The Effect of rPMS on Motor Skill Performance in Persons With a Stroke.

The Effect of Peripheral Sensory Priming Using Repetitive Peripheral Magnetic Stimulation (rPMS) on Motor Skill Performance in Persons With a Stroke.

In the past two decades, even as stroke cases increase around the world, advances in motor rehabilitation have been limited. Clinical trials of stroke rehabilitation have examined the therapeutic utility of several neuromodulatory devices to improve efficacy of motor training. However, there is limited knowledge on the effects of sensory-based priming techniques using repetitive peripheral magnetic stimulation (rPMS) post stroke. This project focuses on understanding the effect of rPMS on motor skill performance in persons with stroke.

The central hypothesis of this study is that rPMS is a suitable priming technique for enhancing motor skill performance in individuals with stroke. The investigators plan to test our hypothesis by pursuing the following specific aim: To determine whether rPMS can facilitate lower limb's motor skill performance more than sham rPMS in individuals with stroke. Hypothesis: The effect of stimulation on lower limb's motor skill performance will be measured using a visuomotor tracking task at different time points: baseline, immediately after, at 30 minutes, and 60 minutes after stimulation. Individuals with stroke during the rPMS condition will demonstrate greater motor skill performance following rPMS and will be able to sustain the enhanced performance at 30 and 60 minutes after the stimulation, compared to sham condition. This study will improve our understanding of the effects of rPMS, thus encouraging the use of a single session of rPMS as a priming tool to enhance motor skill performance. The proposal is important as it is the first to study the time course effects of rPMS on lower limb's motor skill performance in stroke populations.

Participants will receive rPMS at 10% above motor threshold with the coil placed on the Tibialis Anterior muscle belly. rPMS parameters will be: 40 trains, intermittently (3) seconds on, (19) seconds off, with an intensity ~10% above motor threshold.

Participants will receive sham rPMS at a very low intensity with the coil placed on the dorsal part of the foot. rPMS parameters will be: 40 trains, intermittently (3) seconds on, (19) seconds off, with an intensity at 5% of maximum stimulator output.

Repetitive Peripheral Magnetic Stimulation (rPMS) is an external device that delivers repetitive pulsed magnetic fields of sufficient magnitude, will be applied on the tibialis anterior muscle belly at ~ 10% of motor threshold, in order to induce neural action potentials in the lower extremities.

Sham Priming using the Repetitive Peripheral Magnetic Stimulation (rPMS), it will be applied on the dorsal part of the foot with a minimal intensity at 5% of maximum stimulator output, that is of insufficient magnitude to induce changes in the muscle or nerves of lower extremities.

The investigators will assess motor skill performance by asking the participants to track a computer-generated sinusoidal target with ankle dorsiflexion and plantarflexion in a custom-built ankle-tracking device. Each trial lasts for 60 seconds. Participants will be asked to perform 10 familiarization trials, this only to make participants familiar with the task. After the familiarization, participants will perform 5 trials at baseline.

The investigators will assess motor skill performance by asking the participants to track a computer-generated sinusoidal target with ankle dorsiflexion and plantarflexion in a custom-built ankle-tracking device. Each trial lasts for 60 seconds. Participants will be asked to perform 5 trials immediately after the stimulation

The investigators will assess motor skill performance by asking the participants to track a computer-generated sinusoidal target with ankle dorsiflexion and plantarflexion in a custom-built ankle-tracking device. Each trial lasts for 60 seconds. Participants will be asked to perform 5 trials at 30 minutes after the stimulation

The investigators will assess motor skill performance by asking the participants to track a computer-generated sinusoidal target with ankle dorsiflexion and plantarflexion in a custom-built ankle-tracking device. Each trial lasts for 60 seconds. Participants will be asked to perform 5 trials at 60 minutes after the stimulation

Inclusion Criteria: Diagnosed mono-hemispheric stroke More than 3 months since stroke onset. Participants must demonstrate adequate cognitive abilities to be able to follow the protocol (21>MMSE). Exclusion Criteria: Individuals with lesions affecting the brainstem or cerebellum. Other musculoskeletal or neurological impairments such as (Alzheimer, Parkinson, etc.). Complete paralysis that would limit the participant's' ability to perform motor skill tasks.