What is the evidence for different etiologies of sudden sensorineural hearing loss (SSNHL)?
Explore this issue:May 2010
Background: The incidence of SSNHL has been estimated from five to 20 per 100,000 persons per year, but the causes are speculative and probably multifactorial. While identifying the most commonly reported etiologies of SSNHL, the ultimate goal of this study was to develop an evidence-based approach to patient evaluation.
Study Design: Literature and database review
Setting: Researchers from Alberta and British Columbia reviewed databases and 144 research papers.
Synopsis: The review included MEDLINE from 1950-October 2009, EMBASE from 1980-October 2009 and evidence-based medicine (EBM) databases, in addition to a manual reference search of identified papers. Multiple SSNHL patient etiologies were identified, including viral infection, vascular impairment, autoimmune disease, inner ear pathology and central nervous system anomalies.
A second group of papers evaluated patients with specific diagnostic tests, including autoimmune markers, hemostatic parameters and diagnostic imaging. The suspected etiologies were 71 percent idiopathic, 12.8 percent infectious disease, 4.7 percent otologic disease, 4.2 percent trauma, 2.8 percent vascular or hematologic, 2.3 percent neoplastic and 2.2 percent other.
The authors said their review did not identify a specific laboratory test or marker for sudden hearing loss, but they recommended an MRI for diagnostic evaluation. Additionally, the team recommended a directed clinical history and physical examination to identify causes, in addition to routine laboratory screening and screening for certain infectious agents. Study limitations included the lack of a standard SSNHL definition, and the authors said they were unable to pursue negative or unpublished data by the authors of included and excluded studies.
Bottom Line: Establishment of a direct causal link between sudden sensorineural hearing loss and its etiologies remains elusive, with idiopathic the most commonly identified. Diagnostic imaging is a useful method for identification of temporal bone or intracranial pathology that can present with SSNHL as a primary symptom.
Citation: Chau JK, Lin JRJ, Atashband S, et al. Systematic review of the evidence for etiology of adult sudden sensorineural hearing loss. Laryngoscope. 2010;120(5):1011-1021.
—Reviewed by Sue Pondrom