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The Electrodiagnosis of Ulnar Nerve Entrapment at the Elbow

Published online by Cambridge University Press:  02 December 2014

Ralph Z. Kern*
Affiliation:
Mount Sinai Hospital and the University Health Network; and the Division of Neurology, Department of Medicine, the University of Toronto, Toronto, Ontario, Canada
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Abstract

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Entrapment of the ulnar nerve at the elbow is the second most common focal peripheral neuropathy. Recent advances have facilitated the electrodiagnosis of this common nerve entrapment. The goals of electrodiagnosis are to localize ulnar nerve dysfunction, confirm that the disturbance is confined to the ulnar nerve, and assess the severity of ulnar nerve dysfunction. The goal of this review is to highlight the important advances in anatomy, neurophysiology and methodology that impact upon the electrodiagnosis of entrapment of the ulnar nerve at the elbow, illustrate the limits of electrodiagnosis, and discuss methodological issues that may be the subject of further study. Careful attention to elbow position, temperature, and conservative estimates of conduction block should be part of common practice. Awareness of anatomical variations in structural anatomy, anomalous innervation and fascicular arrangement of ulnar nerve fibers are required to interpret electrodiagnostic studies accurately. The most reliable finding is slowing of the ulnar across-elbow motor nerve conduction velocity to less than 50 m/sec while recording from the abductor digiti minimi muscle, and should be carefully interpreted in the presence of a polyneuropathy or other neurogenic process. Alternative techniques such as relative ulnar slowing in different ulnar nerve segments, use of alternative muscles, sensory and mixed nerve techniques provide complementary information, and like all nerve conduction studies are highly operator-dependent and should be used on a case by case basis. Recent studies have focused the electromyographer's attention on the use of shorter across-elbow segments (2-5 cm). This may offer a reasonable trade-off between sensitivity and measurement error and may result in improved electrodiagnosis.

Résumé:

RÉSUMÉ:

La compression du nerf cubital au niveau du coude est la deuxième neuropathie périphérique focale la plus fréquente. Des progrès récents en facilitent l'électrodiagnostic. Les buts de l'électrodiagnostic sont de localiser la dysfonction du nerf cubital, de confirmer que l'atteinte est limitée au nerf cubital et d'évaluer la sévérité de la dysfonction du nerf cubital. Le but de cette revue est de souligner les progrès importants réalisés en anatomie, en neurophysiologie et dans les outils diagnostiques qui ont un impact sur l'électrodiagnostic de la compression du nerf cubital au niveau du coude, d'illustrer les limites de l'électrodiagnostic et de discuter des aspects méthodologiques qu'il serait intéressant d'explorer davantage. On doit porter une attention particulière à la position du coude et à sa température, et une estimation conservatrice du blocage de conduction doit faire partie de la pratique courante. L'interprétation des études électrodiagnostiques nécessite une connaissance des variantes anatomiques structurales, des innervations anormales et de l'arrangement fasciculaire des fibres du nerf cubital. Le signe le plus fiable est le ralentissement de la vitesse de conduction quand le nerf franchit le coude à moins de 50 m/sec lors de l'enregistrement fait au niveau du muscle abducteur du petit doigt et devrait être interprété avec prudence en présence d'une polyneuropathie ou d'un autre processus neurogène. D'autres techniques comme le ralentissement cubital relatif dans différents segments du nerf cubital, l'utilisation d'autres muscles, des techniques pour les nerfs sensitifs et mixtes ajoutent une information complémentaire et, comme toutes les études de conduction nerveuse sont très dépendantes de l'opérateur, devraient être utilisées au cas par cas. Des études récentes ont attiré l'attention de l'électromyographiste sur l'utilisation de segments plus courts au niveau du coude (2 à 5 cm), ce qui peut offrir un compromis raisonnable entre la sensibilité et l'erreur de mesure et peut améliorer l'électrodiagnostic.

