Effects Of Action Observation On Gait In Patients With Multiple Sclerosis: A Pilot Study

Background: Mirror neuron system (MNS) is an observation-execution matching system that discharge not only when an individual performs an action but also when observes actions made by other individuals. Numerous studies suggest that action observation (AO) can activate areas of the motor network and MNS and has been used as a mean for rehabilitating motor control in particular in stroke patients. Despite these evidences, the effect of AO in patients with Multiple Sclerosis (PwMS) has not been fully investigated so far.

Objectives: To assess whether AO may improve gait speed in a group of PwMS.

Methods: Eight PwMS, selected among those followed as outpatients at AISM Rehabilitation Centre, Genoa - Italy, were randomized into two groups: AO group (AOG, 4 subjects) and control group (CG, 4 subjects). All patients were MS defined following McDonald Criteria, with an EDSS lower than 3 and an Ambulation Index lower than 4. Three walking paths (widths: 20, 35, and 50 cm; walking distance: 5m) were drawn on the ground. In a first session the time-to walk baseline (T0) through the three different paths (7 trials for each path) was recorded for each subjects. After T0, in the next week, those subjects in AOG watched a 10 minute-length video clip of an healthy subject walking at 1 m/s speed in one of the three different paths, while those in CG watched a 10 minute-length video clip of static pictures. AOG and CG subjects were then asked to walk for 7 trials through the path selected for AOG immediately after having watched video clip (T1), one hour later (T2) and two days later (T3). The experiment was repeated in the next two consecutive weeks for the other paths considered in the study. Mean time-to-walk was recorded by an electronic stopwatch and considered as outcome measure.

Results: AOG with respect to CG showed a markedly improvement in mean time-to walk and mean gait cadence for each path considered in the study. In particular in AOG the mean overall improvement for time-to-walk, with respect to T0, was of 11,67% at T1 and increased progressively to17,98% at T3, while in CG results showed no improvements between T0, T1, T2 and T3.

Conclusions: This pilot study highlighted that AO could play an important role, in addition to conventional rehabilitative training, in improving walking motor performances and might contribute to reduce clinical disability in PwMS.