Habituation, Motion Sickness, Seasickness, Vestibular Time Constant
Conditions
Keywords
Motion Sickness, Seasickness, Galvanic vestibular stimulation, Rotatory chair, Vestibular time constant
Brief summary
subjects with severe seasickness, who failed to habituate to sea conditions after at least six month of active sailing, were enrolled to the single-blind randomized control study. The intervention group was treated with rotatory chair stimulation at sinusoidal harmonic acceleration protocol coupled with galvanic vestibular stimulation to the mastoid processes. This unique procedure was hypothesized to promote habituation to seasickness. The control group underwent a sham procedure. All study participants filled out seasickness questionnaires at set time points following the intervention and underwent repeated step testing to determine their vestibular time constant. The number of anti-motion sickness clinic visits and scopolamine prescriptions was also recorded in the three months period following the intervention.
Interventions
PROCEDUREGVS stimulation coupled with inverse phase rotatory chair stimulation at sinusoidal harmonic acceleration protocol
GVS stimulation coupled with inverse phase rotatory chair stimulation at sinusoidal harmonic acceleration protocol
PROCEDURESham procedure
Participants with severe motion sickness were sited in the the rotatory chair with the videonystagmography recorder masking their eyes, while two galvanic vestibular stimulation electrodes were connected to the mastoid processes. No active stimulus was given.
Sponsors
Medical Corps, Israel Defense Force
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
MALE
Age
19 Years to 44 Years
Healthy volunteers
Yes
Inclusion criteria
* maximum score of 7 on the Wiker seasickness questionnaire in moderate sea conditions, with wave height of 0 - 1.5 m * All had been sailing regularly for at least six months before enrolling in the study
Exclusion criteria
* history of hearing loss * otoscopic findings of ear pathology * an implanted electrode * a finding of vestibulopathy on otoneurologic examination * withdrawal by any subject of his informed consent.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Vestibular time constant | Until one month following the intervention | Vestibular time constant was measured using repeated rotatory chair stimulation in step protocol. |
| Seasickness severity | Until one month following the intervention | Seasickness severity as determined by Wiker questionnaire at set time frames following the intervention |
| scopolamine drug prescription | Until three months following the intervention | scopolamine drug prescriptions were calculated for each participant and compared between the two groups |
| Anti-motion sickness clinic visits | Until three months following the intervention | Anti-motion sickness clinic visits were calculated for each participant and compared between the two groups |
Outcome results
None listed