Prognostic value of SSEP in early aneurysm surgery after SAH in poor-grade patients.

ABSTRACT

We evaluate the prognostic value of somatosensory evoked potentials (SSEP) in poor-grade patients after early surgery for aneurysmal subarachnoid hemorrhage compared to the Hunt and Hess (H&H) and WFNS scales. Ninety patients with angiographically proven aneurysms graded H&H IV or V were evaluated retrospectively. The aneurysms of 72 patients were clipped. In 53 out of 72 patients 147 SSEP examinations were recorded. The SSEP were classified according to the central conduction time (CCT) and the number of cortical potentials. Outcome was determined according to the Glasgow Outcome Scale. To evaluate the predictability of the SSEP to clinical grading scales receiver operating characteristic (ROC) analysis was done. The H&H scale did not demonstrate statistically significant predictability for poor-grade patients. The WFNS scale predicted the outcome for only one group (survival/death) (p = 0.035). Predictability of outcome by the SSEP was statistically confirmed. Normal CCT indicated a potential for a good recovery, but not consistently so. Bilaterally enhanced CCT was predictive of a poor outcome. Bilateral lack of cortical responses was always related to fatal outcome. ROC analysis confirmed that SSEP are superior to clinical grading scales in determining prognosis in poor-grade patients. In doubt, whether early aneurysm surgery or conservative treatment in a poor-grade patient should be done, SSEP will be helpful.