Targeting analysis of a novel parietal approach for deep brain stimulation of the anterior nucleus of the thalamus for epilepsy

Purpose: Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a promising treatment for refractory epilepsy; however, it remains challenging to successfully target the ANT. The results of Medtronic Registry for Epilepsy (MORE) supported a frontal transventricular(TV) compared to frontal extraventricular (EV) lead trajectory for ANT DBS may have better coverage of the ANT. Here we report the safety and targeting efficacy of a novel, posterior parietal extraventricular (PEV) approach to the ANT. Methods: We conducted a retrospective analysis of ten patients who underwent bilateral ANT DBS (20 total trajectories) for medically-refractory epilepsy. Similar targeting methodology as the MORE trial was used, and the DBS Intrinsic Template Atlas (DISTAL) was utilized for ANT localization and contact position relative to ANT. Clinical data were assessed for DBS targeting efficacy and surgical complications. Results: The demonstrated PEV trajectory showed a successful ANT targeting rate of 90% bilaterally. Two or more contacts within ANT were presented in 75% of all leads. Mean contact number in ANT was 2.2+ 1.2. There were no intracranial hemorrhages, cerebrospinal fluid leakage, or permanent neurologic deficits. Conclusion: In this small series, the novel PEV for ANT DBS is feasible with good targeting accuracy and potential safety advantages. The high accuracy of the PEV trajectory suggests that it is a reasonable alternative trajectory for ANT DBS. Larger studies will be needed to assess this trajectory on clinical outcome of DBS treatment to epilepsy.