Ocular counter-rolling in scuba divers with motion sickness

Area of Science:

• Vestibular Science
• Scuba Diving Medicine
• Otolaryngology

Background:

• Motion sickness (MS) is a common issue for scuba divers.
• Understanding the physiological basis of MS in divers is crucial for prevention and management.

Purpose of the Study:

• To compare otolith organ function in scuba divers experiencing MS versus those who do not.
• To investigate the relationship between otolith function asymmetry and MS susceptibility.

Main Methods:

• Video-oculography (VOG) was used to measure video ocular counter-roll (vOCR) in 50 healthy scuba divers.
• Otolith-ocular function was assessed via vOCR during a 30° head tilt, comparing right-left (R-L) asymmetry (%OCRA) to static OCR.
• Divers were categorized based on Graybiel motion sickness (GMS) scores and completed the Motion Sickness Susceptibility Questionnaire (MSSQ).

Main Results:

• Significant differences in MSSQ and %OCRA scores were found between divers with and without MS (p<0.01 and p<0.001).
• A significant correlation existed between %OCRA scores and MS severity.
• Female divers exhibited higher MS susceptibility, and ROC analysis indicated a high diagnostic value for %OCRA in identifying divers with MS.

Conclusions:

• Asymmetrical otolith organ function may contribute to MS susceptibility and severity in scuba divers.
• Female hormones might play a role in increasing MS susceptibility.
• MS in divers may stem from physiological differences in ear function, necessitating a comprehensive evaluation by otolaryngologists.