The Best Cutoff Point for Median Nerve Cross Sectional Area at The Level of Carpal Tunnel Inlet

  • Payam Sarraf Department of Neurology, Iranian Center of Neurological Research, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
  • Mahrooz Malek Department of Radiology, Medical Imaging Center, Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Imam Khomeini Hospital, Tehran Iran.
  • Mahsa Ghajarzadeh Department of Neurology, Brain and Spinal Injury Research Center (BASIR), Tehran University of Medical Sciences, Tehran, Iran.
  • Shahin Miri Department of Medical, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
  • Ehsan Parhizgar Department of Medical, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
  • Seyedeh Zahra Emami-Razavi Mail Department of Physical Medicine & Rehabilitation, Brain and Spinal Injury Research Center (BASIR), Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Keywords:
Carpal tunnel syndrome, Ultrasound, Cross sectional area, Diagnostic accuracy

Abstract

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. It accounts 90% of all entrapment neuropathies all over the world. Ultrasound is a non-invasive, cost effective and available para-clinical method which could be applied for CTS diagnosis. Cross-sectional area of the median nerve at the level of the inlet is considered as a diagnostic criterion in CTS cases. In this study, thirty-eight patients with electrophysiologically confirmed idiopathic CTS and 22 healthy controls were enrolled. Seventy-one affected nerves and 42 unaffected nerves were evaluated within 14 days after electrophysiological examination. The largest cross-sectional area (CSA) was measured at the level of the carpal tunnel inlet and the maximum nerve perimeter was also recorded by means of the software. Mean CSA and perimeter were 14.02 ± 4.5 mm2 and 1.7±0.28m in all patients and 8.2±2.1 mm2, 1.3±0.19 m in controls (P<0.001, P<0.001). Mean CSA and Perimeter were significantly different between patient's groups and control. The best cut off point for CSA of the tunnel inlet was 10.5 mm2 with sensitivity and specificity of 80% and 76% (AUC (Area under the Curve) = 0.9, P<0.001). The best cut off point for inlet perimeter was 1.44 m with sensitivity and specificity of 85% and 77 % (AUC=0.87, P<0.001). Our findings showed that median nerve CSA at carpal tunnel inlet could be used as the diagnostic criteria for CTS.

References

Atroshi I, Gummesson C, Johnsson R, et al. Prevalence of carpal tunnel syndrome in a general population. JAMA 1999;282(2):153-8.

Aroori S, Spence RA. Carpal tunnel syndrome. Ulster Medical J 2008;77(1):6-17.

Mondelli M, Giannini F, Giacchi M. Carpal tunnel syndrome incidence in a general population. Neurology 2002;58(2):289-94.

Jablecki CK, Andary MT, So YT, 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;16(2):1392-414

Witt JC, Hentz JG, Stevens JC. Carpal tunnel syndrome with normal nerve conduction studies. Muscle Nerve 2004;29(4):515-22.

Pinilla I, Martin-Hervas C, Sordo G, et al. The usefulness of ultrasonography in the diagnosis of carpal tunnel syndrome. J Hand Surg Eur Vol 2008;33(4):435-9.

Mohammadi A, Afshar A, Etemadi A, et al. Diagnostic value of cross-sectional area of median nerve in grading severity of carpal tunnel syndrome.Arch Iran Med 2010;13(6):516-21.

Lee D, van Holsbeeck MT, Janevski PK, et al. Diagnosis of carpal tunnel syndrome. Ultrasound versus electromyography. Radiol Clin North Am 1999; 37(4):859-72.

Padua L, LoMonaco M, Gregori B, et al. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997;96(4):211-7.

Ziswiler HR, Reichenbach S, Vogelin E, et al. Diagnostic value of sonography in patients with suspected carpal tunnel syndrome: a prospective study. Arthritis Rheum 2005;52(1):304-11.

Wong SM, Griffith JF, Hui AC, et al. Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome. Arthritis Rheum 2002;46(7):1914-21.

Yesildag A, Kutluhan S, Sengul N, et al. The role of ultrasonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome. Clin Radiol 2004;59(10):910-5.

Naranjo A, Ojeda S, Mendoza D, et al. What is the diagnostic value of ultrasonography compared to physical evaluation in patients with idiopathic carpal tunnel syndrome? Clin Exp Rhemutatol 2007;25(6):853-9.

Dalili AR, Mardanikivi M, Alizadeh A, et al. Comparison between Sonography and Electrodiagnostic Testing in the Diagnosis of Carpal Tunnel Syndrome. Anesthesiol Pain 2011;2(5):43-51.

Ashraf AR, Jali R, Moghtaderi AR, et al. The diagnostic value of ultrasonography in patients with electrophysiologically confirmed carpal tunnel syndrome. Electromyogr Clin Neurophysiol 2009;49(1):3-8.

Kwon BC, Jung KI, Baek GH. Comparison of sonography and electrodiagnostic testing in the diagnosis of carpal tunnel syndrome. J Hand Surg Am 2008;33(1):65-71.

Kang S, Known HK, Kim KH, et al. Ultrasonography of median nerve and electrophysiologic severity in carpal tunnel syndrome. Ann Rehab Med 2012;36(1):72-9

Yazdchi M, Kazem MK,Tarzemani, et al. Sensitivity and specificity of median nerve ultrasonography in diagnosis of carpal tunnel syndrome. Int J Gen Med 2012;5(1):99-103.

Padua L, Pazzaglia C, Caliandro P, et al. Carpal tunnel syndrome: ultrasound, neurophysiology, clinical and patient-oriented assessment. Clin Neurophysiol 2008;119(9):2064-9.

Visser LH, Smidt MH, Lee ML. High-resolution sonography versus EMG in the diagnosis of carpal tunnel syndrome. J Neurol Neurosurg Psychiatry 2008;79(1):63-7.

El Miedany YM, Aty SA, Ashour S. Ultrasonography versus nerve conduction study in patients with carpal tunnel syndrome: substantive or complementary tests? Rheumatology (Oxford) 2004;43(7):887-95.

Moran L, Perez M, Esteban A, et al. Sonographic measurement of cross-sectional area of the median nerve in the diagnosis of carpal tunnel syndrome: correlation with nerve conduction studies. J Clin Ultrasound 2009;37(3):125-31.

Ghasemi-Esfe AR, Khalilzadeh O, Mazloumi M, et al. Combination of high-resolution and color Doppler ultrasound in diagnosis of carpal tunnel syndrome. Acta Radilogica 2011;52(2):191-7.

de Krom MC, de Krom CJ, Spaans F. Carpal tunnel syndrome: diagnosis, treatment, prevention, and its relevance to dentistry. Ned Tijdschr Tandheelkd 2009;116(2): 97-101.

Karadag YS, Karada O, Ciçekli E, et al. Severity of carpal tunnel syndrome assessed with high frequency ultrasonography. Rheumatol Int 2010;30(6):761-5.

Lee CH, Kim TK, Yoon ES, et al. Correlation of highresolution ultrasonographic _ndings with the clinical symptoms and electrodiagnostic data in carpal tunnel syndrome. Ann Plast Surg 2005;54(1):20-3.

Stein D, Neufeld A, Pasternak O, et al. Diffusion tensor imaging of the median nerve in healthy and carpal tunnel syndrome subjects. J Magn Reson Imaging 2009;29(3):657-62.

How to Cite
1.
Sarraf P, Malek M, Ghajarzadeh M, Miri S, Parhizgar E, Emami-Razavi SZ. The Best Cutoff Point for Median Nerve Cross Sectional Area at The Level of Carpal Tunnel Inlet. Acta Med Iran. 52(8):613-618.
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