Type
Review Article
Copyright
Copyright © The Canadian Journal of Neurological 2003

References

1. Miller, RG. Ulnar Nerve Lesions. In: Brown, WF, Bolton, CF, (Eds). Clinical Electromyography. Stoneham, MA: Butterworths, 1987.Google Scholar
2. Campbell, WW, Carroll, DJ, Greenberg, MK, et al. Practice parameter: electrodiagnostic studies in ulnar neuropathy at the elbow. Neurology 1999; 52: 688690.Google Scholar
3. Campbell, WW, Carroll, DJ, Greenberg, MK, et al. The electrodiagnostic evaluation of patients with ulnar neuropathy at the elbow: literature review of the usefulness of nerve conduction studies and needle electromyography. Muscle Nerve 1999; 22: S175–S205.Google Scholar
4. Campbell, WW, Carol, DJ, Greenberg, MK, et al. Practice parameter for electrodiagnostic studies in ulnar neuropathy at the elbow: summary statement. Muscle Nerve 1999; 22: 408411.Google Scholar
5. Stewart, JD. Focal Peripheral Neuropathies. 3rd ed. Philadelphia, PA: Lippincott, Williams and Wilkins, 2000.Google Scholar
6. Dawson, DM, Hallett, M, Wilbourn, AJ, et al. Entrapment Neuropathies. 3rd ed. Philadelphia, PA: Lippincott, Williams, and Wilkins, 1998.Google Scholar
7. Bradshaw, D, Shefner, J. Ulnar neuropathy at the elbow. Neurol Clin 1999; 17: 447461.Google Scholar
8. Campbell, W. Ulnar neuropathy at the elbow. Muscle Nerve 2000; 23: 450452.Google Scholar
9. Campbell, W. Variations in anatomy of the ulnar nerve at the cubital tunnel: pitfalls in the diagnosis of ulnar neuropathy at the elbow. Muscle Nerve 1991; 14: 733738.Google Scholar
10. Kincaid, JC. AAEE minimonograph # 31: the electrodiagnosis of ulnar neuropathy at the elbow. Muscle Nerve 1988; 11: 10051015.Google Scholar
11. Campbell, WW, Pridgeon, RM, Sahni, KS. Entrapment neuropathy of the ulnar nerve at its point of exit from the flexor carpi ulnaris muscle. Muscle Nerve 1986; 11: 467470.CrossRefGoogle Scholar
12. Campbell, WW, Pridgeon, RM, Riaz, G, et al. Sparing of the flexor carpi ulnaris in ulnar neuropathy at the elbow. Muscle Nerve 1989; 12: 965967.CrossRefGoogle ScholarPubMed
13. Apfelberg, DB, Larson, SJ. Dynamic anatomy of the ulnar nerve at the elbow. Plast Reconstr Surg 1973; 51: 7681.CrossRefGoogle ScholarPubMed
14. Green, JR, Rayan, GM. The cubital tunnel: anatomic, histologic, and biomechanical study. J Shoulder Elbow Surg 1999; 8: 466470.Google Scholar
15. O’Driscoll, SW, Horii, E, Carmichael, SW, et al. The cubital tunnel and ulnar neuropathy. J Bone Joint Surg 1991; 73B: 613617.Google Scholar
16. Gelberman, RH, Yamaguchi, K, Hollstein, SB, et al. Changes in interstitial pressure and cross-sectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow: an experimental study in human cadavera. J Bone Joint Surg Am 1998; 80: 492501.Google Scholar
17. Childress, H. Recurrent ulnar nerve dislocation at the elbow. Clin Orthop 1975; 108:168173.Google Scholar
18. Werner, CO, Olin, P, Elmqvist, D. Pressures recorded in ulnar neuropathy. Acta Orthop Scand 1985; 56: 404406.Google Scholar
19. Spinner, RJ, O’Driscoll, SW, Davids, JR, et al. Cubitus varus associated with dislocation of both the medial portion of the triceps and the ulnar nerve. J Hand Surg 1999; 24A: 718726.Google Scholar
20. Spinner, RJ, Goldner, RD. Snapping of the medial head of the triceps: diagnosis and treatment. Techniques in Hand & Upper Extremity Surgery 2002; 6: 9197.Google Scholar
21. Spinner, RJ, O’Driscoll, SW, Jupiter, JB, Goldner, RD. Unrecognized dislocation of the medial portion of the triceps: another cause of failed ulnar nerve transposition. J Neurosurg 2000; 92: 5257.CrossRefGoogle ScholarPubMed
22. Leibovic, SJ, Hastings, H. Martin Gruber revisited. J Hand Surg 1992; 17A: 4753.Google Scholar
23. Marras, C, Midroni, G. Proximal Martin-Gruber Anastomosis mimicking ulnar neuropathy at the elbow. Muscle Nerve 1999; 22: 11321135.3.0.CO;2-9>CrossRefGoogle ScholarPubMed
