Clinical trial NCT02976168: Intracranial Pressure and Brain Function: Effects of Head Down Tilt Upon Brain Perfusion and Cognitive Performance
Official title: Intracranial Pressure and Brain Function: Effects of Head Down Tilt Upon Brain Perfusion and Cognitive Performance
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Intracranial Hypertension
Keywords: Cognitive functioning
Brain tissue oxygenation
cerebral perfusion
head down tilt
Lead sponsor: DLR German Aerospace Center
Sponsor class: OTHER
Collaborators: name: Forschungszentrum Juelich
name: University Hospital, Umeå
name: University of Cologne
First posted: 2016-11-29
Enrollment: 13
Sex: MALE
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: The aim of the study is to understand the relationship between intracranial pressure regulation, cerebral tissue oxygenation and cognitive functioning. More specifically, the study tests the hypothesis that head down tilt will increase intracranial pressure (not measured in this study, but demonstrated in previous studies), will induce venous congestion and facial swelling, decrease intracranial tissue oxygenation and hamper brain functioning. The objectives of the study therefore are to assess young healthy people during head-down tilt (HDT), and to assess cognitive brain functioning, cerebral tissue oxygenation (non-invasively), frontal skin thickness, cerebral perfusion and neuronal functioning via event-related potentials.


Eligibility criteria: Inclusion Criteria:

* Physically and mentally healthy male test subjects that are able and declare in writing their willingness to participate in the entire study and successfully passed the psychological and medical screening
* Aged between 18-55 years old with a Body Mass Index (BMI) of 20-28 kg/m2, weight between 65-100 kg, and a height between 158-195 cm
* Demonstrable medical insurance and official certificate of absence of criminal record

Exclusion Criteria:

* Inability to sleep on the back
* Drug, medication or alcohol abuse (regular consumption of more than 20-30 g alcohol/day)
* Smoking within the past 6 months prior to study commencement
* Migraine or other chronic head aches
* Previous psychiatric illness
* Subjects suffering from weak concentration
* History of psychological or central nervous disorders
* Hiatus hernia
* Gastro-oesophageal reflux
* Diabetes mellitus
* Pronounced orthostatic intolerance (\< 10 min standing)
* Kidney disorder: deviations from normal values for creatinine in plasma. (Normal value: Creatinine \< 1.20 mg/dl)
* Thyroid gland disorder: deviations from normal values for thyroid stimulating Hormone (TSH) in plasma. (Normal range: TSH 0.55-4.80 mUnits/l)
* Anaemia: Hb under normal values (Normal values of Hb for men: 13.5-17.5 g/l)
* Elevated risk of thrombosis
* High likelihood of coagulopathy assessed by a clinical standard questionnaire
* Chronic back complaints
* History of lumbar surgery
* History of lumbar spine trauma
* Motor or sensory deficits as assessed by neurological examination
* Contraindications against MRI
* Imprisoned at the time of the study
* Taking medications that may impair cognitive function, autonomic function or any of the study procedures
* Ophthalmological conditions including glaucoma, retinopathy, severe cataracts, eye trauma or implants
* Any other medical condition that the investigators consider a contraindication to the study procedures that would make it unsafe or confound the measurements.

Primary outcomes:
measure: Change in cognitive test battery score
timeFrame: Twice at baseline, and 30 minutes and 20 hours after starting the intervention
Secondary outcomes:
measure: Change in mid cerebral artery blood flow velocity
timeFrame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Change in cerebral tissue oxygenation
timeFrame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Magnetic resonance Imaging: Change in cerebral blood flow
timeFrame: Once at baseline, and 2 and 19 hours after starting the intervention
measure: Magnetic resonance Imaging: Change in resting state functional MRI (fMRI)
timeFrame: Once at baseline, and 2 and 19 hours after starting the intervention
measure: Magnetic resonance Imaging: Change in fMRI Response to decision task
timeFrame: Once at baseline, and 2 and 19 hours after starting the intervention
measure: Change in jugular vein filling
timeFrame: Once at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Change in frontal vein filling
timeFrame: Once at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Change in P-300
timeFrame: Twice at baseline, and 30 minutes and 20 hours after starting the intervention
measure: Change in sleep effectiveness
timeFrame: over the entire intervention night
measure: Change in total sleep time
timeFrame: from 22:00 until 6:00 in all nights
Other outcomes:
measure: Change in frontal skin thickness
timeFrame: Once at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Change in arterial blood pressure
timeFrame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention
measure: Change in heart rate
timeFrame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention
Locations:
city: Cologne
country: Germany
facility: DLR German Aerospace Center
Study officials:
affiliation: German Aerospace Center
name: Jörn E Rittweger, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Boschert AL, Elmenhorst D, Gauger P, Li Z, Garcia-Gutierrez MT, Gerlach D, Johannes B, Zange J, Bauer A, Rittweger J. Sleep Is Compromised in -12 degrees Head Down Tilt Position. Front Physiol. 2019 Apr 16;10:397. doi: 10.3389/fphys.2019.00397. eCollection 2019.