Brain plasticity in Parkinson’s disease with freezing of gait induced by action observation training

Abstract

Gait disorders represent a therapeutic challenge in Parkinson's disease (PD). This study investigated the efficacy of 4-week action observation training (AOT) on disease severity, freezing of gait and motor abilities in PD, and evaluated treatment-related brain functional changes. 25 PD patients with freezing of gait were randomized into two groups: AOT (action observation combined with practicing the observed actions) and "Landscape" (same physical training combined with landscape-videos observation). At baseline and 4-week, patients underwent clinical evaluation and fMRI. Clinical assessment was repeated at 8-week. At 4-week, both groups showed reduced freezing of gait severity, improved walking speed and quality of life. Moreover, AOT was associated with reduced motor disability and improved balance. AOT group showed a sustained positive effect on motor disability, walking speed, balance and quality of life at 8-week, with a trend toward a persisting reduced freezing of gait severity. At 4-week vs. baseline, AOT group showed increased recruitment of fronto-parietal areas during fMRI tasks, while the Landscape group showed a reduced fMRI activity of the left postcentral and inferior parietal gyri and right rolandic operculum and supramarginal gyrus. In AOT group, functional brain changes were associated with clinical improvements at 4-week and predicted clinical evolution at 8-week. AOT has a more lasting effect in improving motor function, gait and quality of life in PD patients relative to physical therapy alone. AOT-related performance gains are associated with an increased recruitment of motor regions and fronto-parietal mirror neuron and attentional control areas.

Mental steps: Differential activation of internal pacemakers in motor imagery and in mental imitation of gait

“…Furthermore, the presence of a human model in the virtual walking scenarios makes the imagery task more visually guided and less internally driven, with less need for the activation of subcortical areas such as the MLR. While clinical studies indicate that action observation is successful in defreezing patients with difficulties in gait initiation and maintenance [Agosta et al, ; Pelosin et al, ], our data suggest that full‐blown gait imagery recruits the gait motor network more extensively. Thus, while gait observation may best aid gait rehabilitation in patients with impaired functioning of brainstem centers, motor imagery could be particularly beneficial in those presenting no neurological dysfunction in subcortical areas, for instance, in patients with a functional limitation of locomotion of peripheral origin, as in orthopedic patients.…”

Freezing of gait in Parkinson’s disease: pathophysiology, risk factors and treatments

“…Apart from cues, treadmill training [164][165][166][167][168], obstacle aquatic training [169], supervised slackline training [170], walk-bicycle [171], and action observation [172,173] have also shown positive effects on FOG. Recently, Cosentino C et al [174] performed a systematic review and metaanalysis to evaluate the effectiveness of physiotherapy intervention on FOG symptoms.…”

Action observation in the modification of postural sway and gait: Theory and use in rehabilitation

“…In the study, the authors compared an experimental group who observed video clips showing specific movements and strategies to circumvent freezing of gait episodes and controls who observed a landscape scene in addition to routine physical therapy three times a week, for four weeks. Similarly, Agosta and colleagues [28] examined the efficacy of action observation training on disease symptoms, freezing of gait and motor abilities in Parkinson's disease. Patients were randomised into two groups, an experimental group who observed the gait of an actor over four weeks in addition to physical training and a control group who observed a landscape video in addition to physical training.…”