Multiphasic Side-Switching Seizures Are Easily Misdiagnosed as Unilateral Seizures During a Single EEG Monitoring Session: A Specific Subtype of Bitemporal Epilepsy.

Abstract

Bitemporal epilepsy (BTLE) is a specific anatomoelectroclinical phenotype in the spectrum of temporal lobe epilepsy. The diagnosis of BTLE and the evaluation of the degree of seizure lateralization in BTLE patients are greatly influenced by the duration of EEG recording and the number of recorded habitual seizures. A 25-year-old woman had a 5-year history of seizures. Her habitual seizures were described as sudden behavioral arrest, staring, unresponsiveness, and oral automatisms, with auras of fear and palpitation. Intermittent scalp electroencephalography (EEG) and intracranial EEG monitoring over 3 years showed multiphasic side-switching seizures. The seizures were limited to 1 temporal lobe within 1 phase and switched sides between phases. Despite antiepileptic drugs and vagus nerve stimulation, her seizures remained uncontrolled. The patient finally underwent unilateral anteromedial temporal lobectomy, mainly based on >60% of seizures recorded originating from the left side. The patient has been seizure free for more than 1 year at last follow-up. This patient presented 1 specific subtype of BTLE that is prone to be misdiagnosed as unilateral temporal lobe epilepsy if the patient is recorded for a relatively short term, e.g., over a common EEG monitoring duration of 1 to 2 weeks.