Clinical features of mal de debarquement: adaptation and habituation to sea conditions.
A survey conducted among 116 crew members of seagoing vessels confirmed that mal de debarquement (M-D) is a transient feeling of swinging, swaying, unsteadiness, and disequilibrium. None of the subjects requested medical attention, although there were isolated cases in which a strong sensation of swinging and unsteadiness caused transient postural instability and impaired the ability to drive. In most cases, the sensation of M-D appeared immediately on disembarking and generally lasted a few hours. In addition, subjects usually described bouts or attacks of M-D associated with changes in body posture, head position, or with closing of the eyes. M-D was reported by 72% of our subjects. Sixty-six percent of subjects reported a high incidence following their first voyages. A significant positive correlation was found between M-D and seasickness susceptibility. The nature of M-D may be explained within the framework of multisensorimotor adaptation and habituation to a new or abnormal motion environment. It is suggested that M-D represents a dynamic, multisensorimotor form of CNS adaptive plasticity.
Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, Haifa.
C R
CR
Gordon
O
O
Spitzer
I
I
Doweck
Y
Y
Melamed
A
A
Shupak
D000222:Adaptation, Physiological; D000328:Adult; D006185:Habituation, Psychophysiologic; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000503:physiopathology*; D009792:Oceans and Seas; D012767:Ships; D013997:Time Factors