title: Vestibular disease unmasked by hyperventilation.
abstract: Hyperventilation-induced dizziness is often thought to be psychogenic, but its effects in the presence of known vestibular disease have not been adequately examined. In this study hyperventilation was tested in two models of vestibular disease. These were, first, patients with profound unilateral vestibular deficit (prior translabyrinthine acoustic neuroma resection [postsurgery group]) and, second, patients with variable unilateral vestibular deficit (unoperated unilateral acoustic neuroma [presurgery group]). Patients were hyperventilated for 90 seconds. Using infrared videonystagmography, 100% of the 32 postsurgery patients and 82% of the 28 presurgery patients developed nystagmus with hyperventilation. Hyperventilation was more sensitive than head shake for eliciting nystagmus in these models. The false-positive rate for nystagmus in 29 normal volunteers was 3.5% for hyperventilation and 10% for head shake. Our results show that hyperventilation can unmask underlying vestibular disease.
authors.affiliation: Department of Otolaryngology, University of Toronto, Ontario, Canada.
authors.forename: M L
authors.initials: ML
authors.lastname: Bance
authors.forename: M
authors.initials: M
authors.lastname: O'Driscoll
authors.forename: N
authors.initials: N
authors.lastname: Patel
authors.forename: R T
authors.initials: RT
authors.lastname: Ramsden
mesh_terms: D004244:Dizziness / Q000209:etiology / Q000523:psychology; D005133:Eye Movements / Q000502:physiology; D005189:False Positive Reactions; D019416:Head Movements / Q000502:physiology; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology*; D007259:Infrared Rays; D009464:Neuroma, Acoustic / Q000150:complications / Q000601:surgery; D009760:Nystagmus, Physiologic / Q000502:physiology; D012680:Sensitivity and Specificity; D015837:Vestibular Diseases / Q000175:diagnosis* / Q000209:etiology; D014743:Videotape Recording