Byline: Bonnie Estridge
It is said to be one of the worst pains that a human being can experience - so much so, that sufferers have been driven to selfharm or, shockingly, even suicide. And perhaps one of the most frustrating aspects of trigeminal neuralgia (TN), a condition affecting a major facial nerve, is that it is frequently misdiagnosed - and mistaken - for toothache.
There are around 5,000 sufferers in the UK, although experts believe there are many more who have not yet been given the correct diagnosis. Shock-like attacks occur unpredictably and can last a few seconds recurrently, over minutes or hours.
Dr Anish Bahra, consultant neurologist at The National Hospital for Neurology and Neurosurgery in London, says: 'The pain is horrific.
Sufferers say it is as if they are being electrocuted or stabbed and they will often involuntarily jerk and writhe in agony. After an attack there can be a dull ache that lasts for hours or days.' Nine in every ten cases are thought to be provoked by a blood vessel pressing on the trigeminal nerve. This nerve has three branches that originate at the base of the brain and conduct sensations from the upper, middle and lower portions of the face, including the mouth, lips, teeth, eyes, nose, scalp, forehead and part of the jaw region.
Pressure on it causes wearing away of the protective coating around the nerve (the myelin sheath), resulting in extreme pain.
'One of the reasons for misdiagnosis is that when the pain affects the region of the teeth and jaws, it is often confused with toothache, so the first port of call for many patients is their dentist,' says Dr Bahra. 'The symptoms can also occur in people with Multiple Sclerosis [MS] due to the disease affecting the trigeminal pathways in the brain.' An attack of TN may be triggered or exacerbated by wind or draught, or food or drink that is piping hot or freezing cold.
'Shaving, and brushing teeth, can also be a trigger,' explains Dr Bahra. 'It can even be provoked by a light touch to the face, movements of the mouth or a soft breeze. The condition can occur at any age although it is most likely to affect those over 50. It is more common in women, for reasons unknown, and may be genetic, possibly because of an inherited pattern of blood-vessel formation.' There is no specific test for TN.
The patient's medical history and physical examination, description of symptoms and neurological examination can distinguish TN from similar disorders such as post-herpetic neuralgia (which can develop after shingles), cluster headaches and migraines or injury to the trigeminal nerve as a result of sinus or oral surgery, stroke or a trauma to the face.
An MRI scan can rule out MS or a tumour and may show a blood vessel on the nerve. An angiogram - in which the patient receives an injection of dye to outline blood vessels on an X-ray - can show problems with vessels or a compression of the trigeminal nerve close to the brainstem.
A range of drugs that block nerve messages, known as anticonvulsants, are generally effective in treating more than two-thirds of cases of TN. For others, surgery is possible. Surgical treatments known as rhizotomy aim to damage the TN nerve to block the electrical activity transmitting the pain, and involve passing a needle through the cheek under local anaesthetic to bathe the nerve in glycerol, freeze it, heat it with radio frequency or compress it with a tiny balloon. These procedures can bring relief for periods of time varying from months to several years. …