[Prognostic importance of early recorded somatosensory evoked potentials in patients not neurologically assessable after craniocerebral trauma].

By stimulation of the median nerve at the wrist we recorded the somatosensory evoked potentials (SEP) at several points between the midpoint of the clavicle and the scalp, overlying the area of sensorimotor cortex. The SEP of each side were graded (bilaterally normal SEP's: grade-1/1, pathological SEP's grade-2/1 to grade-4/4). The aim of these recordings is to judge the probability of survival in adult comatous patients in the early phase after a head injury. Our retrospective analysis of these recordings in 108 patients (collective 1988/89) shows a significant correlation of the SEP with the Glasgow Coma Scale score (GCS) (GCS > 8/SEP grade-3 or grade-4: p < 0.005) and the pupillary function (pupillary function disturbed uni- or bilaterally/SEP grade-3 or grade-4: p < 0.0005), being less pronounced with the intracranial pressure (ICP) too. In patients with lack of the component N20 death or vegetative outcome is significantly more frequent than if this component is present (p < 0.005). All the 7 patients without recognisable bilateral component N20 (SEP grade-4/4) died as a consequence of the initial brain injury. 7 out of 9 patients with unilateral lack of the component N20 combined with diminished amplitude ratio and delayed central conduction time (CCT) contralaterally (SEP grade-4/3) died or survived in a vegetative condition; none of them became independent. If the results of the analysis of the patient collective 1988/89 were applied to the patients of 1990 (n = 67) a good correlation between SEP and outcome was confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)