Abstract
Visual evoked potentials and electroretinograms were elicited by light-emitting diode stimulation and recorded simultaneously, with cephalic and noncephalic references, in 30 normal subjects and in 30 brain-dead patients. A characteristic pattern was found in the group of patients: when a cephalic reference was used for both visual evoked potentials and the electroretinogram, the a- and b-waves of the electroretinogram were recognized in all patients, and visual evoked responses consisted of waves with inverse polarity, similar morphologic characteristics, the same latency, and less amplitude than those of the electroretinogram. When a noncephalic derivation was chosen for the electroretinogram and visual evoked potentials, electroretinogram did not change in either morphologic features or latency, whereas the visual evoked potential channel showed no response. Only in two cases was it possible to record waves in the visual evoked potential lead with a noncephalic reference, showing a spread of the electroretinogram to the occipital area, with a considerably reduced amplitude. These results suggest that, although contamination of visual evoked potential records by the spread of the electroretinogram to the occipital area could occur, it is easy to confirm the absence of a true cortical visual response in brain-dead patients by means of a noncephalic reference. This pattern clearly confirms that in the visual pathways of brain-dead patients, electrical activity is confined to the retina.
Similar content being viewed by others
References
Trojaborg W, Jorgensen EO. Evoked potentials in patients with ‘isoelectric EEG’. Electroencephalogr Clin Neurophysiol 1973; 35: 301–9.
Ganes T, Lundar T. EEG and evoked potentials in comatose patients with severe brain damage. Electroencephalogr Clin Neurophysiol 1988; 69: 6–13.
Arfel G. Stimulations visuelles et silence cérébral. Electroencephalogr Clin Neurophysiol 1967; 23: 172–75.
Sament S Alderete JF, Schawab RS. The persistence of the electroretinogram in patients with flat isoelectric EEGs. Electroencephalogr Clin Neurophysiol 1969; 26: 121.
Wilkus R, Chatrian G, Letich E. The electroretinogram during terminal anoxia in humans. Electroencephalogr Clin Neurophysiol 1971; 31: 537–46.
Sims JK, Casler JA, Billinger TW, Aung MH, Shattuck CM, Fleming NI, Bickford RG. The human electroretinogram in alert volunteer and in brain dead patients, new recordings techniques. In: Proc San Diego Biomed Symp 1972.
Walker AE, ed. Cerebral death. Baltimore: Urban & Schwarzenberg, 1985.
Walker AE. An appraisal of the criteria of cerebral death: A summary statement. A collaborative study. JAMA 1977; 237: 982–86.
Belsh JM, Blatt R, Shiffman PL. Apnea testing in brain death. Arch Intern Med 1986; 146: 2385–8.
Ouaknine G, Kosary IZ, Braham J, Czerniak P, Nathan H. Laboratory criteria of brain death. J Neurosurg 1973; 39: 429–33.
American Electroencephalography Society. Minimum technical standards for EEG recording in suspected cerebral death. In: American EEG Society, ed. Guidelines in EEG 1980. Willoughby, OH, 1980: 19–24.
Machado C, Pumariega J, García-Tigera J, Miranda J, Coutin P, Antelo J, Hernández-Meilán O, Román J. A multimodal evoked potential and electroretinography test battery for the early diagnosis of brain death. Int J Neurosci 1989; 49: 241–242.
Machado C, Valdés P, García-Tigera J, Virues T, Biscay R, Miranda J, Coutin P, Román J, García O. Brain-stem auditory evoked potentials and brain death. Electroencephalogr Clin Neurophysiol 1991; 80: 392–98.
Machado C, García-Tigera J, García O, García-Pumariega J, Román J. Muerte encefálica. Criterios diagnósticos. Rev Cub Med 1991; 30 (3): 181–206.
Arfel G. Problèmes èlectroencéphalographiques de la mort. Paris: Masson, 1970.
Walter S. Arfel G. Réponses aux stimulations visuelles dans les états de coma aigu et de coma chronique. Electroencephalogr Clin Neurophysiol 1972; 32: 27–41.
Reilly EL, Kondo C, Brunberg JA, Doty DB. Visual evoked potentials during hypothermia and prolonged circulatory arrest. Electroencephalogr Clin Neurophysiol 1978; 45: 100–6.
Cobb WA, Dawson GD. The latency and form in man of the occipital potentials evoked by bright flashes. J Physiol (Lond) 1960; 152: 108–21.
Ferrillo F, Giunta F, Rivano C, Rodriquez G, Rosadini G, Rossy GF, Sannita F, Sannita, W, Siani C, Turella G, Zattoni J. Analisi dell'attivita elettrica cerebrale spontanea ed evocata nel coma profondo e nella ‘morte del cervello’. Riv Neurol 1969; 39: 589–98.
Ferbert A, Buchner H, Brückman H, Zeumer H, Hacke W. Evoked potentials in basilar artery thrombosis: Correlation with clinical and angiographic findings. Electroencephalogr Clin Neurophysiol 1988; 69: 136–47.
Chiappa KH. Pattern—shift visual evoked potentials: Methodology. In: Chiappa KH, ed. Evoked potentials in clinical medicine. New York: Raven Press, 1989: 37–171.
Anziska B, Cracco RQ. Short latency SEPs to median nerve stimulation: Comparison of recording methods and origin of components. Electroencephalogr Clin Neurophysiol 1981; 52: 531–9.
Guerit JM, Mathieu P. Are evoked potentials a valuable tool for the diagnois of brain death? Transplant Proc 1986; 18: 386–7.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Machado, C., Santiesteban, R., García, O. et al. Visual evoked potentials and electroretinography in brain-dead patients. Doc Ophthalmol 84, 89–96 (1993). https://doi.org/10.1007/BF01203286
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01203286