Migraine with brainstem aura with abnormal EEG discharges easily misdiagnosed as epilepsy: a case series study

Migraine with brainstem aura (MBA) constitutes a rare subtype of migraine, characterized by aura symptoms including vertigo, dysarthria, diplopia, tinnitus, ataxia, and impaired consciousness. Patients with MBA have been reported to exhibit abnormal electroencephalograms (EEGs) featuring diffuse slow-wave activity and bilateral slowing of the posterior head activity. Notably, there have been no documented reports of abnormal discharges specifically localized in the anterior head. The presence of abnormal EEG discharges in MBA patients who experience loss of consciousness may lead to potential misdiagnosis, especially as epilepsy, in the early stages. This study describes three patients who were ultimately diagnosed with MBA, offering a retrospective analysis of their clinical features, electroencephalographic manifestations, and diagnostic procedures. In the three cases described, all patients were female, aged 16-21, and had been admitted to the hospital due to recurrent loss of consciousness. They exhibited a consistent EEG pattern, characterized by paroxysmal moderate-to-high amplitude theta activity in the anterior head, interspersed with spikes and sharp waves. Laboratory tests and imaging studies yielded unremarkable results. They all received a diagnosis of epilepsy and were treated with antiseizure medication, which proved ineffective. After evaluation by an epilepsy specialist, they received a final diagnosis of MBA. Following flunarizine administration, all three patients demonstrated improvement, with no subsequent occurrences of loss of consciousness during the follow-up period. This study describes the pattern of abnormal discharges that may be observed in the interictal EEGs of these MBA patients, which is characterized by a predominantly anterior head pattern. Recognizing this specific condition constitutes a crucial element in the differential diagnosis of epilepsy, with the aim of preventing misdiagnosis. Concurrently, we investigate their pathophysiological origins.