Carpal tunnel syndrome is compression of the median nerve of
the wrist causing pain, paresthesia, numbness, and other symptoms in the
distribution of the median nerve. It is the compression of the median nerve
traveling through the carpal tunnel. The median nerve of the wrist supplies
with feeling and movement of the palm, thumb, index finger, middle finger, and
thumb side of the ring finger of the hand. The carpal tunnel is an anatomical
compartment located at the base of the wrist. It is a tight and narrow space
between the fibrous band of the wrist and the wrist bone. Nine flexor tendons
and the median nerve pass through the carpal tunnel that is surrounded on three
sides by the carpal bones that form an arch. Any condition that causes swelling
or change in position of the tissue within the carpal tunnel can squeeze and
irritate the median nerve. The squeezing or irritation of the median nerve
causes the symptoms of carpal tunnel syndrome such as pain, numbness, tingling
or weakness.
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Causes
Repetitive stress to the wrist joints that causes carpal
tunnel syndrome are
Typing
Computer keyboard use
Sewing
Driving
Writing
Vibratory hand tools
Sports such as racquetball or handball
Playing musical instruments
Some medical conditions that predisposes to carpal tunnel syndrome are
Obesity
Fracture and trauma
Hypothyroidism
Arthritis
Diabetes
Kidney failure and dialysis
Infections
Oral contraceptives
Premenstrual syndrome and pregnancy
Rheumatoid arthritis
Systemic lupus erythematosus
Scleroderma
Some rare diseases can cause deposition of abnormal
substances around the carpal tunnel leading to nerve irritation are
Amylodosis
Sarcoidosis
Multiple myeloma
Leukemia
Other causes are
Intrinsic factors that exert pressure within the tunnel and
extrinsic factors that exert pressure from outside the tunnel.
Benign tumors such as lipomas, ganglion, and vascular
malformation are some of the pressure exerting factors that result in this
condition.
Signs and Symptoms
Patients with carpal tunnel syndrome experience numbness,
tingling, or burning sensation in the thumb and fingers, in particular the
index, middle fingers and radial half of the ring fingers, which are innervated
by the median nerve. Other symptoms include pain in the wrists or
hands and loss of grip strength. Decreased grip strength can lead to frequent
dropping of objects from the hand. As the disease progresses, patients can
develop a burning sensation, cramping, and weakness of the hand. Occasional
sharp shooting pains can be felt in the forearm. Chronic carpal tunnel syndrome
can also lead to wasting of the hand muscles, particularly those near the base
of the thumb in the palm of the hand.
Management and Treatment
The choice of treatment for carpal tunnel syndrome depends
on the severity of the symptoms and any underlying disease that might be
causing the symptoms. Treatment consists of splinting or bracing, steroid
injection, activity modification, physiotherapy, regular massage therapy
treatments, chiropractic, medications, and surgical release of the transverse
carpal ligament.
Initial treatment includes
1. Rest
2. Massage
3. Ice application
4. Immobilization of the wrist in a splint or brace
Those occupations which are causing repetitive stress injury
that aggravates the symptoms should modify their activities. Computer keyboards and chair height may need to be
adjusted to optimize comfort. Periodic resting, range of motion, and stretching exercise of the wrists can prevent the
symptoms of carpal tunnel syndrome that are caused by repetitive overuse.
Underlying conditions or diseases are treated
individually
1. Fractures can require orthopedic management.
2. Obese individuals are advised regarding weight reduction.
3. Rheumatoid arthritis is treated with measures for the
underlying arthritis.
4. Wrist swelling associated with pregnancy resolves after
delivery of the baby.
5. Benign tumors are treated through excision, radiotherapy
etc. for relieving the pressure.
Medications
Several types of medications have been used in the treatment
of carpal tunnel syndrome. Vitamin B6 (pyridoxine) has been reported to relieve
some symptoms of carpal tunnel syndrome.
Nonsteroidal anti-inflammatory drugs help in decreasing
inflammation and reducing the pain.
Corticosteroids can be given by mouth or injected directly
into the involved wrist joint. They can bring rapid relief of the persistent
symptoms of carpal tunnel syndrome.
Surgery
Chronic pressure on the median nerve will result in
persistent numbness and weakness. To avoid serious and permanent nerve and
muscle damage of carpal tunnel syndrome, surgical treatment is considered.
Surgery which is called "carpal tunnel release" is done which
involves severing a band of tissue around the wrist to reduce pressure on the
median nerve. In carpal tunnel release surgery, the goal is to divide
the transverse carpal ligament into two. The patient may undergo
exercise rehabilitation after the surgery.
