Mouth tingler implanted in gum to beat the pain of migraines
01:04 GMT, 27 March 2012
Migraine affects around one in ten of the UK population
A painkilling device implanted in the gum could be a radical new way to beat migraine pain.
The implant, which is about the size of an almond, is connected to nerves in the face that transmit pain signals during an attack.
When the patient feels a migraine coming on, they hold a remote control handset against their cheek.
Pressing a button then activates the implant, triggering a mild electric current to stimulate the nerves and interrupt the flow of pain signals to the brain.
The gadget is currently undergoing trials at several hospitals around Europe.
It’s being tested on patients who suffer at least four migraine attacks a month, experience migraine pain on eight days in the month, and who don’t get relief from drug treatments.
Migraine affects around one in ten of the UK population — with women affected more than men.
The symptoms include a severe throbbing headache, usually on one side of the head, which can be accompanied by nausea, and visual disturbances such as flashing lights, zig-zags and blind spots.
Over-the-counter painkilling tablets such as paracetamol and ibuprofen can help mild attacks.
More severe cases are treated with triptans, drugs that are available on prescription or, in some cases, over the counter.
But in some people these drugs can become less effective over time if used too frequently, and can also actually trigger migraines themselves, called ‘rebound’ headaches.
In recent years, scientists have been looking for drug-free ways to switch off migraine pain using devices that stimulate nerves.
Nerve cells are responsible for processing pain signals and despatching them to the brain. If this process can be blocked, it is possible to stop the signals reaching the brain.
The implant, which is about the size of an almond, is connected to nerves in the face that transmit pain signals during an attack
In one development, several patients in Britain have been fitted with an occipital nerve stimulator, a tiny battery pack implanted near the collar bone with electrodes wired up to nerves in the back of the neck which connect to the brain.
The latest device, developed by California-based firm Autonomic Technologies Inc., is even more discreet, as it can be hidden inside the mouth and works on a different set of nerves called the sphenopalatine ganglion nerve bundle.
These are deep inside the face, on either side of the nose.
For years, doctors have known that injecting drugs into these nerves can ‘block’ pain signals.
But the nerves are difficult to reach and injections can be painful.
The new implant is put in place with the patient under a general anaesthetic.
Then a small incision is made in the gum over the second molar — the second tooth from the back at the top of the mouth.
The implant is then screwed into the jawbone to keep it in place, with wires connected up to the nerve bundle.
The procedure takes about an hour — the patient will need drugs to dull the pain and keep infection at bay for a few days afterwards.
Earlier trials using the gum implant for cluster headache — an excruciating pain that often strikes behind one eye — showed it halved pain in two-thirds of patients.
Patients can activate the implant when they start to experience the pain, and the electrical shocks act to block the transmission of pain signals.
Furthermore, the frequency of the headaches in this patient group was halved.
The trial was carried out at the University of Liege, in Belgium, and presented at the Congress of the International Headache Society in Berlin.
The device is undergoing trials on 30 migraine patients at clinics in Denmark, Belgium, Spain, France and Germany, but is unlikely to be available in the UK for two to three years.
Dr Fayyaz Ahmed, from the Migraine Trust, says research is moving away from medications for migraine and towards ways of blocking the pain in the first place.
‘Medications are not suitable for everyone and are often associated with unpleasant and intolerable side-effects,’ says Dr Ahmed.
‘The focus in future is to develop small and smarter devices with a long battery life and an effective and manageable remote to control the pain as and when needed.
‘This device is a clear example of how scientists are focusing on delivering new modes of treatment.’