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Completed

NCT Number: NCT02976168

Intracranial Pressure and Brain Function: Effects of Head Down Tilt Upon Brain Perfusion and Cognitive Performance

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.

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Key information

Conditions

Intracranial Hypertension Brain Diseases Central Nervous System Diseases Nervous System Diseases

Age range

18 year–55 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

DLR German Aerospace Center

Cologne, 51147, Germany

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

12° head down tilt

Other

supine head down tilt

Primary outcomes

  1. Change in cognitive test battery score

    Time frame: Twice at baseline, and 30 minutes and 20 hours after starting the intervention

    The test battery includes sensomotoric speed, psychomotor vigilance, visual analysis of items, abstract thinking and mathematical processing

Secondary outcomes

  1. Change in mid cerebral artery blood flow velocity

    Time frame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention

    Transcranial Doppler measurements

  2. Change in cerebral tissue oxygenation

    Time frame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention

    Near-infrared measurement

  3. Magnetic resonance Imaging: Change in cerebral blood flow

    Time frame: Once at baseline, and 2 and 19 hours after starting the intervention

    Magnetic resonance imaging will be performed in order to gain information about intracranial blood flow.

  4. Magnetic resonance Imaging: Change in resting state functional MRI (fMRI)

    Time frame: Once at baseline, and 2 and 19 hours after starting the intervention

    Magnetic resonance imaging will be performed to assess resting state functional MRI.

  5. Magnetic resonance Imaging: Change in fMRI Response to decision task

    Time frame: Once at baseline, and 2 and 19 hours after starting the intervention

    Magnetic resonance imaging will be performed in order to assess functional MRI during a decision task combing a reaction time test using a visual stimulus.

  6. Change in jugular vein filling

    Time frame: Once at baseline, and 10 minutes and 19 hours after starting the intervention

    Conventional Imaging ultrasound from jugular veins veins will be used to assess vein cross sections

  7. Change in frontal vein filling

    Time frame: Once at baseline, and 10 minutes and 19 hours after starting the intervention

    Conventional Imaging ultrasound from the frontal veins will be used to assess vein cross sections

  8. Change in P-300

    Time frame: Twice at baseline, and 30 minutes and 20 hours after starting the intervention

    P-300 will be assessed via an EEG electrode during cognitive test battery

  9. Change in sleep effectiveness

    Time frame: over the entire intervention night

    Polysomnographic recordings

  10. Change in total sleep time

    Time frame: from 22:00 until 6:00 in all nights

    Polysomnographic recordings

Other outcomes

  1. Change in frontal skin thickness

    Time frame: Once at baseline, and 10 minutes and 19 hours after starting the intervention

    Conventional Imaging ultrasound will be used to assess Skin thickness at the frontal skull

  2. Change in arterial blood pressure

    Time frame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention

    arterial blood pressure will be assessed non-invasively from a finger artery during transcranial doppler measurements

  3. Change in heart rate

    Time frame: Twice at baseline, and 10 minutes and 19 hours after starting the intervention

    ECG will be recorded during transcranial doppler measurements

Sponsors and collaborators

Lead sponsor

DLR German Aerospace Center

Other

Collaborators

  • Forschungszentrum Juelich
  • University Hospital, Umeå
  • University of Cologne

Registry information

Acronym: IPCog

Important dates

Study start
2016
Primary completion
2016
Study completion
2016
First posted
Nov 29, 2016
Registry last updated
Mar 3, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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