Supplementary Material for: Five-Year Follow-Up of 10 Patients Treated with Globus Pallidus Internus Deep Brain Stimulation for Segmental or Multisegmental Dystonia

<i>Introduction:</i> Globus pallidus internus (GPi) deep brain stimulation (DBS) represents a validated, effective, and safe treatment for patients affected by generalized dystonia resistant to conservative treatment. Segmental and multisegmental dystonia have more recently been proposed as further indications for GPi DBS despite the lack of long-term homogenous follow-up. Here we present an original and detailed long-term follow-up (5 years) of a homogeneous population of 11 patients affected by segmental or multisegmental dystonia. <i>Materials and Methods:</i> Ten patients underwent bilateral GPi DBS electrode implantations under a Leksell stereotactic guide, with intraoperative neurophysiological monitoring. The follow-ups at 1, 3 and 5 years were collected using video-BFMDRS for motor and disability scores. The statistical analysis of the results is provided. <i>Results:</i> We reported a statistically significant improvement in motor and disability overall scores until 5 years after treatment. At the last follow-up, even the single motor subitems were statistically improved. <i>Discussion:</i> We observed a continuous and statistically significant improvement in all of the motor subitems and in the overall disability score until the 3-year follow-up. These results did not improve any further but they appeared steady at the last follow-up. We also report a significant improvement in the cranial-cervical subitems. <i>Conclusions:</i> GPi DBS should definitely be considered a safe and effective treatment also for segmental and multisegmental dystonia even in cases of relevant or prevalent cranial-cervical involvement.