Purpose: The present study investigated the relationship of the frequency of nystagmus to the severity of optokinetic rotation-induced motion sickness.
Methods and results: Eighty-seven subjects viewed a vertically striped, rotating drum for 16 min. Subjects' electrooculograms, ratings of vection, and subjective symptoms of motion sickness (SSMS) were measured during the drum rotation period. Subjects' electrogastrograms (EGGs) were recorded throughout the baseline and drum rotation periods. The ratios of the spectral intensity of EGG 4-9 cycles per minute (cpm) between drum rotation and baseline periods were calculated. The results indicated that the frequency of nystagmus was positively correlated with the ratings of vection (r = 0.40, p < 0.0001), scores of SSMS (r = 0.61, p < 0.0001), and ratios of EGG 4-9 cpm spectral intensity between drum rotation and baseline periods (r = 0.54, p < 0.0001).
Conclusion: These results demonstrated that more rapid eye movement indexed by higher frequency of optokinetic nystagmus are related to the development of symptoms of motion sickness and gastric tachyarrhythmia.