Complex Regional Pain Syndrome
Complex regional pain syndrome (CRPS) is a condition characterized by chronic, severe pain that is out of proportion to the degree of symptoms expected for an injury. The pain is often reported as a continual burning sensation or a tingling, throbbing, aching, stabbing or sharp feeling. In many cases, even a slight sensation against the affected area (like the touch of clothing or wind breeze) triggers the pain. The area may also feel hot or cold to the touch and appear discolored (blotchy, purple, red or pale). Nearby joints may be swollen and stiff. Spasms may occur in the affected area of the body. Patients may also experience insomnia and depression.

The exact incidence of CRPS is unknown. The condition is four to five times more common in women than in men and can occur at any age. Symptoms may follow some type of trauma, infection or surgery.

CRPS appears to progress through several stages. Stage one, lasting about one to three months, is characterized by severe, burning pain, muscle spasms, stiff joints, rapid growth of hair and changes in the color and temperature of the skin. In stage two, patients experience more intense pain and swelling of the affected area, decreased hair growth, nail changes (cracking, brittleness, grooving or spots), bone softening, joint stiffness, and weakened muscles. Stage two lasts about three to six months. In stage three, pain becomes unrelenting and severe. The entire limb may be affected with muscle loss, muscle spasms and limitations in movement/mobility.

Treating CRPS
CRPS usually doesn’t respond to over-the-counter pain medications. Doctors may recommend nerve blocks, topical anesthetics and narcotic painkillers. Some patients respond to antidepressants and anticonvulsants (medications to treat seizures). Physical therapy, exercise and behavior modification may also be helpful. In some cases, patients may need implantable devices to control pain.

Ketamine for CRPS
A large percentage of people with CRPS don’t respond to traditional treatment. Some doctors are trying another approach, using low doses of the anesthetic agent, ketamine. Physicians in Germany are inducing coma in patients with CRPS and giving high doses of ketamine. Researchers believe the ketamine blocks the pain pathways and allows normal nerve transmission to return. The induced coma procedure is reserved for patients with such severe symptoms they are unable to function. The coma procedure is not approved for use in this country. High doses of ketamine are associated with hallucinations, night terrors, flashbacks and depression. Patients who have gone to Germany for the coma-induced procedure can have short booster infusions of ketamine to keep symptoms at bay. Investigators warn the treatment doesn’t address the underlying cause of CRPS, so future injury could trigger a return of the symptoms.