What is MDDS?
Mal De Debarquement Syndrome (MDDS) is a sense of imbalance and self-motion that most commonly occurs after disembarking from a long travel time on a boat or cruise ship, in a plane or in a car. Symptoms are generally absent while on the vehicle and commence once on land.
The cause of MDDS remains unclear. Theories suggest that the vestibular pathways in the brain gets used to the continuous motion and after getting off the ship the vestibular system has trouble readjusting to the land and symptoms appear. Alternatively, it has been suggested that MDDS is an atypical type of migraine.
Signs and Symptoms of MDDS
The symptoms of MDDS usually involve a sense of rocking or swaying like the individual is still on the ship. It is normal for any individual to feel this way for a few hours or days after leaving the ship. However, people with MDDS usually have a long-term persistence of the symptoms lasting weeks to months or years.
Symptoms may be experienced while sitting and standing still and sometimes while walking. Symptoms often settle while moving and while in a moving vehicle such as a car or on a boat. In more severe cases, the disequilibrium may affect mobility.
Generally, MDSS symptoms settle within 1–3 months. In some cases, it may persist for longer. MDSS is more common in women.
Diagnosing MDDS
Diagnosis is usually achieved based on ruling out other causes of dizziness and unsteadiness. Criteria for the diagnosis of MDDS includes:
- Non-spinning vertigo characterized by an oscillatory perception (‘rocking,’ ‘bobbing,’ or ‘swaying’) present continuously or for most of the day
- Onset occurs within 48 hours after the end of exposure to passive motion
- Symptoms temporarily reduce with exposure to passive motion
- Symptoms continue for >48 hours
- Symptoms not better accounted for by another disease or disorder
MDDS is usually associated with a constant sense of motion especially while sitting or lying still and it may disappear with motion such as walking or being in a car or on board a ship again. It is often associated with recent prolonged travel on a cruise, flight or in a car.
Management of MDDS
The dizziness and the imbalance that may be felt can have a large effect on those who suffer from MDDS. There is no standard type of treatment that has been shown to be effective for MDDS.
- Certain medications such as antidepressants, seizure and anxiety medications may be helpful.
- Exercises designed to cause habituation and reduce motion sensitivity may also be helpful.
- Balance exercises can also be useful in retraining the brain to use other senses including vision and proprioception during movements.
- Optokinetic stimulation (in the form of vertical and horizontal stripes) in combination with passive head roll movements can also be used as part of treatment for MDDS, to induce a “re-adaptation” of the vestibular ocular reflex