Atmospheric pressure and basic parameters of intracranial volume-pressure homeostasis.
OBJECTIVE
There are only a few studies in the literature regarding the influence of atmospheric pressure on intracranial homeostasis and the mechanism of the relation has not been clarified. The aim of the study was to evaluate the influence of atmospheric pressure and ambient temperature on parameters of intracranial volume-pressure homeostasis including intracranial pressure and cerebral perfusion pressure as well as on blood pressure and body temperature.


METHODS
The authors analyzed the influence of atmospheric pressure on intracranial pressure, blood pressure, cerebral perfusion pressure and body temperature in 14 patients who were monitored because of suspicion of having normal pressure hydrocephalus.


RESULTS
Atmospheric pressure below 760 mm Hg (1013.3 hPa) significantly affects intracranial pressure, arterial blood pressure, cerebral perfusion pressure and body temperature. Atmospheric pressure above 770 mm Hg (1026.6 hPa) does not affect intracranial pressure, arterial blood pressure, cerebral perfusion pressure or body temperature.


CONCLUSIONS
Atmospheric pressure range of 768 mm Hg (1023.9 hPa) to 770 mm Hg (1026.6 hPa) is the border range to preserve intracranial homeostasis, below which qualitative changes of cerebral blood flow occur. In the high range of atmospheric pressure its increase initiates biological protective mechanisms to maintain normal cerebral blood flow. The mechanism involved in the influence of atmospheric pressure and environmental factors in general on intracranial pressure and other parameters of pressure-volume homeostasis has not been explained.
Herbowski
Leszek
L
Wojewódzki Szpital Zespolony, Oddział Neurochirurgii, ul. Arkońska 4, 71-455 Szczecin. leszekherbowski@data.pl
Gurgul
Henryk
H
D000368:Aged; D001274:Atmospheric Pressure; D001794:Blood Pressure / Q000502:physiology; D001812:Blood-Brain Barrier / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D002555:Cerebrospinal Fluid / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006439:Hemodynamics; D006706:Homeostasis; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged