Renal tubular dysfunction in patients with primary Sjögren syndrome.

BACKGROUND AND PURPOSE: 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.

MATERIAL AND

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.