Supplementary Material for: Successful Treatment of Disabling Paroxysmal Nonkinesigenic Dyskinesia with Deep Brain Stimulation of the Globus Pallidus Internus

Paroxysmal nonkinesigenic dyskinesia (PNKD) causes episodes of treatment-resistant involuntary movements. Previous case reports showed effective treatment of PNKD with deep brain stimulation (DBS). We report 2 patients in whom DBS was highly successful when other treatment modalities had failed. <b><i>Methods:</i></b> Two patients aged 34 and 24 years with a longstanding history of PNKD were treated with globus pallidus internus (GPi) DBS. Motor effects were monitored and followed up postoperatively and again at 6 months after surgery. <b><i>Results:</i></b> Both patients responded very well to GPi DBS with complete suppression of dyskinesia after surgery in 1 patient and in the second after an additional adjustment of stimulation. <b><i>Conclusion:</i></b> GPi DBS might be an effective alternative treatment modality for PNKD.