Temporal lobe epileptic activity mimicking dementia: a case report.

Epileptic activity is an underdiagnosed cause that can determine a disruption of memory and cognitive performance, leading an incorrect diagnosis of dementia. We report a 68-year-old man, referred with a 5-year history of subtle behavioral changes and a subjective memory impairment, who was admitted to our department because of recurrent episodes of confusional state lasting from 1 week. Neuropsychological evaluation demonstrated a marked impairment of all cognitive domains examined. Electroencephalogram (EEG) recording showed frequent almost continuous sharp waves localized on the bilateral posterior temporal regions with mild right side predominance. Treatment with phenytoin reversed his cognitive dysfunction and behavioral disturbances. We presume that ictal temporal lobe epileptiform activity is the cause of his confusional episodes and cognitive dysfunction, showing an electroclinical picture of complex partial status epilepticus. However, we hypothesize that the interictal discharges and ictal and postictal effects of subclinical seizures could be involved in the behavioral changes and memory impairment complained by our patient in the last years.