Elsevier

The Lancet Neurology

Volume 15, Issue 12, November 2016, Pages 1273-1284
The Lancet Neurology

Review
Carpal tunnel syndrome: clinical features, diagnosis, and management

https://doi.org/10.1016/S1474-4422(16)30231-9Get rights and content

Summary

Carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome worldwide. The clinical symptoms and physical examination findings in patients with this syndrome are recognised widely and various treatments exist, including non-surgical and surgical options. Despite these advantages, there is a paucity of evidence about the best approaches for assessment of carpal tunnel syndrome and to guide treatment decisions. More objective methods for assessment, including electrodiagnostic testing and nerve imaging, provide additional information about the extent of axonal involvement and structural change, but their exact benefit to patients is unknown. Although the best means of integrating clinical, functional, and anatomical information for selecting treatment choices has not yet been identified, patients can be diagnosed quickly and respond well to treatment. The high prevalence of carpal tunnel syndrome, its effects on quality of life, and the cost that disease burden generates to health systems make it important to identify the research priorities that will be resolved in clinical trials.

Introduction

Entrapment neuropathies are the most frequent mononeuropathies encountered in clinical practice. In these neuropathies, the nerve is damaged at sites where it passes through narrow, restricted spaces.1 Although entrapment neuropathies affect only a small portion of the nerve, they can have substantial physical, psychological, and economic (eg, loss of earnings) consequences.2, 3, 4 The exact cause of these neuropathies is largely unknown and a multifactorial origin is presumed; in such cases, the entrapment syndromes are defined as idiopathic.

Carpal tunnel syndrome is the most common and widely studied nerve entrapment syndrome.5 It is caused by compression of the median nerve at the wrist as it passes through a space-limited osteofibrous canal. This canal, known as the carpal tunnel, contains the wrist bones, transverse carpal ligament, median nerve, and digital flexor tendons. Oedema, tendon inflammation, hormonal changes, and manual activity can contribute to increased nerve compression and sometimes cause pain, as in the case of tendon inflammation. In more severe cases, weakness of median nerve innervated muscles can occur, resulting in hand weakness.

The diagnosis and treatment of carpal tunnel syndrome has been approached from different perspectives and with different methods. This variation has occurred because of the high incidence of the syndrome, its tendency to be symptomatic even in mild cases, the availability of sensitive electrophysiological measures, the development of patient-centred measures and novel nerve imaging techniques, and the availability of several therapies ranging from non-surgical to surgical management. In this Review, we will present up-to-date information about carpal tunnel syndrome, focusing on the most common and controversial clinical topics.

Section snippets

Epidemiology

The reported prevalence and incidence of carpal tunnel syndrome vary widely according to the diagnostic criteria used in different studies. Overall, it is thought that, clinically, one in ten people develop carpal tunnel syndrome at some point.6 The use of clinical criteria in diagnosis results in a higher estimate than does the use of electrophysiological criteria (table 1). Even when clinical presentation alone is used to define carpal tunnel syndrome, the choice of broad (history or Phalen's

Risk factors and causes

Suspected risk factors of carpal tunnel syndrome include diabetes mellitus, menopause, hypothyroidism, obesity, arthritis, and pregnancy.12, 13, 14, 15 Because hypothyroidism,12 menopause,8, 13 and pregnancy13 are risk factors, there is a strong suspicion that hormonal changes might be causative; however, no evidence exists to support this hypothesis.

Recent research provides evidence in support of established risk factors for carpal tunnel syndrome. A comprehensive meta-analysis12 focusing on

Clinical features

The importance of the clinical presentation of carpal tunnel syndrome is demonstrated by the fact that the long-accepted gold standard for diagnosis is a comprehensive and accurate clinical history, along with the exclusion of other possible causes. The syndrome is characterised first by intermittent, nocturnal paraesthesias and dysaesthesias that increase in frequency and occur during waking hours.22 Subsequently, loss of sensation develops along with weakness and thenar muscle atrophy later

Diagnosis

If we were to ask physicians what test should be used to diagnose carpal tunnel syndrome, the answer would vary widely, depending on their specialty and clinical experience. As previously mentioned, in both clinical and research settings, clinical assessment is considered the gold standard and, in absence of motor and sensory deficits, taking an accurate history is crucial. Controversies exist regarding the need for confirmatory testing and the role of nerve conduction studies,

