Carpal Tunnel Syndrome
Carpal tunnel Syndrome is the commonest entrapment neuropathy affecting humans. It roughly affects 2-4% of adults, with slight preponderance in females. It affects both hands in more than 50% of all cases.
Carpal tunnel syndrome is caused by pressure on the Median nerve, while it courses through the Carpal tunnel across the wrist. The Median nerve supplies the small muscles that control movements of our thumb. It also carries sensation from the palm side of the thumb, index and middle fingers.
Untreated, carpal tunnel syndrome may worsen and progress to permanent sensory loss and thumb weakness in some cases.
What is Carpal Tunnel?
Carpal tunnel is a closed space in our wrist, which is bound by small bones of wrist on one side, and a tough ligament forming the roof of the tunnel. The strong ligament is called the ‘Transverse carpal ligament’.
Within this closed space, Median nerve passes along with nine tendons from the forearm into the wrist. Therefore, any reduction in space within this canal will compress the Median nerve.
What are the symptoms of Carpal Tunnel Syndrome?
Numbness, tingling, burning in affected hand. The pain and tingling typically occur along the distribution of the Median nerve, that includes thumb, index and the middle finger. The symptoms are worse at night. Sometimes, the pain may also involve the forearm as well. As the compression worsens, grip becomes weak because of weakness of thumb muscles supplied by the nerve. The prominence at the base of the thumb, called the ‘Thenar eminence’ formed by the bulk of the muscles of the thumb becomes flat with chronic compression.
What are the risk factors for Carpal Tunnel Syndrome?
The exact cause is still unknown, and can be multi-factorial. Some of the commonest factors associated with Carpal Tunnel Syndrome are listed below.
• Occupations with repetitive hand movements, or vibrations
Family history and female gender are also important risk factors for Carpal tunnel syndrome.
How is Carpal Tunnel Syndrome diagnosed?
High suspicion on history is the first step in diagnosing this condition. Pain and paresthesias in the typical distribution of the nerve point to compression of the nerve in the tunnel. The doctor will check your sensations in the hand and grip.
Tapping at the wrist, flexing the wrist, or holding the wrist elevated should induce similar pain and tingling that the patient normally experiences.
Nerve conduction study- A nerve conduction study is a test that measures how fast signals are transmitted through the nerves. During the test, electrodes are placed on your hand and wrist and a small electrical current is used to stimulate the nerves in the finger, wrist and, sometimes, elbow. The conduction of stimulating current is slowed across the compressed segment.
What is the grading of Carpal Tunnel Syndrome?
It is categorized on a scale of 0-6 based on the degree of slowing of nerve conduction velocities. Grade 0 is normal, and grade 6 is the most severe form. In grade 6 no electrical activity is recordable.
What are the non-operative treatment options for Carpal Tunnel Syndrome?
Mild symptoms of Carpal tunnel syndrome can be treated with non-surgical methods such as reducing or eliminating repeated hand movements. This may require using wrist splints or even a job change.
Sooner the treatment is started, better is the chance of preservation of complete function of the nerve.
Wrist splints prevent bending of wrist and maintain the wrist position in a neutral position. It can be worn during night or throughout the day for better results.
If the pain is very severe, and surgery is not considered unavoidable, then local injection of steroids is advisable. Steroids reduce swelling and improve pain. Single injection is usually recommended to begin with. If the condition responds well to one injection but then recurs, the treatment may be repeated. Oral steroids may also be tried for faster pain relief. However, local steroid injections have shown better and more sustained results as compared to oral steroids.
How is the surgery for Carpal Tunnel syndrome performed?
Surgery for CTS is known as carpal tunnel decompression or carpal tunnel release surgery and is usually performed on an outpatient basis. The procedure lasts approximately 25-30 minutes and is usually performed under local anesthesia.
In case of bilateral Carpal tunnel syndrome, only one hand, usually the more severe is operated at a time. The other side is operated after 3-4 weeks.
During surgery the roof of the carpal tunnel, known as the carpal ligament, is cut to reduce pressure on the median nerve in the wrist.
The surgery is performed as open surgery, which involves making a single cut in the wrist, and is the traditional type of operation. The ligament is directly visualised and cut.
A newer version called Minimally invasive or keyhole surgery, uses special instruments. A small wrist skin crease incision is utilised and an endoscope is inserted to visualise the anatomy. The surgeon can directly see the carpal ligament on a monitor and cut precisely.
How long does it take for recovery after surgery?
After the surgery, analgesics are prescribed. Hand elevation and cold packs help in reducing swelling from the surgery. Keep your fingers moving. One can return to normal job within a couple of weeks.
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