Forgetfulness in adult attention-deficit/hyperactivity disorder masks transient epileptic amnesia: a case report

Background: Inattention due to attention-deficit/hyperactivity disorder (ADHD) can lead to forgetfulness. Transient epileptic amnesia (TEA) can cause forgetfulness, similar to ADHD. We report a patient with ADHD who developed TEA. Case Presentation: The patient was a 40-year-old woman with ADHD. She has been prone to forgetfulness since childhood. Two years before visiting our outpatient clinic, she had begun to occasionally forget events that had occurred several days earlier. However, she was largely unaware of the emergence of new amnestic symptoms. She had also begun to experience various other amnestic symptoms 2 months before she visited our clinic, which prompted her to visit our outpatient clinic. The combination of a detailed interview, electroencephalography (EEG) examination, and consideration of TEA enabled us to diagnose her with TEA and provide treatment accordingly. In our patient, daily forgetfulness due to ADHD delayed the recognition of new additional forgetfulness attributed to TEA. Conclusion: Psychiatrists need to consider TEA when patients with ADHD present with changes in or exacerbation of forgetfulness.