MDDS is a fairly uncommon neurological condition characterized by a pervasive rocking, swaying and/or bobbing sensation (as if one is on a boat in choppy waters). People with MDDS often describe feeling that they are constantly in motion. The hallmark and most unusual feature of this condition is that this continuous sensation of motion improves when a person is in a moving vehicle (car, boat, plane, etc.) but almost immediately returns when the vehicle stops or when the person disembarks.
There are two types of MDDS:
- Motion-triggered MDDS. This is the classic form of MDDS, where the sensation of motion begins after one has been on a cruise, boat ride, long car ride, or flight.
- Non-motion triggered MDDS. This is sometimes called “spontaneous onset MDDS” but I find that to be a bit of a misnomer since there is usually an identifiable trigger for it. Many non-motion triggers have been described in MDDS including virtual reality, stress, pregnancy, medical illness, and a other vestibular disorders.
MDDS typically affects women after the fifth decade of life; it is uncommon (but not unheard of) in men and younger women. There is a strong relationship with migraine as well. It can be associated with a number of other symptoms, including trouble thinking (brain fog), difficulty with busy visual scenes, blurry vision, feeling off balance, and unsteadiness when walking. The pervasive rocking sensation of MDDS can be aggravated by stress, menses, moving around too much, or darkness. It can be more pronounced when a person lies down, leading to significant trouble with insomnia; I have patients who describe difficulty sleeping and having nightmares that they are on a ship in a turbulent ocean.
MDDS can be a very debilitating condition, and cause significant impact on one’s personal and professional life. Many of my patients find that their job performance suffered after MDDS symptoms developed. Almost all MDDS patients have told me that they curtail and limit social, family, and leisurely activities because of it.
The diagnosis of MDDS is made clinically. There are no tests that can confirm its presence. In fact, tests like brain MRIs, and video-nystagmography are often unremarkable, which can be frustrating to patients who are told that there is “nothing wrong with them”. It is important to see a physician so that other neurologic and otologic causes can be excluded.
There are treatments available for MDDS, and remission is very possible. These treatment options include medications (e.g. benzodiazepines, antidepressants), vestibular therapy, and vestibulo-ocular reflex re-adaptation therapy (a special form of therapy designed specifically for MDDS). A physician who is familiar with this condition will be your best ally in helping find and optimize an appropriate treatment.