Short latency somatosensory-evoked potentials in children--Part 4. Findings with cerebral lesions

Cortical somatosensory-evoked potential studies were performed on seven children with unilateral intracerebral lesions. Three patients had neoplasms, and four had hematomas of various etiology. All the lesions involved either directly or indirectly with the thalamocapsular or perirolandic regions of the brain. Patterns of somatosensory-evoked potential asymmetry included abnormality of the primary cortical complex (N1-P1), loss of intermediate and long latency waveform components, and attenuation of the response on the side of the lesion. The most abnormal somatosensory-evoked potentials were seen in patients with major clinical deficits, whereas patients with minimal neurologic signs had minor somatosensory-evoked potential changes. The location, etiology, and duration of the lesions all appeared to influence the somatosensory-evoked potential waveform. The value of somatosensory-evoked potential studies in the diagnosis and localization of cerebral lesions would seem to be limited because of pathophysiologic phenomena related to the primary cerebral lesion.