And can cause a 'lazy ear'

Mar 11, 2010 09:49 GMT  ·  By

Researchers have recently determined that the phenomenon known as a lazy ear actually exists. They say that it can be likened to a lazy eye, a condition that can be treated in small children where one or both eyes have difficulty processing visual images. Scientists believe that ear infections at any stage of life can cause a rewiring of neurons in the areas of the brain that are in charge with processing audio signals. This in turn causes the ear to appear oblivious to the sounds around, but many specialists believe that the real issue may be a delay of processing.

In a new study, it was determined that otitis media with effusion – a condition in which fluid builds up in the middle ear – and general ear infections are directly responsible for the “lazy ear” phenomenon. Doctors say that these conditions are extremely common, and that they represent one of the primary reasons why children need to see doctors. Both conditions dampen the sound waves that the ear is exposed to, causing difficulties hearing. When this happens, the brain rewires itself to make the most out of the incoming signals, which is proof of initiative, but not by far the best thing to do.

According to a paper detailing the new investigation, which appear in the March 11 of the respected scientific journal Neuron, it would appear that a lazy ear is caused by the way nerve cells interpret auditive stimuli, rather than by “hardware” malfunctions in the way the ear itself is set up. But because the brain can still rewire its auditory cortex well into adulthood, experts are optimistic that they will be able to devise methods of fixing this damage in people who have not yet reached a senior age. The work was conducted by experts at the Massachusetts Eye and Ear Infirmary, in Boston, who worked with colleagues from the Vanderbilt University, in Nashville, Tennessee.

The investigation was conducted on rats. Results reveal that there are a number of critical time windows available for exploitation by scientists, as the brain rewires itself. In the experiments, the researchers tied the auditory canal in a single ear in the rodents, and then investigated the animals after 2 months. They learned that the brain rewired itself differently depending on how old the rat was when its hearing was dampened. The team says that they are currently working on a spin-off therapy from lazy eye treatments, that could in the future allow them to help adults that suffer from minor hearing impairments, Wired reports.