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Carpal Tunnel SyndromeAka: Median Neuropathy

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  1. See Also
    1. Overuse Syndromes of the Hand and Wrist
  2. Epidemiology
    1. Bilateral in 50% of cases
    2. Associated with workplace repetitive hand activities
    3. Hand Paresthesias occur in 30% of computer users
      1. Only 10% of these meet criteria for carpal tunnel
      2. Only 3.5% of these have abnormal EMGs
      3. Stevens (2001) Neurology 56:1568
  3. Pathophysiology: Compression of Median Nerve
    1. Occurs between transverse carpal ligament
    2. Inflamed and enlarged synovial lining of flexor tendons
  4. Associated disorders
    1. Hypothyroidism
    2. Diabetes Mellitus
    3. Acromegaly
    4. Rheumatoid Arthritis
    5. Gouty Arthritis
    6. Lyme Disease
    7. Amyloidosis
    8. Multiple Myeloma
    9. Edematous condition
      1. Third trimester of Pregnancy
        1. Symptoms subside after delivery
      2. Congestive Heart Failure
      3. Renal Failure
    10. Aberrant or Anomalous muscles in wrist
      1. Proximal lumbrical insertion
      2. Distal extension of flexor superficialis muscle
      3. Persistent thrombosed median artery
      4. Abnormal palmaris longus tendon
      5. Ganglion Cyst
      6. Lipoma
    11. Double-Crush Syndrome
  5. Symptoms
    1. Image: Median Nerve Sensory Innervation
      1. NeuroMedianNerve.jpg
    2. Paresthesias along Median Nerve course (palmar surface)
      1. Electrical Sensation or Dysesthesias
      2. Commonly involves only Index and Middle fingers
        1. May affect all median innervated 3.5 fingers
    3. Pain in distal, palmar surface of wrist or arm
      1. Distal radiation into thumb, index and middle finger
      2. Proximal radiation into arm, shoulder and neck
    4. Gradually increasing night pain (95% of patients)
      1. Increase in wrist swelling with inactivity
      2. Wrist flexion at night (may awaken patient)
    5. Numbness
      1. Describes "poor circulation" and "Stiffness"
      2. Despite which hand feels warm
    6. Weakness and Clumsiness of hand
      1. Decreased grip strength
    7. Timing
      1. Spontaneous onset
    8. Provocative of Sensory and Motor Symptoms
      1. Precipitated by Typing, Painting, and wrist motion
    9. Palliative
      1. Shaking or moving hand
      2. Allow hand to hang down
      3. Flick Sign
        1. Flicking wrist as if shaking down thermometer
  6. Signs
    1. Sensory deficit over Median Nerve
    2. Two Point Discrimination (33% Sensitive, 100% Specific)
    3. Tinel's sign (44-70% sensitive, 94% specific)
    4. Phalen's Maneuver (70-80% sensitive, 80% specific)
    5. Carpal Compression Test (90% sensitive, 90% specific)
    6. Flick Test
    7. Thenar muscle atrophy in long-standing disease
      1. Associated with decreased grip strength
    8. Tourniquet Test (Not sensitive, not specific)
      1. Inflate Blood Pressure Cuff on upper arm above SBP
      2. Positive Test
        1. Paresthesias and Numbness after inflation <1 minute
    9. Pain not worse with resisted motion
    10. Full range of motion intact
  7. Diagnosis
    1. Findings with highest predictive value
      1. Classic hand symptoms in median distribution
      2. Decreased Pain Sensation at index palmar surface
      3. Weak thumb abduction
    2. References
      1. D'Arcy (2000) JAMA 283:3110
  8. Radiology: Wrist XRay
    1. Evaluate for local bony abnormality
  9. Diagnostics
    1. Electromyogram (EMG)
    2. Nerve Conduction Studies (Electromyography, EMG)
      1. Delayed electrical conduction across wrist
  10. Management: General Measures (Conservative)
