Elsevier

The Journal of Pain

Volume 13, Issue 7, July 2012, Pages 676-684
The Journal of Pain

Original Report
Evidence of Spinal Cord Hyperexcitability as Measured With Nociceptive Flexion Reflex (NFR) Threshold in Chronic Lateral Epicondylalgia With or Without a Positive Neurodynamic Test

https://doi.org/10.1016/j.jpain.2012.04.005Get rights and content
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Abstract

There is emerging evidence of altered pain signal processing as a likely underlying mechanism in chronic lateral epicondylalgia (LE), yet this remains to be assessed. Furthermore, it has been proposed that neurodynamic tests reflect nociceptive withdrawal responses. Therefore, the objective was to improve our understanding of spinal cord excitability as measured by nociceptive flexion reflex (NFR) threshold in chronic LE with and without a positive neurodynamic test. NFR threshold, pain-free grip, and pressure pain threshold were measured in 30 LE participants and 31 healthy controls. Test of neural tissue involvement (using upper limb neural tension, radial bias) was used to differentiate LE participants with or without a positive neurodynamic test. There were significant differences in NFR threshold between the control and LE with or without a positive neurodynamic test (F[2,54] = 5.68, P = .006), after adjusting for age, sex, pain rating at NFR threshold, and reflex size (NFR interval peak z score). The mean differences (95% confidence interval) in NFR threshold between the control and LE with or without a positive neurodynamic test were 3.74 mA (.637, 6.84) and 3.38 mA (.0245, 6.74) respectively.

Perspective

The results suggest evidence of spinal cord hyperexcitability, particularly sensory hypersensitivity, in LE with or without a positive neurodynamic test. Our data appear to support the hypothesis that continued peripheral afferent stimulation results in facilitation of nociceptive pathways in this patient population.

Key words

Nociceptive flexion reflex
RIII
pain
tennis elbow
lateral epicondylalgia

Cited by (0)

Supported in part by the Singapore Health Services Pty Ltd (Talent Development Fund) and The Australian Government's Department of Education, Employment and Workplace Relations (Prime Minister's Australia Asia Endeavour Award) (E.C.W.L.), as well as a fellowship from the National Health and Medical Research Council of Australia (M.S.).

The authors have no conflicts of interest to report.