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How to Get a Diagnosis

The diagnosis can be made by your GP or dentist. It is crucial to give a thorough description of the pain.  If the pain is too severe and affects your ability to speak, write things down and take someone with you who understands your condition.  The following tips may help you to put together a synopsis of your pain:

it's TN

© M.Willett

  • When did the pain start and what were you doing at the time?
  • What does the pain feel like; stabbing, shocking, burning, piercing?
  • How often do you get the pain and how long does each attack last?
  • What happens to you when the pain hits?
  • Where is the pain starting from—in your teeth or actually around one tooth, your cheek, your nose, on the outside of the face or inside your mouth?
  • Is there anything which sets the pain off or triggers it?
  • How is the pain affecting you and the quality of your life?
  • Does it ever cause visible effects, eg, watering or redness of the eye, swelling of the eyelid, runny nose and sweating?

If TN is suspected, you will need to see a neurologist, oral physician or pain specialist.  An MRI scan is usually done to ascertain if there is an obvious cause for the pain and also to rule out other conditions.  As there is no diagnostic test for TN, the procedure of diagnosis may take some time and require persistence.

MRI Scan

A TN diagnosis falls into two categories: Classic TN, also referred to as Idiopathic TN, or Symptomatic (secondary) TN.

Classic Trigeminal Neuralgia

This is typically caused by a blood vessel or vessels compressing the trigeminal nerve as it enters the brainstem.  The loss of the myelin sheath surrounding the nerve will have been caused by the constant rubbing and pulsating of the blood vessel(s), causing erratic messages to be transmitted along the wrong nerve fibres, ie, “cross talk” between light touch and pain fibres.  It is established that the majority of TN cases are caused this way.  It is likely that the offending vessels will be identified on an MRI scan, although this is not always the case.  This type of TN results in clearly identifiable triggers which can provoke pain attacks. These triggers can include:

  • Brushing teeth
  • Yawning
  • Swallowing
  • Face washing
  • Shaving or putting on make-up
  • Vibration or sudden movement, even walking
  • Exposure to cold, a breeze on the face or air conditioning
  • A light touch to the affected area
  • Eating or biting into something
  • Talking or smiling

This is not an exhaustive list and attacks also happen spontaneously with no obvious trigger.


Symptomatic Trigeminal Neuralgia

This includes cases where TN is secondary to an underlying cause such as:

  • Multiple Sclerosis (MS) which may also result in the demyelination of one or more branches of the trigeminal nerve and lead to TN.
  • Other rare diseases which cause damage to the myelin sheath such as benign cysts, a tumour compressing the trigeminal nerve, abnormalities at the base of the skull or arteriovenous malformations, ie, abnormal blood vessels.

Only a very few trigeminal neuralgia cases are caused by one of these underlying medical conditions.

Trigeminal neuralgia is different to trigeminal neuropathy. The latter is a pain syndrome which has resulted from injury to the trigeminal nerve, causing pain with numbness.  Examples of causes are surgery involving the teeth or sinuses, infections or trauma to the face and head.

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Page last updated on 11 Aug 2015