DBS, tcMRgFUS, and gamma knife radiosurgery for the treatment of essential tremor: a systematic review on techniques, indications, and current applications

INTRODUCTION: Essential tremor (ET) may severely impact patient's Quality of Life. Several techniques such as radiofrequency, deep brain stimulation (DBS), gamma knife (GK) radiosurgery and high-intensity focused ultrasound may be used for the surgical treatment of ET. The aim of this paper is to summarize the most recent available literature on DBS, transcranial magnetic resonance-guided focused ultrasound (tcMRg-FUS) and GK, and to compare indications, targets, and effectiveness of these surgical techniques for the treatment of ET. EVIDENCE ACQUISITION: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was performed on the three largest medical databases (PubMed, Scopus, and Web of Science). This systematic review is focused on the effectiveness and safety of GK, DBS, and tcMRgFUS as functional neurosurgical techniques for the treatment of ET. The aim of this study was to compare these techniques by evaluating mode, target, effectiveness in improving motor outcomes, and rates of adverse effects. EVIDENCE SYNTHESIS: Articles meeting the predetermined criteria were included. Data for DBS, tcMRgFUS, and GK were analyzed and compared for indications, patient selection, advantages vs. disadvantages, and treatment targets for essential tremor. CONCLUSIONS: DBS, tcMRgFUS and GK are effective techniques for the treatment of ET. Despite different functioning principles, all three surgical techniques require a proper functional diagnosis to define accurate indications for patient selection. Their indication depends upon the patient's neurological condition and their effectiveness relies on proper targeting.