A case series of epilepsy-derived memory impairment resembling Alzheimer disease.

We report 4 cases of epilepsy-derived progressive memory disturbances that clinically resembled Alzheimer disease. The patients were 3 women and 1 man, aged 56 to 79 years. The greatest disturbance was in recent memory. The patients' remote memory and orientation were relatively intact. Mental dullness and a decline in daily activities were also observed. No overt seizures were observed in any of the patients. Electroencephalography (EEG) revealed spikes in the left temporal region in 3 patients and in the left central region in the other patient. Single photon emission computed tomography or positron emission tomography revealed focal areas of hypofunction in the frontal, parietal, and parietotemporal regions. Performance of activities and memory improved rapidly in all patients after treatment with carbamazepine; the improvement was maintained after more than a year. It might be speculated that epileptic discharges caused dysfunction in the temporal lobe and the remote cortex through the neocortical and mesiotemporal network. EEG would be useful to rule out the possibility of a reversible condition in patients with cognitive disturbance. Moreover, investigation of this epilepsy-related condition with the combination of EEG and neurofunctional imaging might provide clues to clarify the pathophysiology of Alzheimer disease.