Trigeminal Neuralgia 1

5/26/2018 Trigeminal Neuralgia 1

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TRIGEMINALNEURALGIA

Presented By

DR. AJAY CHANDRAN MDSLECTURER,DEPT OF OMFS

SAVEETHA DENTAL COLLEGE


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Definition

A specific painful affection of the facecharacterized by momentary or repeatedparoxysmal attacks of excruciating type ofpain in one or more divisions of thetrigeminal nerve, usually initiated byirritation of the trigger zone and withoutany evidence of sensory impairment of

the face. (kaemmerer 1970)


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TRIGEMINAL NERVE SYNDROME

Trigeminal neuralgia: disease,(tic doloureux) : previously classified into

(1) Classical Trigeminal neuralgia

(idiopathic)(2) Trigeminal neuralgia with definiteetiology


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DEFINITION

Trigeminal neuralgia is defined as sudden, usuallyunilateral, severe brief, stabbing, lancinating, recurring pain in the

distribution of one (or) more branch of 5thcranial nerve.

SYNONYMS

John Locke in 1677 gave the 1st full description with its

treatment.

Nicholaus Andre in 1756 coined the term TIC doloureux.


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In 1773 John Fothergill published description of TN. so has

been referred as Fothergillsdisease.

ETIOLOGY

Vascular factors

Transient ischaemia and autoimmune hypersensitivity

response cause demyelination of nerve.

Mechanical factors

Pressure of aneurysms of intrapetrous portion of internal

carotid artery that may erode through the floor of intracranial fossa

to exert a pulsable irritation on ventral side of TN ganglion.


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Dandy described anomaly of superior cerebellar artery lie in

contact with sensory root of TN.

Probable etiology factor

1. Multiple sclerosis

Olfson (1966) suggested presence of sclerotic plaque located at

root entry.

2. Petrous ridge (Basilar)

Lee (1937) suggested neuralgia may be caused by compression of

nerve at dural foramine or over petrous tip.


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3. Intracranial tumours

Epidermoid tumors, meningiomas of cerebellopontine angle and

Meckel cave. Arteriovenous malformation. Aneurysm and

vascular compression.

4. Viral etiology

Post herpetic neuralgia is seen in elderly patients. Viral lesions of

the ganglion can be the etiological factor. i.e., Herpes zooster

VASCULAR COMPRESSION OVER


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VASCULAR COMPRESSION OVER

THE TRIGEMINAL NERVE ROOT


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GENERAL CHARACTERISTICS

Incidence : It seen in about 4 in 1,00,000 persons

Age : Occurs 5th, 6thdecade of life

Sex : Most common in female (58%)

Side : Predilection for the right side (60%)

Division of trigeminal nerve involvement

V3 is more commonly involved than V2division.

V1opthalmic division is involved in about 5% of case.

Only sensory division is affected.


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CLINICAL FEATURES

1. Pain is usually confined to one part of one division of trigeminal

nerve either mandibular or maxillary nerve.2. Pain rarely crosses the midline

3. Pain is of short duration and lost for a few seconds. Recur with

variable frequency. Even refractory period patient experiencedull pain or complete lack of pain.

4. In extreme cases the patient will have a motionless face frozen (or)

mask like face.

5. The characteristic feature of the disorder is that it does not occur

during sleep.

6 A d l h ti f d t i i


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6.A prodromal phase, sometimes referred as pre-trigeminaneuralgia, comprising pain similar to local pulpitis orsinusitis but without any evident pathology. This is knownas Aura.

7.During an attack, patient grimaces with pain, clutches hihands over the affected side of the face, stopping all theactivities. Eye reddens and waters until the attack subsides8.The paroxysm occurs in cycles. Each cycle lasts for weekor months and with time, the cycle appears closer and

closer.9.A variant of Tic Doulourex involving facial nerve known aTic convulsif which involves trigeminal pain and spasm offacial muscles.10.When Trigeminal Neuralgia is associated with multiple

sclerosis, the pain is usually bilateral. During this conditionwhen the neck is flexed it causes electric-like or shock orparesthesia of the lower extremity and legs, this is knownas Lhermittes sign.


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TRIGGER POINT

V2 - Points are located on the upper lip, alae nasi or cheek

or on the upper gums

V3 - Most frequently involved branch

Trigger point are seen over the lower lip, teeth (or) gums of the

lower jaw. Tongue is rarely involved.

