Carpal Tunnel Syndrome

Dfinition

Carpal tunnel syndrome is a painful condition caused by compression of a key nerve in the wrist.   It occurs when the median nerve, which runs from the forearm into the palm of the hand, becomes pressed or squeezed at the wrist. Symptoms usually start gradually, with  pain, weakness, or numbness in the hand and wrist, radiating up the arm.  As symptoms worsen, people might feel tingling during the day, and decreased grip strength may make it difficult to form a fist, grasp small objects, or perform other manual tasks.  In some cases no direct cause of the syndrome can be identified.   Most likely the disorder is due to a congenital predisposition – the carpal tunnel is simply smaller in some people than in others.  The risk of developing carpal tunnel syndrome is especially common in those who preform repetitive work tasks, such as assembly line work. Carpal tunnel syndrome is also associated with pregnancy and diseases such as diabetes, thyroid disease, or rheumatoid arthritis.

Risk factors

Mechanical:

  • Localized repetitive trauma
  • Occupational
  • Forced wrist flexion

Metabolic:

  • Thyroid Dysfunction
  • Hypothyroid
  • Pregnancy
  • Acromegaly
  • Gout

Inflammation and/or infection:

  • Infiltrative disorders such as amyloidosis
  • Sarcoidosis
  • Inflamatory tenosynovitis
  • Soft tissue infection

Differential diagnosis

  • Cervical spine disease
    • OA
    • Stenosis (C6, C7)
    • Disc herniation
    • Brachial plexus neuropathy
  • Median nerve compression in the arm or forearm
  • Mononeuritis multiplex
  • Cervical cord abnormalities
  • Angina pectoris
  • Thoracic outlet
  • Pancoast tumor
  • TIA
  • Tendonitis

Symptoms

  • Pain distal to lesion
  • Burning paresthesia/dyesthesia
  • Awakens at night with numbness
  • Pain may radiate to shoulder
  • Pain is relieved by shaking, dangling, rubbing
  • Sensory loss (median nerve distribution – 1st 3.5 fingers)
  • Muscle weakness
  • Muscle wasting
  • Hemiparesis, dysarthria, visual changes, HA, neck pain (R/O DDx)

History taking

  • Onset, progression
  • Motor, sensory or autonomic dysfunction
    • Ahnydrosis
    • GI dysmotility
    • Impotence
    • Bladder
    • Pupils
  • Mononeuropathy vs. polyneuropathy
  • Proximal vs. distal
  • Upper vs. lower extremity
  • Associated disease
    • Rheumatoid
    • Diabetes
    • Hypothyroid
    • Acromegaly
    • Vasculitis
    • Amyloidosis
    • Pregnancy
    • Post-injury
    • Alcohol abuse
  • Occupational History:
    • Type and nature of occupation
    • Length of time in that job
    • Total number of hours worked each in that job

Physical exam

  • Examine c-spine & shoulder
  • Examine joint above and below
  • Examine forearm
  • Examine wrist
  • Finger exam
  • Compare both sides
  • Inspection
    • Muscle wasting thenar muscles (late)
    • Asymmetry
    • Fasciculations
    • Swelling
    • Erythema
  • Palpation:
    • Tenderness
    • Anatomical snuffbox
    • Crepitus
  • Sensory:
    • Decreased light touch in thumb, index finger or middle finger
    • Decreased 2 point discrimination (> 6 mm)
    • Vibration
    • Position
    • Temperature
  • Motor:
    • ROM
    • Weakness thumb in flexion (flexor pollicis longus)
    • Weakness in extension
    • Finger movements
  • Special tests:
    • Tinel’s sign (Tap of nerve on wrist ® Tingling from wrist to hand)
    • Phalen’s sign (wrist flexion 90 degrees x 1 min ® numbness, dysethesias in median distribution)
    • Carpal compression test (pressure on carpal tunnel for 30 sec elicits symptoms)

Laboratory work up

  • CBC
  • ESR
  • Fasting Blood Suger
  • Rheumatic Factor
  • TSH
  • Uric acid
  • HbA1c
  • Pregnancy test


Diagnostic tests

  • CXR
  • NCV
  • EMG

Management

Initial treatment generally involves resting the affected hand and wrist for at least 2 weeks, avoiding activities that may worsen symptoms, and immobilizing the wrist in a splint to avoid further damage from twisting or bending. Nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen, other nonprescription pain relievers, and oral steroids (prednisone) may ease pain. Steroid injections can also be used to alleviate the swelling and pressure on the median nerve. For more severe cases of carpal tunnel syndrome, open carpal tunnel release surgery or endoscopic carpal tunnel release may be recommended.

The followings can be considered in treatment  of CTS:

  • Minimize wrist movement
  • Improved occupational and workplace ergonomics
  • Splinting:
    • Neutral wrist splint at bedtime
  • NSAIDS
  • Lasix
  • Corticosteroid injections (50-80% effective)
  • Surgery Indications:
    • refractory pain
    • +++ sensory loss
    • muscle atrophy
  • Release flexor retinaculum (>90% effective)
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