The severity of tinnitus is currently determined by a self-assessment process. ABR measures brain activity in response to a specific sequence of acoustic stimuli.
“We believe our ABR method could be sensitive enough to be used as a diagnostic tool,” said Christopher R. Cederroth, a researcher in the Department of Physiology and Pharmacology, Karolinska Institutet. “The method of measuring actual neural changes in the brain stem in people with persistent tinnitus, could become biomarkers in the future.
Thank you for the patient
The ABR has previously been offered as a tool to measure tinnitus, but it has not reached scientific consensus. However, no previous study has included as many participants as this study. Here, researchers performed ABR measurements on 405 individuals, 228 with tinnitus and 177 without tinnitus. They observed that in people with persistent tinnitus, there was a clear difference in measures compared with those without tinnitus, or those who rated them as having tinnitus infrequently.
Christopher R. Cederroth says: “We need an objective diagnostic method for tinnitus, both to document the patient’s condition and to promote the development of new therapies. “Our study shows a cause-and-effect relationship between such changes in brain neural activity and the development of persistent tinnitus, but we need to do more studies to verify.” We also need to determine if our approach can measure therapeutic benefit.”
Tinnitus getting worse
The researchers also followed more than 20,000 people with no or varying degrees of tinnitus to track how symptoms developed over time. Here, researchers have shown that people with occasional tinnitus are at increased risk for persistent tinnitus, especially if it frequently recurs. Research also shows that for people who already have persistent tinnitus, the problem is most likely to last.
Dr Cederroth adds: “It is important to know that if you have recurrent tinnitus, you are more likely to have persistent tinnitus. “We need to disseminate this information so that people with occasional tinnitus are aware of the risks and have an opportunity to take preventive action.”
The study was carried out in collaboration with Karolinska University Hospital, Stockholm University, University of Bergen and Decibel Therapeutics Inc. ), the Stockholm Stress Center, the GENDER-Net Co-Plus Foundation “TIGER” and the EU programs “ESIT” and “UNITI” Horizon 2020.