OBJECTIVES: Ventralis intermedius deep brain stimulation is an established 
intervention for medication-refractory essential tremor. Newer constant current 
stimulation technology offers theoretical advantage over the traditional 
constant voltage systems in terms of delivering a more biologically stable 
therapy. There are no previous reports on the outcomes of constant current deep 
brain stimulation in the treatment of essential tremor. This study aimed to 
evaluate the long-term efficacy of ventralis intermedius constant current deep 
brain stimulation in patients diagnosed with essential tremor.
MATERIALS AND METHODS: Essential tremor patients implanted with constant current 
deep brain stimulation for a minimum of three years were evaluated. Clinical 
outcomes were assessed using the Fahn-Tolosa-Marin tremor rating scale at 
baseline and postoperatively at the time of evaluation. The quality of life in 
the patients was assessed using the Quality of Life in Essential Tremor 
questionnaire.
RESULTS: Ten patients were evaluated with a median age at evaluation of 74 years 
(range 66-79) and a mean follow up time of 49.7 (range 36-78) months since 
starting stimulation. Constant current ventralis intermedius deep brain 
stimulation was well tolerated and effective in all patients with a mean score 
improvement from 50.7 ± 5.9 to 17.4 ± 5.7 (p = 0.0020) in the total 
Fahn-Tolosa-Marin rating scale score (65.6%). Furthermore, the total combined 
mean Quality of Life in Essential Tremor score was improved from 56.2 ± 4.9 to 
16.8 ± 3.5 (p value = 0.0059) (70.1%).
CONCLUSION: This report shows that long-term constant current ventralis 
intermedius deep brain stimulation is a safe and effective intervention for 
essential tremor patients.