What is CRPS?
Complex regional pain syndrome (CRPS) is a challenging chronic neuropathic pain condition most often affecting one of the limbs (arms, legs, hands, or feet), usually after an injury or trauma to that limb. CRPS is believed to be caused by damage to, or malfunction of, the peripheral and central nervous systems. Complex Regional Pain Syndrome (CRPS), formerly reflex sympathetic dystrophy (RSD) or “causalgia”, reflex neurovascular dystrophy (RND), or amplified musculoskeletal pain syndrome (AMPS), is a chronic systemic disease characterized by severe pain, swelling, and changes in the skin. CRPS is expected to worsen over time. It often initially affects an arm or a leg and spreads throughout the body.
Recent evidence has led to the conclusion that Complex Regional Pain Syndrome is a multifactorial disorder with clinical features of neurogenic inflammation, nociceptive sensitisation (which causes extreme sensitivity or allodynia), vasomotor dysfunction, and maladaptive neuroplasticity, generated by an aberrant response to tissue injury. CRPS is associated with dysregulation of the central nervous system. and autonomic nervous system resulting in multiple functional loss, impairment, and disability.
Who can get CRPS?
The estimated overall incidence rate of CRPS is 26.2 per 100,000 person years. Females are affected at least three times more often than males (ratio 3:1). The highest incidence occurred in females in the age category of 41-50 years. The upper extremity is affected more frequently than the lower extremity and a fracture is the most common precipitating event (44%).
Types of CRPS
Complex Regional Pain Syndrome occurs in two types, with similar signs and symptoms, but different causes:
Type 1: Previously known as reflex sympathetic dystrophy syndrome, this type occurs after an illness or injury that didn’t directly damage the nerves in your affected limb. About 90 percent of people with complex regional pain syndrome have type
Type 2: Once referred to as causalgia, this type follows a distinct nerve injury. Many cases of complex regional pain syndrome occur after a forceful trauma to an arm or a leg, such as a crush injury, fracture or amputation. Other major and minor traumas — such as surgery, heart attacks, infections and even sprained ankles — also can lead to complex regional pain syndrome. Emotional stress may be a precipitating factor, as well. It’s not well understood why these injuries can trigger complex regional pain syndrome, but it may be due to a dysfunctional interaction between your central and peripheral nervous systems and inappropriate inflammatory responses
What are the Symptoms of CRPS?
Signs and symptoms of complex regional pain syndrome include:
- Continuous burning or throbbing pain, usually in arm, leg, hand or foot
- Sensitivity to touch or cold
- Swelling of the painful area
- Changes in skin temperature — at times skin may be sweaty; at other times it may be cold
- Changes in skin color, which can range from white and mottled to red or blue
- Changes in skin texture, which may become tender, thin or shiny in the affected area
- Changes in hair and nail growth
- Joint stiffness, swelling and damage
- Muscle spasms, weakness and loss (atrophy)
- Decreased ability to move the affected body part
Symptoms may change over time and vary from person to person. Most commonly, pain, swelling, redness, noticeable changes in temperature and hypersensitivity. Over time, the affected limb can become cold and pale and undergo skin and nail changes as well as muscle spasms and tightening. Once these changes occur, the condition is often irreversible.
Complex regional pain syndrome occasionally may spread from its source to elsewhere in your body, such as the opposite limb. The pain may be worsened by emotional stress.
How is CRPS diagnosed?
Currently there is no single diagnostic test to confirm CRPS. Diagnosis is based on the affected individual’s medical history and signs and symptoms that match the definition.Triple-phase bone scans sometimes identify CRPS with characteristic changes in the bone metabolism.
How is CRPS treated?
The following therapies are often used:
Rehabilitation therapy: An exercise program to keep the painful limb or body part moving can improve blood flow and lessen the circulatory symptoms. Additionally, exercise can help improve the affected limb’s flexibility, strength, and function
Medications: Several different classes of medication have been shown to be effective for CRPS, particularly when used early in the courses of the disease. Drugs to treat CRPS include:
- Gabapentin, pregabalin, amitriptyline, nortriptyline and duloxetine
- BOTOX injections
- Opioids such as morphine,tramadol and fentanyl
- N-methyl-D-aspartate (NMDA) receptor antagonists such as extromethorphan and ketamine
- Nasal calcitonin, especially for deep bone pain, and
- Topical local anesthetic creams and patches such as lidocaine
Sympathetic nerve block: Sympathetic blocks consists of stellate ganglion block for arms and lumbar sympathetic block for legs. Intially these blocks are done temporarily to see for the response and later they are permanently blocked based on the response .
Spinal cord stimulation: In advanced and resistant cases we have the option of neuromodulation techniques. This involves placing stimulating electrodes through a needle into the spine near the spinal cord provides a tingling sensation in the painful area. Typically the electrode is placed temporarily for a few days to assess whether stimulation will be helpful followed by a permanent implantation of the stimulating device.
Psychotherapy : CRPS and other painful followed by permanent implantation of the device and disabling conditions often are associated with profound psychological symptoms for affected individuals and their families. People with CRPS may develop depression, anxiety, or post-traumatic stress disorder, all of which heighten the perception of pain and make rehabilitation efforts more difficult. Treating these secondary conditions is important for helping people cope and recover from CRPS.