Acute failure of forebrain with sparing of brain-stem function. Electroencephalographic, multimodality evoked potential, and pathologic findings.

We describe a case of acute failure of forebrain with preservation of brain-stem function following cardiopulmonary arrest. This condition is distinguished from persistent vegetative or noncognitive states. Multimodality evoked potentials showed electroretinograms but no cerebral potentials to flash stimulation of both eyes; normal electrocochleograms and brain-stem auditory-evoked potentials to click stimulation of both ears; and Erb's point, N13, and P14 but no cortical responses to electrical excitation of both median nerves. Pathologic alterations consisted of pseudolaminar necrosis involving the whole cerebral cortex and other forebrain regions, with relative preservation of brain stem and spinal cord. Close correspondence existed between electrophysiologic, clinical, and major neuropathologic alterations.