Have you ever heard of someone with complex regional pain syndrome who can’t find the affected arm? I’ve tried to describe this to several people in the health care profession and they don’t seem to know what I’m talking about.

Patients with complex regional pain syndrome (CRPS) are faced with some very unpleasant symptoms. The first is unrelenting burning or aching pain followed by skin sensitivity, swelling, discoloration, sweating, and temperature changes.

The most commonly affected area of the body is the hand or foot, but the symptoms can spread further up the affected limb and even into the opposite limb. If the condition becomes chronic, dystrophy or deterioration of the bones and muscles in the affected body part may occur.

Many patients do have a distorted sense of where the affected arm is. It can be mild or severe enough that they wish the arm could be cut off. They describe not knowing where their limb is even when touching something with that hand. It is difficult to use that arm/hand to insert keys into a lock and open a door, pick up a pen, or even use that hand to wipe themselves after going to the bathroom.

Therapists working with these patients refer to this phenomenon as a distortion of body image or distortion of body schema. The failure to recognize limb position is a problem with position accuracy.

Scientists think this distortion is a central processing problem — in other words, the problem lies in the nervous system (brain, spinal cord, peripheral nerves) rather than in the arm itself.

Efforts are being made to further explore this particular problem. Research can begin to look for the exact neural processing pathways that are affected by CRPS. Researchers hope to find ways to restore normal sensorimotor function.