Have you ever seen the code G56.0 on your medical paperwork? G56.0 is a type of ICD-10 code, which stands for International Classification of Diseases, Tenth Edition. Doctors and other healthcare providers use this system to classify and code diagnoses, procedures, and symptoms. G56.0 is the general, non-billable code for Carpal Tunnel Syndrome (CTS). Its billable variants are G56.00 (unspecified upper limb), G56.01 (right upper limb), and G56.02 (left upper limb.)
“Carpus” comes from the Greek word “karpos”, meaning wrist. Carpal Tunnel Syndrome is a condition that occurs when a narrowing of the carpal tunnel in the wrist puts pressure on the median nerve. The median nerve is one of the main nerves in the hand, controlling movement and feeling in the thumb and all fingers except the pinky. It originates in the neck, runs the length of the arm, and crosses through the carpal tunnel before ending in the hand. The carpal tunnel is a small passageway, about one inch wide. It’s bound on the bottom and sides by small wrist bones called carpal bones, with a strong band of connective tissue on top called the transverse carpal ligament. With such rigid constraints, the carpal tunnel can’t stretch or grow. Along with the median nerve, nine flexor tendons travel through the carpal tunnel. Tissues called the synovium usually lubricate the tendons, creating ease of movement. When the synovium swells, however, it takes up extra space in the carpal tunnel and crowds the nerve.
Symptoms of CTS are varied, but generally include sensations of numbness, tingling, and weakness in the hand. Patients may experience burning or itching in the palm, thumb, or middle and index fingers. They might find themselves dropping things due to weakness, numbness, or lack of proprioception. Occasional sensations of electric shock can radiate out into the thumb and fingers. Symptoms usually begin gradually, without a specific injury. You may be able to ameliorate symptoms by moving or shaking your hands. If left untreated, CTS can cause permanent nerve and muscle damage.
To make a diagnosis of CTS, a physician begins by looking at a patient’s general health and medical history, then moves on to a physical exam and electrophysiological tests. The physical exam involves ruling out other conditions by checking the neck, shoulder, elbows, reflexes, and pulse. A doctor will examine the wrist for swelling, warmth, tenderness, deformity, or discoloration. To test for numbness and tingling, a physician holds the wrist in a flexed position or checks the Tinel sign by pressing or tapping on the median nerve at the inside of the wrist. A doctor may also test for sensitivity in the hands and fingertips by lightly touching them with a special instrument while the patient closes their eyes. Healthcare professionals will check for weakness and signs of atrophy in the muscles at the base of the thumb, as they can be compromised in severe cases of CTS.
Electrophysiological tests are used to rule out neuropathy or other sites of nerve compression. They include nerve conduction studies, electromyograms (EMGs), X-Rays, and Magnetic Resonance Imaging (MRIs). Nerve conduction studies indicate whether nerves are conducting signals effectively, which helps to determine severity and guide treatment. EMGs measure electrical activity in muscles, indicating whether nerve or muscle damage is present. X-rays might be taken if symptoms include limited wrist motion or wrist pain. These bone images can rule out arthritis, ligament injuries, and fractures. MRIs provide images of soft tissues, revealing abnormal tissues and damage to the nerve itself, such as scarring from an injury or tumor.
Especially in the early stages, treatment for CTS includes lifestyle changes such as taking breaks, stretching, strengthening, and limiting activities that cause symptoms. Immobilization by bracing or splinting can be helpful, especially at night or during problematic activities. Anti-inflammatory medications and Vitamin B6 may provide temporary relief. Many patients receive corticosteroid or cortisone injections. These can ease flare-ups, but their effects may not be lasting. Doctors and physical therapist sometimes teach nerve-gliding exercise as well.
In severe cases, surgery might be necessary. Two techniques exist for this type of surgery, known as carpal tunnel release. Both involve cutting the transverse carpal ligament that forms the top of the carpal tunnel in order to increase tunnel size and decrease nerve pressure. In open carpal tunnel release, the ligament is divided by a small incision in the palm. In endoscopic carpal tunnel release, one or two smaller incisions known as portals are created. A miniature camera called an endoscope is used to see as the ligament is cut. Surgery is typically performed on an outpatient basis, under either general or local anesthesia.
Risk factors for CTS include medical conditions such as hypothyroidism, rheumatoid arthritis, diabetes, kidney failure, and obesity. Anatomical factors include small wrists, fractures, dislocations, and arthritis. Women are three times as likely as men to suffer from CTS, especially after menopause and during pregnancy. Certain careers contribute to CTS, affecting assembly line workers, bakers, hair stylist, musicians, and others. Working with vibrating tools is especially problematic. While computer usage is widely assumed to contribute to CTS, the evidence is actually inconsistent.
CTS is a highly treatable condition, so please see a doctor if you have symptoms; don’t hesitate to go to your doctor with any questions or concerns. Waiting too long causes unnecessary suffering, and can eventually lead to permanent damage. With proper treatment, you can once again lead a normal, pain-free life.