This is a condition when a nerve, the median nerve, is injured within the wrist. The name “carpal tunnel” is given to a tunnel made by 8 small bones and a thick piece of tissue, like a tent on top, at wrist level. Many tendons pass through this tunnel, like thick pieces of ropes, which one can see or feel at the base of hand or the wrist. The median nerve also passes through the tunnel.

What is the median nerve?

It is a nerve traveling from upper arm to the hand. At the wrist, it passes through a structure called carpal tunnel. It takes sensations from part of the hand on the thumb side, excluding the little finger and half of the ring finger, to the spinal cord. It also controls an important muscle at the base of thumb.

 

What are the symptoms of CTS?

As the nerve is injured, it may cause pain, numbness, and tingling. Pain can be of aching, throbbing or electric jabs type. It is noted in the thumb, index and the middle finger. It typically occurs more at night, waking the patient from sleep, or when the patient is holding an object in a particular manner, like a newspaper for reading or the steering wheel while driving. Patient can lose sensation in the thumb and the index finger. As the nerve injury extends, the inside nerve fibers are injured, which results in weakness and loss of muscle mass. This may result in weak hand grip or dropping things from hand. For some reasons, despite significant nerve injury, not every patient has pain, many may only complain of weakness. 

 

What are the examination findings of CTS?

In classical case of CTS, one may find pain triggered by applying pressure or stretching the wrist area, which can be done by hyperextension or hyperflexion of the wrist. Another finding is the weakness of thumb, due to the weakness of a muscle called abductor pollicis brevis.

 

How is CTS diagnosed?

It is typically diagnosed by a test called EMG/NCS, or electromyogram and nerve conduction studies. The main finding is the slowing of electrical transmission through the median nerve at the wrist level, in comparison to other nerves and the normal standards. Technically, it can also be diagnosed by ultrasound or an MRI scan, but they are seldom used.

 

What are different causes of CTS?

1. Physical injury to the wrist area
2. Heavy repetitive manual work with injury to the wrist area
3. Metabolic conditions, such as hypothyroidism, pituitary dysfunction or diabetes mellites
4. Fluid accumulation, such as in pregnancy
5. Rheumatological conditions, such as rheumatoid arthritis
6. A lot many do not have any obvious cause. Maybe it is the physical makeup of their wrists that put them at risk

 

Who is at risk for developing CTS?

1. Women
2. People involved in heavy and repetitive manual work
3. People with some medical conditions, as described above

 

Are there different levels of CTS?

For better understanding and to decide about management, the diagnosis of CTS is defined in levels. These levels are determined based upon EMG/NCS findings, as the clinical features or patient’s symptoms are not precise enough. It is a common observation that some patients with mild CTS have severe symptoms while others with moderate to severe condition may not have any. I usually divide CTS in the following manner:

1. Mild: Mild slowing of nerve conduction
2. Moderate: Moderate slowing of nerve conduction
3. Severe: Severe slowing of nerve conduction
4. End-stage: No conduction across the nerve

 

How is CTS treated?

In some mild cases, avoidance of the repetitive activity causing the problem is all what is needed. If symptoms continue, some type of intervention may be needed. Following is an outline of different types of treatment:

1. Avoidance of repetitive activity: In mild cases, this may be the only needed treatment.
2. Wrist splinting: Wearing a wrist splint is helpful. The main purpose of splinting is to keep the hand in a neutral position where there is less pressure on the nerve. I advise patients to put on the splint at night during sleep to give the nerve rest and time to heal, and not necessarily all day.
3. Steroid injection: If the above measures fail, and the patient continues to complain of pain, numbness and tingling, injection of small amount of steroid (or cortisone) near the injured nerve can be helpful. It is a relatively simple and easy to do injection, though not completely risk free.
4. Surgery: Some patients require surgery. Main purpose of surgery is to create little more space in the carpal tunnel to release pressure on the nerve, the so-called carpal tunnel release surgery. Surgery for CTS is under local anesthesia and is an outpatient procedure. It can be an effective treatment resulting in resolution of symptoms and improvement in strength. In some cases, the nerve may get injure again if heavy physical activity continues.

 

How to decide which patient needs which type of treatment for CTS?

This is a not a straight-forward question. Decision about the treatment is partly based upon the guidelines provided above. It also depends upon the cause, patient’s age, line of work, and the nature and type of symptoms.

 

Which patients do not respond well to treatment for CTS?

Common reasons for lack of improvement or failed treatment are as follows:

• Metabolic instead of mechanical cause
• Continuation of repetitive or heavy manual work
• Lack of response to cortisone
• Failed surgery

 

What can be done to prevent CTS?

1. Avoid repetitive heavy manual work
2. Use electrical tools such as a drill instead of a regular screwdriver
3. If repetitive work must be done, give your hands frequent resting intervals
4. If heavy work is done, wear wrist splints for a few nights to give the nerve a chance to heal
5. Prioritize activities. If your job involves manual work, avoid hobbies that may also require similar work
6. Know your limits. Not every hand or wrist is made for hard work, even in young age. People with some underlying conditions have more risk, such as diabetes and rheumatoid arthritis
7. Consult a doctor early to avoid further progression and permanent nerve damage

 

Where can I get more information about CTS?

American Academy of Neurology

American Society of Neurological Surgeons

American Society of Orthopedic surgeons

American Society of Physical Medicine and Rehabilitation