Tuesday, January 18, 2011

Tinnitus

Multitudes of Americans suffer from a condition called tinnitus, a constant ringing in the ears, or, for some, an unrelenting hissing sound like that of steam escaping from a kettle. There's no cure, but researchers have been working on finding effective treatments. Now comes word of a development that may offer hope to millions of people who live with this maddening affliction every moment of every day of their lives:
Scientists have found a way to ease chronic ringing in the ears, known as tinnitus, by stimulating a neck nerve and playing sounds to reboot the brain, according to research published Wednesday.

There is currently no cure for tinnitus, which can range from annoying to debilitating and affects as many as 23 million adults in the United States, including one in 10 seniors and 40 percent of military veterans.

Scientists believe the disorder is caused by hearing loss or nerve damage, to which the brain tries but fails to adjust.

"Brain changes in response to nerve damage or cochlear trauma cause irregular neural activity believed to be responsible for many types of chronic pain and tinnitus," said Michael Kilgard of the University of Texas, co-author of the study in the journal Nature.

"We believe the part of the brain that processes sounds -- the auditory cortex -- delegates too many neurons to some frequencies, and things begin to go awry," he said.

To fix that, researchers used rats to test a theory that they could reset the brain by retraining it so that errant neurons return to their normal state.

In rats with tinnitus, they electrically stimulated the vagus nerve, which runs from the head through the neck to the abdomen, in combination with playing a certain high-pitched tone.

When stimulated, the nerve can encourage changes in the brain by releasing chemicals such as acetylcholine and norepinephrine that act as neurotransmitters.

Rats that underwent the pairing of noise and stimulation experienced a halt to the ringing sounds for up to three and a half months, while control rats that received just noise or just stimulation did not.

An examination of neural responses in the auditory cortexes showed normal levels in the rats who were treated with the combination of stimulation and sound, indicating the tinnitus had disappeared.
The rest of the article can be found here. For the sake of the millions of people who are afraid they'll go insane if they can't stop the noise, let's hope the procedure works.