Our Executive Director of Research, Dr Ralph Holme, updates us on how the charity is funding tinnitus research.
Tinnitus – a roaring, hissing, ringing or any other sound heard in one or both ears or in the head that has no external source – affects eight million people in the UK alone. For many of those living with it, it can cause serious anxiety, stress, sleeping disorders and depression. While there are effective ways to help people manage their tinnitus, there are no approved treatments that can eliminate it.
The research our charity supports aims to discover more about the causes of tinnitus and the biological mechanisms involved. This knowledge will give us the clues we need to develop and test new treatments that can silence tinnitus.
We’ve already learned a lot
Our research has helped to identify regions of the brain involved in tinnitus and shown that these regions act like a ‘volume control’, amplifying signals from the ear when they are weak and turning activity down when they are strong.
Tinnitus may arise when the brain’s ‘volume control’ becomes set too high. It suggests that we might be able to treat tinnitus by developing drugs or other methods able to turn activity down in these parts of the brain. Many researchers are now focusing on this ground-breaking concept.
The causes of tinnitus
Our research has shown that exposure to loud noise can trigger hyperactivity in parts of the brain that process sound. Importantly, if signals from the cochlea (the part of the inner ear that detects sound) to the brain are blocked soon after the onset of tinnitus, then this tinnitus-related hyperactivity is reduced. But if the signals are blocked later on, there is no effect.
This points to a two-stage process in the development of tinnitus. An initial stage, driven by signals from the cochlea, followed by a second phase, where tinnitus becomes established in the brain.
This suggests that we will need different treatments depending on how long someone has had tinnitus. For people who have recently acquired tinnitus, we need to find treatments able to safely block the signals from the ear to the brain that trigger tinnitus. But for those who have had tinnitus for a long time, we need treatments to re-set the tinnitus hyperactivity within the brain.
Our current research
While we’ve made great progress, there is still a lot we don’t know. Our current projects are looking at how stress, anxiety and sleep influence tinnitus – we hope this research may suggest new ways to treat tinnitus. We are also funding research that could lead to objective ways of measuring tinnitus. You can read more about this in a recent blog post I wrote on our website. These measures are urgently needed so that researchers can reliably monitor the effectiveness of new treatments.
Our next tinnitus project
As part of Tinnitus Week 2020, we invited Dr Raj Shekhawat from the UCL Ear Institute, to talk to our staff about his tinnitus research. He told us about his investigations into non-invasive brain stimulation techniques, and whether these can turn down tinnitus-related brain activity. These may have the potential to reduce the perception of tinnitus.
Raj will be leading one of our new research projects at the Ear Institute in April. His research has already seen promising results in some patients, who experienced a reduction in their tinnitus for up to three days after treatment.
Our new project will follow-up on these initial findings. Raj’s team will explore the most effective parts of the brain to stimulate to reduce tinnitus, and carry out brain imaging studies to better understand how activity in the brain changes in response to electrical stimulation.
The brain stimulation technique is called ‘transcranial direct current stimulation’, or ‘tDCS’, and involves applying a small electrical current across the brain.
This project will help establish whether this technique could be used in the clinic as a way to treat tinnitus, as part of our efforts to help those eight million people with the condition.