"Landsickness," otherwise known as debarkation sickness or mal de débarquement syndrome (MDDS), is a rare and poorly understood condition that affects some people who have spent time at sea. After returning to land, it's not unusual to feel, briefly, as if you're still on a rocking boat. This feeling typically passes within hours or days. But for an unlucky few, it continues indefinitely.
The cause is unknown. One theory holds that our brains form internal models of our environment. These models can help many people quickly adapt to motion, such as that of a ship. But if the model continues to shape your perceptions when you disembark, you experience the dizziness, nausea, and feelings of rocking from side to side that characterize landsickness.
There is no medical test to diagnose the condition. An article published in the New York Times on June 12, 2007 reported that sufferers perform normally on tests of balance and coordination, and MRI studies to compare the brains of these patients with normal people are still in the planning stages at the University of California, Los Angeles. An Israeli study did find some differences between the way patients and unaffected people use their visual and vestibular (inner ear) systems to keep their balance during short sails, but did not define any diagnostic criteria.
There is no cure for landsickness, but the Times reported that Valium and similar drugs can help. These drugs don't have an effect on the inner ear but work on brain pathways that control spinning sensations. They are addictive, however, (Valium especially), and long-term use is not advisable. A device designed to supply the brain with spatial information might help but is still under development. You can learn more about the disorder visiting the Web site of a MDDS support group.
For dizziness, I sometimes recommend a trial of the herb ginkgo biloba, which increases blood flow to the brain. Try two capsules three times a day over two months. Ginger can help with nausea, and I would also suggest a session or two of cranial osteopathy and possibly acupuncture.
Andrew Weil, M.D.