Possible Causes
While the etiology (cause) of MdDS is not known, the predominant opinion is that MdDS is caused by inappropriate vestibular (inner ear) adaptation upon cessation of a motion experience.
The balance system is made up of three components:
.The Vestibular System (or workings of the inner ear)
.The eyes
.Proprioceptive sensors (special pressure sensors in your muscles, tendons and joints mainly found in your feet and legs)
The information from these three systems are then processed by the brain. However, the predominant opinion is that MdDS is caused by the brains inability to process these signals correctly. One theory is that somewhere in this circuitry there is a signal or signals mis-firing causing us to feel and/or see the rocking motion.
Whatever the exact reason, MdDS appears to be a failure of the system to readapt correctly to stable ground.
It has long been known that the vestibular system adapts to different environments. In the case of MdDS, it appears that it adapts to the motion encountered on the boat or plane (i.e. constant rocking or swaying), and fails to readapt once that stimulus is removed.
