Peripheral Physiological Measures as Determinants of Pain Risk

Study Overview
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Brief Summary
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This study evaluates peripheral nervous system function using Multiple Excitability Measures (MEM) to obtain electrophysiological pain phenotypes

Detailed Description
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Using MEM for peripheral sensory and motor axons we want to identify a set of excitability measures that: Correlate with parameters of clinical pain and of pain processing in existing pain patients (cross sectional study), with the aim to obtain an objective Pain Biomarker. Predict development of neuropathic pain in susceptible patients (longitudinal study). Neuropathic Pain Predictor for patients: i. Undergoing surgical procedures associated with a relatively high risk of developing neuropathic pain such as thoracotomy and hernia repair ii. Planning to start chemotherapy with potentially neurotoxic agents such as vincristine

Official Title
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DOLORisk: Understanding Risk Factors and Determinants for Neuropathic Pain - Peripheral Physiological Measures as Determinants of Pain Risk

Conditions
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Polyneuropathies, Peripheral Nerve Injuries, Peripheral Nervous System Diseases, Chemotherapy Effects, Neuralgia

Intervention / Treatment
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* Other: Multiple Excitability Measures of peripheral nerves


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic peripheral neuropathic pain Painless Patient with risk to develop neuropathic pain (post-surgery, chemotherapy-induced) Exclusion Criteria: Minors

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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cross-sectional cohort<br>Multiple Excitability Measures of peripheral nerves on patients with chronic peripheral neuropathic pain | Other: Multiple Excitability Measures of peripheral nerves<br>* The technique of threshold tracking can be used to obtain several measures of peripheral nerve excitability (Multiple Excitability Measures or MEM), such as refractoriness, supernormality, strength-duration time constant and 'threshold electrotonus' (i.e. the changes in threshold produced by long-lasting depolarizing or hyperpolarizing current pulses). Each of these measurements depends on membrane potential and on other biophysical properties of the axons. Many of these excitability parameters are very constant among different subjects, while other, such as the current/threshold parameters and the super/sub-excitability parameters, appear to be characteristic of an individual<br>* Other names: Questionnaires;|
| Longitudinal cohort<br>Multiple Excitability Measures of peripheral nerves on painless patients before and after potential chronic neuropathic pain-inducing interventions (chemotherapy, surgery) | Other: Multiple Excitability Measures of peripheral nerves<br>* The technique of threshold tracking can be used to obtain several measures of peripheral nerve excitability (Multiple Excitability Measures or MEM), such as refractoriness, supernormality, strength-duration time constant and 'threshold electrotonus' (i.e. the changes in threshold produced by long-lasting depolarizing or hyperpolarizing current pulses). Each of these measurements depends on membrane potential and on other biophysical properties of the axons. Many of these excitability parameters are very constant among different subjects, while other, such as the current/threshold parameters and the super/sub-excitability parameters, appear to be characteristic of an individual<br>* Other names: Questionnaires;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrophysiological pain phenotypes using MEM. Pain biomarker | Correlate with parameters of clinical pain and of pain processing in existing pain patients | Single assessment (cross sectional study) at the first and only visit | 
| Electrophysiological pain phenotypes using MEM. Pain predictor | Predict development of neuropathic pain in susceptible patients | Single assessment at baseline, before any procedure (surgery/chemotherapy) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Neuropathic pain, Quantitative Sensory Testing, Multiple Excitability Measures, Threshold Tracking