Mal de Debarquement (MDD) is a rare, and usually self-limiting syndrome in which people feel off balance, disoriented or experience a false sensation of movement for a period of time after exposure to movement such as sailing on a boat or riding in a car. It usually goes away in a matter of days, but for some patients it can last for months to years. Historically, typical treatments like vestibular suppressants and vestibular rehabilitation have not been effective in relieving these symptoms.
“Complete resolution of symptoms with a few days is the norm. A very small percentage of patients have symptoms that persist for months to years. Interestingly, many MDD patients experience some temporary relief when re-exposed to the passive motion (e.g., getting back on the boat), but may experience an exacerbation of symptoms upon returning to solid ground.”
I start here in the discussion of the new proposed treatment from MDD, because it seems that the researchers decided to experiment on this particular aspect of MDD. What exposure might provide some relief of symptoms, and could that relief carry over after cessation of re-exposure?
I won’t attempt to describe the experiment step by step, as the interested reader can follow this link. I will say that the authors propose (as has been previously suspected) that MDD is the result of a maladaptive response to prolonged exposure to certain motions. The treatment approach is novel. Rather than expose the patients to motion, they additionally exposed them to full field visual optokinetic stimulation intended to visually offset perceived motion. In other words, they tried to make the room appear as it was moving at exactly the same speed as the patient’s perceived motion. They found that repeated exposure to this stimulus resulted in quick and lasting relief for the majority of patients in the study.
The equipment used for the treatment stimulus is not available in most clinics, but this is important information that may eventually lead to an effective treatment for a fortunately rare, but unfortunately miserable and previously untreatable condition.
Photo courtesy of http://www.workboatsinternational.com/cruise-ships-for-sale.html