Plasma levels of norepinephrine (NE), which are useful index of sympathetic nervous function, were measured in vertiginous patients by gas chromatograph-mass spectrometer using selected ion monitoring method.
There was no significant difference in the resting plasma NE levels between healthy subjects and patients groups such as Meniere's disease, vertigo (central and peripheral origin) and sudden deafness.
NE and blood pressure increased in all groups when the subjects were kept at the standing errect position. No significant differences were found in the increment of NE at the errect position, however, there was less elevation in blood pressure in patients groups, especially in Meniere's disease patients.
Using another patients group of subjecus such as Meniere's disease and sudden deafness patients, pressor response for intravenously administered NE was studied. Meniere's disease patients showed hyporesponsiveness of blood pressure to exogenously administered NE.
These facts suggest that sympathetic effector organs in Meniere's disease patients are functionally disturbed.
