Understanding the Trigeminal Neuralgia: Characteristics, Causes, Investigations, and Treatments

Trigeminal neuralgia is the worst pain known in medicine. It is a facial pain on one side of the face, in one or more division of trigeminal nerve (TN)

This pain is compared to labour pain and kidney stone pain. It causes severe depression, so it is also called SUICIDE DISEASE

CHARACTERISTICS OF PAIN

This pain is of two types- typical and atypical. Typical pain is electric shock like pain, which comes and goes. Spontaneous or precipitated by drinking eating chewing brushing etc. Atypical pain is continuous or prolong burning facial sensation.

CAUSES

Following are the common causes of TN:

• Abnormal neurovascular contact at the root entry zone of the nerve to the brain
• Post herpetic neuralgia
• Stroke
• Trauma
• Multiple sclerosis

INVESTIGATIONS

MRI Brain with CISS sequence is a must investigation for this pain, to rule out tumour causing pain and to look for neurovascular contact, which is commonly missed without a properly done CISS sequence.

TREATMENT OPTIONS

MEDICAL

This pain is responsive to anti-seizure (fits) medications- carbamazepine, phenytoin, gabapentin.

These patients can be given a trial of medications in slowly escalating doses of the above-mentioned medicines if tumour has been ruled out on MRI brain.

SURGERY

If relief from medications is less than 70-80%, pain is still intolerable inspite of maximum tolerable doses of medications and there is evidence of neurovascular contact on MRI, the best form of treatment is minimally invasive microscopic vascular decompression of trigeminal nerve MVD.

Figure 1  TN – TRIGEMINAL NERVE

Figure 2

80% patients have nearly immediate relief with MVD surgery. 10% patients may still require medications in small to moderate doses. Rest 10% will have no relief and may need percutaneous repeated radiofrequency lesioning.

RF LESIONING

It is destructive procedure and has high recurrence rate of pain so reserved for selected patients.

RADIOSURGERY

Again, this is destructive procedure and has more permanent results as compared to RF lesioning. To be opted for when other modalities have failed or patient is unfit for surgery.