Disappearing CT lesions in epilepsy.

A striking but reversible computed tomographic (CT) lesion corresponding to seizure activity is reported in a series of 46 epileptic patients. None of these patients had evidence of tuberculosis or cysticercosis, and all were treated with antiepileptic drugs only. Maximal radiological changes occurred in the area of maximal epileptic discharge; however, multiple lesions were seen in three cases. The CT lesion reappeared with recurrence of the ictus in four cases during follow-up, and this, too, disappeared after complete arrest of the seizures. The clinical, CT scan, and other investigatory findings suggest that the seizures may occasionally cause a CT-demonstrable focal abnormality, probably cerebral edema, a consequence of abnormal vascular permeability. Awareness of this radiological entity should avoid misdiagnosis of cerebral tumor, infarction or tuberculoma in patients with seizure disorder.