Contribution of initial median-nerve somatosensory evoked potentials and brainstem auditory evoked potentials to prediction of clinical outcome in cerebrovascular critical care patients: A statistical evaluation

In a prospective study of 200 patients with cerebrovascular disease (48 int racerebral hemorrhages, [ICH]; 64 subarachnoid hemorrhages, [SAH]; 38 supra tentorial and 40 infratentorial ischemic strokes), we assessed the individu al and combined prognostic value of median-nerve somatosensory evoked poten tials (SEP) and brainstem auditory evoked potentials (BAEP) within 72 hours of admission. Clinical outcome was graded in three ranked categories accor ding to a modified Glasgow Outcome Scale. Likewise, the initial SEP and BAE P findings were graded in a three-class score. In all groups, the SEP were significantly correlated with outcome (P < 0.01). Likewise, after partialli ng out the prognostic effect of SEP, the contingency between BAEP and outco me was statistically significant, except in ICH (P = 0.07). The contingenci es of SEP and outcome in ICH and supratentorial infarcts were higher than t he corresponding partial contingencies for BAEP, while the latter were high er in infratentorial infarction and SAH. Therefore, in all disease groups e xcept for SAH, the multiple contingency coefficients ranging from 0.67 to 0 .75 were statistically significant and greater than either simple or partia l contingencies alone. The results of the two evoked potential modalities c ombined permit statistically significant superior prognostication in most c erebrovascular diseases when compared to those of either of the modalities alone.