Multiple System Atrophy, Pure Autonomic Failure
Conditions
Keywords
autonomic failure, mangenetic resonance, neurochemistry, neurotransmitter, glutamate
Brief summary
This research study will be conducted in patients with primary autonomic failure, a disabling condition that is associated with low blood pressure upon standing. These patients are also not able to control for changes in their blood pressure due to a loss of cardiovascular reflexes that are mediated within the brain. The purpose of this study is to determine whether magnetic resonance spectroscopy (MRS), a non-invasive imaging technique, can measure levels of chemicals (neurotransmitters) in the dorsal medulla, a brain area important for control of cardiovascular function, in autonomic failure patients. Importantly, this study will determine whether there are differences in brain chemicals between patients with peripheral versus central origins of their autonomic failure. The hypothesis is that the neurotransmitter profile in the medulla will be intact in patients with peripheral autonomic failure compared to those with central impairment. Overall, this study will provide insight into understanding the mechanisms involved in autonomic failure and will determine whether a single session of MRS imaging can improve the ability to make an accurate diagnosis in these patients. This would lessen the need for more extensive and invasive clinical testing.
Interventions
Proton magnetic resonance spectroscopy \[1H-MRS\] is an emerging imaging tool that allows for non-invasive assessment of brain neurochemistry in human subjects. This technique allows for in vivo quantification of the concentration of neurotransmitters and metabolites in discrete brain regions through detection of hydrogen nuclei in these molecules. Autonomic failure patients will undergo a single imaging session lasting 30 to 90 minutes (0.5-1.5 hours) in the Vanderbilt Human Imaging Institute.
Sponsors
Vanderbilt University
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Patients with primary autonomic failure who are already participating in the approved Vanderbilt study Evaluation and Treatment of Autonomic Failure * Males and females of all races between 18 and 80 years of age * Able and willing to provide informed consent
Exclusion criteria
* Pregnant women * Patients with diagnosed Parkinson's Disease or secondary forms of autonomic failure * Patients with severe claustrophobia * Patients taking medications known to affect brain neurotransmitter levels \[e.g., anti-depressants, barbiturates, benzodiazepines, gabapentin, namenda, sinemet\] * Patients with implanted medical devices \[e.g., pacemakers, metal clips, cochlear implants, orthopedic hardware\], lead-based tattoos or pieces of metal close to or in an important organ * High-risk patients \[e.g., heart failure, symptomatic coronary artery disease, liver impairment, history of stroke or myocardial infarction\] * Inability to give or withdraw informed consent * Other factors which in the investigator's opinion would prevent the subject from completing the protocol including significant abnormalities in clinical, mental, or laboratory testing
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| N-Acetylaspartate Levels | 0.5-1.5 hours | Differences in levels of N-acetylaspartate in the dorsal medulla of pure autonomic failure versus multiple system atrophy patients using single session imaging. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Myoinositol Levels | 0.5-1.5 hours | Differences in levels of myoinositol in the dorsal medulla pure autonomic failure versus multiple system atrophy patients. |
| GABA Levels | 0.5-1.5 hours | Differences in levels of the neurotransmitter GABA in the dorsal medulla of pure autonomic failure versus multiple system atrophy patients. |
| Creatinine Levels | 0.5-1.5 Hours | Differences in levels of creatinine-containing compounds in the dorsal medulla of pure autonomic failure versus multiple system atrophy patients. |
| Choline Levels | 0.5-1.5 Hours | Differences in levels of choline-containing compounds in the dorsal medulla of pure autonomic failure versus multiple system atrophy patients. |
| Glutamate Levels | 0.5-1.5 Hours | Differences in levels of glutamate in the dorsal medulla of pure autonomic failure versus multiple system atrophy patients. |
Countries
United States
Outcome results
None listed