Some specialists recommend muscle relaxants as a drug therapy for complex regional pain syndrome (CRPS). Muscle relaxants are primarily beneficial for muscle symptoms such as hypertonicity, or an increased in muscle tone in the area affected with CRPS. If left untreated, these muscle symptoms can be debilitating and significantly restricting to the patient’s voluntary movements. As indicated by the name, muscle relaxants may be helpful to CRPS patients by relaxing the muscle and allowing for comfortable movement.
CRPS Muscle Hypertonicity
Patients with CRPS will often experience a variety of symptoms related to muscle hypertonicity. Hypertonicity is defined as an abnormal increase in muscle tone within the affected area. Hypertonicity is typically caused by damage to the central nervous system, particularly damage to motor neurons in the brain. Motor neurons are responsible for proper muscle movement. Hypertonicity may cause a number of side effects, such as muscle spasticity, rigidity, and dystonia.
Muscle spasticity, also referred to as hyperreflexia, is characterized by an unusual stiffness or tightness within the affected muscle. Patients with muscle spasticity have a lack of inhibition that leads to excessive muscle contraction. As a result, many patients experience overly-flexed joints.
Muscle rigidity involves unintentional stiffening and tensing of the muscles. As a result, the patient may experience restricted joint movement due to these involuntary contractions. Muscle tension during rigidity is often continuous, causing significant interference with movement.
Dystonia is a condition characterize by abnormal postures and slow, repetitive movements. In some cases, these movements may be described as twisting. These symptoms result from sporadic and involuntary muscle contractions in the affected area.
How Muscle Relaxants Work
Muscle relaxants affect the function of skeletal muscles by decreasing muscle tone. In turn, they may alleviate CRPS muscle symptoms such as pain, spasms, and hypertonicity. There are two main types of muscle relaxants: spasmolytics and neuromuscular blockers. Spasmolytics and other types of muscle relaxants are most commonly used for treating CRPS. These muscle relaxants are “centrally acting,” and work to reduce spasms, spasticity, and musculoskeletal pain associated with neurological conditions such as CRPS.
Altering Brain Signals
Muscle relaxants primarily work by affecting certain brain signals present within CRPS patients with muscle symptoms. In an unaffected brain, motor neurons in the brain control movement by sending signals to muscles in the body through connections called synapses. The movements resulting from these signals are based on a system of excitation and inhibition of the neurons.
During muscle conditions such as hypertonicity, the patient experiences excessive excitation, which leads to abnormally high levels of contraction. Muscle relaxants work by either decreasing the excitation of these neurons, or increasing the inhibition. As a result, there is less neuron activity, which leads to less excessive movement and reduced muscle symptoms.
Types of Muscle Relaxants
There exists controversy over when and which types of muscle relaxants should be prescribed for CRPS symptoms. One of the primary concerns regarding this medication group is that certain drugs may become addictive to patients. It is therefore recommended to proceed with caution when prescribing muscle relaxants for patients with CRPS. Patients with questions should speak with their doctors to discuss which treatment option has the highest ratio of benefits to risks.
Types of muscle relaxants prescribed for CRPS patients may include:
CRPS Muscle Therapy
In conjunction with muscle relaxants, CRPS patients may also benefit from physical muscle therapy. An example of a potentially effective muscle therapy is aqua therapy. During aqua therapy, a trained therapist will instruct patients to perform therapeutic exercises while submersed in a body of water. Aqua therapy delivers a form of moist heat which can be beneficial to a number of CRPS patients with muscle symptoms such as hypertonicity.
Cahill, Catherine M., et al. “Neuropathic pain: a practical guide for the clinician.” CMAJ: Canadian Medical Association Journal 1 Aug. 2006: 265+. Academic OneFile. Web. 11 Mar. 2014.
McCarberg, Bill. “Contemporary management of chronic pain disorders.” Journal of Family Practice Oct. 2004: S11+. Academic OneFile. Web. 11 Mar. 2014.