Three-dimensional analysis of otolith-ocular reflex during eccentric rotation in humans.
When a participant is rotated while displaced from the axis of rotation (eccentric rotation, ER), both rotational stimulation and linear acceleration are applied to the participant. As linear acceleration stimulates the otolith, the vestibulo-ocular reflex (VOR) caused by the otolith (linear VOR; lVOR) would be induced during ER. Ten participants were rotated sinusoidally at a maximum angular velocity of 50°/s and at frequencies of 0.1, 0.3, 0.5, and 0.7Hz. The radius of rotation during ER was 90cm. The participants sat on a chair at three different positions: on the axis (center rotation, CR), at 90cm backward from the axis (nose-in ER, NI-ER) and at 90cm forward from the axis (nose-out ER, NO-ER). Their eye movements during rotation were recorded and analyzed three-dimensionally. The VOR gain during NI-ER was lower at 0.5 and 0.7Hz, and that during NO-ER was higher at 0.3, 0.5, and 0.7Hz than during CR. These results indicate that lVOR actually worked at 0.5 and 0.7Hz during ER and that the enhancement and decline of the VOR gain relative to the VOR gain during CR was seen in humans. Thus, we suggest that otolith function can be assessed via rotational testing of NI-ER and NO-ER.
Department of Otolaryngology, Suita Municipal Hospital, Osaka 564-0082, Japan. Electronic address: yas.say.yas1.24@gmail.com.
Yasumitsu
Y
Takimoto
Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. Electronic address: timai@ent.med.osaka-u.ac.jp.
Takao
T
Imai
Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. Electronic address: tomoko_iga@yahoo.co.jp.
Tomoko
T
Okumura
Department of Otorhinolaryngology - Head and Neck Surgery, Tokushima University Graduate School of Medicine, Tokushima 770-8503, Japan. Electronic address: takeda@tokushima-u.ac.jp.
Noriaki
N
Takeda
Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan. Electronic address: hinohara@ent.med.osaka-u.ac.jp.
Hidenori
H
Inohara
D000328:Adult; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010037:Otolithic Membrane / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular; D012399:Rotation; D055815:Young Adult
Acceleration; Centric rotation; Eye movements; Linear VOR; Sinusoidally