24. LoMonanco, M. Padua, L, Gregori, B, et al. Ulnar innervation of the thenar eminence with preservation of median innervation of the first lumbrical muscles. Muscle Nerve 1997; 20: 629630.Google Scholar
25. Stewart, J. The variable clinical manifestations of ulnar neuropathies at the elbow. J Neurol Neurosurg Psychiatry 1987; 50: 252258.Google Scholar
26. Sunderland, S. Intraneural topography of radial, median, and ulnar nerves. Brain Nerve 1945; 68: 243299.CrossRefGoogle ScholarPubMed
27. Campbell, W. The electrodiagnostic evaluation of patients with ulnar neuropathy at the elbow: literature review of the usefulness of nerve conduction studies and needle electromyography. Muscle Nerve 1999; 22: S175–S205.Google Scholar
28. Practice parameter for electrodiagnostic studies in ulnar neuropathy at the elbow: summary statement. Arch Phys Med Rehabil 1999; 80: 357359.Google Scholar
29. Checkles, N, Russakov, A, Piero, D. Ulnar nerve conduction velocity-effect of elbow position on measurement. Arch Phys Med Rehabil 1970:362365.Google Scholar
30. Kothari, M, Preston, D. Comparison of the flexed and extended elbow positions in localizing ulnar neuropathy at the elbow. Muscle Nerve 1995; 18: 336340.Google Scholar
31. Bielawski, M, Hallett, M. Position of the elbow in determination of abnormal motor conduction of the ulnar nerve across the elbow. Muscle Nerve 1989; 12: 803809.Google Scholar
32. Kincaid, JC, Phillips, IL, Daube, JR. The evaluation of suspected ulnar neuropathy at the elbow. Normal conduction study values. Arch Neurol 1986; 43: 4447.Google Scholar
33. Britz, G, Haynor, D, Kuntz, C, et al. Ulnar nerve entrapment at the elbow: correlation of magnetic resonance imaging, clinical, electrodiagnostic, and intraoperative findings. Neurosurgery 1996; 38: 458465.Google Scholar
34. Brown, WF, Yates, SK. Percutaneous localization of conduction abnormalities in human entrapment neuropathies. Can J Neurol Sci 1982; 9: 391400.CrossRefGoogle ScholarPubMed
35. Maynard, FM, Stolov, WC. Experimental error in determination of nerve conduction velocity. Arch Phys Med Rehabil 1972; 53: 362372.Google ScholarPubMed
36. Landau, M, Diaz, M, Barner, K, Campbell, W. Changes in nerve conduction velocity across the elbow due to experimental error. Muscle Nerve 2002; 26: 838840.Google Scholar
37. Gert van Dijk, J, Meulstee, J, Zwarts, M, Spaans, F. What it the best way to assess focal slowing of the ulnar nerve? Clin Neurophysiol 2000; 112: 286293.CrossRefGoogle Scholar
38. Pridgeon, RM, Campbell, WW. Evaluating focal neuropathies: the long and short of it. Muscle Nerve 1991; 14: 881882.Google Scholar
39. Miller, R. The cubital tunnel syndrome: diagnosis and precise localization. Ann Neurol 1979; 6: 5659.Google Scholar
40. Kanakamedala, R, Simons, D, Porter, R, Zucker, R. Ulnar nerve entrapment at the elbow localized by short segment stimulation. Arch Phys Med Rehabil 1988; 69: 959963.Google Scholar
41. Campbell, WW, Pridgeon, RM, Sahni, KS. Short-segment incremental studies in the evaluation of ulnar neuropathy at the elbow. Muscle Nerve 1992; 15: 10501054.Google Scholar
42. Payan, J. Electrophysiological localization of ulnar nerve lesions. J Neurol Neurosurg Psychiat 1969; 32: 208220.Google Scholar
43. Azrielli, Y, Weimer, L, Lovelace, R, Gooch, C. The utility of segmental nerve conduction studies in ulnar neuropathy at the elbow. Muscle Nerve 2003; 27: 4650.CrossRefGoogle Scholar
44. Pickett, JB, Coleman, LL. Localizing ulnar nerve lesions to the elbow by motor conduction studies. Electromyogr Clin Neurophysiol 1984; 24: 343360.Google Scholar
45. Pickett, J. The use of regression equations in the localization of ulnar and peroneal nerve lesions. Electromyogr Clin Neurophysiol 1984; 24: 361368.Google Scholar
