Carpal Tunnel Syndrome/Entrapment

What is Carpal Tunnel Syndrome?

Carpal tunnel syndrome is a condition that causes pain and numbness in the hand and wrist. Basically, it’s due to a “pinched” nerve in the wrist (technically called a peripheral nerve entrapment). Specifically, a nerve travels through a space in the wrist, and carpal tunnel syndrome occurs when this nerve becomes compressed or squeezed in this space. This space is called the carpal tunnel, and the nerve is the median nerve.

The size and location of AVMs vary in the brain. AVMS affect less than one percent of the population. Although AVMs are present at the time of birth, their symptoms may appear at any age.

The carpal tunnel is a narrow passageway in the wrist. This tunnel-like space is made up of bones and ligaments. The median nerve and several tendons pass through this space and are protected by it as they travel from the forearm into the hand. The median nerve controls the movement and sensations for parts of the hand. Carpal tunnel syndrome occurs when tissues within this narrow space become inflamed or swollen and in turn compress the median nerve. At some point, the pressure on the nerve can interfere with its normal functioning and result in numbness, pain or weakness in the hand and fingers.

What are the Causes of Carpal Tunnel Syndrome?

Generally, carpal tunnel syndrome is not the result of a single cause, but rather the result of a combination of factors that result in compression of the median nerve. Things that can contribute to the development of carpal tunnel syndrome include:

• Genetics: The carpal tunnel is smaller in some people than in others. This trait can run in families and be passed along from one generation to another. Thus, some people are congenitally predisposed to be affected by carpal tunnel syndrome.

• Hand use: Prolonged, repetitive use (e.g., long periods where the wrists are bent, use of vibrating machinery, etc).

• Wrist injuries: Any trauma (fractures, dislocations or sprains) can cause swelling or compression.

• Other medical conditions: Arthritis, diabetes or thyroid dysfunction.

• Abnormal growths: Development of a tumor or cyst within the carpal tunnel.

• Pregnancy: Hormonal changes can lead to fluid retention. Here, the symptoms typically go away after delivery.

• Sex: Women are more likely to develop carpal tunnel syndrome than men.

Although there are many known factors that can contribute to the development of carpal tunnel syndrome, there are cases where no cause can be identified.

Symptoms of Carpal Tunnel Syndrome

The symptoms of carpal tunnel syndrome often begin gradually and/or come and go. However, as the condition progresses the symptoms can become constant.

The most common symptoms include:

• Numbness and/or tingling on the palm side of the hand, thumb and fingers.

• Pain (which can manifest itself as a burning sensation) in the hand, wrist or forearm. Often any activity that involves use of the hand or wrist will lead to an increase in pain.

• Weakness: Over time the muscles around the thumb can shrink and lose strength (atrophy). This atrophy causes decreased grip strength, which results in difficulty grasping onto objects or forming a fist.

Although symptoms can occur at any time, they often begin to appear at night while sleeping or during the day when grasping an object (e.g., phone, steering wheel, or newspaper). When an individual first begins to have symptoms, shaking or moving the hands may help decrease symptoms and provide some temporary relief.

Diagnosis of Carpal Tunnel Syndrome

A physician may perform following to diagnosis carpal tunnel syndrome:

Medical history: Discussing medical history (including prior wrist injuries), current symptoms, and the activities you do (or have done) with your hands and their frequency.

Physical examination: Looking for tenderness and/or swelling of the wrist. Checking the muscle strength of the thumb and hand. Holding the wrist in a bent position for a period of time to see if symptoms appear or increase. Pressing or tapping on the inside of the wrist (i.e., on the median nerve) to see what sensations occur.

Laboratory tests: To determine if there any medical conditions (e.g., thyroid dysfunction, diabetes, etc.).

Imaging studies: X-rays can help identify things such as arthritis or a fracture. Ultrasound can reveal if there is impaired movement of the median nerve. Occasionally, computed tomography (CT) or magnetic resonance imaging (MRI) may be used to see the anatomy of the wrist; they can also reveal if there is a tumor or cyst pressing on the nerve.

Electrophysiological tests: Nerve conduction study and/or an electromyography (EMG). These test the function of the median nerve and can also reveal any other nerve dysfunction that may be present.

Treatment Options for Carpal Tunnel Syndrome

Underlying medical conditions (e.g., arthritis or diabetes) contributing to carpal tunnel syndrome should be treated first. Resting the affected wrist for a period of time, changing patterns of hand use and avoiding activities that aggravate the symptoms may be helpful.

A brace or splint to keep the wrist in a straight position may reduce pressure on the nerve. A brace can be worn during activities that aggravate symptoms or at night. Putting an ice pack on the wrist can reduce swelling. Physical therapy that includes stretching and strengthening exercises may be helpful. Medications (both prescription and nonprescription) can be used to temporarily decrease inflammation and ease pain. Treatment can also include a corticosteroid injection into the carpal tunnel.

If symptoms are severe or do not improve after a few months, surgery may be needed.
The name of this surgical procedure is carpal tunnel release. Its goal is to enlarge the tunnel and decrease pressure on the median nerve.

Carpal tunnel surgery is typically done on an outpatient basis. Depending on the procedure, the patient may only receive local anesthesia (i.e., the patient is not put to sleep) to numb the procedure area. Next, the surgeon will make incisions near the wrist so they may work on the carpal tunnel area. To enlarge the space within the carpal tunnel, a ligament that makes up part of it is cut, and tissue around the nerve may be removed. Finally, the surgeon will suture the skin and underlying tissues. Following the procedure, the ligament will begin to heal in a way that provides more room in the carpal tunnel.

This surgery can be performed via an open procedure or minimally invasively. The open procedure requires a larger incision to be made (approximately two inches) in the wrist, whereas the minimally invasive (or arthroscopic) procedure requires a significantly smaller incision. In the minimally invasive procedure a small tube inserted into the incision, and the surgery is performed through this small tube. The main advantages of this procedure include less postoperative pain/discomfort, less scarring and a more rapid recovery than with the traditional open procedure.

After surgery, patients may be required to wear a wrist brace/splint for one to three weeks. The first few days after surgery, the wrist should be elevated frequently. To reduce swelling and stiffness patients may be instructed to move their fingers as well as apply an ice pack. Minor soreness around the incision is common and may last for several weeks. Symptoms may be relieved immediately; however, a full recovery can take several months. The length of recovery depends on how badly damaged the median nerve is. Although the majority of patients recover completely, in severe cases some symptoms will decrease but may not completely go away.

The surgeon will determine what postoperative restrictions are necessary and the estimated time required before a patient can return to work. Patients will be required to undergo a period of physical therapy to restore wrist strength.