Wednesday, January 18, 2012

Hearing Loss and Dementia

There is a link between hearing loss and Alzheimer’s disease, according to a study by researchers at Johns Hopkins Medicine. Dr. Frank Lin and his team followed more than 600 people for nearly 12 years. The participants’ degree of hearing loss paralleled their risk of later developing dementia or Alzheimer’s disease. For each 10-decibel loss in hearing, the risk of dementia increased about 20 percent. In other words, the risk doubled with mild hearing loss, tripled with moderate hearing loss, and soared fivefold among those with severe hearing loss. Lin speculates that the brain is overstressed by trying to pick up what it is missing. By devoting more of its resources to hearing, the brain neglects other functions. Social isolation may contribute to a greater risk of age-related disorders as well, according to Dr. Lin. The unanswered question from his research is whether improved hearing through the use of cochlear implants and hearing aids, or improved communication through learning sign language, reverses or delays the development of dementia. Details of the study are in the Archives of Neurology.