The Effect of Hyperventilation on Caloric Nystagmus

Abstract

This study investigated the effect of hyperventilation on caloric nystagmus. Caloric test using cool air (15°C, 6 l/min) was performed in 14 normal volunteers. Each volunteer underwent caloric test twice. One was performed without hyperventilation, while the other was performed after hyperventilation for 60sec. We used maximal slow phase eye velocity and slow phase eye velocity at the time of the cessation of caloric stimulation (initial slow phase velocity) as parameters for electronystagmographic recording. The data from each volunteer were compared and statistically analyzed. Hyperventilation significantly augmented the maximal slow phase eye velocity and the initial slow phase eye velocity.