A Pilot Study Assessing the Effects of Pallidal Deep Brain Stimulation on Sleep Quality and Polysomnography in Parkinson’s Patients

Abstract

Deep Brain Stimulation (DBS) is an established adjunctive surgical intervention to treat poorly controlled motor symptoms in Parkinson's disease (PD). Both surgical targets (the subthalamic nucleus and globus pallidus) have proven equally efficacious in treating motor symptoms but unique differences may exist in effects on nonmotor symptoms. Sleep dysfunction, a common disabling symptom in PD, has only been examined directly in the subthalamic target, demonstrating some beneficial changes in sleep quality. We aimed to explore sleep changes after pallidal stimulation; hypothesizing similar benefits would be seen. We performed a prospective nonblinded clinical trial evaluating sleep in five PD patients already slated for pallidal DBS pre and six months postimplantation using validated sleep surveys and polysomnograms (PSGs). Surveys included the Epworth sleepiness scale, PD sleep scale, Insomnia severity index (ISI), and RLS severity scale. Most patients had notable improvements in sleep quality as measured by PSG metrics such as sleep efficiency and latency to sleep but they did not reach statistical significance. Most surveys reflected an improvement as well with the ISI scale showing the most promising trend post pallidal DBS (14.4 ± 7.02 vs. 9.0 ± 2.55; p = 0.07). In this small pilot trial, pallidal DBS failed to demonstrate statistically significant improvements in sleep metrics postimplantation but did reveal improving trends in several PSG measures including sleep efficiency and latency to sleep onset as well as sleep survey scores. A larger, blinded clinical trial is needed to more definitively determine whether pallidal DBS may benefit sleep.