Comparison of Interpolation Methods in the Diagnosis of Carpal Tunnel Syndrome

Year 2018, Volume: 35 Issue: 5, 378 - 383, 01.09.2018

Veysel Alcan Murat Zinnuroğlu Gülçin Kaymak Karataş Elliot Bodofsky

Abstract

Background: Diagnosis of carpal tunnel syndrome is based on clinical symptoms, examination findings, and electrodiagnostic studies. For carpal tunnel syndrome, the most useful of these are nerve conduction studies. However, nerve conduction studie can result in ambiguous or false-negative results, particularly for mild carpal tunnel syndrome. Increasing the number of nerve conduction studie tests improves accuracy but also increases time, cost, and discomfort. To improve accuracy without additional testing, the terminal latency index and residual latency are additional calculations that can be performed using the minimum number of tests. Recently, the median sensory-ulnar motor latency difference was devised as another way to improve diagnostic accuracy for mild carpal tunnel syndrome.Aims: The median sensory-ulnar motor latency difference, terminal latency index, and residual latency were compared for diagnostic accuracy according to severity of carpal tunnel syndrome.Study Design: Diagnostic accuracy study.Methods: A total of 657 subjects were retrospectively enrolled. The carpal tunnel syndrome group consisted of 546 subjects with carpal tunnel syndrome according to nerve conduction studie (all severities). The control group consisted of 121 subjects with no hand symptoms and normal nerve conduction studie. All statistical analyses were performed using SAS v9.4. Means were compared using one-way ANOVA with the Bonferroni adjustment. Sensitivity, specificity, positive predictive value, and negative predictive value were compared, including receiver operating characteristic curve analysis.Results: For mild carpal tunnel syndrome, the median sensory-ulnar motor latency difference showed higher specificity and positive predictive value rates (0.967 and 0.957, respectively) than terminal latency index (0.603 and 0.769, respectively) and residual latency (0.818 and 0.858, respectively). The area under the receiver operating characteristic was highest for the median sensory-ulnar motor latency difference (0.889), followed by the residual latency (0.829), and lastly the terminal latency index (0.762). Differences were statistically significant (median sensory-ulnar motor latency difference being the most accurate). For moderate carpal tunnel syndrome, sensitivity and specificity rates of residual latency (0.989 and 1.000) and terminal latency index (0.983 and 0.975) were higher than those for median sensory-ulnar motor latency difference (0.866 and 0.958). Differences in area under the receiver operating characteristic curve were not significantly significant, but median sensory-ulnar motor latency difference sensitivity was lower. For severe carpal tunnel syndrome, residual latency yielded 1.000 sensitivity, specificity, positive predictive value, negative predictive value and area beneath the receiver operating characteristic curve. Differences in area under the receiver operating characteristic curve were not significantly different.Conclusion: The median sensory-ulnar motor latency difference is the best calculated parameter for diagnosing mild carpal tunnel syndrome. It requires only a simple calculation and no additional testing. Residual latency and the terminal latency index are also useful in diagnosing mild to moderate carpal tunnel syndrome.

