Computer analysis of the optokinetic pattern test in acoustic tumors, brain stem and cerebellar lesions. Slow and fast phase velocities of optokinetic nystagmus.
Optokinetic pattern (OKP) abnormalities in 36 patients with infratentorial lesions were analyzed by microcomputer (7T18 Nihondenki-Sanei). The parameters used for analysis consisted of slow phase velocity (S-VEL) and fast phase velocity (F-VEL) in optokinetic nystagmus. In 16 patients with acoustic tumors, S-VELs were normal or borderline when the tumors were less than 2 cm in diameter, but when the tumors were more than 2 cm, S-VELs were severely impaired. In 20 patients with brain stem and/or cerebellar lesions, S-VELs were abnormal in all the patients with the exception of 3. F-VEL abnormalities were seen in only 5 patients with brain stem lesions, especially pontine lesions. These findings suggest that S-VEL is a sensitive indicator of infratentorial lesions and F-VEL an important indicator of pontine lesions.
Department of Otolaryngology, Teikyo University School of Medicine, Tokyo, Japan.
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Yamada
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Kaga
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Furuya
D001927:Brain Diseases / Q000503:physiopathology; D001933:Brain Stem; D002526:Cerebellar Diseases / Q000503:physiopathology*; D003201:Computers; D004584:Electronystagmography; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D009464:Neuroma, Acoustic / Q000503:physiopathology*; D009760:Nystagmus, Physiologic / Q000502:physiology