Objective: To investigate the clinical features and natural history of mal de debarquement (MdD).
Design: Retrospective case review with follow-up questionnaire and telephone interviews.
Setting: University Neurotology Clinic.
Patients: Patients seen between 1980 and 2006 who developed a persistent sensation of rocking or swaying for at least 3 days after exposure to passive motion.
Main outcome measure: Clinical features,diagnostic testing, and questionnaire responses.
Results: Of 64 patients(75% women) identified with MdD, 34 completed follow-up questionnaires and interviews in 2006. Most patients had normal neurological exams, ENGs and brain MRIs. The average age of the first MdD episode was 39+/-13 years. A total of 206 episodes were experienced by 64 patients. Of these, 104 episodes (51%) lasted>1 month; 18%, >1 year; 15%, >2 years; 12%, >4 years, and 11%, >5 years. Eighteen patients (28%) subsequently developed spontaneous episodes of MdD-like symptoms after the initial MdD episode.There was a much higher rate of migraine in patients who went onto develop spontaneous episodes(73%) than in those who did not(22%). Subsequent episodes were longer than earlier ones in most patients who had multiple episodes.Re-exposure to passive motion temporarily decreased symptoms in most patients (66%).Subjective intolerance to visual motion increased (10% to 66%)but self-motion sensitivity did not(37% to 50%) with onset of MdD.
Conclusion: The majority of MdD episodes lasting longer than 3 days resolve in less than one year but the probability of resolution declines each year. Many patients experience multiple MdD episodes. Some patients develop spontaneous episodes after the initial motion-triggered episode with migraine being a risk factor.