Acute hearing loss

Abstract

Acute hearing loss (AHL) is a medical urgency. The management of patients presenting with sudden deafness involves detecting the causal mechanism and administering emergency therapeutic drugs to restore hearing by minimizing the period of cellular ischemia to the inner ear. Acute management of AHL consists of administering a 10-day course of high-dose corticosteroids (prednisone 60 to 80 mg) until a cause can be established. Magnetic resonance imaging with gadolinium is indicated, with a study dedicated to the internal auditory canals. The natural history of idiopathic AHL is characterized by spontaneous improvement in two thirds of patients. Maximum improvement occurs within 2 weeks of onset of AHL. In the vast majority of patients (>90%), the AHL is idiopathic. For an identifiable etiology, the treatment is specific and may consist of stopping ototoxic medications, repair of perilymphatic fistulas, administering antimicrobial agents for viral or bacterial infections, correction of metabolic imbalances, management of stroke, and possible surgery for cerebellopontine angle tumors. Management of idiopathic AHL is controversial. Various therapeutic agents, such as vasodilators, diuretics, anticoagulants, plasma expanders, contrast agents, and carbogen inhalation, have been tried in single therapy or as a combination therapy. The empiric use of these drugs is mainly based on improving the blood circulation and restoring the oxygen tension to the inner ear. The use of interventional procedures, such as low-density lipoprotein apheresis as well as newer drug delivery systems for corticosteroids, and immunosuppressive agents have opened new options in the treatment of AHL secondary to immune-mediated diseases of the inner ear. Prognosis for AHL is best when patients are seen early, begin recovery within 2 weeks, and have a mild hearing loss (<90 dB) with upward-sloping audiograms. Greater than 90 dB of hearing loss along with flat or down sloping audiogram, advanced age, and presence of vertigo are adverse prognostic factors for recovery of hearing loss.

Sudden deafness in vertebrobasilar ischemia: clinical features, vascular topographical patterns and long-term outcome

“…Overall, our patients had a recovery rate of 81%, which is above the spontaneous recovery rate (40-69%) reported for idiopathic sudden sensorineural hearing loss [14,16], but is similar to the recovery rate (61-89%) of idiopathic sudden sensorineural hearing loss after steroid treatment [11][12][13]. Like previous studies [15,17,27], we found that patients with profound hearing loss had poorer outcome than the patients with less than profound hearing loss. However, these comparisons must be made with caution since idiopathic sudden sensorineural hearing loss likely represents a mixture of etiologies.…”

“…AICA infarction was unilateral in the both groups. Third, isolated caudal cerebellar infarcts (n=4, patients [24][25][26][27] in the distribution of the medial branch of the PICA. Fourth, isolated brainstem infarcts (n=2) involving the paramedian pons (patient 28) and the lower midbrain and upper dorsolateral pontine tegmentum (patient 29).…”

Idiopathic sudden hearing loss: contradictory clinical evidence, placebo effects and high spontaneous recovery rate – where do we stand in assessing treatment outcomes?

“…In various studies the time between onset of symptoms and presentation has been observed to be a prognostic factor [5,23]. The question is whether a sample of patients presenting early after the onset of symptoms would not have a better outcome regardless of treatment chosen than a sample of patients presenting later.…”

“…Comparing hearing losses in low, middle and high frequencies, low-tone ISHLs seem to have the best prognosis, with an expected spontaneous recovery rate of 80% [4]. Other prognostic factors are age, presence or absence of vestibular symptoms, the time between the onset of symptoms and the start of therapy, previous otological history and presence of risk factors such as hyperlipoproteinemia, obesity, hypertonus, and stress [5].…”

Apheresis for idiopathic sudden hearing loss: Reviewing the evidence

“…Comparing hearing losses in low, middle, and high frequencies, low-tone ISHLs seem to have the best prognosis, with an expected spontaneous recovery rate of 80% [5]. Other prognostic factors are age, presence or absence of vestibular symptoms, the time between the onset of symptoms and the start of therapy, previous otological history, and the presence of risk factors such as hyperlipoproteinemia, obesity, hypertonia, and stress [6].…”