Non-surgical treatment

Various non-surgical treatments are available for the management of carpal tunnel syndrome (table 2). The first-line management approach should include education of the patient.40 Changes in habits (eg, limitation of wrist movement and reduction of heavy work activities) should be considered as a first-line approach and the use of ergonomically friendly work tools can be useful in reducing median nerve stress. However, there is little adequate evidence about the success of this approach. For

Surgical treatment

Surgical treatment, consisting of release of carpal tunnel content by transection of the transverse carpal ligament, is considered the most effective treatment to alter the relation between content (the median nerve and tendons) and container (the carpal tunnel; figure 2).

Surgical decompression can be done by a traditional open technique (long longitudinal wrist incision and direct visualisation of transverse carpal ligament); by a minimally invasive approach (short wrist incision); or by an

Surgical versus non-surgical treatment

As previously described, the literature shows that both non-surgical therapies and surgical intervention have clinical benefit in carpal tunnel syndrome.107, 108, 109 In a randomised trial comparing local corticosteroid injection with surgical decompression, both treatments were similarly effective at alleviating symptoms, with corticosteroids being more effective in short-term follow-up (3 months), and surgical release having additional benefit for symptom resolution in the long term (2-year

Conclusion and future directions

Although carpal tunnel syndrome is a well studied nerve entrapment syndrome, several important questions remain unanswered. Is confirmation by diagnostic testing necessary? Does clinical assessment provide enough information to guide the choice of treatment? Is electrophysiology needed? Is ultrasonography a potential alternative to nerve conduction studies?

The roles of electrophysiology and ultrasonography in diagnosis are well known, but their roles in management and treatment decision making

Search strategy and selection criteria

We searched PubMed, Cochrane, Embase, Web of Science, and Google Scholar for articles published in English between Jan 1, 2011, and Aug 1, 2016, using “carpal tunnel syndrome” as MeSH term in PubMed. We filtered the search for “randomised controlled trial”, “meta-analysis”, and “systematic review”. 119 articles were identified. After excluding inappropriate papers, we selected 79 articles (20 meta-analyses, 52 randomised controlled trials, and seven systematic reviews). Because of the paucity

References (113)

  • E Pratelli et al.

    Conservative treatment of carpal tunnel syndrome: comparison between laser therapy and fascial manipulation

    J Bodyw Mov Ther

    (2015)
  • A Dakowicz et al.

    Comparison of the long-term effectiveness of physiotherapy programs with low-level laser therapy and pulsed magnetic field in patients with carpal tunnel syndrome

    Adv Med Sci

    (2011)
  • NA Baker et al.

    The comparative effectiveness of combined lumbrical muscle splints and stretches on symptoms and function in carpal tunnel syndrome

    Arch Phys Med Rehabil

    (2012)
  • E Yao et al.

    Randomized controlled trial comparing acupuncture with placebo acupuncture for the treatment of carpal tunnel syndrome

    PM R

    (2012)
  • CP Yang et al.

    A randomized clinical trial of acupuncture versus oral steroids for carpal tunnel syndrome: a long-term follow-up

    J Pain

    (2011)
  • H Sim et al.

    Acupuncture for carpal tunnel syndrome: a systematic review of randomized controlled trials

    J Pain

    (2011)
  • HR Aslani et al.

    Comparison of carpal tunnel release with three different techniques

    Clin Neurol Neurosurg

    (2012)
  • M Tarallo et al.

    Comparative analysis between minimal access versus traditional accesses in carpal tunnel syndrome: a perspective randomised study

    J Plast Reconstr Aesthet Surg

    (2014)
  • JD England

    Entrapment neuropathies

    Curr Opin Neurol

    (1999)
  • K Wilson d'Almeida et al.

    Sickness absence for upper limb disorders in a French company

    Occup Med (Lond)

    (2008)
  • M Foley et al.

    The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State

    Am J Ind Med

    (2007)
  • RK Olney

    Carpal tunnel syndrome: complex issues with a “simple” condition

    Neurology

    (2001)
  • Practice parameter for carpal tunnel syndrome (summary statement)

    Neurology

    (1993)
  • I Atroshi et al.

