Tendon Vibrations Effect on Upper Limb Motor Recovery After Recent Stroke

A Pilot Study of Proprioception Stimulation by Repeated Multi-site Tendon Vibrations, on Upper Limb Motor Skills Recovery After Recent Stroke

Stroke is the leading cause of severe acquired disabilities in adults. It can affect sensory and motor functions which are closely entangled. Among them, upper limb function is often strongly impaired. In this study the investigators are interested in the eventuality to improve motor recovery by the mean of stimulating the proprioception.

Proprioception can be stimulated by tendinous vibrations in order to act on the neuromuscular system through the vibratory tonic reflex and by movement illusion.

Stimulation by tendinous vibrations, applied to the musculotendinous endings, has been already proposed in post stroke rehabilitation, but only at late stages. Thus the aim of our study is to observe the effects of repeated tendon vibrations, applied in the early post stroke phase, the effect being measured on the excitability of the motor cortex by the Motor Evoked Potentials and on the motor recovery (motor control and activities).

Stroke is the leading cause of severe acquired disabilities in adults. It can affect sensory and motor functions which are closely entangled. Among them, upper limb function is often strongly impaired. In this study the investigators are interested in the eventuality to improve motor recovery by the mean of stimulating the proprioception.

Proprioception can be stimulated by tendinous vibrations in order to act on the neuromuscular system through the vibratory tonic reflex and by movement illusion.

Stimulation by tendinous vibrations, applied to the musculotendinous endings, has been already proposed in post stroke rehabilitation, but only at late stages.

Thus the aim of our study is to observe the effects of repeated tendon vibrations, applied in the early post stroke phase, the effect being measured on the excitability of the motor cortex by the Motor Evoked Potentials and on the motor recovery (motor control and activities).

Patients: 30 patients recruited after a first ever stroke whatever the cause and the site; age >18; stroke delay< 60 days; the maximum duration of participation for each patient is 3 months.

Protocol:

This rehabilitation protocol will be added to the usual rehabilitation program during inpatient rehabilitation.

Participants are randomized into two groups: experimental group and placebo group.

The experimental group benefits from upper limb tendon vibration sessions produced by small electromechanical vibrators on the elbow and the wrist. Frequency of the vibration is 80 Hz, two 15-minutes sessions per day scheduled for 10 days over a period of two weeks (2 x 5 days). During the sessions, the participant wearing opaque glasses, in a seating position, is asked to move if possible his/her arm in the opposite direction of the perceived movement.

The placebo group receives apparently the same treatment but with "sham" vibration.

Assessment:

Motor recovery will be assessed:

• At the brain level by the efficiency of the primary motor pathway, measured by Motor Evoked Potentials recorded at the contralateral hand (main outcome criteria after 30 days from inclusion).
• At the limb level by the motor control effectiveness measured by the Fugl Meyer scale, the Tardieu scale, the Action Research Arm Test (ARAT), the Box and Blocks Test (BBT) and the range of upper limb exploration with the ArmeoSpring, Hocoma brand.

The secondary objectives are:

• To assess any impact on nerve fibers density on the main motor pathway by Magnetic Resonance Imaging.
• To test the feasibility of such a rehabilitation protocol in a Physical Rehabilitation Medicine department

Four consultations are planned:

D0 (day 0): (before starting stimulation): Motor skills assessments, Motor Evoked Potentials (MEP) and Magnetic Resonance Imaging (MRI).

D15 (day 15): (as soon as stimulation ends): Motor skills assessments. D30 (day 30): Motor skills assessments and Motor Evoked Potentials (MEP) D90 (day 90): Motor skills assessments, Motor Evoked Potentials (MEP) and Magnetic Resonance Imaging (MRI).

Inclusion Criteria:

• 1st ischemic or hemorrhagic stroke
• Motor deficit of the upper limb (Fugl-Meyer between 0 and 50)
• Delay since stroke <or = 60 days
• Subject having given free and informed consent
• Subject affiliated to the social security system

Exclusion Criteria:

• Neurological history responsible for sensory or motor impairment of the concerned upper limb
• Surgical history concerning the nervous or locomotor system of the concerned upper limb
• Uncontrolled epilepsy
• Pace-maker
• Ferro-magnetic intra-cranial clip and any other contraindication to MEP and MRI
• Cochlear implants
• Pregnancy
• Guardianship or curatorship