title: Analysis of optokinetic nystagmus in patients with lesions on the left unilateral parietal lobe or the entire left hemisphere.
abstract: Optokinetic nystagmus (OKN) was studied by computer analysis in nine patients with lesions on the left unilateral parietal lobe (group A) and in five patients with lesions on the entire left hemisphere (group B), as confirmed by CAT or MRI scans. OKN stimulation and recordings were evaluated based on the optokinetic pattern (OKP). In group A, there was no directional preponderance. However, in group B, the Electronystagmography recordings showed typical asymmetry of OKP. This asymmetry was revealed by a low amplitude and a significantly impaired slow-phase eye velocity of the right OKP. Asymmetry of OKP resulted from the impaired slow-phase eye velocity of the contralateral OKN to the damaged hemisphere because of a slight change in fast-phase eye velocity.
authors.affiliation: Department of Otolaryngology, University of Tokyo, Tokyo, Japan. Kimikaga-tky@umin.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kaga
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: N
authors.initials: N
authors.lastname: Furuya
authors.forename: M
authors.initials: M
authors.lastname: Shindo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D001330:Electronic Data Processing; D004584:Electronystagmography; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D010296:Parietal Lobe / Q000503:physiopathology*; D012438:Saccades / Q000502:physiology