Jumat, 11 Mei 2012

A cure for tinnitus? Hope for millions tormented by ringing in ears as scientists edge closer to developing first drug treatments

A cure for tinnitus? Hope for millions tormented by ringing in ears as scientists edge closer to developing first drug treatments

  • Doctors discovered how to tone down overactive neurons in the brain
  • Discovery could lead to new tinnitus treatments
  • Investigations into potential drugs are underway

By Graham Smith

PUBLISHED: 05:49 EST, 11 May 2012 | UPDATED: 11:17 EST, 11 May 2012


The first drug treatments to prevent the onset of tinnitus could soon be developed after doctors discovered how to tone down overactive neurons in the brain.

Researchers from the University Of Leicester have identified a key cellular mechanism that could underlie the development of ringing in the ears following exposure to loud noises.

The discovery could lead to novel tinnitus treatments, and investigations into potential drugs to prevent tinnitus are underway.

Preventable? The first drug treatments to stop the onset of tinnitus could soon be developed after doctors discovered how to tone down overactive neurons in the brain

Preventable? The first drug treatments to stop the onset of tinnitus could be developed after doctors found how to tone down overactive neurons in the brain

Around five million Britons suffer with tinnitus at some point in their lives. The condition causes the patient to hear a sound that has no obvious source.

Although the word tinnitus comes from the Latin for ‘ringing’, the noise can be a buzz, hum or even a whistle - heard in one ear, both ears or in the middle of the head.

For most people the problem is mild, or disappears with time. But for others it can become chronic and almost intolerable.

There are currently no drugs available to treat or prevent tinnitus.

Scientists have previously speculated that it results from damage to nerve cells connected to the ears.

Lead researcher Dr Martine Hamann said: 'We need to know the implications of acoustic over-exposure, not only in terms of hearing loss but also what's happening in the brain and central nervous system.

'It's believed that tinnitus results from changes in excitability in cells in the brain - cells become more reactive, in this case more reactive to an unknown sound.'

Dr Hamann and her team looked at cells in an area of the brain called the dorsal cochlear nucleus - the relay carrying signals from nerve cells in the ear to the parts of the brain that decode and make sense of sounds.

Following exposure to loud noises, some of the nerve cells in the dorsal cochlear nucleus start to fire erratically, and this uncontrolled activity eventually leads to tinnitus.

Around five million Britons suffer with tinnitus at some point in their lives. The condition causes the patient to hear a sound that has no obvious source

Around five million Britons suffer with tinnitus at some point in their lives. The condition causes the patient to hear a sound that has no obvious source

Dr Hamann said: 'We showed that exposure to loud sound triggers hearing loss a few days after the exposure to the sound. It also triggers this uncontrolled activity in the neurons of the dorsal cochlear nucleus.

'This is all happening very quickly, in a matter of days.'

In a key breakthrough, the team also discovered the specific cellular mechanism that leads to the neurons' over-activity.

Malfunctions in specific potassium channels that help regulate the nerve cell's electrical activity mean the neurons cannot return to an equilibrium resting state.

Ordinarily, these cells only fire regularly and therefore regularly return to a rest state.

However, if the potassium channels are not working properly, the cells cannot return to a rest state and instead fire continuously in random bursts, creating the sensation of constant noise when none exists.

Dr Hamann said: 'In normal conditions the channel helps to drag down the cellular electrical activity to its resting state and this allows the cell to function with a regular pattern.

'After exposure to loud sound, the channel is functioning less and therefore the cell is constantly active, being unable to reach its resting state and displaying those irregular bursts.'

Although many researchers have investigated the mechanisms underlying tinnitus, this is the first time that cellular bursting activity has been characterised and linked to specific potassium channels.

Identifying the potassium channels involved in the early stages of tinnitus opens up new possibilities for preventing tinnitus with early drug treatments.

Dr Hamann's team is currently investigating potential drugs that could regulate the damaged cells, preventing their erratic firing and returning them to a resting state.

If suitable drug compounds are discovered, they could be given to patients who have been exposed to loud noises to protect them against the onset of tinnitus.

These investigations are still in the preliminary stages, and any drug treatment wou ld still be years away.

The research was published in the journal Hearing Research.

It was funded by a Research Councils UK fellowship to Dr Hamann, a grant from the Wellcome Trust and a PhD studentship from GlaxoSmithKline, with follow-up investigations funded by a three-month grant from Deafness Research UK.

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Tinnitus cured by new drug fatal side effects ..? Cure indeed !

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my tinnitus is that load its blocked both my ears i cant hear the tv at all,nor can i hear people on the phone,im suffering really bad i want to do this trial.

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I got it while pregnant. They say its because of the hormone imbalance. My son is 10 months now and I still have it. Everytime I see the doc he says it will be gone next time I see you, after 3 months it was still there, now waiting another 6 and Im sure it will still be there. Im trying not to let it bother me as I used to get so upset about it but trying to change how it makes me feel otherwise it would drive me insane. I have it in both ears and in my head so feel Im being attacked at all angles. My Dad has it too but they say his is from his army days just took a long time to come on, and he has hearing loss aswell which I dont.

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Mary Jane:"I looked up Tinnitus and Quinine as I had just drunk a big glass of tonic water. It was there so will drink very small portions in future. It was scary." Quinine is ototoxic ie it causes deafness and tinnitus. Don't drink the stuff.

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I have Menieres. I have empathy with anyone who has Tinnitus. I found that when I drank the strong filtered coffee at work it made the condition worse.

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I've had it for years caused by shooting in the 60's. Didn't know I should avoid chocolate but you are right. Too much caffine dosen't help either. When I was scuba diving the pressure changes knocked it out for a couple of days but it always came back. Always there but I have become used to it. Recruitment is also linked - can't stand loud noise or room full of people babbling. If I go out socially and use ear plugs to reduce the noise I hear the Tinnitus louder until I have to leave the room and take the plugs out. There are worse things I could be suffering from though.

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But England won't have the medicine though Wales will.

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Very often a luxated Atlas bone will cause Tinitus, and can easily be corrected for a modest fee, with the added benefit of no drug dependency. Just Google Marie Atlas.

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I've had ot for close on 40 years. Started with Meniere's disease, but I was so relieved that it wasn't a brain tumour, I just don't mind the noises. I find I can keep it at bay, taking Vitamin B12. If I miss a few days of this, I need to take a double dose for about a week to get back to MY normal. I most certainly wouldn't take a drug for it - there are always side effects from drugs, not known about for several years. I did find homeopathy did help me considerably. At first I couoldn't hear my own footsteps when wearing Scholl wooden clogs. My homeopathic doctor treate me for several months, and there was a definite improvement.

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I've had this since I was about 5 years old. I can remember lying in bed and calling my mum to ask what that sound was. She said there was no sound! It's been there constantly ever since, it's more noticeable at night when trying to get to sleep.It's a high pitched whistle in my head. I don't recall ever being exposed to a loud noise though. I've sort of got used to it now

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