title: Decreased ratio of downward to horizontal smooth pursuit eye movement velocity in a patient with Chiari I malformation: application in early detection of vestibulocerebellar malfunction.
abstract: A 72-year-old man presented with dizziness and left hand muscle atrophy. Magnetic resonance imaging revealed a spinal cord cavity and descent of the cerebellar tonsils. His diagnosis was Chiari I malformation with syringomyelia. No cerebellar signs were observed on physical examination. The cause of dizziness was investigated using a video-based eye movement tracker, which revealed a downward smooth pursuit velocity gain significantly below normal when expressed relative to the horizontal pursuit velocity gain. Vestibulocerebellar damage can cause mild downward pursuit deficit. The downward to horizontal smooth pursuit velocity gain ratio may be a more sensitive means of detecting vestibulocerebellar damage early.
authors.affiliation: Department of Internal Medicine, Asahi General Hospital, Japan. ma-ko@pg7.so-net.ne.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Sugiyama
mesh_terms: D000368:Aged; D001139:Arnold-Chiari Malformation / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D002531:Cerebellum / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D013595:Syringomyelia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*