Systematic review of the evidence for the etiology of adult sudden sensorineural hearing loss.
OBJECTIVE
To determine the evidence for different etiologies of sudden sensorineural hearing loss (SSNHL) identified by clinical diagnostic tests in the adult population.


METHODS
Systematic literature review.


METHODS
Review of MEDLINE (1950-October 2009), EMBASE (1980-October 2009), and EBM Review databases in addition to manual reference search of identified papers. Randomized controlled trials, prospective cohort studies, and retrospective reviews of consecutive patients in which a clear definition of SSNHL was stated and data from consecutive patients were reported with respect to etiology of hearing loss. Three researchers independently extracted data regarding patient demographic information, diagnostic tests employed, and the identified presumed etiologies. Discrepancies were resolved by mutual consensus.


RESULTS
: Twenty-three articles met the inclusion criteria. The first group of papers searched for different etiologies among patients with SSNHL. Multiple etiologies were identified, including viral infection, vascular impairment, autoimmune disease, inner ear pathology, and central nervous system anomalies. The diagnosis for the majority of patients remained idiopathic. The second group of papers evaluated SSNHL patients with specific diagnostic tests such as autoimmune markers, hemostatic parameters, and diagnostic imaging.


CONCLUSIONS
The suspected etiologies for patients suffering sudden sensorineural hearing loss included idiopathic (71.0%), infectious disease (12.8%), otologic disease (4.7%), trauma (4.2%), vascular or hematologic (2.8%), neoplastic (2.3%), and other causes (2.2%). Establishment of a direct causal link between SSNHL and these etiologies remains elusive. Diagnostic imaging is a useful method for identification of temporal bone or intracranial pathology that can present with SSNHL as a primary symptom.
Chau
Justin K
JK
Division of Otolaryngology, Department of Surgery, University of Calgary, Calgary, Alberta, Canada. justin.chau@gmail.com
Lin
June R J
JR
Atashband
Shahnaz
S
Irvine
Robert A
RA
Westerberg
Brian D
BD
D000328:Adult; D019317:Evidence-Based Medicine; D003639:Hearing Loss, Sudden / Q000209:etiology*; D006801:Humans; D016032:Randomized Controlled Trials as Topic