Reversible dementia: subclinical seizure in early-onset dementia.

We report a case of early-onset dementia with subclinical seizures. Aggressive seizure control improved the patient's cognition. Commonly, an EEG is only performed following overt behavioral seizures. Therefore, subclinical seizures tend to be underdiagnosed. Serial or extended EEG should be seriously considered in patients with early-onset dementia.