Mal de debarquement

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

Symptoms most frequently reported include a persistent sensation of motion usually described as rocking, swaying, or bobbing; difficulty maintaining balance; extreme fatigue; difficulty concentrating ("brain fog"). Other common symptoms include dizziness, visual disturbances such as seeing motion, blurred vision, inability to focus etc., headaches and/or migraine headaches, the feeling of pressure in the brain and confusion. 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 work with many MdDs sufferers having to give up work and it affects many other daily, social activities.

In MdDS, the symptoms persist for more than a month, possibly for many years, all medical treatment is palliative and sufferers with "Persistent MdDS" symptoms,^[1] that last beyond 4 years are unlikely to ever remit at all.

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. 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. . 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.

Mal de debarquement Syndrome has been noted as far back to the times of Erasmus Darwin in 1796,^[2] and Irwin J A (1881) The pathology of seasickness.

Epidemiology

The condition is thought to be under-reported in the medical literature. 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.^[3] 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.^[4]

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,^[5] 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,^[6] suggesting a more even distribution.

It has been shown to occur in excursions of as little as 30 minutes though it has been unclear how long it takes for symptoms to occur.^[7] 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.

Diagnosis

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.^[7] There are no definitive tests that confirm MdDS, only tests that rule out other conditions, tests include hearing and balance, and MdDS is generally diagnosed by either a Neurologist or an Ear Nose & Throat Specialist.^[7]

Research Studies

Repetitive Transcranial Magnetic Stimulation for Mal de Debarquement Syndrome

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 electric 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. The TMS studies have proved to help in lowering the symptoms of MdDS if the treatment is ongoing, however it is not a cure for this debilitating disorder.

Triggers that cause MdDS suggest that it maybe a disorder of Maladaptive Neuroplasticity that might be responsive to external neuromodulation.

Vestibulo-Ocular Reflex Research 2014

At least one clinical trial on readaptation of the vestibulo-ocular reflex undertaken by Dr Mingja Dai has produced excellent results for a significant percentage of patients who have participated in the program.^[8]

Dr. Mingjia Dai at Mount Sinai Hospital in New York City has developed a treatment that has successfully provided either a cure or substantial improvement in symptoms for 70% of the patients in the clinical trial phase.^[8] The treatment involves a physical manipulation of the patient intended to readapt the vestibulo-ocular reflex. While the program is no longer in the research phase, Dr. Dai continues to accept patients for treatment.

Treatment Outcome: Seventeen out of 24 subjects (70%) became asymptomatic, 10 subjects had a substantial remission and 7 subjects had remission for 4 months or longer.

Four of eight subjects traveling a long distance home by car and one subject traveling by air had a reversion of their symptoms after the return trip, although initially they had relief of their symptoms after treatment. One additional subject had a reversion of symptoms after working on a large computer screen. One subject did not respond to the treatment. One treated subject experienced a relapse of symptoms after 6 months. The subject was then successfully retreated and reported levels of 0–1. Five subjects developed severe unilateral, pulsing headaches. In all, the headache subsided and the MdDS did not return.

Treatment

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 not proved to be effective in treating MdDS.^[9]

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 if the symptoms do not remit in a short period of time.

See also

• Motion sickness (Travel sickness)
• Seasickness
• Vertigo
• Space adaptation syndrome (Space flight "zero-g" and return)

References

External links

• MdDS in Bio-Medical Literature
• Website of the MdDS Balance Disorder Foundation
• Dr. Timothy Hain's page about Mal de Debarquement (MdDS)
• Foundation Facebook Page
• Support group