A research team at the Seoul National University Boramae Medical Center has released a study result, which identified a biomarker predicting the early occurrence of cognitive impairment in chronic tinnitus patients.
Cognitive impairment refers to a condition in which a defect occurs in overall cognitive ability such as memory, judgment, and language ability. A typical symptom of cognitive impairment is forgetfulness, and if left untreated in old age, it can increase the risk of developing dementia.
The research team, led by Professor Kim Sung-ho at the hospital, conducted a Montreal Cognitive Assessment Test (MoCA) and blood tests on 55 chronic tinnitus patients over 50 who visited the hospital from January 2010 to October 2018. The team then evaluated whether the decrease in body proteasome activity could be used as an index to predict the occurrence of cognitive impairment in chronic tinnitus patients.
After comparing the blood test results of five patients with mild cognitive impairment and a MoCA score of less than 23 with the rest of the control group, the team found that proteasome activity in the blood of chronic tinnitus patients with cognitive impairment decreased to a statistically significant level.
The team also confirmed a significant correlation with amyloid peptide (Ab40), known as a biomarker for predicting dementia.
The recent study was the extension of a previous study led by Professor Kim. The team found that proteasome's, a key enzyme for protein degradation in cells, is significantly reduced in the mouse model with Alzheimer's than normal mice.
"The risk of developing chronic tinnitus also increases with old age when cognitive function deteriorates," Professor Kim said. "If the cognitive function deteriorates, the risk of progressing to dementia is high, and the management of chronic tinnitus is also difficult due to the characteristic of dementia as it makes it difficult to communicate."
To prevent cognitive impairment and dementia, it is important to undergo regular brain cognitive function tests after the age of 50. If there is a hearing loss, patients should receive early auditory rehabilitation such as hearing aids to prevent functional decline, he added.
The Journal of Alzheimer's Disease published the results of the study in its October issue.