Deep brain stimulation timed to the walking cycle proves feasible in five people with Parkinson's

What happened

Walking problems in Parkinson's disease often respond poorly to conventional, continuous deep brain stimulation. This single-centre, blinded, randomised crossover study tested a version that adjusts stimulation in step with the phase of the gait cycle.

Five people receiving pallidal stimulation also had a subdural electrode paddle implanted. In all five, the team found personalised gait-phase biomarkers in cortical or pallidal field potentials and programmed them into a bidirectional neurostimulator; identifying such biomarkers was the primary outcome. In clinic testing, gait-synchronised stimulation improved step variability and step symmetry compared with continuous stimulation. Three participants went on to a double-blinded, multi-day crossover phase, in which the adaptive mode maintained general motor symptom control, reduced falls and produced gait improvements that differed between patients. No adverse events occurred.

Why it matters

Adaptive stimulation driven by beta-band signals already helps other motor symptoms. Gait is cyclical, and this study shows that stimulation can be locked to a movement as it happens, using signals recorded from the patient's own brain.

Caveats

The primary outcome was feasibility, not clinical benefit. Only five people took part and only three completed the multi-day phase, so the reduction in falls is preliminary. The authors call for a larger randomised trial to determine efficacy. This entry is based on the abstract.