Deep Brain Stimulation in Patients With Mutations in Parkinson's Disease–Related Genes: A Systematic Review

ABSTRACT Background Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease (PD), and careful selection of candidates is a key component of successful therapy. Although it is recognized that factors such as age, disease duration, and levodopa responsiveness can influence outcomes, it is unclear whether genetic background should also serve as a parameter. Objectives The aim of this systematic review is to explore studies that have evaluated DBS in patients with mutations in PD‐related genes. Methods We performed a selective literature search for articles regarding the effects of DBS in autosomal dominant or recessive forms of PD or in PD patients with genetic risk factors. Data regarding changes in motor and nonmotor scores and the presence of adverse events after the stimulation were collected. Results A total of 25 studies were included in the systematic review, comprising 135 patients. In the shorter term, most patients showed marked or satisfactory response to subthalamic DBS, although leucine rich repeat kinase 2 carriers of R114G mutations had higher rates of unsatisfactory outcome. Longer term follow‐up data were scarce but suggested that motor benefit is sustained. Patients with the glucosidase beta acid (GBA) mutation showed higher rates of cognitive decline after surgery. Motor outcome was scarce for pallidal DBS. Few adverse events were reported. Conclusions Subthalamic DBS results in positive outcomes in the short term in patients with Parkin, GBA, and leucine‐rich repeat kinase 2 (non‐R144G) mutations, although the small sample size limits the interpretation of our findings. Longer and larger cohorts of follow‐up, with broader nonmotor symptom evaluations will be necessary to better customize DBS therapy in this population.