Sudden sensorineural hearing loss: A vascular cause? Analysis of prothrombotic risk factors in head and neck

OBJECTIVE: This aim of this study was to determine the prevalence of thrombophilic risk factors in sudden sensorineural hearing loss, central retinal vein occlusion, and stroke associated with small vessel disease, with the purpose of investigating and reinforcing the vascular hypothesis in the pathogenesis of sudden sensorineural hearing loss. DESIGN: Case-control study. Genetic and acquired risk factors of these three groups were compared with healthy controls. STUDY SAMPLE: Forty-nine, 60, and 101 patients affected respectively by sudden sensorineural hearing loss, central retinal vein occlusion, or stroke associated with small vessel disease, enrolled during a three-year period were compared with 210 healthy controls. RESULTS: The frequency of hyperhomocysteinemia (homocysteine ≥ 15 μmol/L) was higher in each disease group than in controls. A statically significant, albeit weak, correlation between the MTHFR C677T mutation and hyperhomocysteinemia was found in all three diseases. CONCLUSIONS: Hyperhomocysteinemia proved to be a risk factor for sudden sensorineural hearing loss. Based on these results, we propose to analyse homocysteine in sudden sensorineural hearing loss patients and, if its values are high, to evaluate the presence of MTHFR C677T mutation.