46. Schulte-Mattler, W, Muller, T, Georgiadis, D, et al. Length dependence of variables associated with temporal dispersion in human motor nerves. Muscle Nerve 2001; 24: 527533.Google Scholar
47. Olney, RK, Miller, RG. Conduction block in compression neuropathy: recognition and quantification. Muscle Nerve 1984; 7: 662667.Google Scholar
48. Taylor, PK. CMAP dispersion, amplitude decay and area decay in a normal population. Muscle Nerve 1993; 16: 11811187.Google Scholar
49. Weber, F. Conduction block and abnormal temporal dispersion-diagnostic criteria. Electromyogr Clin Neurophysiol 1997; 37: 305309.Google ScholarPubMed
50. Rhee, EK, England, JD, Sumner, AJ. A computer simulation of conduction block: effects produced by actual block versus interphase cancellation. Ann Neurol 1990; 28: 146156.Google Scholar
51. Rutkove, S, Geffroy, M, Lichtenstein, S. Heat-sensitive conduction block in ulnar neuropathy at the elbow. Clin Neurophysiol 2001; 112: 280285.Google Scholar
52. Kern, RZ, Alex, A. Reference electrode contribution to the ADM CMAP (Abstract). Can J Neurol Sci 1993; 20(suppl 2): S53.Google Scholar
53. McCluskey, L, Feinberg, D, Cantor, C, Bird, S. “Pseudo-conduction block” in vasculitic neuropathy. Muscle Nerve 1999; 22: 13611366.Google Scholar
54. Hermann, DN, Preston, DC, McIntosh, KA, Logigan, EL. Localization of ulnar neuropathy with conduction block across the elbow. Muscle Nerve 2001; 24: 698700.Google Scholar
55. Contreras, M, Warner, M, Charbonneau, WJ. Anatomy of the ulnar nerve at the elbow: potential relationship of acute ulnar neuropathy to gender differences. Clin Anatomy 1998; 11: 372378.Google Scholar
56. Campbell, WW, Sahni, SK, Pridgeon, RM, et al. Intraoperative electroneurography: management of ulnar neuropathy at the elbow. Muscle Nerve 1988; 11: 7581.Google Scholar
57. Campbell, W. The value of inching techniques in the diagnosis of focal nerve lesions. Muscle Nerve 1998; 21: 15541556.3.0.CO;2-Y>CrossRefGoogle ScholarPubMed
58. Geiringer, S. Inching techniques are of limited value. Muscle Nerve 1998; 21: 15571558.Google Scholar
59. Kothari, M, Heistand, M, Rutkove, SB. Three ulnar nerve conduction studies in patients with ulnar neuropathy at the elbow. Arch Phys Med Rehabil 1998; 79: 8789.Google Scholar
60. Tackmann, W, Vogel, P, Kaeser, H, Ettlin, T. Sensitivity and localizing significance of motor and sensory electroneurographic parameters in the diagnosis of ulnar nerve lesions at the elbow. J Neurol 1984; 231: 204211.Google Scholar
61. Benecke, R, Conrad, B. The value of electrophysiological examination of the flexor carpi ulnaris muscle in the diagnosis of ulnar nerve lesions at the elbow. J Neurol 1980; 223: 207217.Google Scholar
62. Felsenthal, G, Brockman, PS, Mondell, DL, Hilton, EB. Proximal forearm ulnar nerve conduction techniques. Arch Phys Med Rehabil 1986; 67: 440444.Google ScholarPubMed
63. Kern, RZ, Alex, AA. Quantitative CMAP analysis in ulnar neuropathy (Abstract). Muscle Nerve 1994; 17: 1087.Google Scholar
64. Lo, Y, Dan, Y, Lee, M, Ratnagopal, P. Segmental mixed nerve conduction studies in ulnar neuropathy at the elbow. J Clin Neurophysiol 2001; 18: 456459.Google Scholar
65. Merlevede, K, Theys, P, van Hees, J. Diagnosis of ulnar neuropathy: a new approach. Muscle Nerve 2000; 23: 478481.Google Scholar
66. Odabasi, Z, Oh, SJ, Claussen, GC, Kim, DS. New near-nerve needle nerve conduction technique: differentiating epicondylar from cubital tunnel ulnar neuropathy. Muscle Nerve 1999; 22: 718723.Google Scholar
67. Bhala, R. Electrodiagnosis of ulnar nerve lesions at the elbow. Arch Phys Med Rehabil. 1976; 57: 206212.Google Scholar
68. Montagna, P, Liguori, R. The motor Tinel sign: a useful sign in entrapment neuropathy? Muscle Nerve 2000; 23: 976978.Google Scholar