Abstract
Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of peripheral nerves, with an incidence of 1–3 patients in 1000. CTS typically occurs between 45 and 60 years of age, and it is more frequent in women than in men. The main cause of CTS is chronic compression of the median nerve and ischemic suffering secondary to increased pressure in the carpal tunnel. There are many possible causes of CTS, which can be differentiated into idiopathic causes, which include most cases, and secondary causes. Classical CTS diagnosis is based on the patient’s clinical examination and electrophysiological tests, such as electromyography and nerve conduction studies. The latter are helpful for determining the site of nerve compression, assessing its severity, monitoring the course of the disease after therapy, and excluding other causes of median nerve pain, such as cervical radiculopathies, brachial plexopathies, polyneuropathy, or other forms of mononeuropathies. However, clinical examination and electrophysiological tests are not able to differentiate idiopathic forms from secondary forms of CTS, and discrepancies are possible between clinical examination and electrophysiological tests (false negatives). Ultrasound examination is able to recognize most of the secondary forms of CTS. It can evaluate the morphological alterations of the nerve and correlate them with the severity of nerve suffering in all cases, even idiopathic ones, with a sensitivity and specificity equal to those of electrophysiological tests. It can also highlight some anatomical predisposing variants or conditions that may represent contraindications to minimally invasive treatments. Ultrasound examination also plays a fundamental role in evaluating patients with an unfavorable outcome after surgical treatment.
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References
Luchetti R, Amadio P (2007) Carpal tunnel syndrome. Springer-Verlag, Berlin, pp 32–59
Lee JC, Healy JC (2005) Normal sonographic anatomy of the wrist and hand. Radiographics 25:1577–1590
Presazzi A, Bortolotto C, Zacchino M, Madonia L, Draghi F (2011) Carpal tunnel: normal anatomy, anatomical variants and ultrasound technique. J Ultrasound 14(1):40–46
Gitto S, Draghi F (2016) Normal sonographic anatomy of the wrist with emphasis on assessment of tendons, nerves, and ligaments. J Ultrasound Med 35(5):1081–1094
Silvestri E, Martinoli C, Derchi LE et al (1995) Echotexture of peripheral nerves: correlation bewteen US and histologic findings and criteria to differentiate tendons. Radiology 197:291–296
Barbuto L, Di Serafino M, Della Vecchia N, Rea G, Esposito F, Vezzali N, Ferro F, Caprio MG, Vola EA, Romeo V, Vallone G (2019) Pediatric musculoskeletal ultrasound: a pictorial essay. J Ultrasound 22(4):491–502
Mitchell I, Chesney A, Seal S et al (2009) Anatomical variations of the carpal tunnel structures. Can J Plast Surg 17:3–7
Chen L, Chen J, Hu B, Jiang LX (2017) Sonographic findings of the bifid median nerve and persistent median artery in carpal tunnel: a preliminary study in Chinese individuals. Clinics 72(6):358–362
Sookur PA, Naraghi AM, Bleakney RR et al (2008) Accessory muscles: anatomy, symptoms and radiologic evaluation. Radiographics 28:481–499
Rodrigues J, Santos-Faria D, Silva J, Azevedo S, Tavares-Costa J, Teixeira F (2019) Sonoanatomy of anterior forearm muscles. J Ultrasound 22(3):401–405
Gitto S, Draghi AG, Draghi F (2018) Sonography of non-neoplastic disorders of the hand and wrist tendons. J Ultrasound Med 37(1):51–68
El Miedany YM, Aty SA, Ashour S (2004) Ultrasonography versus nerve conduction study in patients with carpal tunnel syndrome: substantive or complementary tests? Rheumatology 43:887–895
Rahmani M, Ghasemi Esfe AR, Vaziri-Bozorg SM et al (2011) The ultrasonographic correlates of carpal tunnel syndrome in patients with normal electrodiagnostic tests. Radiol Med 116:489–496
Fowler JR, Munsch M, Tosti R et al (2014) Comparison of ultrasound and electrodiagnostic testing for diagnosis of carpal tunnel syndrome: study using a validated clinical tool as the reference standard. J Bone Joint Surg Am 3:96–113
Martinoli C, Bianchi S, Gandolfo N et al (2000) US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs. Radiographics 20:199–217
Nakamichi KI, Tachibana S (2000) Enlarged median nerve in idiopathic carpal tunnel syndrome. Muscle Nerve 23:1713–1718
Miwa M, Miwa H (2011) Ultrasonography of carpal tunnel syndrome: clinical significance and limitations in elderly patients. Intern Med 50:2157–2161
Mosier BA, Hughes TB (2013) Recurrent carpal tunnel syndrome. Hand Clin 29:427–434
Wong SM, Griffith JF, Hui ACF, Tang A, Wong KS (2002) Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome. Arthritis Rheum 46:1914–1921
Hammer HB, Hovden IAH, Haavardsholm EA, Kvien TK (2006) Ultrasonography shows increased cross-sectional area of the median nerve in patients with arthritis and carpal tunnel syndrome. Rheumatology 45:584–588
Ghasemi-Esfe AR, Khalilzadeh O, Vaziri-Bozorg SM et al (2011) Color and power Doppler US for diagnosing carpal tunnel syndrome and determining its severity: a quantitative image processing method. Radiology 261:499–506
Karadag YS, Karadag Ö, Cicekli E et al (2010) Severity of carpal tunnel syndrome assessed with high frequency ultrasonography. Rheumatol Int 30:761–765
Klauser A, Halpern EJ, De Zordo T et al (2009) Carpal tunnel syndrome assessment with US: value of additional cross-sectional area measurements of the median nerve in patients versus healthy volunteers. Radiology 250:171–177
Klauser A, Halpern EJ, Faschingbauer R et al (2011) Bifid median nerve in carpal tunnel syndrome: assessment with US cross-sectional area measurement. Radiology 250:808–815
Abicalaf CA, De Barros N, Sernik RA et al (2007) Ultrasound evaluation of patients with carpal tunnel syndrome before and after endoscopic release of the transverse carpal ligament. Clin Radiol 62:891–896
Sueleyman T, Staub F, Dombert T et al (2015) Sonographic short-term follow-up after surgical decompression of the median nerve at the carpal tunnel: a single-center prospective observational study. Neurosurg Focus 39:1–5
Vidoni A, Shrivastava M, Botchu R (2018) Intrasynovial spindle cell lipoma of the deep flexor of the middle finger causing intermittent carpal tunnel syndrome-case report and review of the literature. J Ultrasound. https://doi.org/10.1007/s40477-018-0281-x(Epub ahead of print)
Tan TC, Yeo CJ, Smith EW (2011) High definition ultrasound as diagnostic adjunct for incomplete carpal tunnel release. Hand Surg 16:289–294
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Gervasio, A., Stelitano, C., Bollani, P. et al. Carpal tunnel sonography. J Ultrasound 23, 337–347 (2020). https://doi.org/10.1007/s40477-020-00460-z
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DOI: https://doi.org/10.1007/s40477-020-00460-z