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Mal de débarquement syndrome (MDDS), literally, “sickness of disembarkment,” refers to prolonged and inappropriate sensations of movement after exposure to motion. The syndrome typically follows a 7-day sea voyage, but it has also been observed following extended airplane travel, train travel, and space flight.1 Symptoms include rocking and swaying accompanied by imbalance. MDDS is distinguished from ordinary motion sickness, seasickness (mal de mer), and “land-sickness” by persistence of symptoms for a month or longer. Additionally, unlike disorders of the inner ear, most individuals with MDDS report that their symptoms remit with re-exposure to motion, such as driving a motor vehicle.2 A typical case history is as follows: A 50-year-old woman went on her first ocean cruise. She had some motion sickness on the cruise, which responded to transdermal scopolamine. Immediately after returning from the cruise and getting onto solid ground, she developed imbalance and a rocking sensation, accompanied by fatigue and difficulty concentrating. Her description was “Imagine feeling like you are on rough seas 24 hours a day, 7 days a week.”
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Table 16-1 summarizes the available literature about MDDS. It is a disorder that mainly affects women (87%) in their mid-40s. Symptoms last at least 1 month and most frequently abate before 6 months have elapsed (median 4.1 mo).
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Table 16-2 lists the features that distinguish MDDS from simple land-sickness. Land-sickness is common, and between 41% and 73% of persons disembarking from seagoing voyages experience a brief unsteadiness syndrome.3–5 Common land-sickness typically persists for 2 days or less. Persons with land-sickness are also likely to have seasickness,5 although persons with MDDS generally are untroubled by seasickness. Males and females do not appear to differ significantly in the incidence, intensity, or duration of land-sickness symptoms.3 Land-sickness (or LDS), confusingly, is also termed “mal de debarquement” by some. Table 16-1 does not include reports or data concerning subjects whose symptoms last less than 1 month (i.e., potential land-sickness), except for the work of Cha, in whom the duration of symptoms in patients with “classic” MDDS could not be determined due to study design.2
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