Keywords

Carpal tunnel syndrome, diagnosis, interpolation, neural conduction

References

• 1. Aminoff MJ. Electromyography in Clinical Practice. 2th ed. USA: Churchill Livingstone Inc; 1987:165-96.
• 2. Rosenbaum R. Carpal Tunel Syndrome. In: Johnson RT, Griffin WJ, editors. Current therapy in neurologic disease. 5th ed. USA: Mosby-Year book Inc; 1997:374-7.
• 3. Jablecki CK, Andary MT, So YT, Wilkins DE, Williams FH. 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;16:1392-414.
• 4. Rempel D, Evanoff B, Amadio PC, de Krom M, Franklin G, Franzblau A, et al. Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies. Am J Public Health 1998;88:1447-51.
• 5. Chang MH, Liu LH, Lee YC, Wei SJ, Chiang HL, Hsieh PF. Comparison of sensitivity of trancarpal median motor conduction velocity and conventional conduction techniques in electrodiagnosis of carpal tunnel syndrome. Clin Neurophysiol 2006;117:984-91.
• 6. Keith MW, Masear V, Chung K, Maupin K, Andary M, Amadio PC, et al. Diagnosis of Carpal Tunnel Syndrome. J Am Acad Orthop Surg 2009;17:389-96.
• 7. Kohara N. Clinical and Electrophysiological Findings in Carpal Tunnel Syndrome. Brain Nerve 2007;59:1229-38.
• 8. Sandin KJ, Asch SM, Jablecki CK, Kilmer DD, Nuckols TK; Carpal Tunnel Quality Group. Clinical quality measures for electrodiagnosis in suspected carpal tunnel syndrome. Muscle Nerve 2010;41:444-52.
• 9. Demirci S, Sonel B. Comparison of sensory conduction techniques in the diagnosis of mild idiopathic carpal tunnel syndrome: which finger, which test? Rheumatol Int 2004;24:217-20.
• 10. Park KM, Shin KJ, Park J, Ha SY, Kim SE. The Usefulness of Terminal Latency Index of Median Nerve and F-Wave Difference Between Median and Ulnar Nerves in Assessing the Severity of Carpal Tunnel Syndrome. J Clin Neurophysiol 2014;31:162-8.
• 11. Kuntzer T. Carpal tunnel syndrome in 100 patients: sensitivity, specificity of multineurophysiological procedures and estimation of axonal loss of motor, sensory and sympathetic median nerve fibers. J Neurol Sci 1994;127:221-9.
• 12. Simovic D, Weinberg DH. The median nerve terminal latency index in carpal tunnel syndrome: a clinical case selection study. Muscle Nerve 1999;22:573-7.
• 13. Bodofsky EB, Wu KD, Campellone JV, Greenberg WM, Tomaio AC. A sensitive new median- ulnar technique for diagnosing mild Carpal Tunnel Syndrome. Electromyogr Clin Neurophysiol 2005;45:139-44.
• 14. Padua L, Pasqualetti P, Rosenbaum R. One patient, two carpal tunnels: statistical and clinical analysis by hand or by patient? Clin Neurophysiol 2005;116:241-3.
• 15. Padua L, LoMonaco M, Gregori B, Valente EM, Padna R, Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997;96:211-7.
• 16. Cohen JF, Korevaar DA, Altman DG, Bruns DE, Gatsonis CA, Hooft L, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: explanation and elaboration. BMJ Open 2016;6:e012799.
• 17. De Lean J. Transcarpal median sensory conduction: detection of latent abnormalities in mild carpal tunnel syndrome. Can J Neurol Sci 1988;15:388-93.
• 18. Walters RJ, Murray NM. Transcarpal motor conduction velocity in carpal tunnel syndrome. Muscle Nerve 2001;24:966-8.
• 19. Chang MH, Wei SJ, Chiang HL, Wang HM, Hsieh PF, Huang SY. Comparison of motor conduction techniques in the diagnosis of carpal tunnel syndrome. Neurology 2002;58:1603-7.
• 20. Bodofsky EB. Diagnosing mild carpal tunnel syndrome with interpolation. Electromyogr Clin Neurophysiol 2004;44:379-83.
• 21. Bahrami MH, Rayegani SM, Nouri F. Study of interpolation method in diagnosis of carpal tunnel syndrome and comparison with midpalm antideromic sensory method. Electromyogr Clin Neurophysiol 2009;49:259-62.
• 22. Boonyapisit K, Katirji B, Shapiro BE, Preston DC. Lumbrical and interossei recording in severe carpal tunnel syndrome. Muscle Nerve 2002;25:102-5.
• 23. Shahani BT, Young RR, Potts F, Maccabee P: Terminal latency index and late response studies in motor neuron disease, peripheral neuropathies and entrapment syndromes. Acta Neurol Scand 1979;60:118.
• 24. Uzar E, Tamam Y, Acar A, Yucel Y, Palanci Y, Cansever S, et al. Sensitivity and specificity of terminal latency index and residual latency in the diagnosis of carpal tunnel syndrome. Eur Rev Med Pharmacol Sci 2011;15:1078-84.
• 25. Khosrawi S, Dehghan F. Determination of the median nerve residual latency values in the diagnosis of carpal tunnel syndrome in comparison with other electrodiagnostic parameters. J Res Med Sci 2013;18:934-8.
• 26. Perić Z, Sinanović O. Sensory-Motor Index Is Useful Parameter In Electroneurographical Diagnosis Of Carpal Tunnel Syndrome. Bosn J Basic Med Sci 2006;6:23-7.
• 27. Gianneschi F, Dominici F, Milani P, Biasella A, Rossi A. Evidence of altered motor axon properties of the ulnar nerve in carpal tunnel syndrome. Clin Neurophysiol 2007;118:1569-76.
• 28. Yemisci OU, Yalbuzdag SA, Cosar SN, Oztop P, Karatas M. Ulnar nerve conduction abnormalities in carpal tunnel syndrome. Muscle Nerve 2011;44:352-7.
• 29. Chammas M, Boretto J, Burmann LM, Ramos RM, Dos Santos Neto FC, Silva JB. Carpal tunnel syndrome - Part I (anatomy, physiology, etiology and diagnosis). Rev Bras Ortop 2014;49:429-36.
• 30. Norris AH, Shock NW, Wagman IH. Age changes in maximum conduction velocity of motor fibers of human ulnar nerves. J Appl Physiol 1953;5:589-93.