Quantitative assessment of influence of aging on optokinetic nystagmus.
A quantitative assessment of the influence of aging on optokinetic nystagmus (OKN) was investigated using 50 normal adults in ages ranging from 30 to 70 years. In linear stimulus-induced OKN, a statistically significant difference was demonstrated in slow-phase OKN velocity only between the 30-59 year old age group and the 70-79-year-old age group, when OKN stimulus was more than 60 degrees/s. Step stimulus-induced OKN was investigated in the same age groups in order to compare aging effects upon slow-phase OKN velocity. No statistically significant difference was found in slow-phase OKN velocity between younger age groups and the oldest age group. There was no significant difference in fast-phase velocity among the age groups. Thus, step-induced OKN has a wider clinical application than linear stimulus-induced OKN.
Kato
I
I
Department of Otolaryngology, St. Marianna University School of Medicine, Kanagawa, Japan.
Ishikawa
M
M
Nakamura
T
T
Watanabe
J
J
Harada
K
K
Kanayama
R
R
Aoyagi
M
M
Koike
Y
Y
D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004585:Electrooculography; D005133:Eye Movements / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D010775:Photic Stimulation; D012438:Saccades / Q000502:physiology; D012815:Signal Processing, Computer-Assisted