Association of Vertigo With Hearing Outcomes in Patients With Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-analysis.

Importance: Sudden sensorineural hearing loss (SSHL) accompanied by vertigo may portend a negative prognosis in the hearing outcome. Objective: To investigate the association of vertigo with prognosis of hearing variables in SSHL. Data Sources: A literature search of eligible studies was performed in PubMed, Web of Science, and Embase from September 26, 1973, through September 26, 2017. Studies published in English were retrieved with no restrictions on the date of publication. References were identified by screening the proceedings of relevant reviews, and annual meeting and other correlative papers were scanned manually for enrollment. Study Selection: All original research studies and retrospective or prospective studies focusing on the role of vertigo in the prognosis for the hearing outcome of SSHL were systematically retrieved. Studies that did not include data regarding the association between the rate of hearing recovery and vertigo were excluded, as were reviews, comments, case reports, editorials, letters, and practice guidelines. Data Extraction and Synthesis: Data were extracted and evaluated by 2 researchers. Data extracted included research type, number of participants with or without vertigo, treatment regime, definition of pure-tone average, criteria for hearing improvement, and length of follow-up. The quality of included studies was evaluated using the Newcastle-Ottawa Scale (scores range from 0-9, with a score of ≥6 indicating a high-quality study). The data were synthesized in Mantel-Haenszel models; the aggregate results were estimated in forest plots. Main Outcomes and Measures: Association of vertigo with the prognosis for the hearing outcome of SSHL. Results: Of the 4814 unique patients identified in 10 studies, 1709 were included in the SSHL group with vertigo and 3105 were included in SSHL group without vertigo. The Newcastle-Ottawa Scale score of each study selected was greater than 7. The recovery rate of hearing was 42.13% in the group with vertigo, compared with 60.29% in the group without vertigo. Vertigo was significantly associated with a worse hearing recovery (odds ratio, 2.22; 95% CI, 1.54-3.20; I2 = 74%). Similar results were obtained in subgroup analyses of the grading system using the Siegel criteria and systemic corticosteroid therapy. However, no association of vertigo with the prognosis of SSHL was observed within the subgroup receiving intratympanic corticosteroids (odds ratio, 1.78; 95% CI, 0.64-4.94; I2 = 70%). Conclusions and Relevance: Current evidence revealed that vertigo may be negatively associated with hearing recovery in patients with SSHL, except in a subgroup that received intratympanic corticosteroids. Corticosteroid injection may be more effective for treatment of SSHL accompanied by vertigo; future studies are needed to determine whether treatment of vertigo might contribute to the recovery of SSHL.