AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Carpal tunnel syndrome (CTS) is a compressive neuropathy of the median nerve at the wrist. The carpal tunnel is located at the base of the palm and is bounded on 3 sides by carpal bones and anteriorly by the transverse carpal ligament. Inside run the median nerve, flexor tendons, and their synovial sheaths.

Pathophysiology

CTS is caused predominantly by compression of the median nerve at the wrist because of hypertrophy or edema of the flexor synovium. Pain is thought to be secondary to nerve ischemia rather than direct physical damage of the nerve.

Frequency

United States

CTS is the most frequently encountered peripheral compressive neuropathy. The estimated lifetime risk of acquiring CTS is 10%, the annual incidence is 0.1% among adults, and overall prevalence of CTS is 2.7%.

Mortality/Morbidity

Early in the course of CTS, the neurologic findings are reversible. If untreated, CTS can result in thenar atrophy, chronic hand weakness, and numbness in the median nerve distribution of the hand.

Sex

CTS is more prevalent in females than in males.

Age

CTS is most common in middle-aged persons.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

Patients typically complain of an intermittent "pins-and-needles" paresthesia in the median nerve distribution of the hand. Pain is generally worse at night than during the day. Patients may awaken with a burning pain or tingling that may be relieved with shaking their hands. Classic CTS is associated with symptoms that affect at least 2 of the first through third digits; symptoms affecting the fourth and fifth digits, wrist pain, and radiation of pain proximal to the wrist may also occur, but classic CTS is not associated with symptoms on the palm or dorsum of the hand.

Symptoms of probable CTS are the same as classic CTS except palmar symptoms may be present, unless confined solely to the ulnar aspect. Possible CTS involves symptoms in at least one of the first 3 digits. The sensitivity of classic or probable CTS symptoms for diagnosing CTS is 80%. CTS is unlikely if no symptoms are present in any of the first 3 digits.

• Symptoms are most often bilateral, insidious in onset, and progressive in nature.
• With advanced nerve compression, an aching sensation is persistent and static and may radiate to the forearm and elbow.
• Inquire with regard to repetitive strain risk, eg, waitperson, assembly packing, computer keyboard work, playing a musical instrument, craftwork.
• Determine if there has been any significant trauma.
• Inquire with regard presence of any other predisposing factors listed below under causes.

Physical

• Weakness of resisted thumb abduction (ie, movement of the thumb at right angles to the palm) is helpful in establishing the electrodiagnosis of CTS.
• Sensory hypalgesia as demonstrated by diminished ability to perceive painful stimuli applied along the palmar aspect of the index finger when compared with the ipsilateral little finger also is associated with the electrodiagnosis of CTS.
• Hyperflexion of the wrist for 60 seconds may elicit paresthesia in the median nerve distribution (ie, Phalen sign). A recent review showed the average sensitivity and specificity of the Phalen sign to be 68% and 73%, respectively.
• Tapping the volar wrist over the median nerve (ie, Tinel sign) may produce paresthesia in the median distribution of the hand. Pooled data show the sensitivity and specificity of the Tinel sign to be 50% and 77%, respectively.
• Shaking or flicking one's hands for relief during maximal symptoms (ie, Flick sign) has been shown to have a sensitivity of 47% and specificity of 62%.
• The loss of 2-point discrimination in the median nerve distribution or abductor pollicis brevis atrophy has a high specificity (>90%) but low sensitivity (<25%).

Causes

• Inflammation of the flexor tendon sheath caused by activities involving repetitive wrist flexion (eg, assembly packing, computer keyboard work, playing a musical instrument, craftwork)
• Edema from trauma of any type (eg, fractures), which can compress the median nerve
• Compression of the median nerve from pregnancy or oral contraceptive-related edema
• Strong association between being overweight or obese and the presence of CTS
• Acromegaly
• Rheumatoid arthritis
• Gout or pseudogout
• Tuberculosis
• Renal failure and hemodialysis
• Hypothyroidism
• Amyloidosis
• Has been associated with diabetes mellitus

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Compressive neuropathies of the nerve roots and brachial plexus
Proximal median neuropathy
Polyneuropathy

