Numbness in your hands and wrists? Is it Carpal Tunnel Syndrome?

The median nerve is an important nerve that runs through the length of your arm and controls movement or feelings in the wrist and most of the fingers. At the wrist, the median nerve arrives at what is called a Carpal Tunnel. This is a narrow tunnel made up of carpal bones on the bottom and sides and a ligament on the top (like a lid with an opening). The tunnel holds the median nerve and flexor tendons which connect muscles in the forearm to the finger bones.

In some people, soft tissues surrounding the flexor tendons swell up and squeeze, or press on the median nerve. Or, the wrist may become narrow for some reason. These situations restrict flexible movement of the fingers and wrist, causing several symptoms collectively called Carpal Tunnel Syndrome (CTS).

Causes and Risk Factors

• Repetitive motions involving the wrist: Typing on keyboards and any wrist movement where the hands are lower than the wrists is the most common cause.
• Certain occupations: As per the above, people who are in a manufacturing assembly line, construction work and any role that involves vibration or high impact as in hammering or the use of drills, are all at risk. So also, knitters, musicians, bakers, cashiers and hairstylists are at risk.
• Exercises and day-to-day motions that involve extreme wrist-motions are risk factors. All the above risks increase when the motion is happening for long durations either continuously or with breaks.
• Health conditions: A whole lot of conditions like hypothyroidism, obesity, rheumatoid arthritis, diabetes, kidney disease, lymphedema, gout, menopause and obesity can damage nerves and trigger CTS.
• Gender: Women are three times more at risk than men because anatomically, they have smaller carpal tunnels than men.
• Heredity: A family history of small wrists or small carpal tunnels increases the risk for either men or women.
• Fracture, dislocation of the wrist or rheumatoid arthritis: These can cause deformities in the small bones of the wrist, alter the space within the carpal tunnel, and trigger CTS
• Certain medications: The use of anastrozole to treat breast cancer can increase the risk
• Body fluid changes: Hormonal changes during pregnancy, menopause or any other condition, cause swelling and increases the pressure within the carpal tunnel, triggering CTS. However, these are short-term only.
• Position of the hand and wrist: Activities that involve extreme flexion or extension of either the hand or wrist, or both, for long durations puts pressure on the median nerve
• Procedures such as Haemodialysis in which the blood is filtered
• Abnormal deposits of a protein called Amyloid
• Congenital deformity of the hand or wrist
• Tumour in the carpal tunnel
• Alcoholism
• Old age

Symptoms

The following symptoms show up while holding a steering wheel, phone or newspaper, while writing and waking up from sleep. Some people experience different symptoms in day and night. While in the initial stages, shaking or moving the fingers may relieve the symptoms, in later stages, it is not useful.

• Burning, tingling, itching, numbness and pain in the palm, thumb, index and middle fingers
• Weakness in the hand and trouble holding things, leading to dropping of objects; or difficulty in doing simple tasks like buttoning a shirt etc
• Electric shock-like or tingling feeling that moves into the fingers and up into the arm all the way to the shoulder
• A lack of proprioception which is the awareness of where the hand is in space
• Wrist pain that wakes you up at night
• Weakness in the muscles all over the hand
• Decreased feeling in the fingertips

As the condition progresses and becomes severe, the symptoms progress to muscle atrophy and persistent numbness which can cause weakness of the thumb or difficulty in maintaining a pincer grasp.

 Diagnosis

If you or any of your dear ones are showing any of the symptoms listed above, consult a reputed hospital. They will conduct the following tests and based on the results, design a course of treatment for quick recovery and rehabilitation.

• Review of medical history: The doctor will review your family’s medical history. Next the doctor will ask about your symptoms while doing various tasks, during various times of the day.
• X-ray to check for any broken bones or fracture of the wrist
• Ultrasound or MRI scan to observe the median nerve for any swelling or compression
• Physical examination: The doctor will first examine the person’s neck, shoulder and hands for signs of arthritis. After that, he/she will examine the wrists and fingers for any swelling, discoloration, warmth etc.
• Tinel’s sign: The doctor will tap on the person’s wrist at the spot of the median nerve with a tiny hammer. If the person feels tingling or an electric shock-like feeling, CTS is confirmed
• Phalen’s manoeuvre: Here, the doctor will ask the person to interlock the fingers of the two hands, flex the wrists a bit and point the fingers downwards. Person must be in this position for 1 to 2 minutes. If the fingers tingle or wrist feels numb, it could be CTS
• Two-point discrimination test: As the name implies, the doctor will check if the person can discriminate between the touch at two different points on their wrists or fingers, using a special tool.
• Nerve conduction velocity test (NCS): A small electrode is placed near the elbow and current passed through the median nerve. The time taken by the current to reach the fingers can indicate damage to the median nerve. NCS is an important evaluation tool for CTS and can diagnose even early cases and helps to quantify the degree of nerve compression. There are various methods like inching technique which helps to quantify the disease process for better management.
• Electromyogram: Here, the electrical current is passed into muscles of the hand and arm connected to the median nerve, using a needle electrode. The patient must relax and flex the hand several times. The doctor will observe this to detect CTS.

Treatment

There are several methods to treat CTS including nonpharmacological methods like splints for milder cases and avoidance of the trigger to the extent of a surgical decompression. Most cases recover well with control of the primary underlying trigger condition and symptomatic treatment with gabapentin and other neuropathic drugs. Local steroid injections and oral short duration steroid therapy may also help.