Can a zapping headband help people with rare brain diseases walk better?

This study tests whether a non-invasive brain stimulation technique called tDCS, applied while people walk, can improve motor skills like gait, speech, and eye movements. Twenty adults with progressive supranuclear palsy, corticobasal degeneration, or Parkinson's disease will receive both real and sham stimulation in a crossover design. The goal is to see if tDCS boosts the effects of walking practice.