Negative Neurodynamic Tests Do Not Exclude Neural Dysfunction in Patients With Entrapment Neuropathies

Abstract

ObjectiveTo examine differences in somatosensory phenotypes of patients with positive and negative neurodynamic tests and compare these with healthy participants.DesignCase-control study.SettingUniversity department.ParticipantsPatients with electrodiagnostically confirmed carpal tunnel syndrome (CTS) (n=53) and people without CTS (n=26) participated in this study (N=79). Patients with CTS were subgrouped according to the results of the upper limb neurodynamic tests biasing the median nerve into patients with positive or negative neurodynamic tests.InterventionsNot applicable.Main Outcome MeasureAll participants underwent quantitative sensory testing in the median innervated territory of their hand.ResultsOnly 46% of patients with CTS had positive neurodynamic tests. No differences were identified between groups for pain thresholds (P>.247). However, patients with CTS had increased mechanical (P<.0001) and thermal detection thresholds (P<.0001) compared with people without CTS. Patients with negative neurodynamic tests had a more pronounced vibration detection deficit (mean, 7.43±0.59) than people without CTS (mean, 7.89±0.22; P=.001). Interestingly, warm detection was the only domain differentiating positive (mean, 4.03°C±2.18°C) and negative neurodynamic test groups (6.09°C±3.70°C, P=.032), with patients with negative neurodynamic tests demonstrating increased loss of function.ConclusionsPatients with negative neurodynamic tests seem to have a more severe dysfunction of the unmyelinated fiber population. Our findings suggest that neurodynamic tests should not be used in isolation to judge neural involvement. Rather, they should be interpreted in the context of loss of function tests of the small fiber domain.

Effectiveness of physiotherapy in carpal tunnel syndrome (CTS)

“…Sliding mobilization consists in the movement of the axon itself relative to the casing. The authors demonstrate the effectiveness of neurodynamic tests only in 46% of patients with CTS [32].…”

“…Between them on the ventral side, the transverse wrist ligament is spread, commonly referred to as the flexor retinaculum [3]. CTS affects the median nerve by adjacent tissues, which in turn reduces its mobility in the canal [4][5][6]. Compression and reduction of lateral and longitudinal sliding of the mdian nerve is a direct cause of hand discomfort [7][8][9].…”

Concurrent validity of a low‐cost and time‐efficient clinical sensory test battery to evaluate somatosensory dysfunction

“…Forty-four healthy subjects (proportionally matched for age and gender) were recruited in Oxford, UK and Gold Coast, Queensland, Australia to establish z-scores for QST data in the CTS cohort. Part of the data from this cohort has previously been published (Baselgia, Bennett, Silbiger, & Schmid, 2017;Ridehalgh, Sandy-Hindmarch, & Schmid, 2018;Schmid et al, 2014).…”

Diagnostic accuracy of upper limb neurodynamic tests for the assessment of peripheral neuropathic pain: a systematic review

“…assessing the integrity and ability of the nervous system to conduct afferent or efferent impulses (loss of function) (Baselgia et al, 2017). In addition, a thorough examination includes evaluation of increased mechanical sensitivity of the nervous system, since PNP can be present without or with minimal loss of nerve conduction (Schmid et al, 2009).…”