Carpal Tunnel Syndrome

What is Carpal Tunnel Syndrome?

 

Carpal tunnel syndrome is a condition which is brought on by increased pressure in the wrist causing a nerve to be pinched.  The nerve reacts to this pressure by sending singles of numbness, tingling and pain to the hand and occasionally the forearm.  In most instances, releasing the pressure reduces the amount of pinching upon the nerve and alleviates the symptoms.

 

What is the Carpal Tunnel?

 

The carpal tunnel is a channel structure located in the wrist.  It is made of a semi-circle of bones, connected at the tips by a tight ligament called the Transverse Carpal Ligament.  Within this tunnel travel nine tendons which help control the movement of your fingers and the median nerve.  The tendons are lined with tissue which help them glide called the tenosynovium.  The tendons are sturdy and can withstand a lot of motion and force.  The median nerve develops at the neck from nerves leaving the spinal cord, travels down the arm, through the carpal tunnel and into your hand.  The median nerve provides sensation or feeling to the thumb, index, middle and half of the ring finger.  It also provides muscle strength to a small muscle of the thumb.  Unlike the sturdy tendons, the nerve is delicate and vulnerable to changes in pressure. 

 

 

 

What causes Carpal Tunnel Syndrome?

 

The cause of carpal tunnel syndrome is predominantly due to increased pressure in the wrist, or carpal tunnel, which pinches the median nerve at the wrist.  The increased pressure can be caused by multiple reasons:

 

-        swelling of the tendon lining, or tenosynovitis

-        fractures (breaks in the bone), dislocations or arthritis

-        awkward wrist positions, like keeping the wrist in a bent position for long periods of time

-        gripping for long periods of time (ie, driving) brings small muscles into the carpal tunnel for extended periods of time, pinching the nerve

-        fluid retention (ie, pregnancy, especially in the third trimester)

-        other conditions causing increased swelling or inflammation in the body, like diabetes, rheumatoid arthritis and thyroid conditions

-        vibratory tools (ie jackhammers)

 

 

Unfortunately, in most instances, a cause cannot be identified or is unknown.

Women are affected more often then men, by a ratio of 3:1.  Carpal tunnel syndrome affects people mostly between the ages of 30 to 55.

 

What are the symptoms of Carpal Tunnel Syndrome?

 

The symptoms of carpal tunnel syndrome include numbness, tingling and occasionally pain.  These symptoms occur mostly in the thumb, index, and middle fingers.  These symptoms can worsen at night time due to awkward wrist positions and increased swelling in the hands while sleeping.  The symptoms may even wake people from sleep.  When the symptoms continue for long periods of time, weakness in gripping may occur in the hand.  This is due to the pressure affecting the nerve to the small muscle of the thumb.  As the symptoms progress, people may notice frequently dropping objects, clumsiness and the inability to pick up small objects like a pin.  When the nerve is pinched for a long period of time, permanent damage may occur to where the sensation is lost and the hand remains weak.

 

How do you diagnose Carpal Tunnel Syndrome?

 

Your doctor will take a detailed history of your symptoms, medical history, activities and injuries.  Your doctor will then do a physical examination, checking the neck through the hands to assess the nerve.  They will check for swelling, color changes, strength, motion, coloration and sensation.  They will also perform multiple physical manipulations of your wrist and hand, intentionally increasing the pressure of your carpal tunnel to see if your symptoms are reproducible.  An x-ray may be taken to check for arthritis or other bone conditions in the wrist causing swelling.  Laboratory tests may need to be checked to assess any other medical conditions which can affect the carpal tunnel.  More specific tests may be ordered, such as a Nerve Conduction Test and EMG to assess for the specific condition of the median nerve and rule out pinching of the nerve at another location in the arm or neck. 

 

How do you treat Carpal Tunnel Syndrome?

 

Carpal tunnel syndrome may be treated in a variety of ways. Treatment of carpal tunnel syndrome is dependent on the stage of the disease.  In the early stages of the disease, the symptoms are reversible, and less invasive treatment is recommended.  In later stages of the disease, the nerve may be damaged, and therefore surgery may be recommended to protect it from further injury.  Surgery may also be recommended in those patients whose initial treatment is successful, but the symptoms return.

 

The first mode of treatment is to treat the underlying causes of carpal tunnel syndrome.  If the wrists are kept in awkward positions during the day or night, the doctor may recommend a wrist brace to keep the wrist in a steady, neutral position to keep the pressure off the nerve.  If there is arthritis or swelling, the doctor may recommend therapy and medication such as anti-inflammatories for the hand to reduce the swelling. If the symptoms continue, the doctor may recommend a cortisone injection to the carpal tunnel to alleviate the swelling immediately surrounding the nerve. 

 

When the symptoms of carpal tunnel syndrome continue or are severe, your doctor may recommend surgery.  In surgery, the ligament covering the nerve (the transverse carpal ligament) is cut in half, increasing the space around the nerve and giving it more room to breathe.  By increasing the space surrounding the nerve, the pressure on the nerve is taken away.  If caught early enough, the symptoms of the carpal tunnel syndrome may be completely relieved.  However, if there is any existing damage to the nerve from long term symptoms, these symptoms may not improve.  In these cases, the nerve is protected from any further injury and worsening of the condition. In the majority of cases, the surgery is done as a same day surgery.  The symptoms usually are alleviated within a few days of the surgery, however the symptoms can last up to several months depending on the condition of the nerve.  There are many types of incisions for this surgery, however, the end result is to alleviate the pressure on the nerve.  The incision and surrounding tissue may be sore for weeks or months after the surgery as the tissue recovers.  Ultimately, motion and function return to normal within a couple of months from surgery.  For those patients with severe carpal tunnel syndrome, they can expect a slow continued improvement of their symptoms after surgery for up to one year.