MedPath

Cortical Excitability in Cyclic Vomiting Syndrome

Not Applicable
Recruiting
Conditions
Cyclic Vomiting Syndrome
Interventions
Other: TMS Paired-Pulse assessment of cortical excitability
Other: Autonomic activity
Registration Number
NCT05256160
Lead Sponsor
University of Pittsburgh
Brief Summary

This exploratory study will determine if there are differences in cortical excitability between patients suffering from cyclic vomiting syndrome (CVS) and healthy control subjects, as assessed by a non-invasive method of brain stimulation (Transcranial Magnetic Stimulation, TMS).

Detailed Description

This exploratory study will determine if there are differences in cortical excitability between patients suffering from cyclic vomiting syndrome (CVS) and healthy control subjects, as assessed by a non-invasive method of brain stimulation (Transcranial Magnetic Stimulation, TMS).

Using the paired-pulse TMS paradigm, intracortical inhibition and facilitation of cortical circuitry will be assessed by stimulating the motor cortex and using the electromyographic (EMG) response of a target muscle as readout. In such studies, a conditioning stimulus modulates the amplitude of the motor-evoked potential (MEP) produced by the test stimulus. Depending on the inter-stimulus interval, effects can be attributed to different aspects of cortical processing. Brief intervals (1-5 ms) will be used to assess short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF), intermediate intervals (7-20 ms) to assess intracortical facilitation (ICF) and long intervals (50-200 ms) to assess long-interval intracortical inhibition (LICI).

Some clinical, demographic, and autonomic data (i.e. EKG) will be recorded and used as covariates to investigate any systematic impact on cortical excitability measures collected with the paired-pulse protocols.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
110
Inclusion Criteria
  • diagnosis of CVS
Exclusion Criteria
  • history of CVS (for healthy control population only)
  • psychosis or altered cognitive status
  • history of head injury, metal in the skull, stroke, or a history of seizures
  • implantable devices, such as a pacemaker or nerve stimulator
  • current use of the following medications or use of substances which are known to lower the seizure threshold: clozapine (Clozaril), chlorpromazine (Thorazine), amphetamines or methamphetamine, Ecstasy, Ketamine, Angel Dust/PCP, cocaine, or 3 or more alcoholic drinks per day
  • pregnancy

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
CVS subjectsTMS Paired-Pulse assessment of cortical excitabilitySubjects diagnosed with Cyclic Vomiting Syndrome (CVS)
CVS subjectsAutonomic activitySubjects diagnosed with Cyclic Vomiting Syndrome (CVS)
healthy, non-CVS subjectsTMS Paired-Pulse assessment of cortical excitabilitySubjects not diagnosed with CVS
healthy, non-CVS subjectsAutonomic activitySubjects not diagnosed with CVS
Primary Outcome Measures
NameTimeMethod
Paired-pulse ratiosMultiple study sessions spanning up to 12 months

Percentage Change in Paired Pulse (PP) TMS induced MEP responses with inhibitory or facilitatory stimulation.

Secondary Outcome Measures
NameTimeMethod
TMS motor thresholdMultiple study sessions spanning up to 12 months

TMS stimulator output necessary to elicit 200 microvolt MEP responses

Cortical silent periodMultiple study sessions spanning up to 12 months

Length (milliseconds) of EMG inactivity following TMS stimulation

Heart rate variabilityMultiple study sessions spanning up to 12 months

Spectral frequency analysis (via Fast Fourier Transformation) of R-R intervals

Trial Locations

Locations (1)

University of Pittsburgh Medical Center

🇺🇸

Pittsburgh, Pennsylvania, United States

© Copyright 2025. All Rights Reserved by MedPath