Complex regional pain syndrome (CRPS) is a chronic, progressive condition lasting six months or longer that most often affects one limb after an injury. CRPS is thought to be caused by damage to or malfunction of the peripheral and central nervous systems, which are comprised of nerve signaling, the brain, and the spinal cord. Patients with CRPS experience prolonged or excessive pain and changes in skin color, temperature, and/or swelling in the affected area. This due to microcirculation caused by damage to the nerves that control blood flow and temperature.
The associated pain can feel like burning, pins and needles, or a squeezing sensation. Other common symptoms include changes in skin texture on the affected area, abnormal sweating, changes in nail and hair growth patterns, stiffness in the affected joints, muscle coordination issues, decreased range of or abnormal movement in and around the affected body part, and tremors or jerking in the affected limb.
In more than 90% of cases, CRPS occurs because of a history of trauma or injury. The most common triggers are fractures; sprains and strains; soft tissue injury such as burns, cuts, or bruises; limb immobilization; surgery; or minor medical procedures.
There are no specific tests to confirm CRPS, but a medical history and magnetic resonance imaging (MRI) or triple-phase bone scans may be conducted.
Treatment options can include rehabilitation and physical therapy, psychotherapy, and medications such as bisphosphonates, non-steroidal anti-inflammatory drugs, and corticosteroids. OnabotulinumtoxinA (or Botox) may also provide relief by being injected near the pain site. A lumbar sympathetic plexus block is another option, which is administered to the nerves in the lower back to reduce pain, swelling, and changes in the lower extremities in an effort to improve mobility. Your doctor may also administer a sympathetic nerve block, which involves injecting an anesthetic next to the spine to directly block the activity of sympathetic nerves and improve blood flow. Spinal cord stimulation may also be recommended, which involves placing a needle near the spinal cord that emits pulsating electrodes to the affected area. An intrathecal pain pump implantation, which delivers small amounts of medication directly to the area around the spinal cord to prevent pain signals, may also be suggested.