Neuralgia is a medical term that describes intense pain along the length of a particular nerve. Trigeminal neuralgia affects the trigeminal nerve (referred to as the 'fifth cranial nerve' or 'CNV'), which transmits sensation from the face to the brain and controls biting and chewing. TN is normally intermittent pain and affects primarily the head and face. Trigeminal neuralgia is also referred to as 'tic douloureux' or by the abbreviation 'TN'. It is estimated to affect roughly one to two people per thousand in the general population and is most common in women over the age of 50. The condition often worsens over time.
Causes
Many factors may contribute to the development of neuralgia. These include... Pressure on the nerve (this could be from compression by a blood vessel – usually the superior cerebellar artery; or the presence of a brain tumour).
- Multiple sclerosis.
- Diabetes.
- Stroke.
- Trauma.
- Previous surgery.
- Other causes: Infections (including HIV), medications, deficiency in vitamins B1 and/or B12, excess alcohol consumption.
- Symptoms
The main symptom of TN is short, intense 'stabbing' pain in the face which can affect the eyes, forehead, lips, nose, scalp, mouth, teeth and both the upper and lower jaw. TN is usually isolated to one side of the face but can affect both sides particularly in patients with multiple sclerosis. Pain often last just a few seconds, but repeat attacks also occur often over a period of days to weeks, and sometimes months. These periods of TN can then disappear, only to return several months or even years later. There may be triggers that set off these attacks: Applying makeup, brushing teeth, chewing food, washing face, or even blowing of the wind on the face, can cause another onset of intense pain. TN is very disabling, and patients often avoid eating, washing their face and brushing their teeth to prevent these triggers. These symptoms can often be confused with dental problems.
Tests / Diagnosis
The diagnosis of TN involves a review of symptoms and medical history. The diagnosis is mainly based on the characteristics of the symptoms, rather than any particular tests. Tests are often performed to exclude other possible causes. These include an initial CT (computed tomography) and/or MRI (magnetic resonance imaging) scan of the brain. Blood tests may also be recommended to review any risk factors as outlined above. Sometimes a lumbar puncture (LP) may be necessary to exclude other associated conditions, such as multiple sclerosis (MS).
Treatment
First-line treatment for TN is with anti-convulsant medications (e.g. Carbamezepine, or ‘Tegretol’). When medications lose their effects, or their side effects are not tolerable, more invasive procedures may be required. Surgery options include: Microvascular decompression to free the trigeminal nerve from compression from a blood vessel or removal of brain tumour; Needle-based procedures to numb the trigeminal nerve (balloon-compression, radiofrequency ablation or glycerol injection); or Radiosurgery to ablate the nerve.