Impact of Bilateral GPi Deep Brain Stimulation on Dystonia, Functional Outcomes, and Caregiver Burden in Patients with Dystonic Cerebral Palsy

Abstract

Background: Dystonic cerebral palsy (DCP) is a complex, disabling manifestation of secondary dystonia, which significantly impacts motor function, quality of life, and well-being. Conventional pharmacologic therapies frequently do not relieve symptoms sufficiently. Deep brain stimulation (DBS) of the globus pallidus internal segment (GPi) has gained increasing attention as a neuromodulatory therapy for refractory dystonia. Still, the experience of the effect of GPi DBS treatment in adults with DCP has, until recently, been limited. Methods: We performed a retrospective, two-center case series of 11 adult patients with medically refractory DCP who underwent bilateral GPi-DBS. The clinical outcomes were evaluated based on the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), the Functional Independence Measure (FIM), the Gross Motor Function Classification System (GMFCS), and the Caregiver Burden Scale (CBS). The assessments were done preoperatively and at 1-year follow-up. Changes in continuous variables were analyzed using paired t-tests. Results: At the 1-year follow-up, the mean BFMDRS score improved from 69.6 ± 27.6 to 54.3 ± 36.5 (p = 0.001), indicating a significant reduction in overall dystonia severity. Functional independence also improved, demonstrated by the rise in FIM scores from 65.3 ± 33.9 to 79.2 ± 43.4 (p = 0.006). Although GMFCS levels did not change in most patients (p = 0.125), the burden on caregivers decreased significantly, with CBS scores falling from 35.7 ± 18.8 to 32.0 ± 17.1 (p = 0.015). There were no surgical complications. Conclusions: In adults, bilateral GPi-DBS is a safe and effective intervention for DCP, improving motor control and increasing functional independence while decreasing caregiver burden. These findings lend support to its role in the multidisciplinary management of DCP.

Keywords: caregiver burden; deep brain stimulation; dystonic cerebral palsy; functional independence; globus pallidus internus.

Figure 1

Pre- and one-year postoperative Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS) total scores for each patient (P1–P11) after GPi-DBS surgery. Each patient’s pre-DBS score (open circle) and post-DBS score (filled circle) are connected by a line; downward sloping lines indicate improvement (lower scores = less dystonia severity). All patients showed either improvement or no change in BFMDRS score, with an average ~22% reduction in score at 1 year (mean improvement is annotated on the chart). Y-axis shows BFMDRS total score (points); X-axis denotes individual patient IDs.

Figure 2

Pre- and one-year postoperative Functional Independence Measure (FIM) scores for each patient (P1–P11) following GPi-DBS. Each pair of markers represents an individual patient’s FIM before (open circle) and after (filled circle) surgery, connected by a line; upward sloping lines indicate functional gains (higher FIM = greater independence). Most patients experienced improved independence after DBS, with an average ~21% increase in FIM score at 1-year postop (mean improvement annotated). Y-axis shows total FIM score (units on 18–126 scale, higher is better); X-axis indicates patient IDs.