Performance of Closed-Loop DBS During Sleep in Patients with Essential Tremor.

Deep Brain Stimulation (DBS) has emerged as an effective therapy for people suffering from medication refractory essential tremor (ET). Significant tremor suppression for patients can be achieved by targeting and stimulating the thalamic ventral intermediate nucleus (VIM). In clinical practice, DBS is delivered continuously, resulting in stimulation when not needed, particularly during sleep when tremor is not experienced. Although the feasibility of fully embedded intention-based closed-loop DBS (CL-DBS) algorithms for ET has been demonstrated, there is a lack of research on their behavior during sleep. To this end, we are investigating the performance of CL-DBS at night in one ET patient implanted with an investigational neurostimulator (Summit RC+S). We captured at-home recordings to track the adaptive state and stimulation current overnight. The subject was instructed to record 30 minutes of awake data, keep recording through the night, and indicate when they woke up. Although self-reporting indicates that CL-DBS does not disrupt sleep, we have found that stimulation triggered throughout the entire night of sleep and have shown a need to account for sleep when developing CL-DBS algorithms for ET.