A Simple Guide to Trigeminal Neuralgia

A Simple Guide to Trigeminal Neuralgia
-----------------------------------------------

What is Trigeminal Neuralgia?
--------------------------------------

Trigeminal Neuralgia is the sudden ,lightning-like paroxysms of pain which occurs in the distribution of one or more branches of the trigeminal nerve usually on one side of the face.

It is a rare codition affecting more women than men.

It is more common at the age of 60 years and above.

What are the causes of Trigeminal Neuralgia?
----------------------------------------------------

Trigeminal Neuralgia has no known cause,
but may be due to :
1.compression of the trigeminal nerve by tumors or vascular anomalies(eg aneurysm)

2.Trauma- injury to the trigeminal nerve

3.Tumours- compressing the trigeminal nerve

4.Infections-meningeal inflammation of the trigeminal nerve

5.Temporomandibular Joint Syndrome - inflammation in the temporomandibular joint may compress or cause inflammation in the trigeminal nerve.

6.Multiple sclerosis-an area of demyelination from multiple sclerosis may be the cause- more common in younger patient.

What are the symptoms and signs of Trigeminal Neuralgia?
---------------------------------------------------------------

Symptoms:
-----------
1.Pain is brief, lightning-like, paroxysmal with usually severe.

There may be recurrent stabs of pain or spontaneous exacerbations of pain.

It can last from a few seconds to 1-2 minutes and is followed by a refractory period(no pain).

Sometimes the pain occurs in clusters to the extent that the patient complains that it lasts for hours.

Usually the maxillary branch is most commonly involved ,followed by the mandibular, and then the ophthalamic.

Pain is unilateral (rarely bilateral).

Pain may occur several times a day.

It rarely occurs at night.

There are certain triggers which can spark off an attack:
-----------------------------------------------------------

Light touch at the trigger zone such as the lips is the most provocative.

Other triggers are
1.shaving,
2.face washing,
3.chewing
4.talking
5.brushing teeth
6.sneezing

Pain causes brief muscle spasm of the facial muscles, inducing the tic.

Signs:
---------
Physical examination findings are normal.

A normal neurologic examination is part of the diagnosis of idiopathic Trigeminal Neuralgia.

A careful examination of the cranial nerves must be done, including the corneal reflex.

Any abnormality in the neurological examination suggests that the trigeminal neuralguia is secondary to other illnesses.

What are the investigations required in Trigeminal Neuralgia?
----------------------------------------------------------------

1.Blood for infections such as meningitis,

2.MRI of brain to exclude an uncommon mass lesion or aberrant vessel compressing the nerve roots.

What is the treatment of Trigeminal Neuralgia?
-----------------------------------------------------

Medications:
----------------
1.Carbamazepine is the most effective medical treatment.

2.Baclofen (Lioresal)
Most often used after therapy with carbamazepine has been initiated.
A combination of carbamazepine and Baclofen often relieve pain in many patient.

3.Other anticonvulsant such as phenytoin, oxcarbazepine, clonazepam, lamotrigine, valproic acid, and gabapentin.

4.Muscle relaxants
These agents are also useful in the treatment of Trigeminal Neuralgia.

They can depress the sensitivity of the nerve and relax the muscle.

Mental and physical sluggishness and dizziness occur with use of most anticonvulsant and muscle relaxants.

Surgery
-------------
1.Percutaneous radiofrequency ablation of a portion of the trigeminal ganglion
is the method of choice.

2.anesthetic blocks of the trigeminal ganglion.

3.decompression of trigeminal root entry of impinging vascular structures.

4.Surgical division of the affected branch of the nerve.

What is the prognosis of Trigeminal Neuralgia?
------------------------------------------------------

80% of patients respond well to carbamazepine but recurrences and exacerbations are common.

Surgery is usually effective but may leave permanent neurological deficit.

Trigeminal Neuralgia is not life threatening.

A Simple Guide to Facial Palsy

A Simple Guide to Facial Palsy
-----------------------------------------

What is Facial Palsy?
----------------------------------

Facial Palsy is the paralysis of the facial nerve from its origin in the brain right to the branches of the nerve in the face.

It is usually temporary.

What are the causes of Facial Palsy?
------------------------------------------------

Facial Palsy occur as a result of reduced blood supply to or pressure on the facial nerve at 2 areas:

Supranuclear(within the Brain)
1.Cerebral vascular lesions

2.Cerebral tumours

Infranuclear(outside the brain)
1.Bell's palsy - most common with unknown cause, most likely due to viral infection of the facial nerve after the stylomastoid foramen.

2.Trauma- Birth injury,fractured temporal bone, surgery of the ear

3.Tumours- Acoustic neurofibroma, parotid tumours, malinant disease of the ear,
4.Infections- from acute otitis media or chronic otitis media, herpes zoster of the ear, HIV, Lyme's disease

5.Autoimmune disease-Gullian-Barr Syndrome, sarcoidosis,

6.Multiple sclerosis

What are the symptoms and signs of Facial Palsy?
------------------------------------------------------------

The onset of facial palsy is usually very sudden.

The most important part of the diagnosis is to distinguish between the supranuclear and infranuclear causes of facial palsy.

Supranuclear symptoms and signs:
1. The movements of the upper part of the face is unaffected because the forehead muscles have bilateral cortical representations

2.Depressed taste ( lesion above chorda tympani)

3.hyperacusis ( lesion above nerve to stapedius)


Infranuclear symptoms and signs:
1.pain and discomfort at the mastoid region(behind the ear) or in the ear.

2.weakness of facial muscle on 1 side, with sagging eyelids, difficulty in closing the eye, drooping of the mouth on 1 side.

3.dribbling of saliva

4.difficulty in speaking

5.loss of taste at the front of the tongue

6.dryness or watering of the affected eye

7.eyeball rolled up and inward on attempted closure of affected eye

8.ectropion or turned out lower eyelid

9.sharp hearing on the affected side

10.Voluntary twitches (called synkinesis) such as the corner of the mouth turning up in a smile when blinking or tears in the eye while eating.

What are the investigations required in Facial Palsy?
-----------------------------------------------------------

1.Physical examination
a.test muscle movement of the forehead to determine whether cause is
supranuclear(muscle movement present) or
infranuclear( no movement of forehead muscles)

b.test closing of the eye - to test weakness of eyelid muscles

c.ask patient to smile - to check for weakness of the cheek muscles

2.Investigations:
a.Blood for infections, HIV, Lyme's disease

b.MRI of brain to exclude tumours

c.Electromyogram and nerve conduction studies may give an an indication of the severity of damage to the nerve and the subsequent prognosis

What is the treatment of Facial Palsy?
-----------------------------------------------------

1.Start on a course of steroids like prednisolone(about 40-60mg/a day at first, then tapering off the dosage) to hasten rapid recovery.

The steroid usually reduce swelling of the nerve.

2.antiviral drugs such as acyclovir can help recovery especially when the cause is suspected herpes virus

3. Protection of the affected eye (which cannot be closed properly) by wearing glasses or an eyepad.

Use artificial eyedrops during the day to keep the eye moist.

Tape the eye at night to keep it closed.

4.Physiotherapy of the facial muscles -
facial massage,
facial exercises, and
acupuncture may help restore the facial muscle tone.

5.Surgery
Tarsorrhaphy, which narrows the space between the upper and lower eyelids, may improve eye closure.

Plastic surgery may improve permanent facial drooping

What is the prognosis of Facial Palsy?
----------------------------------------

80-90% of patient with facial palsy recover spontaneously and completely within three weeks.

The remainder usually takes up to six months to recover.

Very rarely do you get permanent paralysis of the facial nerve.