Review Investigates Deep Brain Stimulation Treatment Outcomes in Parkinson Disease

Researchers investigated current evidence linking genetic variation to deep brain stimulation treatment and outcomes in Parkinson disease (PD), finding a promising development where genetic profiling may be important for clinicians to personalize medical and surgical therapy for patients.

The review used data from Embase and PubMed and identified 39 publications of interest. The authors found that genetic screening studies indicate that monogenic forms of PD and high-risk variants of glucocerebrosidase (GBA) mutation may be more common in those who are treated with deep brain stimulation. However, studies evaluating deep brain stimulation with outcomes in patients carrying mutations in specific genes were limited in size.

“Deep brain stimulation (DBS) is currently well established as an adjunct therapy in PD patients experiencing either motor complications not controlled by best medical therapy or medication-refractory tremor,” noted the authors. “However, as DBS is ineffective against a number of PD symptoms and carries potential risks and side effects, careful individualized patient screening and target selection are essential for good surgical outcomes.”

In addition, the researchers found reports which demonstrate that the phenotype associated with parkin mutations could be suitable for early surgery. In those with leucine‐rich repeat kinase 2 mutations, deep brain stimulation seemed outcome-equivalent to mutation-negative patients, however less favorable outcomes were apparent in those with GBA mutations.

“Careful assessment of clinical symptoms remains the primary basis for clinical decisions associated with deep brain stimulation surgery in Parkinson’s disease, although genetic information could arguably be taken into account in special cases,” the authors concluded. “Current evidence is scarce, but highlights a promising development where genetic profiling may be increasingly relevant for clinicians tailoring personalized medical or surgical therapy to Parkinson’s disease patients.”

The researchers suggested that the ability to predict PD subtype based on genetic profiling will increase in the future.

Reference

Ligaard J, Sannaes J, et al. Deep brain stimulation and genetic variability in Parkinson’s disease: a review of the literature [published online September 6, 2019]. NPJ Parkinson’s Disease. doi: 10.1038/s41531-019-0091-7.