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Lower body negative pressure to safely reduce intracranial pressure
- Source :
- The Journal of Physiology. 597:237-248
- Publication Year :
- 2018
- Publisher :
- Wiley, 2018.
-
Abstract
- KEY POINTS: During long‐term missions, some astronauts experience structural and functional changes of the eyes and brain which resemble signs/symptoms experienced by patients with intracranial hypertension. Weightlessness prevents the normal cerebral volume and pressure ‘unloading’ associated with upright postures on Earth, which may be part of the cerebral and ocular pathophysiology. By placing the lower body in a negative pressure device (LBNP) that pulls fluid away from cranial compartments, we simulated effects of gravity and significantly lowered pressure within the brain parenchyma and ventricle compartments. Application of incremental LBNP demonstrated a non‐linear dose–response curve, suggesting 20 mmHg LBNP as the optimal level for reducing pressure in the brain without impairing cerebral perfusion pressure. This non‐invasive method of reducing pressure in the brain holds potential as a countermeasure in space as well as having treatment potential for patients on Earth with traumatic brain injury or other pathology leading to intracranial hypertension. ABSTRACT: Patients with elevated intracranial pressure (ICP) exhibit neuro‐ocular symptoms including headache, papilloedema and loss of vision. Some of these symptoms are also present in astronauts during and after prolonged space‐flight where lack of gravitational stress prevents daily lowering of ICP associated with upright posture. Lower body negative pressure (LBNP) simulates the effects of gravity by displacing fluid caudally and we hypothesized that LBNP would lower ICP without compromising cerebral perfusion. Ten cerebrally intact volunteers were included: six ambulatory neurosurgical patients with parenchymal ICP‐sensors and four former cancer patients with Ommaya‐reservoirs to the frontal horn of a lateral ventricle. We applied LBNP while recording ICP and blood pressure while supine, and during simulated intracranial hypertension by 15° head‐down tilt. LBNP from 0 to 50 mmHg at increments of 10 mmHg lowered ICP in a non‐linear dose‐dependent fashion; when supine (n = 10), ICP was decreased from 15 ± 2 mmHg to 14 ± 4, 12 ± 5, 11 ± 4, 10 ± 3 and 9 ± 4 mmHg, respectively (P
- Subjects :
- Adult
Male
0301 basic medicine
medicine.medical_specialty
Supine position
Intracranial Pressure
Physiology
Traumatic brain injury
Posture
Spaceflight
law.invention
Young Adult
03 medical and health sciences
0302 clinical medicine
law
Internal medicine
Humans
Medicine
Cerebral perfusion pressure
Aged
Intracranial pressure
Lower Body Negative Pressure
Weightlessness
business.industry
musculoskeletal, neural, and ocular physiology
Brain
Middle Aged
Space Flight
medicine.disease
Treatment Outcome
030104 developmental biology
medicine.anatomical_structure
Blood pressure
Ventricle
Cardiology
Female
business
030217 neurology & neurosurgery
Gravitation
Neuroscience
Subjects
Details
- ISSN :
- 14697793 and 00223751
- Volume :
- 597
- Database :
- OpenAIRE
- Journal :
- The Journal of Physiology
- Accession number :
- edsair.doi.dedup.....940bfe4b1b32c1c1418fb4accc742e59