Small Fiber Assessment by Cutaneous Silent Period

Study Overview
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Brief Summary
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Our primary objective in this study is to investigate the cutaneous silent period (CSP) in normal subjects in the Egyptian population, as it was not carried out before in Egypt. The aim was to carry out the test in our unit to study the appropriate method, technique, and parameters of this new test so that we can apply it in future research. In addition, to obtain preliminary normative data of the test; onset latency, end latency, duration, and latency difference (LD) of CSP, as well as assess the effect of age, height, upper limb length, and gender on CSP values.

Detailed Description
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Nerve conduction studies performed routinely in electromyoneurography laboratories deal mainly with large myelinated fast conducting nerve fibers. A reliable method allowing the study of small peripheral nerve fibers (Aδ & C) would be of interest (Jovita et al., 2006). As they are initially affected and maybe the earliest exhibited sign of neuropathy. In recent years, the cutaneous silent period (CSP) has received increased attention in health and disease. The CSP is an inhibitory spinal reflex that appears following strong electrical stimulation of the cutaneous nerve and causes suppression of voluntary muscular contraction for a certain period of time (Kofler et al., 2019). This action presents a reciprocal action to the nociceptive flexor withdrawal response (FWR) which serves as an 'excitatory reflex' increasing activity in primary flexor muscles. When taken into context, the interplay between the CSP and FWR can clearly be seen. The evaluation of the CSP represents a useful electrophysiological method for investigating the function of small fibers by using standard electromyography equipment (Eckert et al., 2018).

Official Title
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Small Peripheral Fibers Assessment Using Cutaneous Silent Period In Normal Individuals In Egypt

Conditions
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Small Fiber Neuropathy

Intervention / Treatment
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* Diagnostic Test: cutaneous silent period


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Healthy participants able to cooperate and to follow instructions. Participants having a normal value for electrophysiological parameters (Nerve conduction studies) Participants must be free from any musculoskeletal impairment of the limbs Exclusion criteria: Participants with neurological disorders Participants with cognitive impairment Participants receiving medications that may affect the NCS Participants with small fiber neuropathy (burning sensation, pricking sensation, allodynia, and hyperalgesia) Participants with an abnormal value for Nerve conduction studies Participants with musculoskeletal impairment of the limbs

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: cutaneous silent period|form of Nerve conduction studies|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Normative parameters of cutaneous silent period of the median, ulnar , and sural nerves (measured in milli second) | establishing Normative of CSP enables the diagnosis of small fiber neuriopathy in the future The CSP parameters include: CSP onset latency,CSP end latency, and CSP duration (measured in ms; milli second) | 1 year |