Question: Neurostimulation of which nucleus is used for treatment of dystonia?

Context:
Bilateral globus pallidus internus (GPi) DBS was performed in five SD patients and unilateral ventralis oralis anterior and posterior (Voa/Vop) nucleus of the thalamus DBS in two post-stroke hemiballismus patients. 
BACKGROUND: Deep brain stimulation of the internal pallidum (GPi-DBS) is effective for various types of drug-refractory primary dystonias. 
METHODS: In the parent trial, 40 patients were randomly assigned to either sham neurostimulation or neurostimulation of the internal globus pallidus for a period of 3 months and thereafter all patients completed 6 months of active neurostimulation. 38 patients agreed to be followed up annually after the activation of neurostimulation, including assessments of dystonia severity, pain, disability, and quality of life.
INTERPRETATION: 3 years and 5 years after surgery, pallidal neurostimulation continues to be an effective and relatively safe treatment option for patients with severe idiopathic dystonia. This long-term observation provides further evidence in favour of pallidal neurostimulation as a first-line treatment for patients with medically intractable, segmental, or generalised dystonia.
We describe a patient who received bilateral globus pallidus internus DBS for dystonia with initially good clinical response, but the device eventually failed. 
Bilateral pallidal deep brain stimulation for the treatment of patients with dystonia-choreoathetosis cerebral palsy: a prospective pilot study.
Bilateral pallidal deep brain stimulation (BP-DBS) of the globus pallidus internus (GPi) is an effective treatment for primary dystonia, but the effect of this reversible surgical procedure on dystonia-choreoathetosis CP, which is a subtype of secondary dystonia, is unknown. 
INTERPRETATION: Bilateral pallidal neurostimulation could be an effective treatment option for patients with dystonia-choreoathetosis CP. 
Pallidal deep-brain stimulation in primary generalized or segmental dystonia.
BACKGROUND: Neurostimulation of the internal globus pallidus has been shown to be effective in reducing symptoms of primary dystonia. 
CONCLUSIONS: Bilateral pallidal neurostimulation for 3 months was more effective than sham stimulation in patients with primary generalized or segmental dystonia.
OBJECTIVE: To assess the effects of bilateral pallidal deep brain stimulation (DBS) on mood and cognitive performance in patients with dystonia before surgery (at baseline, while patients received their usual treatment) and 12 months postoperatively (while patients received neurostimulation and their medications) in a multicenter prospective study. 
CONCLUSIONS: Bilateral pallidal stimulation has a good benefit-to-risk ratio as it did not negatively affect cognitive performance and mood in primary dystonia, while a significant motor improvement was obtained.
Despite that deep brain stimulation (DBS) of the globus pallidus internus (GPi) is emerging as the favored intervention for patients with medically intractable dystonia, the pathophysiological mechanisms of dystonia are largely unclear. In eight patients with primary dystonia who were treated with bilateral chronic pallidal stimulation, we correlated symptom-related electromyogram (EMG) activity of the most affected muscles with the local field potentials (LFPs) recorded from the globus pallidus electrodes. 
Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia.
METHODS: We performed a prospective, controlled, multicenter study assessing the efficacy and safety of bilateral pallidal stimulation in 22 patients with primary generalized dystonia. 
CONCLUSIONS: These findings support the efficacy and safety of the use of bilateral stimulation of the internal globus pallidus in selected patients with primary generalized dystonia.
Bilateral pallidotomy or pallidal stimulation may provide major benefit especially in patients with generalized, disabling dystonia with the most dramatic improvements in dystonia type 1 patients.
This suggests that neurostimulation of the VIM may be an effective treatment for myoclonus in pharmacologically intractable IMDS.
We report on the effects of bilateral neurostimulation of the ventral intermediate thalamic nucleus (VIM) in a patient with medically intractable and progressing inherited myoclonus dystonia syndrome (IMDS). 
Neurostimulation of the ventral intermediate thalamic nucleus in inherited myoclonus-dystonia syndrome.
Pallidal and thalamic neurostimulation in severe tardive dystonia.
After informed consent, a bilateral stereotactic electrode placement targeting the ventral intermediate thalamic nucleus (VIM) and the globus pallidus internus (GPi) was performed.
Stimulation of the VIM did not improve the hyperkinetic movements and simultaneous stimulation of both the GPi and the VIM did not result in any additional benefit. 
Bilateral pallidal neurostimulation could be an effective treatment option for patients with dystonia-choreoathetosis CP.
3 years and 5 years after surgery, pallidal neurostimulation continues to be an effective and relatively safe treatment option for patients with severe idiopathic dystonia.
 This long-term observation provides further evidence in favour of pallidal neurostimulation as a first-line treatment for patients with medically intractable, segmental, or generalised dystonia.
INTERPRETATION: 3 years and 5 years after surgery, pallidal neurostimulation continues to be an effective and relatively safe treatment option for patients with severe idiopathic dystonia.
This long-term observation provides further evidence in favour of pallidal neurostimulation as a first-line treatment for patients with medically intractable, segmental, or generalised dystonia.
Bilateral pallidal neurostimulation could be an effective treatment option for patients with dystonia-choreoathetosis CP
3 years and 5 years after surgery, pallidal neurostimulation continues to be an effective and relatively safe treatment option for patients with severe idiopathic dystonia

Answer: Neurostimulation of globus pallidus internus is effective for treatment of dystonia. Ventral intermediate thalamic nucleus has also been tested for neurostimulation in dystonia patients.
Exact answer: globus pallidus internus