Cyclic Vomiting Syndrome
Conditions
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.
Interventions
OTHERTMS Paired-Pulse assessment of cortical excitability
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).
OTHERAutonomic activity
Autonomic function will be determined using continuously recorded EKG and used as covariates to investigate any systematic impact on cortical excitability measures collected with the paired-pulse protocols.
Sponsors
University of Pittsburgh
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
This is a comparative study looking at differences in electrophysiologic measures of cortical excitability between those with Cyclic Vomiting Syndrome and healthy controls.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
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 or a history of syncope (fainting or passing out) * 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Paired-pulse ratios | Multiple study sessions spanning up to 12 months | Percentage Change in Paired Pulse (PP) TMS induced MEP responses with inhibitory or facilitatory stimulation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| TMS motor threshold | Multiple study sessions spanning up to 12 months | TMS stimulator output necessary to elicit 200 microvolt MEP responses |
| Cortical silent period | Multiple study sessions spanning up to 12 months | Length (milliseconds) of EMG inactivity following TMS stimulation |
| Heart rate variability | Multiple study sessions spanning up to 12 months | Spectral frequency analysis (via Fast Fourier Transformation) of R-R intervals |
Countries
United States
Contacts
CONTACTElijah D Wright
CONTACTDavid J Levinthal, MD PhD
PRINCIPAL_INVESTIGATORDavid J Levinthal, MD PhD
University of Pittsburgh
Outcome results
None listed