Functional Electrical Stimulation (FES) for Upper Extremity Hemiplegia in Children With Cerebral Palsy

Functional electrical stimulation (FES) has increasingly gained interest as a therapeutic intervention for the improvement of motor function in individuals with disabilities. FES involves the administration of electrical pulses to stimulate motor neurons and initiate muscle contractions, It has been used primarily for individuals with spinal cord injury or those who have experienced a stroke leading to the loss of or decreased motor function of the limbs. The repeated application of FES to the affected limb has been shown to enable individuals with hemiplegia to voluntarily control movements of the affected upper limb. A new FES system, has recently been developed and indicated for use for the improvement of arm and hand function in patients with hemiplegia due to stroke or spinal cord injury. FES is a non-invasive therapy that involves transcutaneous delivery of electrical stimulation to the affected upper limb, patient participation and the assistance of therapists to improve voluntary arm and hand movements such as reaching and grasping.

The new FES system has shown effectiveness in both adults with acute stroke and children with chronic acquired stroke. In a randomized controlled trial, FES paired with intensive therapy compared to intensive therapy alone was shown to significantly improve hand function for adults with acute stroke. Participants in the trial had limited mobility or complete immobility of the affected arm and those who received FES paired with intensive therapy had clinically significant improvements in hand movements compared to those who only received intensive therapy. Recently, transcutaneous FES paired with intensive hand therapy (3 one-hour sessions per week for 16 weeks) has more recently been shown to improve hand function in children with chronic acquired stroke.

The efficacy of FES seen in patients with stroke opens up the possibility for its use in other similar populations, including children with hemiplegic cerebral palsy (HCP). However, there is currently limited research on the efficacy of FES with this population. In a preliminary study, the use of FES alone over a treatment period of 6 weeks in children with HCP was shown to significantly improve wrist movement. However, most of the research to date on the effects of FES on children with HCP has been focused on gait and lower limb function. There is currently a lack of evidence on the effectiveness of FES paired with intensive therapy on hand function in children with HCP. FES paired with intensive therapy holds significant potential to improve the hand function of children with HCP and warrants further investigation.

Therefore, the proposed research seeks to address two main objectives:

• To investigate the effectiveness of FES to improve upper limb function in children with HCP.
• To assess the effects of FES on upper limb function in children with HCP at six months post-intervention.

Inclusion criteria

• Diagnosis of hemiplegic CP
• Age between 6 to 18 years
• Ability to cooperate, understand and follow instructions during the administration of FES paired with intensive hand therapy
• Baseline total QUEST score between 20-80 out of 100 points
• Be seizure-free for a required period of at least 1 year with or without medication , and have no prior history of known cardiac arrhythmias/stimulants
• No pacemaker or implanted metallic or electronic device
• No edema, skin rash, allergy or wound on the affected upper limb where FES will be administered.
• No Botulinum toxin upper limb injections within 6-months of study entry, and no Constraint-induced movement therapy (CIMT) within 4 months of study entry. Participants should also refrain from receiving these treatments throughout the duration of the study.

Exclusion criteria

• The participant's forearm is too small to accommodate the standard FES electrodes.
• The participant's muscles do not respond to the electrical stimulation as tested at the baseline assessment visit. Response to electrical stimulation will be tested at the baseline visit and is described in detail in the section entitled "Muscle Responsiveness Testing" below. Based on the Muscle Responsiveness Testing procedures and criteria, the withdrawal criteria for non-response to electrical stimulation is defined as:

• More than 3 muscle groups out of 11 not- responding to FES or
• The participant reports a discomfort level score of 8 or 10 on the FACES scale (Appendix A) for any of the 11 muscle groups.
• Participant receives any other active occupational therapy or hemiplegic hand intervention during the FES intervention period.
• Participant attends less than 36/48 FES intervention sessions.
• Participant develops new-onset seizures during the FES intervention period.