V1 - Point usually lies over the supraorbital ridge of

affected side.


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These trigger points are stimulated by

touching them mildly or chewing orspeaking or smiling or brushing orshaving or even washing the face.


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MEDICAL TREATMENT

1. IM morphine/narcotics for pain relief2. Trichloroethylene ampoules-selective analgesia of fifth

nerve

3. Phenytoin sodium (dilantin sodium)

4. Mephenesin

5. Carbamazepine(tegretol/mezetol) maximum dosage-lgm/day

dose adjusted. according to pain relief

dosage:100mg twice daily

effect-80-100% relief of pain drug interaction synergistic with phenytoin sodium


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MEDICAL TREATMENT

VI. Balcofen sodium:lioresal-200mg tid combined withcarbamazipineVII.Percutaneous inj: chemicals used.

1. local anaesthesia, 2. absolute alcohol(0.5ml) 3.phenol-glycerine mixture (2dys-lwk intervals)

injection site: 1.peripheral nerves, 2.trigger zones ,3.gasserian ganglion.

SURGICAL PROCEDURE


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SURGICAL PROCEDURE

To interrupt the pain pathway between

the center & peripheral EXTRACRANIAL PROCEDURE

PERIPHERAL NEURECTOMY:I) INFERIOR ALVEOLAR NERVE

INTRA ORAL APPROACH:(GIN WALLA)EXTRA ORAL APPROACH:(SUBMANDIBULAR)

II). MENTAL NERVEIII). INFRA ORBITAL NERVE

INTRACRANIAL PROCEDURE

I GANGLIONOLYSISII. MICROVASCULAR DECOMPRESSIONIII. RETRO GASSERIAN RHIZOTOMYIV. MEDULLARY TRACTOTOMYV. MIDBRAIN TRACTOTOMYVI. LEUKOTOMYVII. THALAMOTOMY


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DIFFERENTIAL DIAGNOSIS1) Multiple sclerosis:in younger mostly bilateral magnetic

resonance imaging shows characteristic plaques in

cerebral hemispheres.2. Post herpetic neuralgia

3. Neoplasia: in cerebello-pontine angle compressing rootor ganglion of 5 nerve

4. Inflammatory/infective conditions of dental and tmj

problems.5. Glossopharyngeal neuralgia

6. Cluster headache:usually confines to the upper part offace,most commonly centered behind the eye.

7. Depression

8. Atypical facial pain:seldom well localised may bebilateral, often radiates in non anatomic fashion,constant, severe, refractory to medical or surgicaltreatment.


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MANAGEMENT OF TRIGEMINAL NEURALGIA

1. Medical management

2. Surgical management

Medical Management

TN does not response to analgesic including opiates.

Blom (1962) showed TN response to anticonvulsant.

Drug of choice

Carbamazepine, phenytoin, sodium valproate, amitriptyline

baclofen, clonazepam, gabapentin, lamotrigine, felbamate

topiramate, vigabatrin.


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Carbamazepine

Dosage 100mg thrice daily and titrated over 1-5 weeks period

until remission is achieved.

More of daily drug should be taken at night. So that adequate

serum concentration can be present in early morning when pain

mostly occurs.

Side effects

Visual blurring, dizziness, somnolence, skin rash, Ataxia

hepatic dysfunction, Leukopenia, thrombocytopenia, aplastic

anaemia.

When carbamazepine is contraindicated clonazepam

1.5mg/day can be used.


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In order to reduce the high doses ofCarbamazepine taken by the patients, acombination of three drugs are used.

The combination consists ofA.CARBAMAZEPINEB.GABAPENTINE

C.LAMOTRIGINEThis combination is tried to deescalate thelong time high doses of carbamazepine


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Phenytoin

Dosage 100mg three times a day.

Side effect

Slurred speech, abnormal movement, swelling of lymph

gland, gingival hypertrophy, hirsutism, folate deficiency.

Tablet oxycarbazepine

Dosage 1200mg/day. Side effect. hyponatraemia, doublevision.

Valproic acid dosage 600mg/day. Side effect. Irritability, tremors

confusion, hepatotoxicity, weight gain.

