Affiliations: [a] Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, Haifa, Israel | [b] Department of Neurology, Beilinson Medical Center, Petah Tiqva, and the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel | [c] Department of Otolaryngology, Carmel Lady Davis Hospital, Haifa, Israel
Note: [1] Presented at the 63rd Annual Scientific Meeting of the Aerospace Medical Association, Miami Beach, FL, May 10–14, 1992.
Note: [*] Reprint address: Carlos R. Gordon, Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, P.O. Box 8040, 31 080 Haifa, Israel.
Abstract: 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.
Keywords: mal de debarquement, motion, adaptation, habituation
