Guyon's Canal Syndrome
Guyon's canal syndrome (handlebar palsy) is caused by the entrapment of the ulnar nerve within a tunnel-like structure in the wrist known as Guyon's canal. The Guyon's canal is formed by two bones and the ligament that connects them. The ulnar nerve runs down from the neck, through the arm and into the hand, and supplies feeling to the ring and pinky fingers. It also supports the muscles of the palm and thumb. When the ulnar nerve becomes damaged or compressed within the Guyon's canal, it can cause pain, pressure, weakness and numbness in the hand, wrist and fingers.
Causes of Guyon's Canal Syndrome
Because of the constant pressure that the handlebars place on the ulnar nerve within the wrist, bicyclists are often diagnosed with Guyon's canal syndrome. Guyon's canal syndrome can also be the result of pressure on the ulnar nerve that is caused by heavy gripping or twisting of the wrist from weightlifting, or repetitive wrist movements from manual labor or working in construction. It can also be caused by an injury to the wrist that causes swelling that puts pressure on the ulnar nerve; a fractured bone that pinches the nerve; or arthritis in the wrist.
Symptoms of Guyon's Canal Syndrome
The initial symptoms of Guyon's canal syndrome can include numbness or tingling, often felt upon waking, in the hand and fingers. Additional symptoms may include:
- Burning pain in the hand or wrist that radiates up the arm
- Numbness in the ring and pinky fingers
- Weakness in the palm of the hand and thumb
- Difficulty gripping
- Inability to spread fingers apart
- Inability to pinch index finger and thumb together
Treatment of Guyon's Canal Syndrome
Steroid injections are an effective method of treatment for relieving the symptoms of Guyon's canal syndrome. Steroids are injected directly into the ulnar nerve to reduce swelling and ease pressure. The injections help to decrease inflammation, relieving pressure on the nerve. Pain, numbness, weakness and tingling typically subside within a few days of the patient's being injected. The relief provided by the injections lasts for a few weeks to a few months.