Role of Genetic and Acquired Prothrombotic Risk Factors in Genesis of Sudden Sensorineural Hearing Loss

Abstract

The methylenetetrahydrofolate reductase C677T mutation, factor V G1691A (factor V Leiden) mutation, prothrombin G20210A mutation and 8 other laboratory values associated with increased thrombotic risk were analyzed in 40 patients with sudden sensorineural hearing loss (SSHL). The results were compared with those obtained from 120 controls not affected by SSHL. We found a statistically significant higher frequency of hyperhomocysteinemia in the SSHL group compared with controls, and that this was also associated with the presence of homozygosity for the MTHFR C677T mutation. The study results suggest that SSHL might be caused, among other factors, by a combination of these 2 variables. We suggest that this analysis of the MTHFR C677T mutation should be further investigated to establish the etiology of SSHL, and that the same analysis should be taken into account in those patients with high levels of homocysteine.

Is Vestibular Neuritis an Immune Related Vestibular Neuropathy Inducing Vertigo?

“…These findings support the hypothesis of a systemic reaction in these patients that is not only limited to the vestibular organ and supports the idea of a vascular component of the disease, which is similar to what is observed in sudden sensorineural hearing loss [51]. …”

Comparison of Inner Ear Contrast Enhancement among Patients with Unilateral Inner Ear Symptoms in MR Images Obtained 10 Minutes and 4 Hours after Gadolinium Injection

“…Many recent studies have explored the cause and pathogenesis of sSNHL, but most cases of sSNHL remain idiopathic. 12,13 This feature indicates a low possibility of definitive neuritis in patients with sSNHL. In a study of 46 patients with sSNHL, 3D-FLAIR MRI obtained precontrast and at 10 minutes after intravenous gadolinium injection showed significant signal-intensity ratio differences.…”

Increased levels of mean platelet volume: a possible relationship with idiopathic sudden hearing loss

“…The etiology for sudden hearing loss has been implicated in some theoretical pathways such as viral infections [27], intracochlear membrane rupture [28,29], immunemediated inner ear disease [30], vascular events [31], thrombotic genetic and acquired factors such as C677T MTHFR, V Leiden G1G91A, prothrombin G20210A, platelet GIyIIIaA1/A2 gene mutations, homocysteinemia, cholesterolemia and fibrinogenemia and etc [32,33].…”