Inner Ear Decompression Sickness and Mal de Debarquement *Dror Tal, *Liran Domachevsky, *Ronen Bar, *Yochai Adir, and †Avi Shupak *Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, IDF Medical Corps, and †Department of Otolaryngology–Head and Neck Surgery, Carmel Medical Center and the Otoneurology Unit, Lin Medical Center, Haifa, Israel Objective: To present a case series of vestibular symptoms appearing after combined sailing and diving activity, and to discuss the differential diagnosis and the workup algorithm. Study Design: Case series. Setting: Tertiary referral center. Patients: Three patients aged 25 to 31 years suffering from unsteadiness and movement sensations after sailing and scuba diving. Interventions: Neurotologic evaluation and recompression therapy in a hyperbaric chamber. Main Outcome Measures: The increasing popularity of marine sports and leisure activities has resulted in the exposure of a growing number of people to unique abnormalities not encountered under terrestrial conditions. The otolaryngologist who is involved in the care of these patients is required to diagnose and treat diving-related sinus and ear injuries such as barotrauma and decompression sickness, and also to be familiar with sailing-related disorientation syndromes such as seasickness and mal de debarquement. Treatment modalities for the various abnormalities differ significantly, and early com- mencement of treatment is often crucial for a successful outcome. Conclusion: Whenever doubt exists, recompression treatment must be instituted as soon as possible because of the potential for severe sequelae if the patient is left untreated, and because the risks involved in this therapy are minimal. Key Words: Barotrauma—Decompression sickness—Hyperbaric oxy- gen—Inner ear—Mal de debarquement—Seasickness—Ves- tibular function tests. Otol Neurotol 26:1204–1207, 2005. The attractiveness of combined diving and sailing activities, and the inaccessibility of some of the world’s most beautiful and undamaged diving sites via land, have recently increased the popularity of scuba (self- contained underwater breathing apparatus) diving sail- ing trips. Unfortunately, participants in this leisure activity are potentially exposed to both the vestibular insults of diving (1) and sensory mismatch situations that might lead to the syndrome of mal de debarquement (sickness of disembarkment) (2). We describe three female divers who suffered four events of unsteadiness and a sensation of movement that appeared on dis- embarking after 2 to 6 days of intensive diving. The differential diagnosis is discussed and a workup algo- rithm is proposed focusing on the identification of injuries that require immediate therapy. CASE REPORTS Case 1 A 31-year-old woman complained of a sensation of movement, unsteadiness, and fullness of the right ear that appeared after 4 days of intensive compressed-air scuba diving during a boat trip in the Red Sea. The symptoms appeared 5 hours after her last dive imme- diately on disembarking from the boat and resembled the ship motion sensation she had experienced during the sea voyage. The patient reported significant seasick- ness while at sea that was self-treated by dimenhydri- nate. A review of the diving log revealed repeated violations of the required decompression stops, as recommended by the U.S. Navy diving manual (3) in 8 of the 10 dives the patient had performed. Her medical history was unremarkable. Physical examination 24 hours after disembarking was significant for posture abnormalities, as reflected by the Fukuda stepping test and an inability to perform tandem walking. Audiometry and tympanometry were normal. The patient was treated in the hyperbaric chamber by hyperbaric oxygenation (HBO 2 ) according to U.S. Navy Treatment Table 6 (3) Address correspondence and reprint requests to Avi Shupak, M.D., Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, P.O. Box 8040, 31 080 Haifa, Israel; E-mail: shupak@internet-zahav.net Drs. Tal and Domachevsky contributed equally to the study. Otology & Neurotology 26:1204–1207 Ó 2005, Otology & Neurotology, Inc. 1204