Diagnostic Value of Compound Nerve Action Potential in Ulnar Neuropathy at the Elbow
Background: Ulnar neuropathy is the second most common neuropathy of the upper extremity. However, routine electrodiagnostic tests may not reveal some cases. To determine the diagnostic value of compound nerve action potential (CNAP) of the ulnar nerve as a complementary test, this study was done.
Methods: In a cross-sectional analytical study, 34 subjects (68 limbs) who had presented with clinical symptoms and signs of the ulnar neuropathy were evaluated with CNAP. Then the subjects were re-evaluated with standard electrodiagnostic tests. Subjects with neuropathy based on standard electrodiagnostic tests were assigned to the patient group and those without it were assigned to the healthy group. Data were analyzed with the use of receiver operating characteristic (ROC) analysis.
Results: The latency and amplitude parameters had diagnostic value given the significance of the area under the ROC curve. In relation to the latency parameter, the two thresholds which had relatively acceptable accuracy were 0.2 ms and 0.7 ms; in patients in whom the difference between the peak latency of the healthy and symptomatic sides was more than 0.7 ms, at likelihood ratio positive (LR+) = 5.7 and specificity = 95%, the results were in favor of ulnar neuropathy.
Conclusion: CNAP evaluation has diagnostic value and can be used as an adjunct to other diagnostic techniques in suspected cases of ulnar neuropathy in the elbow region.
2. Raeissadat SA, Youseffam P, Bagherzadeh L, Rayegani SM, Bahrami MH, Eliaspour D. Electrodiagnostic findings in 441 patients with ulnar neuropathy - a retrospective study. Orthop Res Rev 2019; 11: 191-8.
3. Farzan M, Espandar R, Fallah Y, Farhoud AR. Frequency of upper extremity nerve entrapment syndromes in surgically operated patients: A ten- year study. Tehran Univ Med J 2009; 67(9): 672-7. [In Persian].
4. Jose RM, Bragg T, Srivastava S. Ulnar nerve compression in Guyon's canal in the presence of a tortuous ulnar artery. J Hand Surg Br 2006; 31(2): 200-2.
5. Eliaspour D, Sedighipour L, Hedayati-Moghaddam MR, Rayegani SM, Bahrami MH, Roghani RS. The pattern of muscle involvement in ulnar neuropathy at the elbow. Neurol India 2012; 60(1): 36-9.
6. Robertson C, Saratsiotis J. A review of compressive ulnar neuropathy at the elbow. J Manipulative
Physiol Ther 2005; 28(5): 345.
7. Campbell WW. Guidelines in electrodiagnostic medicine. Practice parameter for electrodiagnostic studies in ulnar neuropathy at the elbow. Muscle Nerve Suppl 1999; 8: S171-S205.
8. Yoon JS, Walker FO, Cartwright MS. Ulnar neuropathy with normal electrodiagnosis and abnormal nerve ultrasound. Arch Phys Med Rehabil 2010; 91(2): 318-20.
9. Heise CO, Toledo SM. Mixed latency difference for diagnosis of ulnar neuropathy at the elbow. Arch Phys Med Rehabil 2006; 87(3): 408-10.
10. Merlevede K, Theys P, van Hees J. Diagnosis of ulnar neuropathy: A new approach. Muscle Nerve 2000; 23(4): 478-81.
11. Nakamichi K, Tachibana S, Ida M, Yamamoto S. Patient education for the treatment of ulnar neuropathy at the elbow. Arch Phys Med Rehabil 2009; 90(11): 1839-45.
12. Rayegani SM, Raeissadat SA, Kargozar E, Rahimi-Dehgolan S, Loni E. Diagnostic value of ultrasonography versus electrodiagnosis in ulnar neuropathy. Med Devices (Auckl) 2019; 12: 81-8.
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