II. 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 56:1568-70

III. Pathophysiology: Compression of Median Nerve

  1. Occurs between transverse carpal ligament
  2. Inflamed and enlarged synovial lining of flexor tendons

IV. Risk Factors

  1. Repetitive motion of hand and wrist
    1. Most common cause, and typically work related
  2. Local wrist or hand trauma
  3. Obesity

V. Associated Conditions

  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

VI. 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

VII. Signs

  1. Classic exam findings have poor predictive value and are falling out of favor
    1. Tinel's sign (44-70% sensitive, 94% specific)
    2. Phalen's Maneuver (70-80% sensitive, 80% specific)
  2. Flick Test (93% Sensitive, 96% Specific)
  3. Sensory deficit over Median Nerve
    1. Hypalgesia in Median Nerve distribution has highest Likelihood Ratio
    2. Two Point Discrimination <6 mm with caliper (33% Sensitive, 100% Specific)
  4. Carpal Compression Test (90% sensitive, 90% specific)
  5. Thenar muscle atrophy
    1. Associated with decreased grip strength
    2. Only present in severe, long-standing disease
    3. Other hand and wrist neuropathies will cause this as well
  6. 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
  7. Abductor pollicis brevis weakness
    1. Abduct thumb perpendicular to palm against examiner's resistance
  8. Pain not worse with resisted motion
  9. Full range of motion intact

VIII. 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&#39;Arcy (2000) JAMA 283:3110-7

IX. Differential Diagnosis

  1. Flexor carpi radialis Tenosynovitis
    1. Extends from proximal 1st Metacarpal to medial epicondyle
  2. Raynaud Syndrome
  3. Other Neuropathy
    1. Cervical Radiculopathy (C6 nerve)
    2. Median Nerve compression at elbow
    3. Ulnar Tunnel (or Cubital Tunnel)
  4. Degenerative Joint Disease
    1. Wrist Osteoarthritis
    2. Thumb carpometacarpal Osteoarthritis

X. Radiology: Wrist XRay

  1. Evaluate for local bony abnormality

XI. Diagnostics

  1. Nerve Conduction Studies (Electromyography, EMG)
    1. Indicated in unclear cases or in pre-surgical assessment of severity
    2. Delayed electrical conduction across wrist at the Median Nerve
    3. Efficacy: 56-85% sensitive, 94% specific
  2. Other diagnostic studies (CT, MRI, Ultrasound) are not typically indicated

XII. Management: General Measures (Conservative)

  1. Efficacy
    1. Spontaneous resolution with Placebo: 50%
      1. Goodyear-Smith (2004) Ann Fam Med 2:267-73
    2. Short-term: 80% respond
    3. Long-term: 80% of responders recur after one year
  2. Eliminate cause and modify work conditions
    1. Avoid repetitive trauma
    2. Avoid the extremes of wrist flexion or extension
    3. Avoid vibratory tool use
    4. Employ ergonomics (wrist rest, adjust chair/desk, voice recognition software)
  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 75:1241-4
      2. Sevim (2004) Neurol Sci 25:48-52
  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 52:612-9
    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 51:390-3
  6. Local Ultrasound
    1. Six weeks of therapy provides up to 6 months relief
    2. Reference
      1. Ebenbickler (1998) BMJ 316:731-5
  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, 39:2122-7

XIII. 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 44:1184-93
      2. Gerritsen (2001) Br J Surg 88:1285-95
  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 ArchLaceration

Images: Related links to external sites (from Google)

Ontology: Carpal Tunnel Syndrome (C0007286)

Definition (MEDLINEPLUS)

You're working at your desk, trying to ignore the tingling or numbness you've had for some time in your hand and wrist. Suddenly, a sharp, piercing pain shoots through the wrist and up your arm. Just a passing cramp? More likely you have carpal tunnel syndrome.

The carpal tunnel is a narrow passageway of ligament and bones at the base of your hand. It contains nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the nerve to be compressed. Symptoms usually start gradually. As they worsen, grasping objects can become difficult.

