Carpal tunnel syndrome is a common condition affecting the hand and wrist. This condition arises when the median nerve, which runs through a narrow passageway in the wrist called the carpal tunnel, becomes compressed. Cortisone injections are a frequently used treatment option to help manage the condition.
Understanding Carpal Tunnel Syndrome and Cortisone’s Action
Carpal tunnel syndrome develops when increased pressure within the carpal tunnel compresses the median nerve as it travels from the forearm into the hand. This narrow space in the wrist is formed by bones and a ligament, and it also houses several tendons. When tissues within or around this tunnel swell, they can press on the median nerve, leading to symptoms like pain, numbness, tingling, and weakness in the thumb, index, middle, and part of the ring finger.
Inflammation often contributes to this swelling, aggravating the nerve. Cortisone, a type of corticosteroid, is a synthetic medication that mimics cortisol, a hormone naturally produced by the body. It is known for its potent anti-inflammatory properties, reducing the body’s production of chemicals that cause inflammation. When injected into the carpal tunnel, cortisone reduces swelling in the surrounding tissues, such as the flexor tendons and their sheaths, which then lessens the pressure on the median nerve. This reduction in pressure can alleviate the associated pain, tingling, and numbness.
The Injection Procedure
Cortisone injections for carpal tunnel syndrome are typically performed in a clinical setting. Before the injection, the skin over the wrist area is thoroughly cleaned with an antiseptic solution to minimize any risk of infection. A local anesthetic is often applied or included in the injection mixture to numb the skin and reduce discomfort.
The injection is administered into the carpal tunnel, usually near the wrist crease. Many healthcare providers use ultrasound guidance during the injection to ensure precise placement of the needle. This real-time imaging allows the doctor to visualize the median nerve, surrounding tendons, and other structures, helping to deliver the medication accurately into the carpal tunnel while avoiding nerves or blood vessels. Patients might feel a brief sensation of pressure or mild discomfort as the needle is inserted and medication is injected. After the injection, a small bandage is typically placed over the site. Patients are generally advised to rest the hand and wrist for a short period, often a few hours to a few days, to allow the medication to settle and reduce any immediate soreness.
What to Expect After the Injection
Following a cortisone injection, relief from symptoms is not usually immediate. The local anesthetic mixed with the cortisone may provide rapid, temporary numbness for a few hours, but the anti-inflammatory effects typically begin to manifest within a few days, sometimes taking up to a week to become noticeable. The duration of symptom relief can vary considerably, ranging from several weeks to several months. Some people may experience long-lasting relief, while for others, symptoms may gradually return over time.
Common temporary side effects at the injection site include mild to moderate pain or soreness, which usually subsides within a few days. A “cortisone flare” can occur, where pain temporarily worsens for one to two days after the injection. This can often be managed with rest and ice. Other possible, though less common, temporary effects include facial flushing or a temporary increase in blood sugar levels, particularly for individuals with diabetes, which usually normalizes within five days.
While generally considered safe, there are rare but possible complications. These include a very small risk of infection, minimized by sterile technique. Other rare risks involve temporary nerve irritation, localized skin discoloration (lightening or thinning), or fat atrophy at the injection site. Seek medical attention promptly if severe pain, increasing swelling, redness, heat at the injection site, or a fever above 101°F (38.3°C) occurs.
Place in Overall Treatment
Cortisone injections are generally considered a temporary measure for symptom relief rather than a permanent cure for carpal tunnel syndrome. While they reduce inflammation and alleviate nerve compression, they do not resolve the underlying anatomical or repetitive strain issues that may contribute to the condition. The effectiveness of the injection can also serve as a diagnostic tool; a good response often helps confirm that median nerve compression is the cause of the symptoms.
Healthcare providers typically limit the number of cortisone injections a person can receive in the same wrist over a specific period, often suggesting no more than two or three injections per year. This limitation is due to concerns about potential long-term side effects, such as weakening of tendons or thinning of soft tissues and cartilage, which could worsen the condition. Injections often fit into a broader, conservative treatment plan that may include wrist splinting, particularly at night, to keep the wrist in a neutral position and reduce pressure on the nerve. Physical therapy, activity modification, or ergonomic adjustments are also recommended alongside injections to manage symptoms and prevent recurrence. If symptoms return quickly, are severe, or if injections are no longer providing sufficient relief, other treatment options, including surgical decompression of the carpal tunnel, may be considered.