Healthy
Conditions
Brief summary
This is an exploratory study that will determine and standardize how best to record gastric evoked potentials (GEPs) elicited by a non-invasive method of brain stimulation (Transcranial Magnetic Stimulation, TMS), by optimizing the TMS parameters and cortical sites necessary to evoke GEPs.
Detailed description
The overall goal of this exploratory study is to determine the optimal conditions to elicit gastric evoked potentials (GEPs) with Transcranial Magnetic Stimulation (TMS). Aim 1: Determine the optimal stimulation parameters and the optimal location for eliciting GEPs in cortical motor areas. Aim 2: Determine whether various modes of repetitive TMS (rTMS) neuromodulation targeted to GEP hotspots shape gastric motor responses to a water load. The investigators will record some clinical, demographic, and autonomic data (i.e. EKG) in our enrolled subjects. Secondary analyses will use these variables as covariates to investigate any systematic impact on the measures from Aims 1 and 2.
Interventions
The best location for evoking an electromyographic (EMG) response of the first dorsal interosseus (FDI) muscle in the dominant hand and the minimum stimulation intensity required to evoke a certain EMG response amplitude (Motor Threshold, MT) are used as reference to determine the best location and stimulation parameters to evoke GEPs. After identification of the GEP hot-spot, a water load test is administered to determine whether satiety shapes GEP responses. In subsequent study visits, the water load test is preceded by application of neuromodulatory repetitive TMS (rTMS), targeted to the GEP hotspot.
Sponsors
University of Pittsburgh
National Institute of Neurological Disorders and Stroke (NINDS)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
\-
Exclusion criteria
* psychosis or altered cognitive status * history of head injury, metal in the skull, stroke, or a history of seizures, loss of consciousness or syncope * implantable devices, such as a pacemaker or nerve stimulator * current use of antiepileptic medications or current use of the following medications or 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 * BMI \> 30 * history of bariatric surgery such as sleeve gastrectomy or Roux-en-Y gastric bypass * diabetes * suffering from a neurodegenerative disorder.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in GEP hotspot location | Multiple study sessions spanning up to 12 months | Stimulation location evoking the largest GEP response, relative to FDI hotspot location |
| Change in optimal stimulation parameters at GEP hotspot | Multiple study sessions spanning up to 12 months | Stimulation pattern (single pulses or brief bursts) and strength relative to MT for FDI |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Effect of satiety | Multiple study sessions spanning up to 12 months | Change in GEP amplitude after water load test |
| Effect of neuromodulation | Multiple study sessions spanning up to 12 months | Change in GEP amplitude when water load test is preceded by rTMS |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORDavid J Levinthal, MD PhD
University of Pittsburgh
Outcome results
None listed