fMRI in Postural Tachycardia Syndrome

Summary

Participation Requirements

Description

A randomized, double blind, crossover study will be conducted to determine if there are differences in resting brain structure and blood oxygen perfusion in postural tachycardia syndrome (POTS) compared with healthy subjects, and to identify the pattern of brain activation produced by cognitive test...

A randomized, double blind, crossover study will be conducted to determine if there are differences in resting brain structure and blood oxygen perfusion in postural tachycardia syndrome (POTS) compared with healthy subjects, and to identify the pattern of brain activation produced by cognitive testing under resting conditions and in the presence of a physical challenge mimicking orthostatic stress (lower body negative pressure, LBNP). This is an outpatient study that requires a screening visit in the Clinical Research Center within the Penn State Hershey Medical Center, and if eligible, two study visits in the Penn State Center for Nuclear Magnetic Resonance Imaging involving blood oxygen level dependent functional magnetic resonance imaging (BOLD-fMRI) and cognitive tests while lying in a magnetic resonance imaging (MRI) scanner with the lower body placed in the LBNP chamber. The LBNP chamber applies suction to the lower body to pool blood in the legs and physiologically mimic what happens when standing up. Blood pressure, heart rate, and oxygen saturation will be measured throughout the study. A scan will be performed while at rest to look at the structure and blood oxygen perfusion in the brain. The LBNP or sham pressure will then be initiated, with the order determined randomly and the other stress applied at the second study visit. Once the appropriate level of pressure is achieved, brain oxygen perfusion will be measured and subjects will be asked to complete two tests of cognitive function. At the end of the cognitive tests, brain oxygen levels will be measured and the testing will end. The time inside the MRI scanner at each study visit will be approximately 45 minutes.

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