Definition: It is aneuropathic disorder characterized by episodes of intense pain in the face, originating from the trigeminal nerve. It has been described as among the most painful conditions known.
- It is thought to be caused by an aberrant loop of the cerebellar arteries compressing the trigeminal nerve as it enters the brain stem.
- Other compressive lesions, usually benign are occasionally found.
- When trigeminal neuralgia occure in multiple sclerosis, there is a plaque of demyelination in the trigeminal root entry zone.
- Pain in the lips, gums, check or chin.
- Pain seldom lasts more than a few seconds or a minute or two.
- Intense that the patient winces hence the term tic.
- Physical signs are usually absent.
[A] Medical therapy:
- Carbamazepine is effective in 50-75% of patient. Carbamazepine shpuld be started as a single daily dose of 100 mg taken with food and increased gradually(by 100 mg daily every 1-2 days) up to 1200mg.Most patients require a maintence dose of 200 mg qid.
- Gabapentin or pregabalin may be effective in patient who cannot tolerate carbamazepine.
[B] Surgical therapy:
- Injection of alcohol or phenol into peripheral branch of the nerve.
- The most widely applied procedure creates a heat lesion of the trigeminal (gasserian) ganglion or nerve a method termed radiofrequency thermal Rhizotomy.
- The vascular compression of the trigeminal nerve can be relieved through a posterior craniotomy.
Trigeminal nerve disorder:
[A] Nuclear lesions:
- Muliple sclerosis.
[B] Preganglionic lesions:
- Acoustic neuroma.
- Chronic meningits.
[C] Gasserian ganglion lesion:
- Trigeminal neuroma.