Constant tinnitus is linked to altered brain activity
Date:
January 26, 2022
Source:
Karolinska Institutet
Summary:
There has to date been no reliable objective method of diagnosing
tinnitus. Researchers now show that brainstem audiometry can be used
to measure changes in the brain in people with constant tinnitus.
FULL STORY ========================================================================== There has to date been no reliable objective method of diagnosing
tinnitus.
Researchers from Karolinska Institutet in Sweden now show that brainstem audiometry can be used to measure changes in the brain in people with
constant tinnitus. The study has been published in The Journal of
Clinical Investigation.
========================================================================== Tinnitus is currently not classified as a distinct disorder, but as
a symptom with many possible causes, such as impaired hearing, noise,
disease or stress.
Tinnitus is often described as a phantom sound that is only audible to
the sufferer. Today, some 20 per cent of the Swedish population has some
form of tinnitus, and the risk increases with age.
Measuring brain activity The degree of tinnitus severity is currently
defined by a process of self- rating. A study by scientists at
Karolinska Institutet conducted in collaboration with the company
Decibel Therapeutics has now shown that auditory brainstem responses
(ABR) is a possible objective diagnostic tool in identifying people with constant tinnitus. ABR measures the activity of the brain in response
to a specific sequence of sound stimuli.
"We believe that our ABR method can be sufficiently sensitive to be used
as a diagnostic tool," says Christopher R. Cederroth, researcher at the Department of Physiology and Pharmacology, Karolinska Institutet. "The
method measures the actual neural alterations in the brainstem in people
with constant tinnitus, which could become a future biomarker.
Acknowledgement for patients ABR has previously been put forward
as a tool for measuring tinnitus, but it has not reached scientific
consensus. No earlier study has, however, included as many participants
as this one. Here, the researchers have done ABR measurements on 405 individuals, 228 with tinnitus and 177 without. They observed in people
with constant tinnitus a clear difference in the measures when compared to people without tinnitus, or people who rated their tinnitus as occasional.
"We need an objective diagnostic method for tinnitus, both to acknowledge
the condition to sufferers and to promote the development of new
therapies," says Christopher R. Cederroth. "Our study suggests a causal relationship between such alterations in the brain's neural activity and
the development of constant tinnitus, but we need to do more studies
to verify this. We also need to determine if our method can measure
a therapeutic benefit." Tinnitus is exacerbated The researchers also
followed over 20,000 people with no or varying degrees of tinnitus in
order to track how the symptoms develop over time. Here the researchers
showed 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.
"It's important to know that if you've had recurring tinnitus, you're
more likely to develop lasting tinnitus," adds Dr Cederroth. "We need to
spread this information so that people with occasional tinnitus become
aware of the risks and have the chance to act preventatively." The study
was conducted in collaboration with the Karolinska University Hospital, Stockholm University, the University of Bergen and Decibel Therapeutics
Inc. It was financed by several bodies, including the Swedish Research
Council, the Swedish Research Council for Health, Working Life and Welfare (FORTE), the Stockholm Stress Centre, the GENDER-Net Co-Plus Fund "TIGER"
and the EU's Horizon 2020 "ESIT" and "UNITI" programmes.
special promotion Explore the latest scientific research on sleep and
dreams in this free online course from New Scientist -- Sign_up_now_>>> ========================================================================== Story Source: Materials provided by Karolinska_Institutet. Note: Content
may be edited for style and length.
========================================================================== Journal Reference:
1. Niklas K. Edvall, Golbarg Mehraei, Martin Claeson, Andra Lazar, Jan
Bulla, Constanze Leineweber, Inger Uhle'n, Barbara Canlon,
Christopher R.
Cederroth. Alterations in auditory brainstem response distinguish
occasional and constant tinnitus. Journal of Clinical Investigation,
2022; DOI: 10.1172/JCI155094 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/01/220126122458.htm
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