Analysis of optokinetic nystagmus in patients with localized lesions of unilateral visual cortices.
Optokinetic nystagmus (OKN) asymmetry in 4 patients with localized lesions of the unilateral visual cortices (2 in the right hemisphere and 2 in the left hemisphere), confirmed at autopsy or by CAT scan, was detected by computer analysis. The ENG recordings showed typical asymmetry of OKP: lower amplitude in the contralateral optokinetic pattern (OKP) than on the side with the visual cortex lesion. Analysis of this asymmetry revealed lower amplitude, remarkably impaired slow-phase velocity, and mildly impaired fast-phase velocity, with a slight difference in number of OKN. The findings suggested that asymmetry of OKP in patients with localized lesions of the unilateral visual cortices is primarily caused by the impaired slow-phase velocity of the contralateral OKN because of a slight change in number of OKN.
Kaga
K
K
Department of Otolaryngology, Teikyo University School of Medicine, Tokyo, Japan.
Furuya
N
N
Suzuki
J
J
Yamada
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001927:Brain Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D002648:Child; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic / Q000502:physiology*; D014057:Tomography, X-Ray Computed; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*