Insulinoma as a Potential Insidious Presenter in Medical Refractory Epilepsy

BACKGROUND: Insulinoma as a cause of epileptic seizure has been thoroughly described but often not considered in differentials for previously established diagnoses of seizure disorder. Hypoglycemic symptoms can mimic neurological disorders such as epilepsy. CASE PRESENTATION: A 52-year-old woman presented with a history of epilepsy on anti-epileptic drugs (AEDs) developed repeated episodes consisting of seizures and neuropsychiatric symptoms with no predisposing factors for epilepsy at age 52. She had received full AED treatment before the possibility of hypoglycemia was considered. Following a clinical diagnosis of insulinoma, distal pancreatectomy was performed, and her seizures did not occur again. CONCLUSION: The early diagnosis of insulinoma requires vigilance, not only for hypoglycemia in patients with neuropsychiatric symptoms, but also for the possible masking effects of a history of epilepsy and preceding AED usage.