K. Yamamoto et al., Assessment of the otolith-autonomic response using spectral analysis of the R-R interval and blood pressure, OTO H N SUR, 123(5), 2000, pp. 582-586
The effects of otolith stimulation on systolic blood pressure (SBP) and R-R
interval fluctuations were investigated in 12 healthy subjects and 5 patie
nts with loss of labyrinthine function. The vestibular otolith organs were
stimulated by centrifugal forces, the constant rotation of a chair fixed ou
tside of the rotation axis on the horizontal plane. The chair was fixed alo
ng the direction of centrifugal force (eccentric rotation (ECR)) or along t
he tangent line (eccentric lateral rotation (ECLR)). The ECR stimulates bot
h the utricular and saccular maculae, whereas the ECLR stimulates only the
utricular maculae, Spectral analysis showed that in the healthy subjects, l
ow-frequency SBP increased significantly during ECR but not during ECLR. Th
ere was no significant increase in low-frequency SBP in patients with labyr
inthine loss. In the R-R interval analysis, however, the low- and high-freq
uency components did not change significantly in the healthy subjects durin
g ECR, Our findings indicate that stimulation of the otolith maculae, espec
ially the saccular organs, predominantly produces augmentation of the a-sym
pathetic activities rather than cardiac sympathovagal outflow to the heart.