Accuracy in the Evaluation of Brain Response to Mechanical and Radiofrequency Stimuli in Humans

NCT06183593 | Completed DMC

• 1 other identifier: IS004486
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

Under normal conditions, pain arises as a consequence of the activation of nociceptive afferents (small fibers) by an external stimulus with sufficient intensity to potentially cause tissue damage. This peripheral activation is processed as perception of pain by the central nervous system. In order to reliably evaluate the state of the nociceptive system in both clinical and experimental settings, standardized tests are essential. Quantitative sensory testing (QST) is a set of tests used to measure the intensity of a stimulus that produces a specific sensory perception in a subject. For example, if we gradually apply pressure, the point where the sensation changes from pressure to pain is called the pressure pain threshold. This type of test can be performed with different types of stimuli, including hot and cold stimuli or mechanical stimuli. Although these tests have been shown as reliable in healthy volunteers and pain patients, they are subjective in their nature, since they are based on a conscious evaluation of tested subjects. Likewise, these measures show substantial variability due to differences in the application of the tests by individual examinators. In short, even though the method is quantitative, its methodological characteristics make it subjective and dependent on both the operator and the subject under study. Moreover, contrasting results have been recently found regarding the measurement variability when repeating the QST at intervals of days. Thus, it is essential to investigate and develop new QST alternatives to obtain objective markers that may potentially contribute to the understanding of the mechanisms behind chronic pain conditions.

Conditions

Brain Response Evoked by Radiofrequency Stimuli in Humans; Brain Response Evoked by Pinprick Stimuli in Humans

Outcome Measures

Primary Outcomes (2)

• Latency and amplitude of the evoked potentials induce by pinprick stimuli

  Latency (ms) and amplitude (mv) of the evoked potentials after pinprick stimulation

  2 hours during each experimental setting

• Latency and amplitude of the evoked potentials induce by RF

  Latency (ms) and amplitude (mv) of the evoked potentials after RF

  2 hours during each experimental setting

Secondary Outcomes (2)

• Changes in responses to somatosensory stimuli with Pinprick thresholds

  after each pinprick stimulation

• Conduction velocity in radiofrequency stimuli

  10 minutes at the end of the RF setting

Study Arms (2)

Radiofrequency-evoked potentials (RFEPs)

EXPERIMENTAL

The application of RF stimuli will be carried out using an adapted electrocoagulation device (ECD). These devices have several types of applicators, depending on the type of stimulation to be performed. In the bipolar mode, the applicator consists of a small clamp whose tips constitute the active and return electrodes, and the electric current flows only through the tissue captured between the two tips of the clamp. In the unipolar mode, the active electrode is an interchangeable tip with a variable surface (resembling for example a blade or a needle), and the return electrode is a metal plate in contact with another part of the volunteer's body. In this case, the current also flows from the active electrode to the return electrode, but over a considerably longer path. In both cases the physiological effect is similar: the stimulation elicits superficial, localized and limited heating of the tissue in the vicinity of the active electrode.

Other: Radiofrequency application

Pinprick evoked potentials

EXPERIMENTAL

An automatic stimulator with a section of approximately 0.35 mm in diameter and with a blunt tip was developed to apply this type of stimulus. This stimulator has a calibrated spring, which allows force to be gradually applied, while providing a safety margin to avoid accidents during tests. This allows two types of measurements to be made depending on the speed with which the stimulus is applied.

Other: Pinprick stimuli

Interventions

Radiofrequency application OTHER

Radiofrequency stimuli will be applied at pain threshold intensity. Arm and leg will be stimulated.

Radiofrequency-evoked potentials (RFEPs)

Pinprick stimuli OTHER

Pinprick stimuli will be administered at varying speeds and forces using an automated device

Pinprick evoked potentials

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• ● Age between 18 and 60 years.
• Willingness and ability to fully understand the content and scope of the experiment and comply with its instructions.
• Have signed the informed consent.

You may not qualify if:

• ● Pregnancy.
• Ongoing chronic pain or neuromuscular disorder, or any Desis that effect the nociceptive system and not allowed to be evaluated in normal Condition
• History of addictive behavior, defined as abuse of alcohol, cannabis, opioids, or other drugs.
• History of heat sensitivity disorders.
• History of mental illness.
• Presence of fever, tuberculosis, malignant tumors, infectious processes, acute inflammatory processes
• Implantation of pacemakers or metal prostheses.
• Use of analgesics within 24 hours prior to participation in the experiment.
• Lack of sleep (\< 6 hours) the night before the experiment.
• High alcohol intake the evening before the experiment.

Sponsors & Collaborators

• National Council of Scientific and Technical Research, Argentina: lead
• Medical School Hamburg: collaborator

Study Sites (1)

Facutlad de ingenieria UNER

Oro Verde, Entre Ríos Province, 3100, Argentina

Location

Related Publications (4)

• Iannetti GD, Baumgartner U, Tracey I, Treede RD, Magerl W. Pinprick-evoked brain potentials: a novel tool to assess central sensitization of nociceptive pathways in humans. J Neurophysiol. 2013 Sep;110(5):1107-16. doi: 10.1152/jn.00774.2012. Epub 2013 May 15.

  PMID: 23678019 BACKGROUND

• Backonja MM, Walk D, Edwards RR, Sehgal N, Moeller-Bertram T, Wasan A, Irving G, Argoff C, Wallace M. Quantitative sensory testing in measurement of neuropathic pain phenomena and other sensory abnormalities. Clin J Pain. 2009 Sep;25(7):641-7. doi: 10.1097/AJP.0b013e3181a68c7e.

  PMID: 19692807 BACKGROUND

• van den Broeke EN, Lambert J, Huang G, Mouraux A. Central Sensitization of Mechanical Nociceptive Pathways Is Associated with a Long-Lasting Increase of Pinprick-Evoked Brain Potentials. Front Hum Neurosci. 2016 Oct 20;10:531. doi: 10.3389/fnhum.2016.00531. eCollection 2016.

  PMID: 27812331 BACKGROUND

• Vuilleumier PH, Biurrun Manresa JA, Ghamri Y, Mlekusch S, Siegenthaler A, Arendt-Nielsen L, Curatolo M. Reliability of Quantitative Sensory Tests in a Low Back Pain Population. Reg Anesth Pain Med. 2015 Nov-Dec;40(6):665-73. doi: 10.1097/AAP.0000000000000289.

  PMID: 26222349 BACKGROUND

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: December 14, 2023
• First Posted: December 27, 2023
• Study Start: March 11, 2024
• Primary Completion: August 2, 2024
• Study Completion: August 2, 2024
• Last Updated: August 23, 2024

Record last verified: 2024-08

Data Sharing

• IPD Sharing: Will not share

Locations

AR (1)