Study of Acceleration and Deceleration in Optokinetic Nystagmus Testing

• Published in: Equilibrium Research Vol. 44; no. 2; pp. 150 - 155
• Main Authors: Sasahara, Kinuyo, Iho, Kiyoko, Saito, Akira, Tokumasu, Kohji
• Format: Journal Article
• Language: English
• Published: Japan Society for Equilibrium Research 1985
• ISSN: 0385-5716; 1882-577X
• DOI: 10.3757/jser.44.150

Electronystagmogram recordings in OKP test should show a symmetric pattern. However, asymmetric patterns are not rare This study was done to confirm this and to clarify the characteristics of the asymmetric pattern related to age in both normal subjects and patients. The mean eye-velocity of the slow phase of nystagmus and the number of beat every 5 seconds were compared in the acceleration and deceleration phase. Each normal group included 10 to 12 cases, seven groups from the first to the seventh decade were tested. Patients in the third decade, whose OKN was markedly suppressed, were also tested. 1. The eye-speed of the slow phase of nystagmus in the deceleration phase was slower than in acceleration at drum-speeds of 40 to 140°/sec in males and 20 to 100°/sec in females in the seventh decade. However, the eye-speed in the acceleration phase was slower than in deceleration at drum-speeds of 80 to 140°/sec in males and 80 to 120°/sec in females in the second decade. 2. The number of nystagmus beats was less in the deceleration phase than in acceleration at drumspeeds of 80 to 120°/sec in males and 60 to 100°/sec in females in the seventh decade. 3. In the patients, the eye-speed in the nystagmus slow phase in the deceleration phase was slower than in acceleration at drum-speeds of 80 to 140°/sec.