- Carpal tunnel syndrome.

Carpal tunnel syndrome 

*Def:- is a medical condition in which the median nerve is compressed inside the flexor retinaculum leading to paresthesias, numbness and muscle weakness in the hand.

*Causes:-

Due to fibrosis,fluid accumulation,soft tissue or bone hypertrophy which my be due to:-

"MEDIAN TRAP"(1)

Myxoedema
Edema
Diabetes mellitus,Drugs(e.g Oral contraceptive pills)
Idiopathic
Acromegaly
Neoplasm 

Trauma,Typists(Occuptional).
Rheumatoid arthritis
Amyloidosis
Pregnancy

*Clinical Picture:-

• Many people who have carpal tunnel syndrome have gradually increasing symptoms over time.
• The first symptoms of CTS may appear when sleeping, and typically include numbness and paresthesia (a burning and tingling sensation) in the thumb, index, and middle fingers, although some patients may experience symptoms in the palm as well.(2)
• These symptoms appear at night because people tend to bend their wrists when they sleep, which further compresses the carpal tunnel.

1-Sensoey manifestations:-

numbness and paresthesia then loss of cutaneous sensation from the palmar surface and nail bed  of the lateral three and half fingers.

2-Paralysis of voluntary muscles supplied:-

Paralysis of all thenar  muscles and 1st and 2nd lumbrical muscles.

*Diagnosis:-

• The reference standard for the diagnosis of carpal tunnel syndrome is electrophysiological testing.
• Phalen's maneuver is performed by flexing the wrist gently as far as possible, then holding this position and awaiting symptoms.(3) A positive test is one that results in numbness in the median nerve distribution when holding the wrist in acute flexion position within 60 seconds. The quicker the numbness starts, the more advanced the condition.
• Tinel's sign, a classic, less specific test, is a way to detect irritated nerves. Tinel's is performed by lightly tapping the skin over the flexor retinaculum to elicit a sensation of tingling or "pins and needles" in the nerve distribution.
• Testing of oponens muscle:- by asking the patient to approximate thumb and little fingers to each other and press firmly and then try to pass your finger in between,normally there is a resistance.
• Testing of long flexors of phalanges:- by checking  the hand of the patient,ask him to press firmly,then pull your hand rapidly.

*Treatment:-

1. Avoidance of trauma or repetitive actions. 
2. Immobilizing braces:- a wrist splint helps limit numbness by limiting wrist flexion. Night splinting helps patients sleep. There is no evidence that wrist splinting is disease modifying.
3. Localized steroid injections can be quite effective for temporary relief from symptoms of CTS for a short time.
4. Medications:- anti-inflammatory such as aspirin, ibuprofen or naproxen can be effective as well for controlling symptoms.
5. Carpal tunnel release surgery.

*Reference:-

(1)Carpal tunnel syndrome: Causes. LifeHugger.
(2)EMERG/83 at eMedicine.
(3)Cush JJ, Lipsky PE (2004). Approach to articular and musculoskeletal
disorders, In: Harrison's Principles of Internal Medicine (16th ed.).
McGraw-Hill Professional. pp. 2035. ISBN 0-07-140235-7.

Dr Ibrahim

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