Successful Combination of Pallidal and Thalamic Stimulation for Intractable Involuntary Movements in Patients with Neuroacanthocytosis

OBJECTIVE: Neuroacanthocytosis (NA) is a rare neurodegenerative disease that involves severe involuntary movements including chorea, dystonia, and trunk spasms. Current treatments are not effective for these involuntary movements. Although there are a few reports on the use of deep brain stimulation to treat patients with NA, the optimal stimulation target is not yet definitive. Some authors have reported successful improvement of NA symptoms with stimulation of the globus pallidum interna, and others have reported a reduction in trunk spasm with stimulation of the ventralis oralis complex of the thalamus. We investigated whether the optimal target is well defined for NA. METHODS: We describe the effect of combination stimulation of the globus pallidum interna and the ventralis oralis complex of the thalamus in 2 patients with NA who presented with severe intractable involuntary movements. RESULTS: Gpi stimulation alone was an insufficient effect for trunk spasm and/or chorea. Vo complex stimulation given without Gpi stimulation resulted in improvement of trunk spasm after 2 weeks and might also have had an incomplete effect on involuntary movement including a chorea. The combination of Gpi and Vo complex stimulation reduced the trunk spasms and chorea. This improvement was maintained at 3 months after surgery. The Unified Huntington's Disease Rating Scale score at 1 year after surgery was lower than that before surgery. CONCLUSIONS: Gpi stimulation appears to be insufficient to control violent involuntary movements; therefore, combined GPi and Vo complex stimulation provided some moderate advantage over Gpi stimulation alone.