title: Hyperventilation-induced nystagmus in vestibular schwannoma and unilateral sensorineural hearing loss.
abstract: We evaluated the incidence and characteristics of hyperventilation-induced nystagmus (HVN) in 49 patients with gadolinium-enhanced magnetic resonance imaging evidence of vestibular schwannoma and 53 patients with idiopathic unilateral sensorineural hearing loss and normal radiological findings. The sensitivity and specificity of the hyperventilation test were compared with other audio-vestibular diagnostic tests (bedside examination of eye movements, caloric test, auditory brainstem responses) in the two groups of patients. The hyperventilation test scored the highest diagnostic efficiency (sensitivity 65.3 %; specificity 98.1 %) of the four tests in the differential diagnosis of vestibular schwannoma and idiopathic unilateral sensorineural hearing loss. Small tumors with a normal caloric response or caloric paresis were associated with ipsilateral HVN and larger tumors and severe caloric deficits with contralateral HVN. These results confirm that the hyperventilation test is a useful diagnostic test for predicting vestibular schwannoma in patients with unilateral sensorineural hearing loss.
authors.affiliation: Otology and Skull Base Surgery Department, University of Siena, Policlinico "Le Scotte", Viale Bracci 11, 53100 Siena, Italy. marcomand@hotmail.com
authors.forename: Marco
authors.initials: M
authors.lastname: Mandalà
authors.forename: Annalisa
authors.initials: A
authors.lastname: Giannuzzi
authors.forename: Serena
authors.initials: S
authors.lastname: Astore
authors.forename: Franco
authors.initials: F
authors.lastname: Trabalzini
authors.forename: Daniele
authors.initials: D
authors.lastname: Nuti
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000503:physiopathology; D046088:Hearing Loss, Unilateral / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis* / Q000503:physiopathology; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D014724:Vestibular Function Tests