Long term clinical disease progression in patients with Parkinson’s disease after STN Deep Brain Stimulation

Abstract

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder with severe longterm impact on patients, their caregivers and on the society in general [1]. The treatment of PD is symptomatic. Surgical treatment with chronic high frequency stimulation of the subthalamic nuclei (STN-DBS) has been shown to provide long term symptom relief with few complications in selected patients with PD [2-4]. Aim: The aim of the thesis has been to elucidate the long-term effects of STN-DBS on the development of clinical symptoms in PD. Materials and methods: All PD patients treated with STN-DBS between 2001-2007 at Rikshospitalet (N=144) and at Stavanger University Hospital (N=28) were prospectively followed with standardized examinations, and all 172 STN-DBS operated PD patients were included in the scientific material for the thesis. As reference we used the patients from a population-based prevalence study conducted with patient recruitment between September 1992 and May 1993, before STN-DBS was available. Results: We confirm that STN-DBS surgery can be performed with good and stable long time results on dopaminergic motor symptoms. Perioperative mortality was low and the rate of major adverse events low. The non-motor features of PD seem to develop independently of intervention with STN-DBS, as do FOG and falls. Fatigue is observed to develop at a high rate in STN-DBS operated patients after the first year postoperatively. Conclusions and implications: STN-DBS is a very good treatment option for motor symptoms in selected patients with advanced PD. The benefits of the treatment are limited to motor symptom control as the underlying PD pathology continues to develop in operated patients similar to the natural history of PD. Fatigue seem to develop at a high rate in STN-DBS operated patients after the first year postoperatively. Our findings are relevant to advising patients both about the indication for, and the timing of, STN-DBS surgery in PD