Non-motor effects of deep brain stimulation in dystonia: A systematic review

Deep brain stimulation (DBS) has emerged as an effective treatment in medically intractable dystonia, with the globus pallidus internus (GPi) being most frequently targeted. Non-motor symptoms, including pain and psychiatric, cognitive and sleep disturbances, are increasingly recognized as important determinants of disease burden in dystonia patients. We reviewed non-motor outcomes of DBS in dystonia, focusing on GPi-DBS.

A systematic literature search of Pubmed and Embase was performed according to the PRISMA guidelines.

Fifty-two studies were included. GPi-DBS reduced pain related to dystonia. No major effects on anxiety, mood, and cognition were found. In contrast to motor outcome, non-motor outcome seems more independent of the etiology of dystonia. However, the impact of potential confounders (e.g. patient factors, changes in pharmacological treatment) is unclear.

Despite the growing interest in non-motor symptoms in dystonia, DBS studies still focus primarily on motor outcome. We recommend systematic evaluation of both non-motor and motor features before and after DBS interventions to improve quality of life and management of patients with dystonia.