Sensory profiles are comparable in patients with distal and proximal entrapment neuropathies, while the pain experience differs

Abstract

Objective: Distal and proximal entrapment neuropathies such as carpal tunnel syndrome (CTS) and cervical radiculopathy (CR) share similar etiologies. Experimental models suggest that, despite comparable etiology, pathomechanisms associated with injuries of the peripheral and central axon branches are distinct. This study therefore compared self-reported and elicited sensory profiles in patients with distal and proximal entrapment neuropathies.

Methods: Patients with electrodiagnostically confirmed CTS (n = 103) and patients with CR (n = 23) were included in this study. A group of healthy participants served as controls (n = 39). Symptoms and sensory profiles were evaluated using quantitative sensory testing (QST) and a self-reported neuropathic pain questionnaire (painDETECT).

Results: Both patient groups were characterized by a loss of function in thermal and mechanical detection in the main pain area and dermatome compared to healthy reference data (p < .001). There was no significant difference between patients with CTS and CR in pain and detection thresholds except for reduced vibration sense in the main pain area (p < .001) and reduced pressure pain sensitivity in the dermatome in patients with CR (p < .001). However, patients with CR reported higher pain intensities (p = .008), more severe pain attacks (p = .009) and evoked pain by light pressure (p = .002) compared to patients with CTS.

Conclusion: While QST profiles were similar between patients with CTS and CR, self-reported pain profiles differed and may suggest distinct underlying mechanisms in these patient cohorts.

Keywords:

• Nerve compression syndromes
• carpal tunnel syndrome
• radiculopathy
• somatosensory profiles
• quantitative sensory testing

Transparency

Declaration of funding

The studies were funded by the National Health and Medical Research Council (grant 425560) Australia, Arthritis Australia (Victorian Ladies’ Bowls Association Grant) and the Physiotherapy Research Foundation (seeding grant) Australia. The research was supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

Author contributions: A.B.S. and B.T. designed the studies and collected the data. J.V. performed the statistical analyses. All authors contributed to the preparation of the manuscript and approved the final version.

Declaration of financial/other relationships

A.B.S. has disclosed that she is supported by a Neil Hamilton Fairley Fellowship from the National Health and Medical Research Council Australia (APP1053058) and an advanced postdoc mobility fellowship from the Swiss National Science Foundation (P00P3-158835). B.T. and J.V. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgements

The authors thank A/Prof Kathy Briffa, Prof Helen Slater, School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia and Prof David Bennett, Nuffield Department of Clinical Neurosciences, Oxford University, UK for their contribution to the design of the patient cohorts. The assistance of Dr Toby Hall, School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia and Prof Gabriel Lee, Department of Neurosurgery, Sir Charles Gairdner Hospital, School of Surgery, University of Western Australia, Perth, Western Australia in the validation of patients’ diagnosis (cervical radiculopathy) is gratefully acknowledged.