Biomaterial Database

Cerebral tissue oxygen status and psychomotor performance during lower body negative pressure (LBNP). 1990

D H Glaister, and N L Miller

Crew Technology Division, USAF School of Aerospace Medicine, Brooks AFB, TX.

Cerebral oxygen sufficiency was studied noninvasively, using multiwavelength near-infrared spectrophotometry, in eight subjects exposed to lower body negative pressure (LBNP) of up to -90 mm Hg to induce presyncopal symptoms and signs. LBNP caused only small changes in the forebrain measures until the last 60 s of the exposures, whereupon oxyhemoglobin (HbO2) and oxidised cytochrome c oxidase fell, reduced hemoglobin (Hb) rose slightly, and the tissue blood volume (HbO2 + Hb) fell. In subjects showing presyncope, these changes anticipated the onset of a terminal bradycardia by some 20 s and may provide the trigger for cardiovascular decompensation, while the cessation of LBNP led to an overshoot in cerebral blood volume suggestive of a reactive hyperemia. Psychomotor testing showed a significant slowing of reaction time with LBNP, but only for the easiest component of a complex task, while saccadic latencies were found to be shortened following LBNP exposure.

UI	MeSH Term	Description	Entries
D008150	Lower Body Negative Pressure	External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated hemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth.	Abdominal Decompression,Decompression, Abdominal,LBNP
D008297	Male		Males
D008833	Microcirculation	The circulation of the BLOOD through the MICROVASCULAR NETWORK.	Microvascular Blood Flow,Microvascular Circulation,Blood Flow, Microvascular,Circulation, Microvascular,Flow, Microvascular Blood,Microvascular Blood Flows,Microvascular Circulations
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D011597	Psychomotor Performance	The coordination of a sensory or ideational (cognitive) process and a motor activity.	Perceptual Motor Performance,Sensory Motor Performance,Visual Motor Coordination,Coordination, Visual Motor,Coordinations, Visual Motor,Motor Coordination, Visual,Motor Coordinations, Visual,Motor Performance, Perceptual,Motor Performance, Sensory,Motor Performances, Perceptual,Motor Performances, Sensory,Perceptual Motor Performances,Performance, Perceptual Motor,Performance, Psychomotor,Performance, Sensory Motor,Performances, Perceptual Motor,Performances, Psychomotor,Performances, Sensory Motor,Psychomotor Performances,Sensory Motor Performances,Visual Motor Coordinations
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D002560	Cerebrovascular Circulation	The circulation of blood through the BLOOD VESSELS of the BRAIN.	Brain Blood Flow,Regional Cerebral Blood Flow,Cerebral Blood Flow,Cerebral Circulation,Cerebral Perfusion Pressure,Circulation, Cerebrovascular,Blood Flow, Brain,Blood Flow, Cerebral,Brain Blood Flows,Cerebral Blood Flows,Cerebral Circulations,Cerebral Perfusion Pressures,Circulation, Cerebral,Flow, Brain Blood,Flow, Cerebral Blood,Perfusion Pressure, Cerebral,Pressure, Cerebral Perfusion
D003072	Cognition Disorders	Disorders characterized by disturbances in mental processes related to learning, thinking, reasoning, and judgment.	Overinclusion,Disorder, Cognition,Disorders, Cognition