Improvement of Non-motor Symptoms and Quality of Life After Deep Brain Stimulation for Refractory Dystonia: A 1-Year Follow-Up

Introduction: Deep brain stimulation (DBS) is a treatment option for refractory dystonia's motor symptoms, while its non-motor symptoms (NMS) have been less systematically assessed. We aimed to describe the effects of DBS on NMS in refractory generalized inherited/idiopathic dystonia prospectively. Methods: We evaluated patients before and 1 year after DBS surgery and applied the following scales: Burke-Fahn-Marsden Rating Scale (BFMRS), NMS Scale for Parkinson's Disease (NMSS-PD), Parkinson's Disease Questionnaire-8, short-form Brief Pain Inventory (BPI), Neuropathic Pain Symptom Inventory (NPSI), and short-form McGill Pain Questionnaire (MPQ). Results: Eleven patients (38.35 +/- 11.30 years) underwent surgery, all with generalized dystonia. Motor BFMRS subscore was 64.36 +/- 22.94 at baseline and 33.55 +/- 17.44 1 year after DBS surgery (47.9% improvement, p = 0.003). NMSS-PD had a significant change 12 months after DBS, from 70.91 +/- 59.07 to 37.18 +/- 55.05 (47.5% improvement, p = 0.013). NMS changes were mainly driven by changes in the gastrointestinal (p = 0.041) and miscellaneous domains (p = 0.012). Seven patients reported chronic pain before DBS and four after it. BPI's severity and interference scores were 4.61 +/- 2.84 and 4.12 +/- 2.67, respectively, before surgery, and 2.79 +/- 2.31 (0.00-6.25) and 1.12 +/- 1.32 (0.00-3.00) after, reflecting a significant improvement (p = 0.043 and p = 0.028, respectively). NPSI score was 15.29 +/- 13.94 before, while it was reduced to 2.29 +/- 2.98 afterward (p = 0.028). MPQ's total score was 9.00 +/- 3.32 before DBS, achieving 2.71 +/- 2.93 after (p = 0.028). Conclusions: DBS improves NMS in generalized inherited/idiopathic dystonia, including chronic pain.

Automated summary

The study demonstrates that DBS surgery has significant improvement on non-motor symptoms in patients with refractory generalized inherited/idiopathic dystonia, especially in alleviating chronic pain.