Clinical trial NCT04863820: Small Fiber Assessment by Cutaneous Silent Period
Official title: Small Peripheral Fibers Assessment Using Cutaneous Silent Period In Normal Individuals In Egypt
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Small Fiber Neuropathy
Lead sponsor: Cairo University
Sponsor class: OTHER
First posted: 2021-04-28
Enrollment: 64
Sex: ALL
Minimum age (years): 20
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Gender: males and females, age group: 20-60, healthy subjects

Brief summary: 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: 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).

Eligibility criteria: 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

Primary outcomes:
measure: Normative parameters of cutaneous silent period of the median, ulnar , and sural nerves (measured in milli second)
timeFrame: 1 year
Secondary outcomes:
Other outcomes:
Locations:
city: Cairo
country: Egypt
facility: Medicine
Study officials:
affiliation: Cairo University
name: Hebatallah R Rashad, Professor
role: STUDY_DIRECTOR
affiliation: Cairo University
name: Lamia M Afifi, Professor
role: STUDY_DIRECTOR
affiliation: Cairo University
name: AlShaimaa S Khalil, MD
role: STUDY_DIRECTOR
References:
citation: Svilpauskaite J, Truffert A, Vaiciene N, Magistris MR. Electrophysiology of small peripheral nerve fibers in man. A study using the cutaneous silent period. Medicina (Kaunas). 2006;42(4):300-13.
citation: Onal MR, Ulas UH, Oz O, Bek VS, Yucel M, Taslipinar A, Odabasi Z. Cutaneous silent period changes in Type 2 diabetes mellitus patients with small fiber neuropathy. Clin Neurophysiol. 2010 May;121(5):714-8. doi: 10.1016/j.clinph.2009.12.024. Epub 2010 Feb 6.
citation: Lopergolo D, Isak B, Gabriele M, Onesti E, Ceccanti M, Capua G, Fionda L, Biasiotta A, Di Stefano G, La Cesa S, Frasca V, Inghilleri M. Cutaneous silent period recordings in demyelinating and axonal polyneuropathies. Clin Neurophysiol. 2015 Sep;126(9):1780-9. doi: 10.1016/j.clinph.2014.11.013. Epub 2014 Nov 25.
citation: Eckert NR, Poston B, Riley ZA. Differential processing of nociceptive input within upper limb muscles. PLoS One. 2018 Apr 25;13(4):e0196129. doi: 10.1371/journal.pone.0196129. eCollection 2018.