Surdez súbita idiopática: aspectos etiológicos e fisiopatogênicos

Abstract

Several factors have been postulated to elicit the etiology of idiopathic sudden sensorineural hearing loss. Through a bibliographic review, we made a critical analysis of the different etiopathogenic aspects of its clinical manifestation. The most recent studies concerning the possible causes of sudden hearing loss suggest vascular disorders, rupture of the inner ear membrane and autoimmune diseases; however, viral infections have received a great deal of attention in recent years. Little is known about the mechanism of sudden hearing loss. Viruses can cause sudden hearing loss in an acute infection, however the latent form, and its possible reactivation have also been considered as explanations of the cochlear injury mechanism. Even though hearing loss can be explained by a blood viscosity change, experimental and clinical studies do not show any evidence of labyrinthine fibrosis and new bone formation, or labyrinthine membrane breaks. These findings are not in agreement with vascular and rupture membrane factors, respectively. The eventual presence of antibodies against the inner ear suggests that sudden hearing loss pathogenesis may be of autoimmune nature, but the difficulty in establishing the correlation of its morphological and clinical aspects to the hearing loss also do not help to support this statement. Sudden hearing loss is still a controversial and obscure subject in several aspects.

Auditory and vestibular dysfunctions in systemic sclerosis: literature review

“…The irregular structure of blood vessels associated with the reduced density of capillaries may result in decreased blood flow and, consequently, hypoxia (16) . The cochlea is a highly sensitive organ to blood changes, and the hypoxia resulting from vascular changes of the disease may lead to the death of hair cells (18) . Clinically, these changes are expressed by SNHL, which corroborates the findings of the studies that indicate lower prevalence of this type of hearing loss.…”

Alterações auditivas na esclerose sistêmica

“…In addition, decreased cochlear blood flow may play an important role in hearing loss in individuals with SS due to inflammation of the small vessels of the epineurium or inflammation of the cochlear nerve vasa vasorum (11) . This event is plausible if there is anatomical alteration of the terminal vessels of the cochlea associated with decreased capillary density, resulting in reduced blood flow and therefore tissue hypoxia (28) . Thus, tissue hypoxia causes the death of hair cells in the cochlea, which is an organ highly sensitive to blood changes and, consequently, this change is expressed with sensorineural hearing loss.…”

Surdez súbita em paciente em uso de tadalafil: um relato de caso clínico

“…Por ano, a cada 100 mil habitantes, cerca 5 a 20 são acometidos por SS (3) . A média de idade do acometimento é de 45,4 anos, sendo mais prevalente na etnia branca (4) .…”