Abstracts

Rationale: Temporal lobe epilepsy with bilateral independent foci often presents difficult management decisions and there is little information about long-term outcome for patients with this condition. This study examines the epidemiology of medication-resistant bitemporal lobe epilepsy at a Level IV epilepsy center.

Methods: We retrospectively identified 54 consecutive adult patients with bilateral independent temporal lobe seizures recorded during their epilepsy monitoring unit admissions between 2010 and 2021. Forty-five cases met the criteria for medication-resistant epilepsy. We evaluated the subsequent clinical course for these patients including diagnostic evaluation, treatment, and clinical outcome. The International League Against Epilepsy (ILAE) surgical outcome scale was used to compare treatment outcomes. This study was approved by the Vanderbilt University IRB.

Results: Of the 45 patients with medication-resistant bitemporal independent epilepsy, 70% had bilateral interictal activity, 36% had lesions on MRI (unilateral: 22% and bilateral: 14%) and 18% of patients underwent invasive monitoring with intracranial electrodes.  Fifteen patients (33%) had surgical treatment (7 resective, 4 Vagal nerve stimulation (VNS) only, 1 responsive neurostimulation (RNS) alone, 3 RNS+VNS) and the remainder had medical management (Table 1). The outcome was evaluated for the 39 patients who had at least one year of follow-up. Seizure freedom was achieved in 33% for the surgical resection group, 25% for the neuromodulation group, and 20% for the anti-seizure medication (ASM) only group (Table 2).

Conclusions: This study shows that patients with bitemporal independent epilepsy are frequently treatment resistant.  The number of patients who achieved >1 year of seizure freedom was not significantly different among the surgical resection, neurostimulation, and medical management groups, but there was a trend toward better outcome in those who had surgical treatments. 

Funding: None