What is Carpal Tunnel Syndrome?

 

Carpal tunnel syndrome (CTS) is a condition causing numbness, tingling, pain and even weakness in the hand as a result of nerve compression of the median nerve. Often, the numbness and tingling is initially experienced at nighttime and can be relieved by “shaking out” the hand. 

 

The numbness and tingling is on the palm side of the thumb, index finger, middle finger and half of the ring finger.  This is the only area of the hand the median nerve goes to. As the condition progresses, the symptoms intensify and may occur during the daytime as well.  Like most things, the earlier the diagnosis the better.

 

To understand how carpal tunnel can develop, it’s important to understand the anatomy of the carpal tunnel. It is an area at the wrist where two rows of small bones form a c-shape with a thick ligament (called the flexor retinaculum) closing the space into a tunnel. In this tunnel, there are nine tendons and one nerve passing through.  The median nerve is one of three nerves that provide sensation and motor control to the hand. The tendons passing through the carpal tunnel are the tendons that move our fingers and our thumb.

 

What causes Carpal Tunnel Syndrome?

 

Individuals can experience CTS as a result of a variety of factors. Here are a few causes associated with CTS, but they don’t necessarily mean you will develop CTS. 

 

The most common theme you will notice is each factor leads to an increase in inflammation/irritation or fluid, which will cause pressure on the median nerve. The position of the wrist also impacts the amount of pressure placed on the median nerve. In a neutral position, there is very little pressure. If the wrist is bent into extreme positions, either forward or backward, (think poor typing position) there is a significant increase in the pressure in the carpal tunnel causing compression of the median nerve.    

 

-        Repeated hand or wrist movement

• Repetitive use of the tendons passing through the carpal tunnel can cause inflammation of the tendon sheaths. The carpal tunnel is small so, the median nerve is often affected since it is the only structure that is pliable. 

-        Trauma

• A traumatic injury to the wrist such as a broken bone or dislocation can cause swelling in the hand and wrist, which would cause increased pressure on the median nerve. 

-        Pregnancy

• During pregnancy, the body has an increased volume of fluids and women often experience fluid retention.  When there is an increase in fluids, the pressure may increase within the carpal tunnel causing irritation to the median nerve.  For most women, this goes away after the baby is born, but some women will experience ongoing symptoms depending on the amount of injury to the nerve.

-        Medical conditions

• There are medical conditions that can cause swelling or decreased blood flow to the hands, which may result in inflammation of the median nerve.  These include diabetes, rheumatoid arthritis, gout, lupus, diabetes, thyroid disorders, menopause, and obesity or kidney failure.

-        Work-related factors

• Working in an environment with exposure to vibration of the hand/arm, forceful or repetitive hand movements or even holding the hand in an awkward position for prolonged periods of time can lead to irritation of the median nerve. 

 

What is the treatment for Carpal Tunnel Syndrome?

 

The most important step is to be evaluated by a physician if the condition is interfering with daily activities or sleep. Early treatment is important because there is a risk of permanent nerve or muscle damage. For proper diagnosis, a physician may include gathering a history of the symptoms, physical examination, x-rays, electromyogram (EMG) or a nerve conduction study (NCS).  A referral to a specialist may be needed. 

 

CTS treatment options may include a referral to occupational therapy, splinting, medications (non-steroidal anti-inflammatories), injections or possibly surgery for advanced cases.  

 

How does Occupational Therapy help Carpal Tunnel Syndrome?

 

Occupational therapy (OT) can benefit a person with mild symptoms of CTS. Your occupational therapist will evaluate your symptoms and consider factors from your occupation and hobbies to help identify changes that can be made to minimize pressure in the carpal tunnel. OT emphasizes education on the proper exercises, which often include tendon gliding and nerve flossing. Often, the OT will recommend the use of a wrist splint to support the wrist in a neutral position at night to decrease pressure and inflammation on the wrist.