Cerebral autoregulation
Conditions
Interventions
Group 1: Measurement of cerebral blood flow using ultrasound and magnetic resonance imaging
Group 2: Measurement of cerebral blood flow by ultrasound and magnetic resonance imaging using a lower body
Sponsors
Deutsches Zentrum für Luft- und Raumfahrt
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Inclusion criteria
Inclusion criteria: Age = 18 years Informed Consent before first measurement
Exclusion criteria
Exclusion criteria: - Pregnancy - Any clinical abnormal finding during the medical screening MRI Exclusion Criteria: - currently implanted electrical medical devices (those for example remained in the body after flex work) - Pacemaker, infusion pump, neurostimulator, inner ear implant - Claustrophobia - Permanent make-up or tattoos with dyes containing metal - Non-removable piercings Medical examination: - Current diseases of the heart, lungs, liver, kidneys or brain - History of psychiatric illnesses that could lead to inability to consent - Regular use of medication (hormonal contraceptives are not an exclusion criterion) - Regular alcohol consumption (> 20 g/day) or nicotine consumption (> 3 cigarettes/day) - Consumption of illegal drugs (cannabis, coke, heroin, crystal meth, etc.) - Blood donation three months (women) or two months (men) before the study - Clinically relevant ECG changes - Hypertension (> 140/90 mmHg) or hypotension (< 90/50 mmHg) while lying down - Orthostatic hypotension (sharp drop in blood pressure when standing
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Difference of the average volumetric flow in the A. cerebri media pars sphenoidalis (average of left and right) between LBNP and baseline (measured by real-time MRI) Difference of the average flow velocity in the A. cerebri media pars sphenoidalis (average of left and right) between LBNP and baseline (measured by TCD) Side difference of the difference in average volumetric flow in the A. cerebri media pars sphenoidalis between LBNP and baseline (measured by real-time MRI) Side difference of the difference in the average flow velocity in the A. cerebri media pars sphenoidalis between LBNP and baseline (measured by TCD) Difference of the average flow velocity in the A. cerebri media pars sphenoidalis between LBNP and baseline (measured by real-time MRI) Side difference of the difference in the average flow velocity in the A. cerebri media pars sphenoidalis between LBNP and baseline (measured by MRI) Difference of the average cross-sectional area of the A. cerebri media pars sphenoidalis (average of left and right) between LBNP and baseline (measured by real-time MRI) Side difference of the difference in the average cross-sectional area of the A. cerebri media pars sphenoidalis between LBNP and baseline (measured by real-time MRI) Difference of the transfer function between flow velocity in the A. cerebri media pars sphenoidalis (measured by TCD) and finger blood pressure (FBP) between LBNP and baseline (individually for each side) Difference of the transfer function between volumetric flow in the A. cerebri media pars sphenoidalis (measured by MRI) and finger blood pressure (FBP) between LBNP and baseline (individually for each side) Difference of the mean perfusion in the whole brain between LBNP and baseline (measured by ASL) Regional differences in perfusion between LBNP and baseline (measured by ASL) | — |
Countries
Germany
Contacts
Public ContactJens Tank
Deutsches Zentrum für Luft- und Raumfahrt (DLR) Institut für Luft- und Raumfahrtmedizin
Outcome results
None listed