Mephenesin carbamate 5-15ml / five times a day to every thre

hours.


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Baclofen

Dosage 10mg/thrice daily.

Side effectFatigue, vomiting

SURGICAL MANAGEMENT

Peripheral injection

Long acting anesthetic agents without adrenaline such as

bupivacaine with or without carticosteroid may be injected at

proximal nerve site.

The selective nerve block can be given as an emergency

measure when patient is suffering a lot.


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Alcohol injection

Intraoral injection of 95% absolute alcohol (0.5-2ml)

Repeated alcohol injection causes local tissue toxicity, inflammation

and fibrosis, burning alcohol neuritis. Alcohol provide pain relief for

a period of 6-12 months.

Peripheral neurectomy (Nerve avulsion)

Oldest and most effective peripheral nerve destruction technique

It act by interrupting the flow of a significant number of afferen

impulse to central trigeminal apparatus.

Indicated in patient, in whom craniotomy a more extensiveprocedure is contraindicated, because of age and disability (or)

systemic disease.

Di d t


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Disadvantage

Produces full anaesthesia or deep hypoesthesia related

dysfunction.

To achieve better results peripheral nerve is always avulsed

both from the bone as well as from the soft tissue.

Infraorbital neurectomy

1. Conventional intra oral approach2. Braunstransantral approach

Braunsapproach

Intra oral incision made from the maxillary tuberosity tomiddle maxillary vestibule. Expose anterior and labial maxillary

antral wall, zygoma and infraorbital nerve.

3 i d i d i th t l t l ll f ill


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3cm window is made in the anterolateral wall of maxillary

sinus. Operating microscope is required for remaining procedure.

The lining in the posterosuperior portion of the antrum is

carefully excised and bone is removed to create posterior window.

Careful dissection is now performed to expose the descending

palatine branches of V2, which are than traced superiorly to the

sphenopalatine ganglion.

Trunk of maxillary nerve is sectioned near foramen

rotundum.

Complications

1. Inadvertent section of vessel in pterygopalatine fossa2. Inadvertent sectioning of branches of sphenopalatine ganglion (or

vidian nerve


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Inferior alveolar neurectomy

1. Intra oral aproach

2. Extra oral approachExtra oral approach

Through Risdonsincision, where after reflection of masseter

a bony window is drilled in outer cortex and nerve is lifted with

nerve hook and avulsed from it superior attachment and mentalnerve is avulsed anteriorly.

Intra oral approach

Via Dr. Ginwallasincision, is made along the anterior borderof ascending ramus, extending lingually and buccally and ending in

a fork like an inverted Y.


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Incision is thin deepend on medial aspect of ascending ramus

by means of blunt and sharp dissection.

Two heavy black linen thread are then looped around thenerve using nerve hook and then nerve is divided between 2

threads.

Upper end is cauterized and lower end is held with

haemostat.

Another linear incision is made in the buccal vestibule

overlying mental foramen. After exposing the mental nerve tied

with black linen, just away from foramen and is divided. Distal part

is wound around and the peripheral branches entering the mucosa

are avulsed out.


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After mental nerve is freed, then at the mandibular foramen,

distal part of nerve is pulled until the entire nerve length of the cana

avulsed out.

Cryotherapy

Direct applications of cryotherapy probe at temperature colder th

-60C are known to produce wallerian degeneration without destroy

the nerve sheath.

Exposed nerve is frozen with cryoprobe for a period of 1-2m

followed by 3 minutes thaw to be repeated three times.

P i h l di f l i (Th l ti )


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Peripheral radiofrequency neurolysis (Thermocoagulation)

Gregg and Small in 1986 reported surgical management of

trigeminal pain with radiofrequency. RF neurolysis induce pain

remission in 80% of cases with 20% per year recurrence rate.

Procedure

Topical anaesthetic with mild sedation is used. Patient is

grounded in an electronic circuit and 22 gauge lesion probe is

positioned adjacent to nerve. Lesioning is the carried out at 65-75C

for 1-2 minutes.

Advantage

Low morbidity in high risk elderly patient.

Di d t


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Disadvantage

Need specific electronic armamentarium. In accessibility of

some pain triggering nerve trunk, the technique will fail to achieve

pain relief.

