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

Abstract

Idiopathic sudden hearing loss (ISHL) has an estimated incidence of 10-20/100,000 per year, impairing not only patients' hearing but also their ability to interact socially and their quality of life. Confronted with patients who demand successful treatment, physicians need to judge potential treatment options with regard to their reported efficiency, as well as their suitability for the individual patient. The dilemma of assessing treatment outcomes and options in ISHL will be discussed regarding a lack of knowledge of the disease's etiology, contradictory clinical evidence, high spontaneous recovery rate, and possible placebo effects. In conclusion, there is a dearth of structured research adhering to a common protocol, which makes comparison of trials and assessment of potential treatment outcomes difficult. Further research is warranted, taking some key recommendations into consideration.

Early-onset sensorineural hearing loss in Lassa fever

“…It is known that about 60% of sudden SNHL mainly caused by viral infections recover spontaneously even without the treatment within 6 weeks of infection [34,35]. However, the acute severe SNHLs following LAV were not responsive to conservative management-oxygen supplementation, labyrinthine vasodilators (e.g., nicotinic acid), vitamin supplementation and steroid therapy (given after the active phase of infection).…”

Sudden Onset Sensorineural Hearing Loss: Management Protocol

“…16 There is little convincing evidence that any one treatment produces any improvement in the audiometric results. 17 It is, however quite difficult for various reasons to design and conduct a study on this condition in order to show a statistically and more importantly a clinically significant difference. There are many reasons for this.…”

Mögliche molekulare Mechanismen einer Spontanremission nach Hörsturz

“…Gelingt es den angegriffenen Zellpopulationen jedoch, endogene Schutzund Reparaturmechanismen zu aktivieren, so kann der programmierte Zelltod vermieden werden [12,34,37,42,64]. Dies erlaubt den Zellen, ihre physiologischen Aufgaben wieder aufzunehmen, was sich klinisch in einer Spontanremission manifestieren kann [15].…”

“…In 85% der Fälle trat zusammen mit dem plötzlichen Hörverlust ein Tinnitus und in 30% der Fälle ein vestibulärer Schwindel auf [84]. Die Angaben zur Spontanheilung des akuten Hörverlusts -sowohl bei Vollremission als auch bei Teilremission -variieren sehr stark [50,93], sodass grob ein mittlerer Wert von 50% angenommen werden kann [15,25,50,74]. …”