Clinical utility of residual latency in ulnar neuropathy at elbow: Is there any correlation?

Authors

1 Department of Physical Medicine and Rehabilitation, Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Neurology, Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Residual latency is the time difference between measured and predicted distal conduction time. We investigated ulnar nerve residual latency in patients with ulnar neuropathy at elbow for the possibility of its clinical utility. Materials and Methods: In a cross-sectional study and based on the inclusion and exclusion criteria, ulnar nerve residual latency was calculated by using standard settings in 63 hands of patients who had signs and symptoms suggesting ulnar neuropathy at elbow and 94 healthy hands as the control group. Results: Mean ulnar nerve residual latency for case and control groups were 1.82 ± 0.45 and 1.59 ± 0.54 ms, respectively, which showed a statistically significant difference (P = 0.01). There was no significant difference in mean ulnar nerve residual latency between males and females and also between right and left hands ( P > 0.05). By considering different cut-off points, the sensitivity and specificity of a residual latency of 2.86 ms were 70% and 56%, respectively. Conclusion: Ulnar nerve residual latency may reflect the effects of an axonal injury at elbow on distal ulnar motor fibers. So, its measurement may help in the diagnosis of ulnar neuropathy at elbow.

Keywords

1. Kaplan P, Sahgal V. Residual latency: New applications of an old technique. 
Arch Phys Med Rehabil 1978;59:24-7.
2. Radziwill AJ, Steck AJ, Renaud S, Fuhr P. Distal motor latency and 
residual latency as sensitive markers of anti-MAG polyneuropathy. J Neurol 
2003;250:962-6.
3. Cutts S. Cubital tunnel syndrome. Postgrad Med J 2007;83:28-31.
4. Jia ZR, Shi X, Sun XR. Pathogenesis and electrodiagnosis of cubital tunnel 
syndrome. Chin Med J (Engl) 2004;117:1313-6.
5. Kaplan PE. Sensory and motor residual latency measurements in healthy 
patients and patients with neuropathy-part 1. J Neurol Neurosurg Psychiatry 
1976;39:338-40.
6. Bae JS, Kim BJ. Subclinical diabetic neuropathy with normal conventional 
electrophysiological study. J Neurol 2007;254:53-9.
7. Suh J, Park JH, Jung KH, Chang JY, Choi JH, Kim YS. The clinical 
significance of residual latency in diagnosis of diabetic neuropathy. J Korean 
Acad Rehabil Med 1998;22:1254-62.
8. Dumitru D, Amato AA, Zwartz MJ. Special nerve conduction techniques. 
In: Dumitru D, Amato AA, Zwarts M, editors. Electrodiagnostic Medicine. 
2nd ed. Philadelphia: Hanley and Belfus; 2002. p. 196.
9. Dumitru D, Amato AA, Zwartz MJ. Special nerve conduction techniques. 
In: Dumitru D, Amato AA, Zwarts M, editors. Electrodiagnostic Medicine. 
2nd ed. Philadelphia: Hanley and Belfus; 2002. p. 201.
10. Dumitru D, Amato AA, Zwartz MJ. Special nerve conduction techniques. 
In: Dumitru D, Amato AA, Zwarts M, editors. Electrodiagnostic Medicine. 
2nd ed. Philadelphia: Hanley and Belfus; 2002. p. 1081.
11. Kraft GH, Halvorson GA. Median nerve residual latency: Normal value and use 
in diagnosis of carpal tunnel syndrome. Arch Phys Med Rehabil 1983;64:221-6.
12. Uzar E, Tamam Y, Acar A, Yusel 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.
13. Kuntzer T. Carpal tunnel syndrome in 100 patients: Sensitivity, specificity of 
multi-neurophysiological procedures and estimation of axonal loss of motor, 
sensory and sympathetic median nerve fibers. J Neurol Sci 1994;127:221-9.
14. 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.
15. Anantharaman V, Bhatnagar OP. Influence of age on residual latency. Indian 
J Physiol Pharmacol 1977;21:141-3