What is Mal de Debarquement Syndrome (MdDS)?
Mal de Debarquement syndrome (MdDS) is the persistent feeling of dizziness and imbalance that may follow a boat cruise. It can be chronically debilitating, even lasting for years. MdDS must be distinguished from land sickness, which commonly occurs immediately after travel but resolves within 48 hours after disembarkment. Motion sickness, on the other hand, is a prevalent condition which gradually builds up and occurs during the motion stimulus.
How common is Mal de Debarquement Syndrome, and what triggers it?
MdDS is not common, accounting for around 1% of patients generally seen in a neur-otology or dizziness practice. It may be overlooked in general rule, as not everyone knows its existence. In most cases, MdDS occurs after a sea voyage but can also occur after other forms of travel such as aeroplanes, trains, coaches and motorcars. It can also happen after platform-mediated passive movement of individuals, such as waterbeds, swaying buildings and exercise equipment.
Who gets MdDS?
It is much more common in females (75-100%), especially in the 40–50-year age group. This suggests a hormonal influence, and peri-menopausal or peri-menstrual states at the time of the travel may be a risk factor for the development. Migraine also occurs more in females, and a link with MdDS has been proposed. It has rarely been reported in children and the elderly.
What are the characteristics of MdDS?
Patients complain of a chronic and persistent sensation of non-spinning vertigo characterised by a very slow oscillating (2Hz) sensation of “bobbing”, “rocking or “swaying”, presently most of the day. MdDS is diagnosed when the perception lasts longer than two days after the cessation of the triggering activity. The motion trigger should last longer than two hours.
Typically, symptoms temporarily reduce or even disappear with exposure to passive motion such as driving a vehicle. In addition, patients may suffer from additional non-specific symptoms such as headache, brain “fog”, anxiety, photo-and-phonophobia and tiredness.
What is the mechanism of MdDS?
Many theories are trying to explain the mechanism. Migraine sufferers are more likely to develop it. When travelling on a ship, a person’s brain adapts to the motion by creating a “blueprint” of the motion. This “blueprint” is disposed of when back on solid land. It is believed that a patient suffering from MdDS cannot dispose of this “blueprint”. The patient will still feel as if on the ship, which is wrong and will lead to symptoms. MdDS is not a psychological condition.
How is MdDS diagnosed?
Mal de Debarquement Syndrome is diagnosed on the history with a clinical examination not contributing to a positive diagnosis. The Classification Committee of the Bárány Society has recently published clear guidelines to aid in making a diagnosis. No specific test exists that can confirm the diagnosis. Other vestibular pathology should be ruled out as some conditions may mimic it.
Treatment of MdDS.
Treatment includes medication and specific vestibular therapy. Many different drugs have been used with some success, but evidence for a universally effective treatment is still lacking. It appears that drugs, ordinarily used as vestibular suppressants, are not very effective. Regular vestibular rehabilitation is not beneficial and, if so, may be co-incidental as the condition may also resolve spontaneously.
The role adaptation is a treatment modality where a patient’s head is rolled whilst observing a rotating optokinetic stimulus that seems effective in 60% of cases. This is available in South Africa and is worth trying in long-standing cases. There are many other “cures” offered in the literature, even devices such as the Bertec VR device and the Gyrostim, which are not available in South Africa. The long and the short is that nothing is really proven, and a lot of research still must be conducted. It is important to note that MdDS can recur in 25% of patients.
Patients should be careful of any other treatment suggestions without proper reference. There appear to be a lot of them.
Can MdDS be prevented?
It is not always practical to advise patients with a previous history of MdDS not to travel. Using suppressive travel sickness medication, especially if it is sedating, is an option to prevent MdDS. The idea is that medicine will suppress the central vestibular and reticular activation system and thereby reduce the sensory input to the brain.
Although sedation caused by some prescription drugs may be beneficial, care should be taken as immobilisation during sleep for extended periods may increase the risk of blood clot formation. It is therefore advised to use anticoagulants to help prevent blood clot formation. Travellers should also be woken from time to time to stretch their legs and improve circulation by moving around in the aeroplane. Migraine prevention and hormones have not been proven to help.
MdDS support group
Further reading
- Mal de débarquement syndrome diagnostic criteria: Consensus document of the Classification Committee of the Bárány Society
- Mal de débarquement syndrome (MdDS)
- Neuroimaging Markers of Mal de Débarquement Syndrome
- New Treatment Successful for Rare and Disabling Movement Disorder, the Mal de Debarquement Syndrome (MdDS)