Persistent ringing in the ears (known as tinnitus) is a common and often disabling condition. Effective treatments for tinnitus are lacking largely because its mechanisms are not fully understood. The research team believes that the period surrounding the initial onset of tinnitus is of huge importance in the condition as a whole, for a number of reasons:
- There may be a time window in which tinnitus can be reversed. During this window, blocking certain abnormal brain processes may prevent tinnitus from becoming permanently established, whereas targeting them once the window has closed may be less effective. If researchers can identify these processes and target them with specific drugs, it’s possible that treatments which have only a limited effect on long-term tinnitus could stop tinnitus completely if given early enough.
- It offers an opportunity to study the underlying factors that lead to tinnitus in the first place.
Current evidence suggests that if someone develops tinnitus that lasts for four weeks, they have an almost 9 in 10 chance of still having tinnitus 6 months later (and therefore most likely for the rest of their life). There are some compelling theories that suggest that the abnormal processes that cause tinnitus may only be present for a short time, when tinnitus first occurs. However, even if these processes return to normal at a later time point, the tinnitus persists and becomes permanent. These brain processes might nonetheless remain a factor throughout the course of tinnitus and therefore represent important targets for treatment.
The aim of the project is to study the acute period after tinnitus onset (defined by the researchers as the first four weeks of a person developing tinnitus) in people with newly-developed tinnitus, and identify the processes that cause tinnitus to become permanent.
Electroencephalography (EEG), a non-invasive method whereby electrodes are placed along the participant’s scalp, will be used to record both spontaneous (always present) and sound-driven electrical brain activity in people who have developed tinnitus within the previous 4 weeks. These participants will then be tested again 6 months later. Measures will be compared across the two time points as well as against a group of carefully matched controls (people without tinnitus).
The researchers hope to identify brain processes that are specifically altered in tinnitus, including those which are only altered for a limited amount of time, and those that develop over a longer period of time. Processes known to be driven by specific brain chemicals which are thought to be linked to tinnitus will be monitored as part of this research. If any of these chemicals are shown to be involved in tinnitus development, this could pave the way for clinical trials using existing medications that are known to target these chemicals.
This work could lead to better treatments for people with newly developed tinnitus, and improve treatments for those already living with the condition.
If the early stages of tinnitus are shown to be important in understanding the condition, the results could lead to a major change in the way researchers study and test tinnitus treatments, potentially leading to improved treatments.