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).
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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
110
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).
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.
University of Pittsburgh Medical Center
Pittsburgh, Pennsylvania, United States
RECRUITINGPaired-pulse ratios
Percentage Change in Paired Pulse (PP) TMS induced MEP responses with inhibitory or facilitatory stimulation.
Time frame: Multiple study sessions spanning up to 12 months
TMS motor threshold
TMS stimulator output necessary to elicit 200 microvolt MEP responses
Time frame: Multiple study sessions spanning up to 12 months
Cortical silent period
Length (milliseconds) of EMG inactivity following TMS stimulation
Time frame: Multiple study sessions spanning up to 12 months
Heart rate variability
Spectral frequency analysis (via Fast Fourier Transformation) of R-R intervals
Time frame: Multiple study sessions spanning up to 12 months
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