Objectives
To determine characteristics and the prognostic values in idiopathic sudden sensorineural hearing loss (SSNHL) with comorbid ipsilateral canal paresis (CP) and/or benign paroxysmal positional vertigo (BPPV).
Methods
Of the 338 patients with a diagnosis of idiopathic SSNHL, 29 patients (8.6%) with CP and 24 patients (7.1%) with BPPV were recruited and compared to 23 patients with SSNHL and vertigo but without CP or BPPV. The patients were evaluated for their initial hearing threshold, type of canal involved, response to repositioning maneuvers, and hearing outcome for 6 months.
Results
Patients with CP (+) BPPV (-) showed lower pure-tone averages than those with CP (-) BPPV (+) on initial and follow-up audiograms. The improvement in pure-tone averages was less in the CP (+) BPPV (-) group than in the CP (-) BPPV (+) group. The improvement in speech discrimination scores was less in the CP (+) BPPV (-) group than in the CP (-) BPPV (-) group. BPPV most commonly involved the posterior canal (15/24, 62.5%), followed by the horizontal canal (13/24, 54.2%). Three (12.5%) of 24 patients had recurrences of BPPV.
Conclusion
CP is more serious sign for hearing recovery than BPPV, although both CP and BPPV are negative prognostic indicators of auditory function in SSNHL. Concurrent CP and/or BPPV in SSNHL suggest combined damage to the vestibule and may indicate severe and widespread labyrinthine damage, leading to the poor prognosis.