Robot-assisted Gait Training on Mobility in Severely Disabled Multiple Sclerosis Patients

This is a prospective, randomized, single-blinded, controlled study. Ninety-eight MS subjects will be recruited from the identification of subjects at U.O. Rehabilitative Medicine and Rare Diseases and Neuroimmune Center, IRCCS Neurosciences "Bellaria" (BO).

After evaluation of their eligibility and when obtained the informed consent, patients will be enrolled and randomized to the two groups through a randomization stratification approach. Subjects will be grouped into strata defined by the degree of impairment (e.g. using outcomes from the Expanded Disability Status Scale or EDSS) and then randomized separately within each stratum according to a block randomization and will be assigned to one of the two treatment groups:

• robot-assisted gait training (experimental group)
• conventional therapy (control group)

Robot-assisted gait training:

Patients will receive 12 training sessions over 4 weeks (3 sessions/week) of RAGT. During these sessions subjects will wear a harness attached to a system to provide body weight support and they will walk on a treadmill with the help of a robotic-driven gait orthosis. The legs are guided according to a physiological gait pattern. The torque of the knee and hip drives can be adjusted from 100% to 0% for one or both legs. The speed of the treadmill can be adjusted from 0 km/h to approximately 3 km/h and body weight support from 0% to 100%. During the first session we will set these training parameters according to subject characteristics and demand level. As training will progress, adjustments in the assistance provided by the driven-gait orthosis, the amount of body weight support and treadmill speed will be performed. Training sessions will last for an hour with 30 minutes of real walking time, because subject set-up in the device take approximately 30 minutes.

Conventional therapy:

The control group will receive 12 conventional therapy sessions over 4 weeks (3 sessions/week), that will focus on gait training. Subjects will receive 1 hour of individual conventional physiotherapy for session. During the first 5-10 minutes the subjects will perform lower-limb and core stretching exercises to increase muscles flexibility; then they'll deal with lower-limb muscles strengthening exercises tailored on their baseline characteristics (10 minutes). After that, assisted over-ground walking training will be performed.

Outcome measures Outcome measures will be assessed a week before the treatment initiation (T0), after two weeks (T1), after 4 weeks (T2) and at 3 months follow-up (T3). Personnel blinded to the treatment will assess the effects of the intervention.

Inclusion criteria

• severe gait impairments defined as EDSS 6-7
• lack of EDSS worsening in the last 3 months

Exclusion criteria

• neurologic conditions in addition to MS that may affect motor function and other medical conditions likely to interfere with the ability to safely complete the study protocol
• impaired cognitive functioning: score less than 24 on the Mini Mental State Examination
• spasticity (Ashworth scale >3) or contractures that may limit range of motion or function
• changes in disease modifying drug therapy or in any other confounding factor during the study.