Visual Epilepsy Mimicking Migraine Aura Leading to Delayed Diagnosis of an Occipital Cavernoma: A Case Report.

Cerebral cavernous malformations, also known as cavernomas, are uncommon vascular malformations that may present with seizures, headache, or focal neurologic deficits depending on lesion location. Occipital cavernomas are rare and may manifest with positive visual phenomena, thereby mimicking migraine aura and delaying diagnosis. We report the case of a 54-year-old woman who presented in March 2018 with recurrent brief visual episodes described as flashing lights, colored shapes, scotomas, and distortion of object contours, associated with a persistent headache. She was initially treated for migraine with aura for approximately two years without clinical improvement. Repeated electroencephalography (EEG) later demonstrated rare focal epileptiform discharges in the left temporo-occipital region. Brain magnetic resonance imaging (MRI) revealed a rounded left occipital cortico-subcortical lesion measuring 17 x 16.5 x 16 mm, with imaging features suggestive of a cavernoma and without significant mass effect or perilesional edema. Carbamazepine was gradually titrated to 800 mg/day orally in two divided doses, with complete resolution of visual seizures. No surgical treatment was required, and the patient remained seizure-free during long-term follow-up. This case highlights the diagnostic overlap between visual epilepsy and migraine aura in patients with occipital cavernoma. It also underscores the importance of early MRI and EEG in patients with atypical or treatment-resistant visual symptoms, as timely recognition may permit effective medical management and avoid prolonged diagnostic delay.