Author Response: Deep Brain Stimulation in Early-Stage Parkinson Disease: Five-Year Outcomes.

Abstract

We appreciate the interest in our research of deep brain stimulation in early-stage Parkinson disease (PD).1 Bradykinesia and tremor are both troubling cardinal motor features of Parkinson disease. There was no significant difference in bradykinesia between the groups throughout the trial. On the other hand, rest tremor was markedly and significantly reduced for subjects receiving early deep brain stimulation, which is notable because tremor is often very distressing for patients with early-stage PD.2 Gun-Marie et al. found that “The common view in the medical community that tremor is a less problematic symptom does not fit with our patients' depiction of the impact of tremor….”3 That said, we do not advocate for a change in clinical practice based on Class II evidence from a single study. Most importantly, there are currently no therapies proven to slow the progression of any feature of PD, and as researchers, we are compelled to continue this line of investigation. The results of this study are encouraging, and we look forward to leading the FDA-approved [IDEG050016] phase III, multicenter, clinical trial of bilateral subthalamic nucleus deep brain stimulation implanted during very early-stage Parkinson disease.