Sudden sensorineural hearing loss (SSHL) is a common condition in which hearing is lost unilaterally within a three day period. About 40,000 people are affected each year in the United States alone, and most commonly affects those between 30-60 years of age. While SSHL is generally unknown in cause and is estimated to have a spontaneous recovery rate of around 70%, there are still many cases where systemic treatment is the desired option. The standard treatment for this condition involves the administration of systemic glucocorticoids to the affected site, however, there are side-effects associated with their prolonged usage, and up to 20% of patients treated in this way do not respond to the medication.
In a research article in BMC Medicine this week, Nakagawa and colleagues examine whether insulin-like growth factor 1 (IGF-1) applied topically through gelatin hydrogels could both improve hearing, and minimize adverse effects in patients who were initially unresponsive to treatment with systemic glucocorticoids for SSHL. Inner ear cells have limited regenerative capacity, and so it seems that using a growth factor topically to protect against further degeneration has a positive effect on hearing. These initial findings suggest that this approach may have great potential in helping tackle SSHL and provides hope for hitherto untreatable patients.
Whilst there is still much controversy surrounding both the etiology and potential treatments for SSHL, this is an area of intense research and so with positive breakthroughs such as that presented by Nakagawa et al, it appears we are going some way to reduce the misery experienced by sufferers of SSHL.