Carpal tunnel syndrome:
The carpal tunnel is the space between
the bones and ligaments of the wrist through which median nerve passes. Carpal
tunnel syndrome develops when the nerve becomes compressed. It is common
condition of the hand that affects women more frequently than men.
The symptoms of carpal tunnel syndrome
include:
-
Pins and needles or
tingling sensations (Paraesthesias)
-
Pain or numbness in the
hand, typically worse at the night.
-
Clumsiness and weakness
of the hand.
-
A weak grip and an
impaired ability to bring the thumb across the palm to meet the other fingers.
-
Pain in the wrist,
forearm or shoulder.
Causes:
Any condition that narrows the carpal
tunnel or produces swelling of or fluid retention by the contents of the tunnel
can cause carpal tunnel syndrome. The many possible causes include
-
Hormonal changes.
-
Obesity,
-
Diabetes mellitus,
-
Rheumatoid arthritis,
-
Acromegaly – bone
enlargement due to pituitary gland abnormality.
-
Under activity of
thyroid (hypothyroidism)
-
Renal failure,
-
Alcoholism
-
Amyloidosis : rare
condition in which abnormal proteins accumulate in tissues and organs.
-
Paget’s disease: a
chronic bone disease that affects elderly people. The bones become deformed and
thickened.
-
Tumors: such as lipoma
(Fatty tumours), ganglions (fluid filled cysts formed in tendon), and
deformities of wrist after the fractures.
-
The use of hand held
vibrating tools – very rarely causes carpal tunnel syndrome.
Diagnosis:
The
typical history of pain and weakness in the hands usually suggest the diagnosis
of carpal tunnel syndrome, but it is important to exclude other conditions that
may produce similar symptoms, such as a prolapsed cervical disc or arthritis of
thumb joint.
Clinical examination:
This
may reveal disturbances in sensation in the area supplied by the median nerve,
wasting of the muscles at the base of thumb and poor grip.
Tinel’s
sign: tapping the median nerve at the wrist may reproduce the pain and tingling
of carpal tunnel syndrome in the affected person. Flexing the wrist against resistance
has a similar effect.
Imaging:
an x-ray of the wrist may be used to rule out bony abnormalities, while MRI
gives a clear picture of the soft tissues.
Nerve
conduction studies: Nerve conduction studies are conducted to see the
conduction and velocity of impulses across the median nerve. This test can be
used for documentation of carpal tunnel syndrome.
Treatment:
Treat
the underlying cause:
The
underlying causes should be treated. For example overweight patients should be
encouraged to lose some weight and patients with hypothyroidism should receive
thyroid hormone replacement therapy.
Some
patients recover without treatment, while others respond to rest or simple measures
such as the use of wrist splint for week or so. In cases where the condition is
persistent however several treatments are available.
-
Anti-inflammatory
drugs: may help to relive tendon swelling and pressure on the wrist in
rheumatoid arthritis.
-
Wearing night splints
at night, which hold the wrist, slightly forward, may help night pain.
-
Diuretics (which
increase the volume of urine) are sometimes prescribed to remove excess fluid
from the body.
-
Steroid injections into
the carpal may provide relief, but must be performed with utmost care. It is
particularly important not to inject the median nerve itself any improvement
may be temporary.
-
In persistent cases,
surgery will be performed in order to reduce pressure on the large media nerve.
Surgery:
Surgery is usually advisable for
persistent or worsening symptoms to prevent permanent loss of sensation and
wasting of the muscles in the hand. In such cases without surgery, symptoms are
likely to persist.
Surgical treatment usually involves
dividing transverse carpal ligament in order to relieve the pressure on the median
nerve. Freeing the nerve enables normal nerve conduction to resume.
Traditionally, median nerve decompression was open surgical procedure, but also
new technique of endoscopic carpal tunnel release is also being practiced.
Generally, both open and endoscopic
techniques have excellent results although it may take few months for grip
strength to return to normal.