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Imaging Studies

• The diagnosis of CTS is made from the ED presumptively. The physician who follows the patient after the acute presentation usually orders the imaging studies and other tests discussed below.
• • Magnetic resonance imaging (MRI) is reasonably accurate in diagnosing CTS. Currently, this imaging modality is only recommended when the clinical picture is confusing or when nerve conduction studies are equivocal or contradictory. Dynamic MRI imaging may be useful in identifying dynamic CTS (CTS symptoms brought on only by repetitive wrist motion). MRI may also identify causative lesions in carpal tunnel.
  • Plain radiography is low-yield.
  • High-resolution ultrasonography (US) has received increased attention in the evaluation of CTS. US as a modality is more widely available than electrodiagnostic studies and is noninvasive and has lower costs. Recent US studies have shown that patients with CTS have an increased cross-sectional area of the median nerve in the carpal tunnel than controls. One study concluded that sonography is comparable to electrodiagnostic studies in the diagnosis of CTS. However, further studies are needed to further establish the role of sonography in CTS.

Other Tests

• Electromyographic (EMG) and nerve conduction studies
• • EMG and nerve conduction studies help to confirm the diagnosis of CTS.
  • They are most helpful in the determination of the site and severity of nerve compression.
  • Electrodiagnostic testing has been found to have an 85% sensitivity and specificity greater than 95% for diagnosing CTS.
  • Clinically symptomatic CTS may have normal nerve conduction findings.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

• The mainstay of treatment is rest, wrist immobilization with a splint, and nonsteroidal anti-inflammatory drugs (NSAIDs).  Corticosteroid injections, oral steroids, and diuretics are other treatment modalities that have been used. 
• • A volar splint should be placed in neutral position because flexion and extension of the wrist increases carpal intracanal pressure. Splinting has been shown to have a statistically significant decrease in symptoms compared with controls.  Initial success rates of 70% are seen with splinting, but relapses are common and 1-year success rates are 12-30%.
  • No data support that NSAIDs are superior to placebo in the treatment of CTS. However, in absence of contraindications, a trial of NSAIDs may be appropriate.
  • A corticosteroid injection has been shown to have a statistically significant benefit in CTS at 1 month compared with placebo. The effects of corticosteroid injection appear to be time limited, and the benefit beyond 1 month is unclear. Local injections have been shown to be superior to systemic corticosteroids. Resolution of symptoms after local injection can aid in the diagnosis of CTS.
  • Diuretics have not been shown to be superior to placebo in the treatment of CTS.

• Surgery

• Definitive therapy consists of surgical release of the transverse carpal ligament.
• The surgical approach may be open or endoscopic. Both approaches have similar efficacy. A recent randomized controlled trial showed that patients who underwent endoscopic surgery for carpal tunnel syndrome had less postoperative pain than patients who underwent open surgery; however, the difference was small. An article in the Cochrane Database of Systematic Reviews states that endoscopic surgery gives more transient nerve problems, while open surgery has more wound problems. 
• A recent randomized controlled trial showed that surgery is superior to steroid injection for symptomatic and neurophysiologic outcomes in patients with CTS.
• Surgery for CTS has a long-term success rate of greater than 75%. 

Consultations

Referral to a hand specialist (plastic surgeon or orthopedic surgeon) for follow-up care is recommended.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goal of therapy is to reduce inflammation and prevent complications.

Drug Category: Nonsteroidal anti-inflammatory agents

Most commonly are used for the relief of mild-to-moderate pain. Although the effects of NSAIDs in the treatment of pain tend to be patient specific, ibuprofen usually is the DOC for the initial therapy. Other options include flurbiprofen, ketoprofen, and naproxen.

Drug Name	Naproxen (Anaprox, Naprelan, Naprosyn, Aleve)
Description	Used for the relief of mild-to-moderate pain; inhibits inflammatory reactions and pain by decreasing activity of cyclooxygenase enzyme, which results in a decrease of prostaglandin synthesis. Inexpensive and effective.
Adult Dose	250 mg PO q6-8h; or 500 mg PO q12h; not to exceed 1 g/d
Pediatric Dose	<2 years: Not established >2 years: 2.5 mg/kg/dose PO; not to exceed 10 mg/kg/d
Contraindications	Documented hypersensitivity; peptic ulcer disease; diathesis; recent GI bleeding or perforation; renal insufficiency; high risk of bleeding
Interactions	Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; monitor PT closely (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions	Acute renal insufficiency, interstitial nephritis, hyperkalemia, hyponatremia, and renal papillary necrosis may occur; patients with preexisting renal disease or compromised renal perfusion risk acute renal failure; leukopenia occurs rarely, is transient, and usually returns to normal during therapy; persistent leukopenia, granulocytopenia, or thrombocytopenia warrants further evaluation and may require discontinuation of drug

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Outpatient Care

• Perform EMG and nerve conduction studies to help confirm diagnosis.

