A Multimodal Training Modulates Short Afferent Inhibition and Improves Complex Walking in a Cohort of Faller Older Adults With an Increased Prevalence of Parkinson's Disease

Overview

Parkinson’s disease and aging are associated with falls. The impairment of attentional supervision of gait mediated by cholinergic inputs may increase the fall risk, especially when obstacles challenge the gait. Motor-cognitive interventions have been shown to improve motor performance, cognitive skills, and the frequency of falls. In this study, we hypothesized that an intervention simulating an attention-demanding walking condition would affect not only complex gait performance and fall risk, but also short-latency afferent inhibition (SAI), a measure of cholinergic activity.

Methods:

In a randomized controlled trial, 39 participants at risk of falling (24 Parkinson’s disease participants and 15 older adults) were recruited. The participants trained three times a week for six weeks either on the treadmill or on the treadmill with non-immersive virtual reality intervention. Cholinergic activity was assessed using transcranial magnetic stimulation, or SAI. Walking and negotiating physical obstacles were used to measure gait kinematics. An assessment of transcranial magnetic stimulation and gait was conducted pre, post, and six months after the intervention.

Results:

Combining treadmill training with non-immersive virtual reality increased inhibition of the SAI protocol on cortical excitability, improved obstacle negotiation performance, and reduced injury rates compared with treadmill training alone. In addition, the higher SAI after training, the better the obstacle negotiation performance, and the lower the fall rate.

Conclusions:

A novel rehabilitation approach targeting cognitive components of complex motor actions can induce changes in cortical cholinergic activity as measured by SAI, enabling improvements in functional gait.