Somatosensory Phenotype of Patients Suffering From Unspecific Neck and Arm Pain

Study Overview
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Brief Summary
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The aim of this study was to evaluate potential differences in somatosensory function in patients with unilateral NSNAP with and without positive ND compared to healthy controls. Furthermore, we determined whether there are any differences between groups in symptom severity, functional deficits, psychological parameters, quality of life and sleep.

Detailed Description
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Neck pain is a common musculoskeletal problem, with up to 30-50 % of adults experiencing neck pain in any given year. Neck pain in combination with arm pain is more common than neck pain alone and is associated with higher Ievels of self-reported disability and psychological impairment. In most cases, no pathophysiological correlate can be found in various investigations including magnetic resonance imaging of the cervical spine and tests for nerve conductivity (bedside neurological examination and standard electro diagnostic tests). In such cases, the neck-arm pain is labelled as non-specific. Although clinical examinations that evaluate the conductivity of the nervous system are normal in non-specific neck-arm pain (NSNAP), neurodynamic tests (ND) have been identified as positive in a subgroup of patients. ND are clinical tools designed to elongate the nerve bed, therefore increasing the mechanical loading of neural tissues. As such, ND provide information about alterations of neural tissue mechanosensitivity, i.e. the presence of heightened nerve mechanosensitivity. It is assumed that increased neural mechanosensitivity reflects gain of function, presumably mediated by small nociceptive fibres intraneurally or within the epineurium (nervi nervorum). However, it remains unclear whether the subgroup of patients with NSNAP and positive ND have indeed increased gain of function of this small fibre population compared to those patients with normal ND. Quantitative sensory testing (QST) is a commonly used tool to determine the function of different subsets of small (C, Ad-fibres) and large nerve fibres (Ad-fibres). Using QST, a recent study has identified a loss of small fibre function in patients with unilateral NSNAP and positive ND as apparent by reduced warm detection thresholds compared to the non-affected side. However, this difference was small and potentially not clinically rele-vant and the relatively small sample size of n=8 does not allow generalization of the results. In the same study, patients with NSNAP were also characterized by a gain of function, i.e. cold hypersensitivity. Similarly, widespread thermal and pressure hypersensitivity have been documented in patients with nonspecific arm pain (with or without neck pain). None of these studies has however investigated a potential difference between patients with NSNAP with positive versus negative ND, leaving it unclear whether the QST findings can indeed be attributed to a positive ND. A recent study compared patients with NSNAP and neuropathic features using ND testing and a self report neuropathic pain screening tool and patients with NSNAP and no neuropathic features. Interestingly, the first group showed heightened nerve mechanosensitivity apparent by an earlier onset of symptoms during ND testing. This raises the question whether patients with NSNAP and positive ND have indeed a dysfunction of their nervous system that differentiates them from patients with normal ND.

Official Title
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Somatosensory Profiles in Patients With Non Specific Neck Arm Pain With and Without Positive Neurodynamic Tests

Conditions
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Neck Pain

Intervention / Treatment
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* Other: neurodynamic testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - unilateral non specific neck-arm pain Exclusion Criteria: specific neck-arm pain (e.g., cervical radiculopathies, myelopathies) underlying diseases (e.g, central neurological condition, metabolic disease) upper limb or spinal surgery or significant trauma in the preceding two years manifest psychiatric or mental diseases insufficient German language skills

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: neurodynamic testing|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mechanosensitivity of neural tissue in neurodynamic testing |  | at enrolment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sensation thresholds for cold and warm temperatures in quantitative sensory testing |  | at enrolment | 
| pain thresholds for cold and warm temperatures in quantitative sensory testing |  | at enrolment | 
| vibration sensation threshold in quantitative sensory testing |  | at enrolment | 
| disability due to neck pain | neck disability index questionnaire | at enrolment | 
| presence of neuropathic pain | neuropathic pain symptom inventory questionnaire | at enrolment | 
| presence of anxiety | hospital anxiety and depression scale questionnaire | at enrolment | 
| presence of depression | hospital anxiety and depression scale questionnaire | at enrolment | 
| insomnia severity | insomnia severity index questionnaire | at enrolment | 
| sleep quality | visual analogue scale | at enrolment | 
| presence of pain catastrophizing | pain catastrophizing scale questionnaire | at enrolment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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neck pain, arm pain, neurodynamic tests, quantitative sensory testing, somatosensory profile