Spinal cord stimulation therapy for gait impairment in Parkinson’s disease: a double-blinded, randomised feasibility trial with an open extension

A trial of spinal cord stimulation (SCS) was performed in people with gait-impaired Parkinson's (ClinicalTrials.gov: NCT05110053 ). Fourteen patients underwent gait assessments and [¹⁸F]-FDG and [¹⁸F]-FEOBV PET at baseline, six, and twelve months after SCS. Twelve participants were randomised to six-month MicroBurst or sham, followed by six-month extension with stimulation. The primary outcomes were feasibility and safety, as captured by the trial process measures and nature and frequency of adverse events, respectively, and the Postural Instability and Gait Disorder (PIGD) score as a clinical outcome. Secondary outcomes included assessments of balance and gait at home and at visits, including the Lower Body and Gait (LBG) score, imaging, and patient-reported outcomes of changes in gait, balance and quality of life. Seventeen patients (12%) were eligible for enrolment. Recruitment was feasible (1.2 participants/month) and SCS was well-tolerated. At six months, MicroBurst did not significantly improve gait compared with sham, although bradykinesia/rigidity improved. At 12 months, LBG scores improved (-4.31 points, p = 0.0012) with bilateral decreased thalamic metabolism and decreased right anterior insula [¹⁸F]-FEOBV uptake. The trial met its primary feasibility and safety endpoints by achieving recruitment targets and demonstrating that SCS was well-tolerated. However, it did not meet the primary clinical endpoint of a significant PIGD improvement at six months. Larger trials are warranted, as SCS may improve LBG and leg rigidity/bradykinesia, especially as time progresses. We reported data for power calculations and identified important risks for designing future trials.