Multimodality Evoked Potentials in Comatose Patients

Abstract

Several authors (Greenberg et al., 1977; Bricolo et al., 1978; Lindsay et al., 1981; Anderson et al., 1984; Pfurtscheller et al., 1985) have demonstrated that electroencephalographic (EEG) and multimode evoked potential (EP) studies may be helpful supplements to the clinical examination of comatose patients. These studies may be used to support and document clinical impressions. Additionally, multiparametric measurements appear to be helpful in estimating the clinical prognosis. They are acquiring an increasing role in both acute and chronic patient care (Greenberg et al., 1977; Lindsay et al., 1981; Anderson et al., 1984). We have completed over 500 measurements of EEG power spectra, brainstem auditory (BAEP), somato-sensory (SEP), visual evoked potentials (VEP) and heart-rate variability (HRV) in more than 100 comatose patients in the intensive care unit of the Department of Anesthesiology (Head, Professor List), University of Graz (Pfurtscheller et al., 1985; Pfurtscheller, 1986a, b). In order to simplify the interpretation of the results and recognition of differences between studies, a special display program was developed. This display allows a direct comparison of electrophysiological data for any two studies of a patient. For monitoring purposes, a display of compressed EEG spectra, compressed BAEPs and compressed SEPs is used.