Background Deep brain stimulation (DBS) has proven to be a safe and effective therapy for refractory essential tremor, but information regarding long-term outcomes is lacking.

Objectives We aimed to assess the long-term safety and efficacy of DBS in patients with essential tremor.

Methods Patients treated with DBS for essential tremor for at least 8 years were evaluated in the ‘on’ and ‘off’ state using the Fahn–Tolosa–Marin tremor rating scale, and their medical records were reviewed to assess complications related to this therapy.

Results We studied 13 patients (7 men): median age at evaluation 79 years (range 47–88), median age at electrode implantation 68 years (range 37–78) and mean time since electrode implantation 132.54±15.3 months (range 114–164). The difference between the ‘off’ and ‘on’ state on the motor items of the tremor rating scale was 41.9% (58.62 vs 34.08, p<0.001) in the non-blinded and 37.2% (56.07 vs 35.23, p<0.001) in the blinded rating. DBS provided a functional improvement of 31.7% in the ‘on’ state (15.07 vs 22.07, p<0.001). A total non-blinded improvement in the tremor rating scale of 39% was observed in the ‘on’ state (49.15 vs 80.69, p<0.001). Dysarthria and disequilibrium were common in patients with bilateral stimulation. A DBS-related surgery (electrode revision or internal pulse generator exchange) was necessary on average every 47.9 months to continue with the DBS therapy.

Conclusions Thalamic DBS is a safe and effective therapy in patients with essential tremor followed for up to 13 years.