Serum Fibrinogen as a Prognostic Factor in Sudden Sensorineural Hearing Loss: A Meta-analysis.

OBJECTIVE: High blood viscosity has been proposed as a mechanism for sudden sensorineural hearing loss (SSNHL); however, the relationship between blood markers of fibrinolysis or coagulation and severity or prognosis of SSNHL is still unclear. The aim of this study is to investigate the relationship between serum fibrinogen and SSNHL.

DATA SOURCES: PubMed and Scopus were searched for English language articles using the following keywords: SSNHL, sudden hearing loss, sudden deafness, idiopathic hearing loss or idiopathic sensorineural hearing loss, and fibrinogen.

STUDY SELECTION: The articles in the study related to SSNHL and provided data about the serum fibrinogen level.

DATA EXTRACTION: The data included patient profiles, fibrinogen level, recovery, and treatment modality.

DATA SYNTHESIS: Nineteen articles were selected. The aggregated data were analyzed using the random effect model. Two articles that included the fibrinogen level with recovery rates were analyzed for the relationship between the fibrinogen level and recovery.

CONCLUSIONS: The average fibrinogen level was 318 ± 8.5 mg/dl (mean ± standard error, within normal range). There was no difference in the fibrinogen level between SSNHL patients and the control group. The fibrinogen level of the recovery group was lower than that of the no recovery group. This showed that a high fibrinogen level was associated with poor prognosis, and it could be related to the severity of the pathological change rather than being the cause of the SSNHL. SSNHL includes various pathologies; therefore, the appropriate therapy should be selected based on each condition.