What causes the problem? Some people have smaller carpal tunnels than other people do. Other causes include performing assembly line work, wrist injury, or swelling due to certain diseases, such as rheumatoid arthritis. Women are three times more likely to have carpal tunnel syndrome than men. Treatment includes resting your hand, splints, pain and anti-inflammatory medicines, and surgery.

NIH: National Institute of Neurological Disorders and Stroke

Definition (MSH) Entrapment of the MEDIAN NERVE in the carpal tunnel, which is formed by the flexor retinaculum and the CARPAL BONES. This syndrome may be associated with repetitive occupational trauma (CUMULATIVE TRAUMA DISORDERS); wrist injuries; AMYLOID NEUROPATHIES; rheumatoid arthritis (see ARTHRITIS, RHEUMATOID); ACROMEGALY; PREGNANCY; and other conditions. Symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally. Impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur. (Joynt, Clinical Neurology, 1995, Ch51, p45)
Definition (CSP) entrapment of the median nerve in the carpal tunnel, which is formed by the flexor retinaculum and the carpal bones; this syndrome may be associated with repetitive occupational trauma, wrist injuries, amyloid neuropathies, rheumatoid arthritis, acromegaly, pregnancy, and other conditions; symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally; impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur.
Concepts Disease or Syndrome (T047)
MSH D002349
ICD9 354.0
ICD10 G56.0 , G56.00
SnomedCT 155073007, 57406009, 246611002, 193126005
English Carpal Tunnel Syndromes, Syndromes, Carpal Tunnel, CARPAL TUNNEL SYNDROME, CARPEL TUNNEL SYNDROME, MEDIAN NERVE COMPRESSION, SYNDROME CARPEL TUNNEL, Syndrome, Carpal Tunnel, MEDIAN NERVE ENTRAPMENT, AMYOTROPHY, THENAR, OF CARPAL ORIGIN, CTS1, CTS, CTS (carpal tunnel syndrome), carpal tunnel syndrome, carpal tunnel syndrome (diagnosis), Compression Neuropathy, Carpal Tunnel, Entrapment Neuropathy, Carpal Tunnel, Median Neuropathy, Carpal Tunnel, Carpal Tunnel Syndrome [Disease/Finding], median nerve entrapment, carpal tunnel syndrome (CTS), Carpal tunnel syndrome, unspecified upper limb, Carpal canal, Carpal tunnel, Carpal tunnel syndrome, Median nerve entrapment, Median nerve compression, CTS - Carpal tunnel syndrome, Carpal tunnel syndrome (disorder), Median nerve entrapment (disorder), Carpal Tunnel Syndrome, carpal tunnel; syndrome, compression; median nerve (in carpal tunnel), entrapment; neuropathic, nerve, median, n.medianus; compression (in carpal tunnel), neuropathy; entrapment, nerve, median, syndrome; carpal tunnel, carpal tunnel median neuropathy, Carpel tunnel syndrome, Syndrome carpel tunnel
German Syndrom, Karpaltunnel, CARPALTUNNELSYNDROM, Karpaltunnel-Syndrom, Karpaltunnelsyndrom, Druckneuropathie, Karpaltunnel, Nervenkompressionssyndrom, Karpaltunnel
Portuguese Síndrome do túnel cárpico, SINDROME DO TUNEL CARPICO, Sindrome do canal carpico, Síndrome do canal cárpico, Neuropatia de Aprisionamento do Túnel Carpal, Neuropatia de Compressão do Túnel Carpal, Síndrome do Túnel Carpal, Síndrome do Túnel Carpiano, Síndrome do Túnel Cárpico, Síndrome do Túnel do Carpo
Swedish Karpaltunnelsyndrom, KARPALTUNNELSYNDROM
Japanese シュコンカンショウコウグン, 手根管圧迫症候群, 手根管症候群, 手根トンネル症候群
Czech karpální tunelový syndrom, Syndrom karpálního tunelu
Spanish CTS - Carpal tunnel syndrome, Carpal tunnel syndrome, SINDROME TUNEL CARPIANO, Sindrome del tunel carpiano, compresión de nervio mediano, compresión de nervio mediano (trastorno), atrapamiento del nervio mediano (trastorno), atrapamiento del nervio mediano, síndrome del túnel carpiano (trastorno), síndrome del túnel carpiano, Síndrome del túnel carpiano, Neuropatía por Atrapamiento del Túnel Carpiano, Neuropatía por Compresión del Túnel Carpiano, Síndrome del Túnel Carpiano, Neuropatia por Atrapamiento del Tunel Carpiano, Neuropatia por Compresion del Tunel Carpiano, Sindrome del Tunel Carpiano
Finnish Rannekanavaoireyhtymä, KARPAALISYNDROOMA
Russian ZAPIASTNOGO KANALA SINDROM, ЗАПЯСТНОГО КАНАЛА СИНДРОМ
Norwegian CARPAL TUNNEL SYNDROMET
Dutch Carpaal tunnel syndroom, Carpale tunnelsyndroom, carpale tunnel; syndroom, compressie; nervus medianus (in carpale tunnel), inklemming; neuropathie, nervus, medianus, n.medianus; compressie (in carpale tunnel), neuropathie; inklemming, nervus, medianus, syndroom; carpale tunnel, carpaletunnelsyndroom, Carpale-tunnelsyndroom, Compressieneuropathie van de carpale tunnel, Syndroom, carpale-tunnel-
Danish Karpal tunnel syndrom
French SYNDROME DU CANAL CARPIEN, Syndrome du canal carpien, Neuropathie de compression du nerf médian dans le canal carpien, SCC (Syndrome du Canal Carpien)
Hungarian carpal tunnel syndroma(alagut sy), Carpalis alagút-syndroma, Carpalis alagút syndroma, Carpalis alagút tünetegyüttes
Italian STC, Neuropatia da compressione del nervo mediano nel tunnel carpale, Neuropatia da compressione nel tunnel carpale, Neuropatia da intrappolamento nel tunnel carpale, Sindrome del tunnel carpale
Korean 팔목 터널 증후군
Croatian SINDROM KARPALNOG KANALA
Basque KARPIOKO KANALEKO SINDROMEA
Hebrew tismonet minheret hakarpus
Polish Zespół cieśni nadgarstka, Zespół ciasnoty kanału nadgarstka, Zespół tunelowy nadgarstka