    Prevalence of carpal tunnel syndrome in a general population

    JAMA

    (1999)
  • M Mondelli et al.

    Carpal tunnel syndrome incidence in a general population

    Neurology

    (2002)
  • JDP Bland et al.

    Clinical surveillance of carpal tunnel syndrome in two areas of the United Kingdom, 1991–2001

    J Neurol Neurosurg Psychiatry

    (2003)
  • JC Stevens

    AAEM minimonograph #26: the electrodiagnosis of carpal tunnel syndrome. American Association of Electrodiagnostic Medicine

    Muscle Nerve

    (1997)
  • CK Jablecki et al.

    Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. AAEM Quality Assurance Committee

    Muscle Nerve

    (1993)
  • R Shiri

    Hypothyroidism and carpal tunnel syndrome: a meta-analysis

    Muscle Nerve

    (2014)
  • L Padua et al.

    Systematic review of pregnancy-related carpal tunnel syndrome

    Muscle Nerve

    (2010)
  • MH Pourmemari et al.

    Diabetes as a risk factor for carpal tunnel syndrome: a systematic review and meta-analysis

    Diabet Med

    (2016)
  • R Shiri et al.

    The effect of excess body mass on the risk of carpal tunnel syndrome: a meta-analysis of 58 studies

    Obes Rev

    (2015)
  • Z Mediouni et al.

    Is carpal tunnel syndrome related to computer exposure at work? A review and meta-analysis

    J Occup Environ Med

    (2014)
  • R Shiri et al.

    Associations of cardiovascular risk factors, carotid intima-media thickness and manifest atherosclerotic vascular disease with carpal tunnel syndrome

    BMC Musculoskelet Disord

    (2011)
  • MH Pourmemari et al.

    Smoking and carpal tunnel syndrome: a meta-analysis

    Muscle Nerve

    (2014)
  • CH Shin et al.

    Carpal tunnel syndrome and radiographically evident basal joint arthritis of the thumb in elderly Koreans

    J Bone Joint Surg Am

    (2012)
  • L Padua et al.

    Italian CTS Study Group. Multiperspective assessment of carpal tunnel syndrome: a multicenter study

    Neurology

    (1999)
  • JC Stevens et al.

    Symptoms of 100 patients with electromyographically verified carpal tunnel syndrome

    Muscle Nerve

    (1999)
  • F Tecchio et al.

    Carpal tunnel syndrome modifies sensory hand cortical somatotopy: a MEG study

    Hum Brain Mapp

    (2002)
  • J Brüske et al.

    The usefulness of the Phalen test and the Hoffmann-Tinel sign in the diagnosis of carpal tunnel syndrome

    Acta Orthop Belg

    (2002)
  • JW Brandsma et al.

    Sensible manual muscle strength testing to evaluate and monitor strength of the intrinsic muscles of the hand: a commentary

    J Hand Ther

    (2001)
  • P Mafi et al.

    A systematic review of dynamometry and its role in hand trauma assessment

    Open Orthop J

    (2012)
  • J Geere et al.

    Power grip, pinch grip, manual muscle testing or thenar atrophy—which should be assessed as a motor outcome after carpal tunnel decompression? A systematic review

    BMC Musculoskelet Disord

    (2007)
  • RA Werner et al.

    Electrodiagnostic evaluation of carpal tunnel syndrome

    Muscle Nerve

    (2011)
  • CK Jablecki et al.

    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

    (2002)
  • JR Fowler et al.

    The sensitivity and specificity of ultrasound for the diagnosis of carpal tunnel syndrome: a meta-analysis

    Clin Orthop Relat Res

    (2011)
  • MS Cartwright et al.

    Evidence-based guideline: neuromuscular ultrasound for the diagnosis of carpal tunnel syndrome

    Muscle Nerve

    (2012)
  • C Barcelo et al.

    3-T MRI with diffusion tensor imaging and tractography of the median nerve

    Eur Radiol

    (2013)
  • S Buchan et al.

    Cochrane corner: ergonomic positioning or equipment for treating carpal tunnel syndrome

    J Hand Surg Eur Vol

    (2013)
  • D O'Connor et al.

    Ergonomic positioning or equipment for treating carpal tunnel syndrome

    Cochrane Database Syst Rev

    (2012)
  • Cited by (0)

    View full text