Deep brain stimulation and essential tremor.

Essential tremor (ET) is one of the most common movement disorders and can cause significant functional disability in some patients. Although medications can improve tremor in some patients, approximately 50% of patients have medication-resistant symptoms. In patients with ET who experience marked disability due to the tremor, surgical therapy, primarily deep brain stimulation (DBS) of the ventral intermediate (Vim) nucleus of the thalamus, is a viable treatment option. Multiple studies of DBS of the thalamus have shown that it is efficacious in the treatment of ET hand tremor, often with secondary improvement in voice and head tremor. Long-term studies have reported that a majority of patients continue to experience improvement in tremor. Adverse effects related to stimulation are usually mild and can be managed with changes in stimulation parameters. Long-term hardware complications include equipment malfunction, skin erosion, and battery replacements, which require additional surgery. Deep brain stimulation of the thalamus is a safe and efficacious procedure and should be considered in patients with ET who experience medication-resistant disabling tremor.