Sensation of Dizziness-Correlations of Induced Vertiginous Sensations and Motion Sickness.

Patients with vertigo complain about various degrees of vertiginous sensation. In the present study, vertiginous sensations were induced by caloric and optokinetic stimuli in normal volunteers. A questionnaire survey concerning daily life, including susceptibility to motion sickness, was also conducted.The subjects consisted of 63 volunteers (24 males and 39 females) ranging in age from 17 to 72 years old, with a mean of 49.5 years of age. None of the subjects had any central nervous disorders or peripheral vestibular dysfunction, as assessed by equilibrium test.Vertiginous sensation was induced by bilateral caloric stimuli at 30°C. Vertiginous sensation was also induced by optokinetic stimuli at 0-150°/sec with constant bilateral acceleration. A questionnaire containing 26 items concerning daily life was answered by all subjects.Subjects were classified according to their ability to recognize rotational sensation during caloric and optokinetic stimuli. Nineteen subjects recognized rotational sensation during caloric stimuli but not during optokinetic stimuli. Only three subjects recognized rotational sensation during optokinetic stimuli but not during caloric stimuli. Nine subjects did not recognize rotational sensation during either caloric or optokinetic stimuli. Rotational sensation tended to be recognized during caloric stimuli rather than during optokinetic stimuli.The twenty-six items on the questionnaire concerning daily life were related to constitutional, physical and psychological factors and susceptibility to motion sickness. The results of the questionnaire were compared among groups classified by the presence or absence of rotational sensation during caloric and optokinetic stimuli.There were no significant relationships between constitutional, physical and psychological factors and/or susceptibility to motion sickness among the other three groups of subjects. The majority of subjects in all groups replied that they tended to experience motion sickness while traveling by ship or by car, especially when driven by other persons.