Validating the targets for neurostimulation in essential tremor

Deep brain stimulation (DBS) is considered for the treatment of essential tremor (ET) that is resistant to pharmacologic treatment.1 To date, the neuroanatomic target of choice for ET is the nucleus ventralis intermedius (VIM) of the thalamus. Although VIM-DBS has shown good efficacy, side effects such as stimulation-induced ataxia or deterioration of speech may hamper therapeutic success in at least a subgroup of patients undergoing DBS. Furthermore, the effects of VIM stimulation may attenuate over time. Some studies have reported such “tolerance” in as little as 10 weeks,2 while other studies have reported more sustained benefit.3