Gasserian ganglion procedure

1910 Harris, Harter introduced percutaneous approach to the

ganglion via foramen ovale.

Three types of percutaneous electrocoagulation procedure is

a. Glycerol injection

b. Thermocoagulation

c. Balloon compression


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Technique for percutaneous approach to gasserian ganglion.

Procedure

Patient is made to lie on a table with neck well extended.Foramen ovale is best visualized in submaentovertex x-rays.

Three points of Hartel

First point is marked at lateral orbital rim and a perpendicular

line in drawn till the inferior border of the mandible.

Second point marked at about 15mm (3 inches) lateral to the

angle of mouth on the perpendicular first line. This is a point of

penetration of needle /electrode.

Third pointis marked at the level of TMJ 2.5cm from the center

of external auditory meatus.


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This line will form a plane, which is the plane of elevation. It

should be perpendicular to the floor.

Pass the needle along the plane of elevation till it reach theanterior border of ramus of mandible then turn needle medial is

ramus pass it upwards to the base of the skull in pupillary plane.

Engagement of the needle is foramen ovale is best confirms

by biplanar radiology or image intensifier.

Glycerol is injected into Meckels cave or ganglion. It

produces damage to nerve cell by dehydration.

Controlled radiofrequency thermocoagulation. Introduced by

Kirschner (1931) and later modified by sweet 1970.

Advantages


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Advantages

1. Avoidance of denervation of cornea

2. It preserve the motor function of trigeminal nerve3. Recurrence rate is low

4. Tolerate by elderly patient.

Procedure

Trigeminal ganglion is approach through foramen ovale

using 22 gauge probe under fluoroscopic guidance.

Stimulation is initiated utilizing square wave pulses at 50

cycle per second. Slowly raising the voltage until full area of pain is

covered.

Lesion Production


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Lesion Production

At this stage neurolept analgesia is given. Thermal lesion of

30-90 seconds duration are then made at 65 to 75C using RF

generator of microwave energies.

Power

25 watts, 40-45 volts, current 120-140mA. Temperature range

of 65-75C. A 5mm bare tip electrode with 2mm diameter willproduce a lesion of 10 x 6mm within trigeminal root at 75C.

An alternating current of high frequency is paired through

the electrode and it produces ionization in biologic tissues.

- Heat is produced due to ionic function which leads to

coagulation of tissues.


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- A facial blush usually appears and helps to localize the nerve roo

undergoing thermal destruction. this is due to the vasodilator

system emerging from brainstem and pausing to the faciavasculature with trigeminal nerve.

Balloon Decompression

- Done under GA

- A mechanical technique

- Destroys the root fibers partially by advancing 4FG Fogarty

Catheter 1 to 2 cm within Meckels cave and inflating the balloon a

the ventral aspect of ganglion root.


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- A 12 gauge spinal needle is paired to foramen ovale and

balloon catheter is paused through it.

- Once in position the balloon is inflated with x-ray contrast

medium upto 0.75ml.

- When inflated the balloon should take the pear shape of

Meckelscave and it should remain inflated for 1 minute.

Intracranial approach


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Intracranial approach

Retro gasserian rhizotomy

The most definitive techniques for controlling severeneuralgia in 1970.

In the operation trigeminal sensory root fibers are section

between the ganglion and point of root entry into pons.

Recurrence rate of pain in approximately 15% of cases.

Disadvantages

Due to profound numbness leads to anesthesia dolorosa aswell as recurrent herpes zoster, corneal ulcerations, and other

trophic tissue changes.

Microvascular nerve root decompression


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Microvascular nerve root decompression

Dandy observed that vascular loops usually arising from the

superior cerebellar arteries were often found to be caught betweensensory root and surface of the brain sterm. Based on these Jannetta

has advocated a posterior fossa approach to decompress the neuro

vascular anomalies by placing alloplastic materials between the

vessels and roots.

Success rate of 85%

Mortality rate is less than 5%

Tractotomy procedure


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y p

The descending tract of trigeminal nerve may be interrupted

by lesion placed 4mm below the obex in the medulla.

A desirable sensory dissociation often results, in which tactile

senses are retained but pain sensitivity in lost.

Pain may recur in 50% within 1 year of operation.

Medullary tractotomy has a significant mortality rate than the

rhizotomy.


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Trigeminal Neuralgia 1