What is Guyon Canal Syndrome?
Guyon canal syndrome is a term used to describe a series of symptoms and findings that occur as a result of compression of the ulnar nerve at the level of the wrist. Compression of the ulnar nerve at the level of the wrist is seen less frequently than other nerve compressions seen in the wrist. The ulnar nerve runs from the elbow to the hand as it passes through a tunnel approximately 4 cm in length referred to as the Guyon canal outside the inner side of the wrist and the compression occurs within this tunnel.
What Causes Guyon Canal Syndrome?
The nerve ends at the little finger and the ring finger after passing through the tunnel. Guyon canal syndrome can develop as a result of old fractures around the wrist, masses occupying the tunnel, connective tissue diseases such as rheumatoid arthritis, but in the majority of patients no definite cause can be determined. It is frequently seen in those who put a lot of strain on their wrist, particularly in bicycle athletes. Guyon canal syndrome is most commonly seen in men between the ages of 30 and 60, but it can also occur in women.
What are the Symptoms of Guyon Canal Syndrome?
Loss of sensation: The most common symptoms of Guyon canal syndrome are numbness, pain, and loss of sensation in the area that corresponds to the spread of the ulnar nerve in the hand, which is the little finger and half of the ring finger.
Weakness: The motor signals from the brain that control the muscles that move the arm are transmitted by the ulnar nerve. Therefore, in advanced stages, there are also losses in motor skills in the hand, the muscles in the hand weaken and the hand becomes clumsy. Patients unconsciously describe dropping objects from their hands. In advanced stages, there is also significant weakening in the muscle between the thumb and index finger.
How is the Diagnosis of Guyon Canal Syndrome Made?
The diagnosis of Guyon canal syndrome is a clinical diagnosis made based on the patient's history and the result of the physical examination. The Tinel test is important in the diagnosis, the nerve is tapped on the possible compression area in the wrist. The perception of a tingling sensation or an electric shock sensation spreading to the area that provides sensation to the nerve by the patient means that the test is positive.
There are some examination methods that can help confirm or differentiate the clinical diagnosis of Guyon canal syndrome. The standard examination method for Guyon canal syndrome is electrodiagnostic evaluations consisting of nerve conduction studies and needle electromyography (EMG). These evaluations measure the electrical conductivity of the nerves, thus determining whether there is a compression in the nerve and, if so, exactly at what level. Determining the compression level of the nerve is important, because the ulnar nerve is mostly compressed in the elbow area and the treatment for these types of compression is different. If a mass that could cause pressure inside the tunnel is suspected, an MR imaging method can be used.
How is the Guyon Canal Syndrome Surgery Performed?
The treatment of Guyon canal syndrome is surgical, relaxing the ulnar nerve in the wrist, freeing the tissues that cause compression. The surgery is performed on the inside of the wrist with an incision of approximately 2-3 cm and is performed under regional or general anesthesia.
Immediately after the surgery, all symptoms disappear in all patients and patients feel significantly relieved. Factors affecting the outcome include the patient's age, the duration of the disease history, and the severity of symptoms before surgery. With advancing age, especially after 65 years of age, improvement in symptoms and hand functions may decrease. Because cell death can occur in the nerve due to compression in advanced stages of the disease, surgery should be performed as soon as the Guyon canal syndrome diagnosis is made. However, even in elderly patients over 70 years of age, a significant improvement in clinical symptoms is seen and most patients are very satisfied with the outcome. Therefore, regardless of age and stage of the disease, surgical treatment should not be avoided in patients with Guyon canal syndrome.