    1. Efficacy
      1. Spontaneous resolution with Placebo: 50%
        1. Goodyear-Smith (2004) Ann Fam Med 2:267
      2. Short-term: 80% respond
      3. Long-term: 80% of responders recur after one year
    2. Eliminate cause
      1. Avoid repetitive trauma
      2. Avoid the extremes of wrist flexion or extension
      3. Avoid vibratory tool use
    3. Wrist Splint or Wrist brace (neutral position)
      1. Polypropylene occupational wrist splint
      2. Maintains wrist in neutral position
        1. Avoid cock-up (hyperextension) brace
      3. Most effective if started early (within 3 months)
      4. Wear during both day and night (best results)
        1. Burke (1994) Arch Phys Med Rehabil 75:1241
        2. Sevim (2004) Neurol Sci 25:48
    4. Wrist and Hand Exercises
      1. Brief (1 minute)
      2. Intermittently done during or after work
    5. Local or Systemic Corticosteroid
      1. Carpal Tunnel Steroid Injection
        1. As effective as surgery
        2. Ly-Pen (2005) Arthritis Rheum 52:612
      2. Consider Systemic Corticosteroids
        1. First: Prednisone 20 mg PO qd for 14 days
        2. Next: Prednisone 10 mg PO qd for 14 days
        3. Chang (1998) Neurology 51:390
    6. Local ultrasound
      1. Six weeks of therapy provides up to 6 months relief
      2. Reference
        1. Ebenbickler (1998) BMJ 316:731
    7. NSAIDs (e.g. Ibuprofen)
    8. Pyridoxine may be indicated in pregnancy
      1. Dose: Pyridoxine 25-50 mg PO tid
      2. Unproven benefit
      3. Reference
        1. (1993) Can Fam Physician 39:2122
  11. Management: Surgical release transverse carpal ligament
    1. Indications
      1. Persistent symptoms refractory to above
      2. Progressive motor weakness
    2. Efficacy
      1. Results in prompt, permanent pain relief
      2. Very effective in 66% of patients
      3. May be effective even if EMG normal
      4. References
        1. Katz (2001) Arthritis Rheum 44:1184
        2. Gerritsen (2001) Br J Surg 88:1285
    3. Course
      1. Sensory, Motor function improvement may take months
    4. Adverse affects
      1. No Disability from sectioning transverse ligament
      2. Residual discomfort may continue from Tenosynovitis
    5. Complications
      1. Median Nerve branch injury
      2. Hypertrophic Scar
      3. Superficial Palmar Arch Laceration
  12. References
    1. Katz (1994) Am Fam Physician 49(6):1371
    2. Viera (2003) Am Fam Physician 68(2):265

Median Neuropathy (C0751922)

Definition (MSH)Disease involving the median nerve, from its origin at the BRACHIAL PLEXUS to its termination in the hand. Clinical features include weakness of wrist and finger flexion, forearm pronation, thenar abduction, and loss of sensation over the lateral palm, first three fingers, and radial half of the ring finger. Common sites of injury include the elbow, where the nerve passes through the two heads of the pronator teres muscle (pronator syndrome) and in the carpal tunnel (CARPAL TUNNEL SYNDROME).
ConceptsDisease or Syndrome (T047)
MSHD020423
EnglishLesion of median nerve, MEDIAN NERVE DIS, Median Nerve Disease, Median Nerve Diseases, Median nerve lesion, Median nerve palsy, Median Neuropathies, Median Neuropathy
Spanishlesion de nervio mediano, lesion del nervio mediano, neuropatia del nervio mediano
Parent ConceptsMononeuropathies (C0494491), Peripheral Neuropathy (C0031117), [X]Other lesions of median nerve (C0154742), Neuropathy (C0442874), Upper limb nerve lesion (C0574717), Ambiguous concept (C1274012), Disorder of upper extremity (C1290869)
SourcesMSH, NDFRT, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



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