*2.1. Meta-Analysis*

### 2.1.1. Search Strategy and Selection Criteria

We conducted a PubMed search for DBS parameters in ET on 05/03/2018, using the following string: ("DBS" OR "Deep Brain Stimulation") AND ("essential tremor"). The search was conducted by two independent reviewers (DB and MO). Articles written in English, containing the key terms "DBS" or "stimulation" and "essential tremor" were included for full text screening. Animal studies, experiments in which patients had co-existing movement disorders (e.g., Parkinson's disease), as well as review articles were excluded from further analysis. For full text screening the following exclusion criteria were applied: (1) either stimulation parameters or outcomes were not reported; (2) interventions following failed DBS or thalamotomy (the latter might still exert therapeutic effects); (3) reports earlier than three months post-operatively (when the microlesion effect might influence tremor) or with unspecified follow-up moment; (4) cohorts already reported; (5) irretrievable articles; (6) pooled data of ET with Parkinson's patients; (7) IPG malfunctions. Review articles were checked for any relevant missing articles. The remaining articles were selected for data extraction.
