Motor Adaptation to Split-Belt Treadmill in Parkinson's Disease

Influence of Multiple Ratio Split-belt Treadmill on Gait Asymmetry and Motor Learning in PD Patients With Freezing of Gait

Freezing of Gait (FOG) is a disabling symptom common in advanced Parkinson's Disease. FOG is an independent contributor to fall risk and is only partially relieved by medication. Parkinson's patients with FOG are known to have more difficulty with gait adaptation in their day to day environment. Further, asymmetry of gait has been implicated in FOG as these episodes are often elicited during asymmetric tasks such as turning. This study will examine the effect of a single session of split-belt treadmill walking on gait adaptation, gait symmetry and FOG as well as 24 hour retention of these effects.

In this proposal, the investigators will investigate whether adapting gait to modulations imposed by a split-belt treadmill, improves walking ability and reduces FOG. The investigators will test the hypothesis that motor adaptation deficits underlie FOG and that these problems are modifiable with training. To address these suppositions, the investigators propose a multi-centric study conducted in two research labs with expertise in split-belt gait analysis and FOG: University of Leuven (KUL) and Christian-Albrechts-University Kiel (CAUK). As freezers have been shown to have more difficulty with consolidation of motor learning, the investigators aim in study I (pilot phase) to first understand which split-belt parameters are optimal for training gait flexibility and lead to consolidated gains in daily walking. For this study, the investigators will recruit 60 freezers and 60 healthy controls, pooled across centers, and manipulate different split-belt conditions in one learning and retention session.

Inclusion Criteria:

• Diagnosis of Parkinson's Disease as per the UK Parkinson's Disease Society Brain Bank Criteria
• Classification as a Freezer with the New Freezing of Gait Questionnaire (score > 0)
• Ability to walk at least 5 min. without any aid
• Stable anti-parkinsonian medication at least 1 month prior to participation

Exclusion Criteria:

• Neurologic diseases other than PD
• Orthopedic injuries that could influence gait and balance
• Participation in treadmill training more than once a week
• Cognitive impairment (MMSE<24) or inability to follow test instructions
• Self-reported DBS-related postural or gait disturbances
• Cardiovascular risk factors
• Peripheral neuropathy