Looking Back on 2011: Hearing Loss and Alzheimer's
Looking back over 2011, a number of interesting things happened that influenced and affected the healthcare and welfare of people with Alzheimer's. One of these were reports about continuing research into the impact of hearing loss and dementia. We were already aware of the importance of this sensory loss to people with all types of dementia with Azheimer's being the most common. Investigations continue into the association between hearing loss and dementia. In a study published during 2011 the intriguing suggestion is the greater the loss of hearing, the greater the risk of dementia and possibly Alzheimer's disease.
Dr. Frank Lin, MD, PhD and Doctors Metter, O'Brien, Resnick, Zonderman, and Ferrucci, at the Johns Hopkins University objective was to determine whether hearing loss is associated with the incident of all-cause dementia and Alzheimer disease. Over 600 adults aged 36 to 90 who had their hearing tested between 1990 and 1994. They followed them up to the end of May 2008 to see who developed dementia or Alzheimer's disease. They found that those with hearing loss were more likely to be diagnosed with dementia or Alzheimer's disease during the average 12 year follow-up. They also found that the more severe the hearing loss the more likely they were to have a diagnosis of dementia.
Compared with those who had normal hearing, those with mild hearing loss were 89% more likely to be diagnosed with dementia. Those with moderate hearing loss were three times more likely to receive this diagnosis, and those with severe hearing loss were nearly five times more likely to be diagnosed with dementia. It does remain unclear whether hearing loss is an early sign of the disease or a risk factor for it, so much more research is needed.
Hearing loss can exacerbate the symptoms of Alzheimer's and many people with Alzheimer's have difficulty making sense of what they hear, following conversations and in their ability to identify where sounds come from. Could it be that problems linked with Alzheimer's disease are linked to changes in the brain or is it that people with Alzheimer's have difficulty making sense of what they hear? A current research project at UCL is looking into whether these symptoms are often put down to memory loss or if it is due to the disease affecting the part of the brain responsible for interpreting sound. It could help with early diagnosis of Alzheimer's.