Abstracts

Rationale: It has recently been reported that epileptic auras were equally common (70%) among patients with idiopathic generalized epilepsy (IGE) as they were among those with localization related epilepsy. The auras reported were non specific and included “feeling light-headed”, “a strong head rush”, “feeling shaky and spacey” and similar subjective sensations. Limbic auras such as olfactory hallucinations, gustatory hallucinations and déjà vu were not observed and are usually interpreted as manifestations of localization related epilepsy. We report five patients with IGE whose seizures are preceded by classic limbic auras and were therefore, on the basis of clinical semiology and outpatient EEG misdiagnosed as localization related epilepsy.Methods: Patients were identified from a larger group with intractable seizures and poor response to the antiepileptic drug (AED) regimen who were referred to a comprehensive Epilepsy Center. Four of the five patients had been diagnosed with and treated for localization related epilepsy based on the clinical presentation and outpatient EEG. One patient had been diagnosed with attention deficit hyperactivity disorder. All patients subsequently underwent a comprehensive history and physical and an epilepsy protocol MRI. Four of the five patients underwent video-telemetry monitoring.Results: Four patients had generalized convulsive seizures and one patient had absence seizures. All five patients had auras lasting from 10 seconds to a minute preceding their seizures. The auras were an olfactory hallucination (two patients), olfactory and gustatory hallucination (one patient) and a feeling of déjà vu (two patients). All patients had onset of seizures in adolescence. Four patients were diagnosed with localization related seizures and had several years (average 27.7 years) of poor response to the chosen anti epileptic drugs including phenytoin (three patients), carbamazepine (three patients) and oxcarbazepine (one patient). All patients had a normal neurological exam and a normal epilepsy protocol MRI. Three patients had focal abnormalities on interictal EEG. Video-telemetry monitoring was performed in four patients. All five patients were determined to have a syndrome of IGE and had a complete resolution of their seizures when treated with a broad spectrum AED.Conclusions: Patients with IGE may have seizures preceded by limbic auras. Clinical semiology and interictal EEG were misleading in our patients and led to a delay in appropriate therapy for several years. Video-telemetry should be performed earlier in patients with a poor response to AEDs in order to ensure appropriate characterization of seizure disorder and anti convulsant therapy.