Tinnitus is a condition that means you hear noises in your ear not generated by a usual source, including ringing, buzzing and throbbing. At best, it can be unpleasant, but at worst, it can be debilitating.
However, a group of US scientists think they may just have a breakthrough treatment for the condition, which can cause stress, sleep difficulties, anxiety and hearing loss, and is often linked with Meniere's disease, diabetes, multiple sclerosis and depression. It also has no cure.
It's not always known how tinnitus develops, but in their study - which was published in the journal PLOS Biology - the scientists suggest it could be caused by a molecule called TNF-A (tumour necrosis factor alpha), which disrupts communication between neurons.
The scientists managed to stop the condition in mice (that had developed tinnitus after being exposed to loud noise for two hours) by blocking a protein that fuels brain inflammation.
The team said the findings suggest neuro-inflammation may be a therapeutic target for treating tinnitus and other hearing problems.
Study co-author Professor Shaowen Bao said: "Genetic knock out of TNF-A or pharmacologically blocking its expression prevented neuro-inflammation and ameliorated the behaviour associated with tinnitus in mice with noise induced hearing loss."
The team's analysis showed inflammation in a sound-processing region of the brain controlled ringing in the ears of affected mice.
Bao, who is a neuroscientist at the University of Arizona in the US, continued: "Hearing loss is a widespread condition that affects approximately 500 million individuals, and is a major risk factor for tinnitus - the perception of noise or ringing in the ears."
Recent research suggests hearing loss causes inflammation - which is the immune system's response to injury and infection - in the auditory pathway.
But how this relates to hearing loss-related conditions like tinnitus is still poorly understood.
Dr Bao and his colleagues examined inflammation that affects the nervous system in the auditory cortex of the brain following noise-induced hearing loss, and its role in tinnitus, in the rodent models.
He said: "The results indicate noise-induced hearing loss is associated with elevated levels of molecules called proinflammatory cytokines and the activation of non-neuronal cells called microglia - two defining features of neuroinflammatory responses - in the primary auditory cortex."
Bao added: "These results implicate neuro-inflammation as a therapeutic target for treating tinnitus and other hearing loss related disorders."
However, Bao also pointed out that although the therapy was successful in the animals, potential adverse affects need to be thoroughly investigated before any human trials take place.Featured Image Credit: PA