Cortical activation during optokinetic stimulation - an fMRI study.
CONCLUSIONS
Activation of cortical areas related to visual motion processing and control of eye movement, and deactivation of parieto-insular vestibular cortices (PIVC) were revealed by functional magnetic resonance imaging (fMRI) with small-field optokinetic stimulation (OKS). The results agreed well with those of previous studies, which indicates that the current protocol is reliable enough to be used as a clinical examination.


OBJECTIVE
To propose an fMRI set-up with OKS that is reliable and simple enough to be performed as a clinical test.


METHODS
Ten right-handed healthy volunteers participated in this study. fMRI was used to measure blood oxygen level-dependent (BOLD) signal increases (contrast: OKS - rest) and decreases (contrast: rest - OKS) during small-field OKS. Functional images were acquired using a standard clinical scanner operating at a magnetic field strength of 1.5 T. The data were analyzed by statistical parametric mapping (SPM2), and the significance level was set at p<0.001, uncorrected.


RESULTS
BOLD signal increases were observed in the visual association area of both hemispheres (BA19) (MT/V5), primary visual cortex (BA17) of the right hemisphere, bilateral superior parietal lobules (BA7), and bilateral frontal eye fields (BA6). Decreases of BOLD signals were observed in the PIVC bilaterally.
Kikuchi
Masahiro
M
Department of Otolaryngology, Kobe City Medical Center General Hospital, Kobe, Japan.
Naito
Yasushi
Y
Senda
Michio
M
Okada
Tomohisa
T
Shinohara
Shogo
S
Fujiwara
Keizo
K
Hori
Shin-Ya
SY
Tona
Yosuke
Y
Yamazaki
Hiroshi
H
D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D017120:Nystagmus, Optokinetic; D015835:Ocular Motility Disorders / Q000175:diagnosis; D014793:Visual Cortex / Q000502:physiology*