Functional Electrical Stimulation (FES) for spinal cord injury

Overview

Functional electrical stimulation (FES) is a treatment that uses electrical currents to stimulate nerves and muscles, prompting them to contract and restore muscle function. It is often used to help with conditions like foot drop or muscle weakness caused by brain or spinal cord damage. Although FES can be effective, it may not be suitable for everyone, as the electrical impulses can cause varying sensations, from mild tingling to discomfort, depending on the intensity.

FES is frequently used in rehabilitation for individuals with spinal cord injuries, with electrodes placed over specific nerves to stimulate muscle movement. This stimulation can help patients perform activities like walking or cycling by promoting muscle contractions. In addition to improving muscle control, FES can also help reduce muscle spasms and increase muscle size and strength.

Beyond muscle recovery, FES offers other health benefits, such as improving range of motion, blood circulation, aerobic conditioning, and overall fitness. It may also prevent bone density loss and support functional use of hands, arms, and legs. Typically, FES is combined with other therapy techniques and exercise programs to help individuals enhance their daily activities and continue their wellness journey at home.

Reasons for undergoing the procedure

Functional electrical stimulation (FES) is a treatment option that may be recommended for individuals who experience muscle weakness, paralysis, or have conditions affecting their central nervous system. It is also considered for those who have suffered an injury that impairs movement. To determine if you are a candidate for FES, your healthcare provider will conduct an assessment to evaluate how your body responds to this therapy. If your body responds positively, you may be eligible for treatment.

The assessment typically takes about an hour and is conducted in the provider’s office. During the evaluation, the provider will test whether your muscles and nerve fibers can effectively respond to FES. In cases where there is damage to the nerve fibers between your muscles and spinal cord, your body may not respond to the treatment, making FES an unsuitable option.

FES is not appropriate for everyone, especially those with certain medical conditions. Individuals with implanted electrical devices, cancer, osteomyelitis, epilepsy, severe muscle spasticity, or osteoporosis may not be good candidates. Additionally, those with a history of thrombosis or hemorrhage and women who are currently pregnant should explore alternative treatments with their healthcare provider. It is essential to discuss all relevant medical conditions to ensure the best course of action for your treatment.

Risk

Risks of using an external functional stimulation device:

• Discomfort during treatment: Some users may experience discomfort while using the device.
• Skin irritation: There can be irritation at the site where electrodes are placed.
• Worsening spasticity: In some cases, spasticity may worsen.
• Strained muscles: The device may cause muscle strain.
• Sensory challenges: The sensation caused by functional electrical stimulation (FES) can be uncomfortable and may deter some individuals from continuing treatment. It can take time to adjust to these sensations.

Risks of using an implanted functional electrical stimulation device:

• Irritation or infection: The site where the electrode is implanted may become irritated or infected.
• Scar tissue formation: Scar tissue, known as encapsulation, may form around the electrode.
• Broken wires: Wires within the system can break over time.
• Electrode displacement: Electrodes may shift from their original placement.

Important considerations

Your neuromuscular rehabilitation therapist will work closely with you to determine the appropriate type and placement of electrodes to minimize complications. Regular check-ins with your care team are essential to reduce your risk of complications. Be sure to know when to contact your healthcare provider if you suspect any issues.

Magnetic resonance imaging (MRI) considerations

Due to the metal components in FES systems, individuals with implanted FES systems may not be able to undergo magnetic resonance imaging (MRI). Since MRI is a valuable tool for diagnosing various health conditions, it’s crucial to discuss any concerns with your healthcare provider.

Procedure

FES equipment comes in various forms depending on the treatment area and desired outcomes. most devices consist of the following components:

• Neuromuscular electrical stimulator unit: a small external box generating electrical impulses.
• Wiring or wireless connectors: these transmit the electrical impulses from the stimulator to the electrodes. some devices feature wireless connectors using radio waves.
• Electrodes: these are connected to the wires and stimulate targeted muscles or nerves. there are several types of electrodes:
• Surface electrodes: adhere to the skin using adhesive pads.
• Percutaneous electrodes: inserted just under the skin during a clinical visit.
• Implantable electrodes: surgically placed deep into the muscle or near the targeted nerve during outpatient surgery.

Electrode placement options:

• Surface and percutaneous electrodes: ideal for short-term treatment, often used in the early phases of recovery and rehabilitation.
• Implantable electrodes: recommended for long-term treatment and involve a surgical procedure.

Your neuromuscular rehabilitation team

your healthcare team, which may include occupational therapists, physical therapists, and speech-language pathologists (SLPs), will guide you through the FES process. their role includes:

• Assessing and selecting the most appropriate FES device for your condition.
• Identifying the specific muscles or nerves that need stimulation.
• Adjusting the intensity of stimulation (voltage and pattern) to suit your treatment goals.

What to expect during FES treatment

• Sensation: FES should be painless, but you may experience mild discomfort. the sensations can vary depending on intensity, ranging from tingling to a burning sensation, with muscle contractions possible. your healthcare provider will ensure the intensity is comfortable.
• Treatment duration: the length of FES treatment varies depending on individual needs. it may range from short-term rehabilitation lasting a few months to long-term therapy over several years. for conditions like spinal cord injuries, FES is often a long-term therapy that requires extensive training and practice under the supervision of a rehabilitation therapist.

Consult your healthcare provider

Every patient’s journey with FES is unique. your healthcare provider will assess your needs, guide you through the therapy, and provide an estimate of how long treatment may last.

For concerns or questions about your FES device or treatment plan, always consult with your healthcare provider.

Outcome

The reasons why individuals choose functional electrical stimulation treatment vary widely. Some may require short-term rehabilitation over a few months, while others may need long-term, continuous treatment spanning several years to achieve their goals.

Functional electrical stimulation (FES) can offer a range of benefits to your specific treatment goals, including:

• Alleviating muscle spasms and the effects of spasticity.
• Assisting in weight management.
• Building muscle mass to decrease the risk of fractures.
• Enhancing blood circulation.
• Facilitating coughing to clear secretions, thereby reducing the risk of pneumonia, lung infections, and choking hazards.
• Improving standing and walking abilities.
• Preventing and reversing muscle atrophy (loss of muscle tissue due to lack of use).
• Reducing fatigue and energy loss during activities.
• Restoring lost bone mass.

Functional electrical stimulation (FES) can greatly enhance your independence and confidence during recovery from an injury or diagnosis, while also reducing the risk of future injuries, such as falls. Many individuals undergoing FES see improvements in muscle function and overall quality of life. This treatment can help you sit up, stand, walk short distances, use your hands, and restore various bodily functions that may have been impacted by a condition or injury.

Regular follow-up appointments with your healthcare providers are crucial for adjusting electrode placement and stimulation intensity as your muscles strengthen and your nerves adapt to the stimulation.

If you experience discomfort or find the sensation during FES unpleasant, it’s important to inform your healthcare provider. Tolerance to the sensation can vary, and if FES proves unsuitable for you, your provider can explore alternative treatment options. Also, let your provider know if you experience pain or notice skin irritation at the electrode site. They may adjust the type of electrode used or modify the stimulation settings to address these issues.