Constant tinnitus and altered brain activity
People with constant tinnitus can be identified by altered brain activity
A new paper published in The Journal of Clinical Investigation shows that people with constant tinnitus have different auditory brainstem response test results compared to people with no tinnitus, or only occasional tinnitus.
Currently, the presence of tinnitus is confirmed by a report from the person experiencing it, and its impact and improvement measured by questionnaires. These questionnaires have limitations.
If tinnitus can be detected by changes in brain activity, this could lead to the development of a reliable objective measure of tinnitus.
Such a measure would allow future treatments to be accurately assessed, leading to more effective management of tinnitus, and ultimately, it would also be able to confirm that someone’s tinnitus is ‘cured’.
Researchers from Karolinska Institutet in Sweden were able to access data collected by two large biobanks, the Swedish Longitudinal Occupational Survey of Health (SLOSH) and the Swedish Tinnitus Outreach Project (STOP). Data from almost 21,000 people was used in the study.
Survey data from SLOSH had been collected every two years which enabled the researchers to see changes in people’s tinnitus over time. Similar data had been collected from the STOP participants, but these people have also had auditory brainstem responses (ABR) measurements taken. ABR measures the activity of the brain in response to a specific sequence of sound stimuli.
The researchers found that people with constant tinnitus showed clear differences in their ABR measures compared to people with no tinnitus, or only occasional tinnitus.
There were no differences between results of people with no tinnitus and occasional tinnitus.
The researchers have suggested that constant tinnitus can be classed as a distinct subtype (grouping within those experiencing tinnitus).
The SLOSH data revealed that people with occasional tinnitus are at increased risk of developing constant tinnitus, especially if it recurs often.
The study also found that for those who already experience constant tinnitus, the chances are that the problem will persist.
What does this mean for people with tinnitus?
ABR measurements may be able to be used to diagnose tinnitus, and to determine its subtype. This could lead to more tailored treatments.
If the ABR measurement is characteristic of occasional tinnitus, this may provide reassurance and again, more tailored treatments.
People with occasional tinnitus should be aware of the risks that the condition could become more constant and use appropriate precautions.
What happens next?
As always with new research, more research will need to be undertaken to see if these results can be repeated.
We have awarded one of our Large Research Grants to a team from Macquarie University who are also examining recordings of brain waves using artificial intelligence to see if this may provide an objective measure. We are eagerly awaiting the first results of this study.
More research is also needed to find out if ABR measurements can assess the effectiveness of tinnitus treatments.
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