance with local clinical signs (e.g., hemiparesis) we observed corresponding local hypoperfusion. These results were also confirmed by several follow-up studies in which good correlations between the rCBF findings, the angiography and the CT scan were found. As the rCBF investigation can be repeated within a very short time, we used this method for the testing of vasoactive drugs. Nimodipine (Bayer) showed promising results which suggest further clinical investigations. The main problem connected with the rCBF measurement is the limited ability of the patient to cooperate. For the detection of vasospasm the low resolution both in localisation and depth of this method is of only minor importance. We partly overcame this disadvantage by developing a special respirator enabling us to investigate artificially ventilated patients. We think that the measurement of rCBF is an important aid for the timing of the operation.