Another clue has emerged in the mystery of sudden sensorineural hearing loss, with evidence suggesting some cases are linked to codeine misuse.
Professor William Gibson, founder of the Sydney Cochlear Implant Centre, said the clinic had identified 25 patients with a codeine addiction who had sought treatment for sudden sensorineural hearing loss in recent years.
All of the patients had macrocytosis, causing blood vessels in the ear to become blocked, he said.
These patients had been taking more than 20 codeine tablets daily over an extended period, and unusually, all had bilateral hearing loss, which occurred in less than 5% of sudden sensorineural hearing loss cases, Professor Gibson said.
However, the finding was likely to have implications for the 5000 Australians a year who develop unilateral sudden hearing loss every year, he said.
fact that we identified macrocytosis in the codeine group makes me think sudden hearing loss is probably a vascular thing in other patients as well,” he said.
“Now we know this, we would like to do some blood films on people that go deaf suddenly and see what’s happening.”
He urged GPs to urgently refer patients who developed sudden hearing loss to an ENT specialist, or to hospital, saying there was some evidence that cortico-steroids could restore hearing if given within one to two weeks of hearing loss.
A seminar paper published in the
(3 April) said the causes of sudden hearing loss were still largely unknown, although viral and vascular mechanisms had been proposed.
Aspirin, antivirals and stellate ganglion blocks have all been suggested as treatments for the condition, but the authors said evidence for these was inconclusive.