Efficacy and safety of multiple-target deep brain stimulation in non-parkinsonian movement disorders: a systematic review.

INTRODUCTION

To analyze studies employing multiple-target deep brain stimulation (DBS) for non-parkinsonian movement disorders and identify potential indications, therapeutic outcomes, and associated side effects.

METHODS

We systematically screened PubMed and included studies involving patients treated with DBS targeting at least two brain regions, synchronous stimulation of ≥2 regions, patient data regarding symptoms/disease, and reported outcomes. Exclusion criteria included animal studies and reports lacking original data.

RESULTS

Twenty-seven studies were identified, included and analyzed; general trends were noted for each disorder. For essential tremor multi-target DBS (VIM+VOA/VOP) demonstrated promising outcomes regarding symptom improvement and reduction of side-effects. For multiple Sclerosis Tremor limited evidence suggested positive outcomes, comparable to standard DBS. The VIM/VOP border has been highlighted as a promising target. Regarding holmes Tremor although limited to case reports, multi-target DBS yielded favorable outcomes with minimal adverse effects. Finaly for dystonia multi-target DBS (GPi+VIM, GPi+VO) effectively addressed tremor and dystonic features. Statistically significant advantages were demonstrated over single-target stimulation in myoclonus-dystonia and hemidystonia.

CONCLUSION

While variability in target selection, methodologies, and outcomes precludes a meta-analysis, evidence supports the potential role of multi-target DBS in cases where single-target stimulation is inadequate. Promising target combinations, such as GPi+VIM (myoclonus-dystonia) and VIM+VOA (essential tremor), warrant further clinical exploration. The heterogeneity and predominance of case reports highlight the need for high-quality, controlled studies to refine indications and optimize strategies for multi-target DBS.