Ontology: 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).
Concepts Disease or Syndrome (T047)
MSH D020423
SnomedCT 397828008, 29833009
English Median neuropathy (finding), MEDIAN NERVE DIS, Median nerve lesion, nerve palsy median, median nerve palsy, median nerve palsy (diagnosis), Median Nerve Disease, Median Nerve Diseases, Nerve Disease, Median, Nerve Diseases, Median, Median Neuropathies, Neuropathies, Median, Neuropathy, Median, Median Neuropathy [Disease/Finding], Median Neuropathy, median nerve lesion, lesions median nerve, median neuropathy, Median nerve palsy, Median neuropathy (disorder), Median neuropathy, disease (or disorder); median nerve
Swedish Medianneuropati
Spanish neuropatía del nervio mediano (hallazgo), neuropatía del nervio mediano (trastorno), neuropatía del nervio mediano, Enfermedades del Nervio Medio, Neuropatía Mediana, Neuropatia Mediana
Czech nervus medianus - nemoci, nervus medianus - neuropatie
Finnish Keskihermon neuropatia
Russian SREDINNOGO NERVA BOLEZNI, SREDINNOGO NERVA NEVROPATIIA, СРЕДИННОГО НЕРВА БОЛЕЗНИ, СРЕДИННОГО НЕРВА НЕВРОПАТИЯ
Croatian Not Translated[Median Neuropathy]
Polish Neuropatia nerwu pośrodkowego, Neuropatia pośrodkowa
Japanese 正中神経障害, 正中神経疾患, 正中神経麻痺
Dutch aandoening; nervus medianus, Nervus-medianusneuropathie, Neuropathie van de nervus medianus, Neuropathie, nervus-medianus-
French Neuropathie du nerf médian
German Medianus-Neuropathie, Nervus-medianus-Krankheiten, Neuropathie, Nervus medianus
Italian Neuropatia del nervo mediano
Portuguese Doenças do Nervo Mediano, Neuropatia Mediana