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Mal de debarquement (or Mal de débarquement) syndrome (MdDS, or disembarkment syndrome) is a rare condition usually occurring after a cruise, aircraft flight, or other sustained motion event. It has only recently received attention and very little scientific research has been conducted. The phrase "mal de débarquement" is French for "disembarkation sickness".
Symptoms most frequently reported include a persistent sensation of motion usually described as rocking, swaying, or bobbing; difficulty maintaining balance; extreme fatigue; and difficulty concentrating ("brain fog"). Other common symptoms include dizziness, visual disturbances (such as seeing motion, inability to focus etc.), headaches and/or migraine headaches, the feeling of pressure in the brain, confusion, and anxiety. Many patients also describe ear symptoms such as hyperacusis, tinnitus, "fullness", pain, or even decreased hearing. Cognitive impairment ("brain fog") includes an inability to recall words, short term memory loss, and an inability to multi-task, unable to use a computer for any length of time and some MdDS sufferers report they are even unable to watch television, the symptoms are very debilitating and can fluctuate on a daily basis, affecting greatly daily and social activities.
Interestingly, the condition often abates when the patient is in motion such as in a car, train, plane, or boat. Symptoms are increased by stress, lack of sleep, crowds, flickering lights, loud sounds, fast or sudden movements, enclosed areas or busy patterns.
In MdDS, the symptoms persist for more than a month, possibly for many years, all medical treatment is palliative and symptoms that persist beyond 6 months show a very low likelihood of ever remitting. MdDS is unexplained by structural brain or inner ear pathology. This differs from the very common condition of "land sickness" that most people feel for a short time after a motion event such as a boat cruise, aircraft ride, or even a treadmill routine.
MdDS is thought to be a neurological syndrome with no known cause or cure. Research is being undertaken into the neurological nature of this syndrome through imaging studies.
Despite MdDS causing significant disability, therapy for persistent MdDS remains virtually non existent, of more recent times a pilot study has commenced utilizing Repetitive Transcranial Magnetic Stimulation (rTMS) this being a method of neuromodulation in which a local magnetic field is applied over the scalp to induce an electrical current in the cortical structures underlying the coil. Low-frequency rTMS (e1 Hz) induces local inhibition, whereas high frequency rTMS (Q5 Hz) induces local excitation.
Triggers that cause MdDS suggest that it maybe a disorder of Maladaptive Neuroplasticity that might be responsive to external neuromodulation.
The condition is thought to be under-reported in the medical literature, where fewer than 100 cases have been studied. A study of 27 cases, conducted by Timothy C Hain in 1999, noted all but one patient to be female. The average age in this series was 49 years. This apparent gender disparity, however, may be due in part to the fact that the questionnaire, which formed the basis of the study, was circulated in a publication with a predominantly female reader base.
Subsequent studies have produced conflicting results with regard to the gender distribution of MdDS. The trends in Hain's report have recently been supported by the MdDS Balance Disorder Foundation in a study of over 100 individuals diagnosed with MdDS. The female:male ratio was approximately 9:1; the average age of onset was 43–45 years. However, another recent study found that 44% of subjects who had experienced MdDS for 2 years or more were male, suggesting a more even distribution.
It has been shown to occur in excursions of as little as five hours though it has been unclear how long it takes for symptoms to occur. The most commonly reported inciting event was a prolonged ocean cruise (~45%), however shorter boating excursions (~22%), aircraft travel (~15%), and automobile travel (~8%) have all been described.
This disorder has been noted as far back as the 1700s when crew and passengers disembarked from their long journeys travelling from country to country on a ship, MdDs sufferers will increase as people are travelling more than ever on cruise ships, airplanes and by car, more awareness of this disorder is needed.
MdDS is diagnosis several ways, that being by the symptoms in particular the "constant rocking, swaying feeling" and the abatement of this feeling when in motion again and as a matter of exclusion. There are no definitive tests that confirm MdDS, only tests that rule out other conditions, tests include hearing and balance.
There is no known cure for the condition. In the series cited above, more than 50% of patients had resolution of symptoms within three years of onset. For most balance and gait disorders, some form of displacement exercise is thought helpful (for example walking, jogging, or bicycling but not on a treadmill or stationary bicycle). This has not been well-studied in MdDS however. Medications that suppress the nerves and brain circuits involved in balance (the benzodiazepine clonazepam for example) have been noted to help, but don't seem to offer a permanent cure. It is not known whether medication that suppress symptoms prolong symptom-duration or not. Vestibular Therapy has proved to be in effective in treating MdDS.
Treatment options need to be explored further for MdDS sufferers which remains incurable if the symptoms do not remit in a short period of time.