Introduction: Unilateral vestibular atelectasis (UVA), an entity first described by Merchant and Schuknecht in 1988, has rarely been reported in vivo as of yet. We specify here the clinical characteristics of 22 patients diagnosed with UVA.
Materials and methods: Patients with a radiological diagnosis of UVA who underwent delayed inner ear MRI were included between April 2017 and January 2020. Full clinical testing including ocular infrared video-oculography, oVEMPs, cVEMPs, vHIT, bithermal caloric testing and auditory testing was performed.
Results: There were 13 men and 9 women, of mean age 58.6 ± 13.7 years. Onset was more frequently sudden (73%) than insidious (27%) though both clinical presentations were reported, and positional vertigo was described in 41% of cases. There were only two (9%) patients reporting Tullio's phenomenon. Vestibular testing showed that in 90% of cases, there was utricular dysfunction on oVEMP, while in 77% of cases, saccular function was preserved on cVEMP. vHIT showed high-velocity canal function impairment in all 22 patients: 8 patients (36%) had one impaired canal, 5 (23%) had two and 9 (41%) had all three canals affected. Caloric tests found complete unilateral areflexia, in 65% of tested cases, and partial deficiency in 35% of cases. Nine patients (40%) displayed asymmetrical hearing.
Conclusion: We described in this study the various clinical presentations of a disease rarely reported in vivo, UVA. Initial clinical presentation can appear similar to an acute vestibular deficit, a recurrent positional vertigo, or fluctuating dizziness.
Keywords: Acute vestibular syndrome; Endolymphatic hydrops; Positional vertigo; Vestibular atelectasis; cVEMP; oVEMP.