Microneurographic Assessment of Peripheral Nerves in Healthy Volunteers and Individuals With Sensory Dysfunction Caused by Inherited Mutations in the PIEZO2 Gene

Background:

PIEZO2 Deficiency Syndrome (PDS) is a genetic disorder that affects a person s ability to feel touches and pain. Researchers want to know more about how PDS changes nerve function.

Objective:

To compare nerve function in people with PDS to that in people without PDS.

Eligibility:

People aged 18 years and older with PDS enrolled in protocol 16-AT-0077. Healthy volunteers are also needed.

Design:

Participants will have at least 1 clinic visit. They will undergo a test that measures activity in the nerves.

For the test:

Participants will place their arm or leg in a comfortable position.

Ultrasound will be used to locate nerves. A smooth wand will be slid over the skin to capture images of the structures below.

Two thin needles will be inserted through the skin. These needles are much smaller than the kind used to draw blood.

The needles will record nerve activity as different sensations are applied to the skin. These include mild electrical pulses; heat and cold; bending of the knee or elbow; vibration; air puffs; pulling a hair; and tapping, stroking (brushing), stretching, pinching, and pushing on the skin at different levels of force.

Each test takes 5 to 10 minutes. Participants will describe the sensations they feel.

Participants may opt for an additional test that measures how nerves respond after heat pulses are used to create mild redness on the skin.

Researchers would like at least 2 tests from each person. Participants may return for up to 3 additional visits, if desired, to complete all the testing.

Study Overview

Status

Not yet recruiting

Detailed Description

Study Description:

The study aims to characterize peripheral nerve function and physiology in healthy participants and participants with inherited mutations in the PIEZO2 gene (otherwise known as PIEZO2- Deficiency Syndrome [PDS]). PIEZO2 encodes a stretch-gated ion channel whose function has been shown to be essential for aspects of gentle touch sensation, vibration detection, mechanical allodynia and proprioception in humans. The physiological effects of PIEZO2 mutations on sensory neurons in humans are unknown. The study will improve our understanding of the molecular mechanisms for touch and mechanical pain sensation and determine if the peripheral neurons remain otherwise healthy in the absence of a functioning PIEZO2 channel.

Objectives:

Primary Objective:

To determine whether peripheral neurons have a blunted response to gentle mechanical stimulation (e.g., soft brushing) in PDS patients compared to healthy participants using direct electrical recording from peripheral nerves.

Secondary Objectives:

To examine the physiological properties of different types of mechanically sensitive sensory neurons in response to innocuous and noxious stimuli in PDS patients and healthy participants. We expect the loss of PIEZO2 to have greater impact on the responsiveness of certain types mechano-receptor subtypes over others.

Endpoints:

Primary Endpoint:

Our primary endpoint is evidence of reduced responsiveness (i.e., firing rate [Hz]) of peripheral neurons to gentle mechanical (brushing) stimulation in PDS patients compared to controls. We expect a reduction of at least 50% in firing rate (Hz).

Secondary Endpoints:

Our secondary endpoint is the emergence of a differential effect of the loss of PIEZO2 on mechanoreceptor subclasses. Mechanoreceptor subclasses will be identified using established criteria (e.g., stimulus sensitivity, receptive field size, spike morphology and axon conduction velocity). The effect of the loss of PIEZO2 on the responsiveness of single-unit subclasses will be quantified by firing rate measures on single-unit data. In addition, the percept evoked to intraneural electrical stimulation of single-unit subclasses will be noted.

Study Type

Observational

Enrollment (Estimated)

16

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center
        • Contact:
          • NIH Clinical Center Office of Patient Recruitment (OPR)
          • Phone Number: TTY dial 711 800-411-1222
          • Email: ccopr@nih.gov

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

All participants will be screened and selected from an existing NCCIH protocol, 16-AT-0077. PDS participants will be referred to 16-AT-0077 for screening from an existing NINDS protocol, 12-N-0095.

Description

  • INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

All Participants

  • Stated willingness to comply with all study procedures and availability for the duration of the study
  • Male or female, aged 18 years and over.
  • The ability to provide written informed consent.
  • Enrolled in 16-AT-0077, Clinical and Scientific Assessment of Pain and Painful Disorders .

PDS Patients

-Clinical and genetic diagnosis of PIEZO2-LOF.

Healthy participants

-In good general health as evidenced by medical evaluation under 16-AT-0077.

EXCLUSION CRITERIA:

All Participants:

  • Difficulties with communication that make subjective innocuous and pain assessments impossible or unreliable.
  • Unable to comply with study procedures or visits.
  • Has a dermatological condition that might influence cutaneous sensitivity.
  • Congenital limb deficiency or amputation of any limb.
  • Prior history of syncope.
  • Peripheral neuropathy or current chronic pain condition or has had chronic pain in the past year (painful condition lasting more than six months), including ongoing treatment with medications for neuropathic pain (e.g. gabapentin, tricyclic antidepressants, pregabalin, tramadol).
  • Has a major medical condition, such as kidney, liver, cardiovascular, autonomic, pulmonary, or neurological problems (e.g., epilepsy) or a chronic systemic disease (e.g., diabetes), or Raynaud s Disease.
  • Current and untreated diagnosis of depression, post-traumatic stress, syndrome, bipolar disorder, psychosis, anxiety or panic disorder, alcohol or substance use disorders.
  • Pregnant (verbal confirmation) or breastfeeding.
  • Are participating in other ongoing research protocols involving interventions that would interfere with somatosensation.
  • Employees or staff that work at NCCIH.
  • Adults who are unable to provide their own consent.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Healthy controls
Healthy participants
PIEZO2 Deficiency Syndrome (PDS)
Participants with a diagnosis of PIEZO2 Deficiency Syndrome; an inherited mutation in the PIEZO2 gene

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Firing rate (Hz) in response to fast and slow brushing.
Time Frame: At each visit (max of 4 visits) during microneurography procedure.
PDS patients have major deficits in touch detection. Therefore, we predict the response (firing rate) to gentle brush stimuli to be reduced by at least 50% (compared to healthy controls), corresponding to decreased sensitivity to mechanical stimuli. The neural measure of firing rate (Hz) captures both the magnitude of the response and its temporal pattern and has been shown to reliably distinguish between normal and pathological responses and the effects of pharmacological manipulations.
At each visit (max of 4 visits) during microneurography procedure.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Firing rate (Hz) in response to other sensory modalities, e.g., thermal, and other mechanical stimuli.
Time Frame: At each visit (max of 4 visits) during microneurography procedure.
Our secondary endpoint is the emergence of a differential effect of the loss of PIEZO2 on mechanoreceptor subclasses. Mechanoreceptor subclasses will be identified using established criteria (e.g., stimulus sensitivity, receptive field size, spike morphology and axon conduction velocity). The effect of the loss of PIEZO2 on the responsiveness of single-unit subclasses will be quantified by firing rate measures on single-unit data. In addition, the percept evoked to intraneural electrical stimulation of single-unit subclasses will be noted.
At each visit (max of 4 visits) during microneurography procedure.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Alexander T Chesler, Ph.D., National Center for Complementary and Integrative Health (NCCIH)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 5, 2024

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

September 22, 2023

First Submitted That Met QC Criteria

September 22, 2023

First Posted (Actual)

September 25, 2023

Study Record Updates

Last Update Posted (Estimated)

April 30, 2024

Last Update Submitted That Met QC Criteria

April 29, 2024

Last Verified

September 20, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • 10001678
  • 001678-AT

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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