What percentage of the given population is affected and how exactly were those people affected? Dr. Hoffer said. We don’t know those things. No denominator and a very poor numerator make this very hard to calculate.
Explore This IssueDecember 2006
Regardless of the who, what, and where, with America at war in Iraq, the number of SSHL cases Dr.Hoffer is seeing continues to rise.He said hearing loss from noise accounts for one in five hearing losses severe enough to be reported, and that one-quarter (24.9%) of servicemen and women report a hearing loss when they leave active duty.
Sixty to 90 percent of those soldiers in Iraq that report being close to a big explosion report hearing loss, he said.We did a series of studies…one showing that after a two-week rifle and weapons training evolution 11 percent of the population walked out with hearing loss they didn’t have before they started.
Another study showed new-onset hearing loss after three weeks with the same percentages. That 10 to 11 percent number just keeps coming up and…it all goes back to genetics.
Lorne S. Parnes, MD, of the University of Western Ontario in London, Canada, talked about his research into the Englishlanguage literature comparing the efficacy of oral steroids to antiviral medications. While the data in the studies that made the cut were thin-only 183 total subjects participated in the 17 studies selected-Dr. Parnes said he came to the conclusion that although oral steroids are the standard-of- care therapy used in most otolaryngology practices, there is no real proof as to the therapy’s efficacy versus placebo.
There was no significant positive effect shown with oral steroids…and they do not seem to be the gold standard they are advertised to be, he said.There was also no positive effect seen when using oral steroids over other treatments.
On the other hand, Dr. Parnes said, the work he did on animals using transtympanic medical therapy has shown promise.
The research team hypothesized first that corticosteroids could permeate from the middle ear through the round window membrane into the inner ear fluids. Second, they believed that administering the drugs this way would result in higher inner ear fluid drug concentrations and lower systemic blood concentrations as compared with systemic administration.
The study concluded that all three steroids could permeate the blood barriers and…the intratympanic route provides the highest drug levels, Dr. Parnes said.Half of the 26 patients were treated right away…and we have concluded that the treatment needs to be done within 30 days of an arbitrary hearing loss or it will not be effective. For those that were treated early, you can see statistically significant improvement in all of the measured parameters for all of the patients.