Mal de debarquement (or Mal de débarquement) syndrome (MdDS, or common name disembarkment syndrome) is a rare neurological condition usually occurring after a cruise, aircraft flight, or other sustained motion event. The phrase "mal de débarquement" is French for "Sickness from Disembarkation". MdDS is typically diagnosed by a Neurologist or an Ear Nose & Throat Specialist when a person reports a persistent rocking, swaying, or bobbing feeling (though they are not necessarily rocking). This usually follows a cruise or other motion experience. Because most vestibule testing proves to be negative, doctors may be baffled as they attempt to diagnose this rare neurological syndrome. A major diagnostic indicator is that most patients feel better while driving or riding in a car or while in passive motion. The syndrome has recently received increased attention due to the number of people presenting with the condition and more scientific research has commenced now for a number of years to determine what triggers MdDs and how to cure it.
Symptoms most frequently reported include a persistent sensation of motion usually described as rocking, swaying, or bobbing; difficulty maintaining balance, will be more susceptible to falls, so care should be taken with sudden movements or turns; extreme chronic fatigue; can become fatigued quickly with minimal exertion. Difficulty concentrating, other common symptoms include dizziness, visual disturbances such as seeing motion, blurred vision, inability to focus etc., headaches and/or migraine headaches, nausea, the feeling of pressure in the brain and confusion, fluctuations in temperature also affect suffers in particular heat. Many patients also describe ear symptoms such as hyperacusis, tinnitus, "fullness", pain, or even decreased hearing, and will also startle more easily. May have Photosensitivity and find it more difficult to walk in the dark as well as other sensitivities to chemicals and their smells. Cognitive impairment ("brain fog") includes an inability to recall words, short term memory loss, and an inability to multi-task, misspelling and mispronunciation of words, unable to use a computer for any length of time due to the visual over stimulation and some MdDS sufferers report they are even unable to watch television, the symptoms are extremely debilitating and fluctuate high and low on a daily basis. Excessive sleeping, MdDS sufferers can sleep up to 12 or more hours a day, depending on their symptom levels. Research reveals MdDS is not migraine related and many sufferers have never had migraine symptoms prior to the onset of the disorder.
Mal De Debarquement greatly effects the working capacity of sufferers with many having to relinquish work, it also limits most other daily and social activities. Interestingly, the condition often abates to some degree when the patient is in motion such as in a car, train, plane, or boat, however once the motion ceases, the symptoms return often at much higher levels than when the journey first commenced. Symptoms can be increased by stress, lack of sleep, crowds, flickering lights, loud sounds, fast or sudden movements, enclosed areas or busy patterns.
MdDS is unexplained by structural brain or inner ear pathology and is thought to be perhaps a neurological syndrome most often caused by a motion trigger, but can occur spontaneously. Recent research has revealed that MdDs is vision and other sensors related. 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.
So far, nobody knows the functional cause of MDDS. From the studies which have been done, it appears certain that it is not an injury to the ear or brain (vestibular and CNS tests for MDDS patients invariably turn out normal results). Speculation about the cause of MDDS includes the following:
- Psychiatric condition (particularly linked to depression)
- A hormonal related condition (may occur more often in females)
- Otolith organ or central nervous system abnormalities
- Some link to a variant of migraine
Whatever the exact reason, MDDS appears to be a failure of the vestibular 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.
While MDDS usually eventually disappears, it also more often than not seems to return once a former MDDS sufferer takes another long boat or plane trip. Hence, preventing MDDS is also an area of active concern. Once again, possible prevention is largely speculative, but medications which diminish the response of the vestibular system may be useful. In particular, Valium and Ativan have been suggested as pre-trip medications to prevent reoccurrences of MDDS. In addition, the recently restored availability of the Transderm patch (active ingredient scopolamine) may be effective in preventing a recurrence of MDDS while performing any activities involving motion.
Diagnosis of MDDS is generally a process of exclusion. As noted in the literature, quantitative vestibular and neural tests on MDDS sufferers nearly always turn out to be normal. Diagnosis is usually via a combination of the patient history (i.e. the sensation arose immediately after prolonged exposure to a boat or airplane travel), and exclusion of possible alternatives such as Meniere's disease. If you feel a constant rocking sensation which started immediately after a period of prolonged motion exposure and remains for days, yet everything else appears to be normal (i.e. you don't have numbness down one side, or hearing problems etc), then it's possible that you have MDDS.
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 and can lower symptoms, but it is not a cure. It is not known whether medication that suppress symptoms prolong symptom-duration or not. Vestibular Therapy has not proved to be effective in treating MdDS.
Additional research is being undertaken into the neurological nature of this syndrome through imaging studies. Treatment options need to be explored further for MdDS sufferers which remains incurable and permanent if the symptoms do not remit in a short period of time.