Unusual scalp recorded somatosensory evoked potentials after removal of a large intraventricular meningioma.

Very unusual scalp recorded SEPs were seen in a case after removal of a large intraventricular meningioma. One day before death (ten days after surgery) when the patient was moribund, SEPs from the clinically and radiologically affected hemisphere in which a hematoma and thalamic infarct were found, had a normal latency and were decreased in amplitude. SEPs from the clinically and radiologically nonaffected hemisphere, where only minimal findings were seen, had an abnormally short latency (16.9 msec) and the CCT was only 3.1 msec. We do not offer any logical explanation of these unusual SEP findings from both hemispheres shortly before death.