Stimulation-Induced Dyskinesia, Interleaving Settings, and Management of Subthalamic Nucleus Deep Brain Stimulation in DYT1 Dystonia

DYT1 dystonia is a primary dystonia with potential for significant symptomatic improvement after bilateral deep brain stimulation (DBS) of the globus pallidus interna (GPi). GPi is the historical target of choice for this disease. This chapter presents a case of an adolescent with disabling generalized DYT1 dystonia who underwent bilateral subthalamic nucleus (STN) DBS as part of a prospective clinical trial. While limb and cervical dystonia dramatically improved with DBS, programming was limited by stimulation-induced bilateral limb dyskinesia, including in the left arm, which was previously unaffected by dystonia. After years of evolving symptoms and complex programming, bilateral interleaved settings using both a contact in motor STN and the most dorsal DBS contact in the zona incerta resulted in sustained, near-complete resolution of dystonia without side effects. This case illustrates the use of the STN as an effective DBS target for primary dystonia, although complex programming was necessary to mitigate stimulation-induced dyskinesia.