Spectroscopic Imaging at 4T: A Drug Challenge Study (CEBRA2)
An advanced technique for rapid magnetic resonance proton spectroscopic imaging (1H-MRSI) will be employed in a drug challenge study in healthy volunteers to spatially map and measure acute changes in the brain chemicals GABA, glutamate and glutamine after administration of a drug. Three condition will be tested in a double-blind fashion, i)depressant, ii)stimulant, iii)placebo. It is hypothesized that unique and reproducible spatial and directional metabolic response patterns will be observed, unique to each condition within the brain.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
|Official Title:||Spectroscopic Imaging of GABA and Glutamate/Glutamine in Healthy Volunteers at 4T: A Double Blind, Crossover Drug Challenge Study|
- Magnitude of metabolite level changes throughout the brain with separate administration of Dexedrine and Alprazolam [ Time Frame: Measures taken in 20 minute intervals for 2 hours ] [ Designated as safety issue: No ]The primary goal of this study is to assess the efficacy of an advanced spectroscopic imaging protocol in detecting changes in the levels of brain GABA, glutamate and glutamine in response to an acute drug challenge. In addition to detecting changes in metabolite levels, it is anticipated that our protocol will allow us to spatially map the distribution of these changes within the brain.
- Spatial distribution of metabolite level changes throughout the brain with separate administration of Dexedrine and Alprazolam [ Time Frame: Measures taken in 20 minute intervals for 2 hours ] [ Designated as safety issue: No ]
|Study Start Date:||June 2013|
|Study Completion Date:||December 2013|
|Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
Experimental: Healthy Volunteers
Healthy male volunteers receiving drug and undergoing 1H-MRSI scanning
Alprazolam, gel-capsule, 1mg, single-dose, 1-day
Other Name: XanaxDrug: Dextroamphetamine
Dextroamphetamine, gel-capsule, 20mg, single-dose, 1-day
Other Name: Dexedrine
Proton magnetic resonance spectroscopy (1H MRS) is a powerful tool for assessing neurochemistry non-invasively in vivo. However, the primary shortcoming in most studies is the lack of spatial coverage afforded by the typical single-voxel design. Limits on participant tolerance and financial resources restrict single-voxel studies to an examination of one or two carefully chosen voxels per scan, thus inadequately addressing the question of focal vs. global pathophysiology. A secondary shortcoming is that most studies report on either GABA or glutamate-glutamine (Glu-Gln) due to the technically demanding spectral-editing techniques that must be implemented in order to resolve and quantify those metabolites with any accuracy.
1H MRS imaging (MRSI) can partially overcome these limitations by providing a global picture of brain chemistry rather than just the focal snapshot afforded by the single-voxel design. However, the scan time necessary for collecting enough data for adequate spatial resolution and signal-to-noise, particularly if also using specialized spectral-editing techniques, is still too lengthy. We recently developed a method that combines Spectroscopic Imaging with the MEGAPRESS-based difference-editing acquisition for optimal GABA detection as well as for optimal detection of Glu and Gln. This MEGACSI sequence will permit us to obtain the maximum amount of neurochemical information in a clinically sound scan time, while using the current state-of-the-art MRS editing methods for optimal detection of GABA, Glu, and Gln.
|United States, Massachusetts|
|McLean Imaging Center, McLean Hospital|
|Belmont, Massachusetts, United States, 02478-9106|
|Principal Investigator:||John E Jensen, Ph.D.||Mclean Hospital|