title: Variants of windmill nystagmus.
abstract: Windmill nystagmus is characterized by a clock-like rotation of the beating direction of a jerk nystagmus suggesting separate horizontal and vertical oscillators, usually 90° out of phase. We report oculographic characteristics in three patients with variants of windmill nystagmus in whom the common denominator was profound visual loss due to retinal diseases. Two patients showed a clock-like pattern, while in the third, the nystagmus was largely diagonal (in phase or 180° out of phase) but also periodically changed direction by 180°. We hypothesize that windmill nystagmus is a unique manifestation of "eye movements of the blind." It emerges when the central structures, including the cerebellum, that normally keep eye movements calibrated and gaze steady can no longer perform their task, because they are deprived of the retinal image motion that signals a need for adaptive recalibration.
authors.affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Pusan, Korea.
authors.forename: Kwang-Dong
authors.initials: KD
authors.lastname: Choi
authors.affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Pusan, Korea.
authors.forename: Hae Kyung
authors.initials: HK
authors.lastname: Shin
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-Do, 463-707, Korea. jisookim@snu.ac.kr.
authors.forename: Ji-Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, School of Medicine, Kyungpook National University, Daegu, Korea.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Jae-Hwan
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Biomedical Laboratory Science, Kyungdong University, Goseong-gun, Korea.
authors.forename: Hyo-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Johns Hopkins School of Medicine, Baltimore, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Zee
mesh_terms: D000368:Aged; D002531:Cerebellum / Q000473:pathology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000503:physiopathology*
keywords: Blindness; Gaze stabilizing mechanism; Periodic alternating nystagmus; Velocity-storage mechanism; Windmill nystagmus