Assessment of variation throughout the year in the incidence of idiopathic sudden sensorineural hearing loss.

OBJECTIVE: This study was conducted to determine whether the incidence of idiopathic sudden sensorineural hearing loss (ISSHL) varies throughout the year. STUDY DESIGN: This study is a retrospective case review. SETTING: This study was conducted at a tertiary referral center within a teaching hospital. PATIENTS: Inclusion criteria were a diagnosis of ISSHL confirmed by audiometric data. Exclusion criteria were intracranial neoplasms, a history of Ménière's disease, previous ear procedures, chemotherapy, or radiation therapy to the head or neck. There was no exclusion criterion based on age. Ninety-seven patients met these criteria. The median age was 52 years (range, 26-85 yr), and there were 53 (54.6%) women and 44 (45.4%) men. MAIN OUTCOME MEASURES: Monthly incidence counts were compiled across a 3-year period. Counts were analyzed for uneven incidence distributions and seasonal variation via standard statistical tests. RESULTS: Overall, no evidence was found for an uneven distribution or for a peak either by chi2 (p > 0.1), which assesses for any uneven distribution, or by the circular mean (p > 0.1), which assesses for a pattern of seasonal variation. In the subset of patients (24 of 97; 24.7%) who reported experiencing an upper respiratory infection before or concurrent with the onset of ISSHL, no evidence was found for an uneven distribution of hearing loss onset throughout the year either by chi2 (p > 0.1) or by the circular mean (p > 0.1). CONCLUSION: The results of this study suggest that ISSHL incidence does not display uneven distribution throughout the year.

Cost-effective diagnosis of acoustic neuromas: a philosophical, macroeconomic, and technological decision.

OBJECTIVE: Our goals were to define the most sensitive techniques of acoustic neuroma diagnosis, to examine their relative costs, and to propose diagnostic modality selection given the rarity of acoustic neuroma incidence and given the other costs that society faces in more commonly encountered diseases. METHODS: We conducted a MEDLINE search of the English language from 1966 to 2001 using the following keywords: acoustic neuroma, acoustic tumor, vestibular schwannoma, diagnosis, cost effectiveness, MRI, auditory brainstem response, brainstem audiometric evoked response, incidence, and prevalence. RESULTS: Although magnetic resonance imaging with gadolinium remains the most sensitive diagnostic modality in the discovery of acoustic neuromas, its cost may be prohibitive for some societies. CONCLUSION: Which modality to use in acoustic neuroma diagnosis is just as much a philosophical and macroeconomic question as a technological one. CLINICAL SIGNIFICANCE: The cost of a timely diagnosis of acoustic neuromas must be weighed against using resources for other, more pressing, health concerns.