Affiliations: [a] Department of Otolaryngology, University of Pittsburgh, PA, USA | [b] Department of Bioengineering, University of Pittsburgh, PA, USA
Note: [*] Corresponding author: Joseph M. Furman, M.D., Ph.D., University of Pittsburgh, Department of Otolaryngology, The Eye and Ear Institute, Suite 500, 200 Lothrop Street, Pittsburgh, PA 15213, USA. Tel.: +1 412 647 2117; Fax: +1 412 647 2080; E-mail: [email protected]
Abstract: We assessed the influence of age on the otolith-ocular reflex and semicircular canal-otolith interaction. Healthy young (n=30) and healthy older (n=60) subjects were rotated about an earth vertical axis, and about a 30 degree off-vertical axis. Eye movements during and following rotation were recorded using electro-oculography. Results indicated that there were statistically significant changes in the otolith-ocular reflex and semicircular canal-otolith interaction as a function of age. The modulation component during off-vertical axis rotation (OVAR) was greater in the older group compard to the young adults, whereas the bias component was smaller with advanced age. The foreshortening of the vestibulo-ocular reflex time constant induced by post-rotatory head tilt following cessation of rotation was less prominent in the older group. There were no consistent changes in the semicircular canal-ocular reflex. Overall, response parameters showed more variability in the older subjects. We conclude that age related changes in the otolith-ocular reflex and semicircular canal-otolith interaction are a result primarily of a degradation of central vestibular processing of otolith signals rather than a decline of peripheral vestibular function.
