Rheumatoid arthritis (RA) complications may affect the nervous system. Nerve symptoms caused by RA can occur from:1
- Inflammation and irritation of the small blood vessels (vasculitis) that feed the nerves
- Nerve damage (demyelination)
- Compression of the nerves by damaged joints and related structures
RA treatments may also impact the nervous system.1
Nerve symptoms are common in RA. About 20 percent of those with RA may experience nerve symptoms that are diagnosed by a doctor. However, up to 85 percent may experience symptoms that are not serious enough to satisfy any specific diagnosis.1
Small blood vessel nerve symptoms
RA may damage the small vessels that feed the nerves. This damage is known as rheumatoid vasculitis (RV). RV impacts only about 1 percent of those with RA, but the condition may be severe. RV can cause damage to the nerves of the hands and feet, which can disable the person impacted. RV may lead to damage to multiple nerves in the body. Signs of RV may include:2
- Numbness, tingling, burning, or pain in the hands or feet
- Muscle weakness or paralysis
- Muscle wasting, or loss of muscle
Although rare, RV may affect the small vessels in the brain. This may increase the risk of conditions such as stroke.2
Non-compressive nerve symptoms
Nerve symptoms may result from inflammation that affects the nerve directly. This results in demyelination. Demyelination is a process where the outer protective layer of the nerve (myelin) and the part of the nerve cell that transmits electrical nerve impulses (axon), is damaged. Demyelination and axonal damage can result in symptoms like:1,3
- Pain
- Abnormal sensations, such as tingling and “pins and needles”
- Muscle weakness
- Loss of the ability to extend the wrist (wrist drop) or move the toes or ankle upward (foot drop), as in the motion used for walking
Compressive nerve symptoms
Nerve compression (also called entrapment) can occur early in the course of RA as changes take place in the joints. This results in direct pressure on nerves located near the joints. The most common example of this is carpal tunnel syndrome. Carpal tunnel syndrome affects as many as 2 out of 3 every people with RA.3-5
The bones of your wrist are called carpal bones. The carpal bones and a ligament form a tunnel in your wrist. A nerve and tendons run through this tunnel. The nerve supplies sensation and feeling to the thumb side of your hand. If this nerve becomes compressed within that tunnel, numbness in your thumb and fingers can occur. This nerve compression also leads to wrist pain and hand muscle breakdown. This condition is known as carpal tunnel syndrome.3-5
Similar nerve entrapment disorders may also occur:3-5
- Cubital tunnel syndrome, with the ulnar nerve in the elbow
- Tarsal tunnel syndrome, with the tibial nerve that runs along the inner leg near the ankle
Central nervous system symptoms
RA-related inflammation may affect the cervical spine, causing swelling in the joints between the bones of the spine. This swelling may compress or squeeze the spinal cord, resulting in a range of symptoms like:1,3,6
- Neck pain (with movement)
- Headache
- Weakness
- Abnormal reflexes
- Loss of normal sensation in various parts of the body
- Changes in blood pressure and breathing
How RA drugs may affect the nervous system
Common drugs used to treat RA may affect the nervous system. For example, steroid treatment can be linked to impaired thinking, hypomania (an abnormal increase in energy or decreased need for sleep), and depression. Methotrexate, a disease-modifying anti-rheumatic drug (DMARD), may cause headaches or problems with concentration.7-10
Some DMARDs, such as sulfasalazine or leflunomide, may lead to peripheral neuropathy (damage to the nerves outside the brain and spinal cord). TNF-inhibitors, which may be known as biologic drugs, are known to lead to demyelinating disorders, such as multiple sclerosis (MS) or Guillain-Barré syndrome. These can result in life-threatening paralysis. Though these conditions may be possible, they are rare.7-10
Overcoming RA-related nerve symptoms
Treatment of RA-related nerve symptoms depends on the nature, location, and severity of the symptom. Initial treatment options may include drugs used to control RA-related inflammation and pain. These treatments may include non-steroidal anti-inflammatory drugs (NSAIDs), steroids, and DMARDs, a group of drugs that includes newer biologic treatments.7-10
When inflammation of joints in the cervical spine is causing nerve compression, treatment may include the use of a neck brace or collar and application of heat or cold. Spinal manipulation should not be used in those with RA-related involvement in the cervical spine.1,7
Additionally, surgery may be needed to address nerve symptoms. In cases of nerve entrapment in the wrist, elbow, or ankle/foot, treatment options include bracing to restrict movement, exercise and physical therapy, alternative approaches (e.g., acupuncture), and surgical options to relieve nerve compression.1,7