Using Cranial Nerve Non-invasive Neuromodulation to Improve Pain and Upper Extremity Function After a Stroke

The strength training program will last 4 weeks (3 X/week, 60 minutes). Using dead weights, the 1RM (i.e. the maximal load that an individual can lift once) will be estimated by the 10RM in order to avoid tendino-muscular injuries and fatigue. The 10RM will be determined for the muscles playing a key role in the functional performance of the upper limb (the wrist extensors and the elbow and shoulder flexors). In addition, the grip muscles of the affected hand will be trained with a JAMAR® dynamometer. Training will start at 50% of 1RM and progress by 10% each week to reach 80% of 1RM by week 4. The same gradation of intensity will be applied to the grip muscles. The training will begin and end by a 5-minute warm-up and relaxation period comprising of active movements of the trained muscles.

During each strength training session, the CN-NINM will be applied, with the help of a portable stimulator comprising a network of 18 electrodes, directly on the tongue of the participants for 20 minutes. The participants will hold the CN-NINM in place by pressing their tongue upwards. The CN-NINM will generate high-frequency pulses (50 μsec to 150 Hz), and the intensity of the stimulus will be set by each participant to a comfortable level of sensation, similar to the sensation in the mouth of a soft drink.