Measurement of motion sickness relief

Usefulness of the methods

Quantification of drug effects against symptoms of common motion sickness is a useful practical aim which can be realised by the methods offered by HPR. Many drugs which are effective against motion sickness more or less reduce vigilance and performance at least at higher dosages. Concomitant measurement of vigilance and performance allows to compare the anti-motion sickness dose range with that influencing vigilance and performance in order to find out effective doses with tolerable side effects for ambulant treatment.

Principle of the methods

• Electro-Nystagmography:
  Persisting nystagmus is initiated by permanent caloric stimulation of the eardrum. The resulting nystagmus is recorded by surface skin electrodes and evaluated on-line by a sophisticated computer programme.
• Vegetative symptoms:
  Caloric stimulation initiates changes in Na-secretion in the sweat, in heart rate and blood pressure. These parameters are recorded and also evaluated on-line.
• Body sway test:
  The subject follows light signals by changes in his body position in the state of caloric stimulation. Deviations from ideal body movement are recorded and evaluated.
• Measurement of vigilance and performance:
  Combination with our test battery investigating vigilance and performance provides quantitative information on the most important undesired effect of drugs which are effective against motion sickness.
  
  

Advantages of the methods

In contrast to rotatory induction, the caloric stimulation used in connection with nystagmography in our experimental setting is permanent, constant and reproducible. This in addition to the reproducibility of the body sway test makes it possible not only to quantify anti-motion sickness effects but also to record their onset, maximum and duration.

Reference data

Data are available for several antihistamines with and without caffeine.

Options

• Proof of anti-motion-sickness effects of drugs
• Determination of the dose-effect and time-effect relationships of anti-motion sickness drugs
• Concomitant measurement of influences on vigilance and performance and of pharmacokinetics