Clinical Outcome of Patients with Deep Brain Stimulation of the Centromedian Thalamic Nucleus for Refractory Epilepsy and Location of the Active Contacts

Abstract

Objectives: To investigate the clinical outcome of patients treated with chronic deep brain stimulation (DBS) of the centromedian nucleus (CM) for refractory epilepsy and to determine the location of active contacts. Methods: The outcome of CM stimulation was evaluated as percent seizure reduction compared to the baseline 3 months. To establish the location of active contacts, 27 leads were studied in 14 patients with refractory epilepsy. An analysis was conducted to reveal whether any coordinates of the center of the active contacts predicted percent seizure reduction. Results: With an average follow-up of 18.2 ± 5.6 months, the mean percent seizure reduction (n = 14) was 68 ± 22.4% (25-100%). Eleven of the 14 patients (78.6%) achieved >50% improvement in seizure frequency. Specifically, all 4 patients (100%) with generalized epilepsy (Lennox-Gastaut syndrome) and 7 of 10 patients (70%) with multilobar epilepsy showed >50% reduction in seizure frequency. The mean coordinates of the center of the active contact were located in the superior part of the anterior ventrolateral CM. The calculated coordinates of laterality from midline (x), anterior-posterior (y) and height (z) from the posterior commissure did not correlate with seizure outcome measured by percent seizure reduction. However, the locations of active contacts used during chronic CM stimulation in multilobar epilepsy were identified more dorsal to those used in generalized epilepsy. Conclusions: Chronic CM stimulation is a safe and effective means in the treatment of refractory epilepsy.