Complications

• Chronic hand pain
• Chronic hand weakness and numbness
• Chronic disability

Prognosis

• Prognosis is excellent with definitive therapy.
• CTS during pregnancy seems to be less severe than idiopathic CTS and has milder course with fewer cases requiring surgical treatment.
• Risks factors for poorer-than-average prognosis include the following:
• • Advanced disease
  • Atypical symptoms (normal nerve conduction studies, symptoms in fifth digit)
  • Longer symptom duration
  • Older age
  • Coexisting disease (diabetes, other peripheral neuropathy)
  • Heavy manual occupation
• Despite treatment, some patients may have residual fingertip numbness.

Patient Education

• For excellent patient education resources, visit eMedicine's Hand, Wrist, Elbow, and Shoulder Center and Arthritis Center. Also, see eMedicine's patient education article Carpal Tunnel Syndrome.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Median nerve injury following steroid injection has been reported.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Anto C, Aradhya P. Clinical diagnosis of peripheral nerve compression in the upper extremity. Orthop Clin North Am. Apr 1996;27(2):227-36. [Medline].
• Atroshi I, Gummesson C, Johnsson R, et al. Prevalence of carpal tunnel syndrome in a general population. JAMA. Jul 14 1999;282(2):153-8. [Medline].
• Atroshi I, Gummesson C, Johnsson R, et al. Severe carpal tunnel syndrome potentially needing surgical treatment in a general population (1). J Hand Surg [Am]. Jul 2003;28(4):639-44. [Medline].
• Atroshi I, Larsson GU, Ornstein E, Hofer M, Johnsson R, Ranstam J. Outcomes of endoscopic surgery compared with open surgery for carpal tunnel syndrome among employed patients: randomised controlled trial. BMJ. Jun 24 2006;332(7556):1473. [Medline].
• Bindra RR, Evanoff BA, Chough LY, Cole RJ, Chow JC, Gelberman RH. The use of routine wrist radiography in the evaluation of patients with carpal tunnel syndrome. J Hand Surg [Am]. Jan 1997;22(1):115-9. [Medline].
• Bland JD. Carpal tunnel syndrome. BMJ. Aug 18 2007;335(7615):343-6. [Medline].
• Brahme SK, Hodler J, Braun RM. Dynamic MR imaging of carpal tunnel syndrome. Skeletal Radiol. Aug 1997;26(8):482-7. [Medline].
• Chen P, Maklad N, Redwine M, et al. Dynamic high-resolution sonography of the carpal tunnel. AJR Am J Roentgenol. Feb 1997;168(2):533-7. [Medline].
• D'Arcy CA, McGee S. The rational clinical examination. Does this patient have carpal tunnel syndrome?. JAMA. Jun 21 2000;283(23):3110-7. [Medline].
• de Araujo MP. Electrodiagnosis in compression neuropathies of the upper extremities. Orthop Clin North Am. Apr 1996;27(2):237-44. [Medline].
• Franzblau A, Werner RA. What is carpal tunnel syndrome?. JAMA. Jul 14 1999;282(2):186-7. [Medline].
• Gerritsen AA, de Vet HC, Scholten RJ. Splinting vs surgery in the treatment of carpal tunnel syndrome: a randomized controlled trial. JAMA. Sep 11 2002;288(10):1245-51. [Medline].
• Gerritsen AA, Korthals-de Bos IB, Laboyrie PM. Splinting for carpal tunnel syndrome: prognostic indicators of success. J Neurol Neurosurg Psychiatry. Sep 2003;74(9):1342-4. [Medline].
• Graham RG, Hudson DA, Solomons M. A prospective study to assess the outcome of steroid injections and wrist splinting for the treatment of carpal tunnel syndrome. Plast Reconstr Surg. Feb 2004;113(2):550-6. [Medline].
• Hilburn JW. General principles and use of electrodiagnostic studies in carpal and cubital tunnel syndromes. With special, attention to pitfalls and interpretation. Hand Clin. May 1996;12(2):205-21. [Medline].
