Hidden cases of epilepsy in cognitive impairment clinics: Exploring the use of a portable device for simplified electroencephalography testing

Late-onset epilepsy, particularly focal impaired awareness seizures, often present without convulsions and can cause memory impairment. This can lead patients to initially seek consultation at memory clinics, potentially delaying referral to epilepsy specialists. We report on three patients, aged 40s to 70s, admitted for cognitive evaluation who were finally diagnosed with epileptic seizures as the underlying cause of their symptoms. Notably, all initially presented to local clinics with symptoms suggesting cognitive impairment. Despite initial diagnostic uncertainty, all patients exhibited epileptic activity on electroencephalography (EEG) and responded positively to antiepileptic drugs, suggesting epileptic mechanisms were involved in their symptoms. Both traditional clinical EEG systems and newly developed, one-minute portable EEG devices were used in their evaluations. The portable device, medically approved in Japan, successfully captured sharp-waves like activities with the same durations, amplitudes, and shapes as traditional devices. This highlights its potential to improve epilepsy diagnosis and future screening due to its portability and ease of use. Implementing portable EEG devices could promote timely and appropriate treatment, preventing misdiagnosis of neurological conditions.