Idiopathic Dandy's syndrome.

In 1941 Dandy described patients in whom he had performed bilateral vestibular nerve sections who reported "jumbling" objects in their visual fields when in motion and difficulty walking in the dark. We use the term Dandy's syndrome to describe patients with bilateral vestibular loss as the cause of the above symptoms. The caloric response in these patients is either markedly reduced or absent when the cause is in the peripheral vestibular system. This study explored whether differences exist between those patients in whom the cause is known and those patients with no known cause. We reviewed our experience with 105 patients in whom Dandy's syndrome was diagnosed between 1984 and 1994. Information on their presenting symptoms, findings on physical examination, audiometric status, electronystagmographic findings, laboratory test results, symptom outcome, and cause was collected. Patients with known causes (Meniere's disease, ototoxicity, tumors, vascular disease, trauma, heredity, autoimmune disease, infection) were compared as a group with those with no known cause. Of the 105 patients 34 (32%) had no obvious cause for their symptoms despite an extensive evaluation. This group was similar to those with a known cause except for having a greater preponderance of women (68% vs. 41%, p = 0.018) and an increased likelihood to have normal audiogram findings (53% vs. 19%, p = 0.0009). All other variables, including age, duration of and age at onset of symptoms, physical examination, and electronystagmographic findings did not differ significantly between the two groups. Only 28% of patients with known causes and 40% (p < 0.05) of those with idiopathic Dandy's syndrome had improvement of their symptoms, underscoring the problem with rehabilitation. The results of this study are compared with earlier reports from our and other institutions.