Comparison of the Claassen and Fisher CT Classification Scale to Predict Ischemia After Aneurysmatic SAH?

Background: Delayed cerebral ischemia (DCI) is an important cause of morbidity and mortality after aneurysmatic subarachnoid hemorrhage (SAH). The severity of SAH, reflected by the amount of blood in the initial CCT, is a well-established predictor of DCI and infarction. The Fisher CT scale is widely used to predict DCI, but recent studies criticised the scale due to the fact that this scale does not differentiate between intracerebral blood clots and intraventricular hemorrhage. Thus Claasen et al. recently proposed a new grading scale to predict DCI. The aim of this study was to compare clinical scales with the CT findings and to verify this newly developed scale in a different population in order to predict DCI.[nl]

Patients And Methods: We selected from our databank of patients suffering from aneurysmatic SAH 292 cases who had been treated between 1995 and 2000. The data acquisition included clinical data, radiological diagnostic data, the postoperative surgical course as well as a follow-up according to the Glasgow outcome scale.[nl]

Results: 83 out of 292 patients (28.5 %) developed ischemic lesions on the CT scans reflecting DCI. The severity of SAH according to the Hunt and Hess grading, the Fisher CT scale and the Claassen CT scale correlated statistically significant to DCI. All three scales showed an increasing odds ratio, but the most consistent increase was demonstrated by the Fisher scale.[nl]

Conclusions: The newly proposed Claassen CT scale provides no additional information and seems not to be superior compared to the well-established Fisher scale to predict DCI.