• Horch RE, Allmann KH, Laubenberger J, et al. Median nerve compression can be detected by magnetic resonance imaging of the carpal tunnel. Neurosurgery. Jul 1997;41(1):76-82; discussion 82-3. [Medline].
• Hui AC, Wong S, Leung CH. A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome. Neurology. Jun 28 2005;64(12):2074-8. [Medline].
• Jablecki CK, Andary MT, Floeter MK. Practice parameter: Electrodiagnostic studies in carpal tunnel syndrome. Report of the American Association of Electrodiagnostic Medicine, American Academy of Neurology, and the American Academy of Physical Medicine and Rehabilitation. Neurology. Jun 11 2002;58(11):1589-92. [Medline].
• Katz JN, Stirrat CR. A self-administered hand diagram for the diagnosis of carpal tunnel syndrome. J Hand Surg [Am]. Mar 1990;15(2):360-3. [Medline].
• Kaufman MA. Differential diagnosis and pitfalls in electrodiagnostic studies and special tests for diagnosing compressive neuropathies. Orthop Clin North Am. Apr 1996;27(2):245-52. [Medline].
• Kele H, Verheggen R, Bittermann HJ. The potential value of ultrasonography in the evaluation of carpal tunnel syndrome. Neurology. Aug 12 2003;61(3):389-91. [Medline].
• Keles I, Karagulle Kendi AT, Aydin G. Diagnostic precision of ultrasonography in patients with carpal tunnel syndrome. Am J Phys Med Rehabil. Jun 2005;84(6):443-50. [Medline].
• Kerwin G, Williams CS, Seiler JG 3rd. The pathophysiology of carpal tunnel syndrome. Hand Clin. May 1996;12(2):243-51. [Medline].
• Kulick RG. Carpal tunnel syndrome. Orthop Clin North Am. Apr 1996;27(2):345-54. [Medline].
• Lee CH, Kim TK, Yoon ES. Correlation of high-resolution ultrasonographic findings with the clinical symptoms and electrodiagnostic data in carpal tunnel syndrome. Ann Plast Surg. Jan 2005;54(1):20-3. [Medline].
• MacDermid JC, Wessel J. Clinical diagnosis of carpal tunnel syndrome: a systematic review. J Hand Ther. Apr-Jun 2004;17(2):309-19. [Medline].
• Mondelli M, Rossi S, Monti E, Aprile I, Caliandro P, Pazzaglia C. Prospective study of positive factors for improvement of carpal tunnel syndrome in pregnant women. Muscle Nerve. Jul 26 2007;[Medline].
• O'Connor D, Marshall S, Massy-Westropp N. Non-surgical treatment (other than steroid injection) for carpal tunnel syndrome. Cochrane Database Syst Rev. 2003;(1):CD003219. [Medline].
• Padua L, LoMonaco M, Aulisa L, Tamburrelli F, Valente EM, Padua R. Surgical prognosis in carpal tunnel syndrome: usefulness of a preoperative neurophysiological assessment. Acta Neurol Scand. Nov 1996;94(5):343-6. [Medline].
• Scholten RJ, Gerritsen AA, Uitdehaag BM, van Geldere D, de Vet HC, Bouter LM. Surgical treatment options for carpal tunnel syndrome. Cochrane Database Syst Rev. 2004;(4):CD003905. [Medline].
• Stallings SP, Kasdan ML, Soergel TM, Corwin HM. A case-control study of obesity as a risk factor for carpal tunnel syndrome in a population of 600 patients presenting for independent medical examination. J Hand Surg [Am]. Mar 1997;22(2):211-5. [Medline].
• Sternbach G. The carpal tunnel syndrome. J Emerg Med. May-Jun 1999;17(3):519-23. [Medline].
• Tavares SP, Giddins GE. Nerve injury following steroid injection for carpal tunnel syndrome. A report of two cases. J Hand Surg [Br]. Apr 1996;21(2):208-9. [Medline].
• Witt JC, Hentz JG, Stevens JC. Carpal tunnel syndrome with normal nerve conduction studies. Muscle & Nerve. Apr 2004;29(4):515-22. [Medline].
• Wong SM, Griffith JF, Hui AC. Carpal tunnel syndrome: diagnostic usefulness of sonography. Radiology. Jul 2004;232(1):93-9. [Medline].
• Wong SM, Hui AC, Tang A. Local vs systemic corticosteroids in the treatment of carpal tunnel syndrome. Neurology. Jun 12 2001;56(11):1565-7. [Medline].

Article Last Updated: Nov 13, 2007