TRIGEMINAL NEURALGIA

JEFF ZACHARIA

BAPUJI DENTAL COLLEGE & HOSPITAL

CONTENTS• INTRODUCTION• ANATOMY• DEFINITION • ETIOLOGY• CLINICAL FEATURES• TYPES OF TRIGEMINAL NUERALGIA• TRIGGER ZONES• DIAGNOSIS• MANAGEMENT• CONCLUSION

INTRODUCTION

• THE TRIGEMINAL NERVE IS A MIXED CRANIAL NERVE RESPONSIBLE FOR SENSORY DATA SUCH AS TACTITION (PRESSURE), THERMOCEPTION (TEMPERATURE), AND NOCICEPTION (PAIN) ORIGINATING FROM THE FACE ABOVE THE JAWLINE; IT IS ALSO RESPONSIBLE FOR THE MOTOR FUNCTION OF THE MUSCLES OF MASTICATION, THE MUSCLES INVOLVED IN CHEWING BUT NOT FACIAL EXPRESSION.

• DISEASE AFFECTING THIS NERVE CAN CAUSE OROFACIAL PAIN OR SENSORY LOSS OR BOTH.

MAJOR CRANIOFACIAL NEURALGIAS INCLUDE:

1. TRIGEMINAL NEURALGIA

2. GLOSSOPHARYNGEAL NEURALGIA

3. OCCIPITAL NEURALGIA

4. GENICULATE NEURALGIA

5. POSTHERPETIC NEURALGIA

ANATOMY OF TRIGEMINAL NERVE

DEFINITION• NEURALGIA MEANS ‘PAIN IN A NERVE.’

• IT IS A DISORDER OF THE TRIGEMINAL NERVE THAT CAUSES EPISODES OF UNILATERAL INTENSE, STABBING ELECTRIC SHOCK LIKE PAIN IN THE AREAS OF THE FACE WHERE THE BRANCHES OF THE NERVE ARE DISTRIBUTED- LIPS, EYES, NOSE, FOREHEAD, UPPER AND LOWER JAW.

• NOT FATAL BUT VERY PAINFUL.

ETIOLOGY• THE CAUSE IS UNCLEAR

• APPROXIMATELY 10% OF THE CASES HAVE DETECTABLE UNDERLYING PATHOLOGY, SUCH AS :

1. COMPRESSION OF NERVE

2. DEMYELINATION

3. MULTIPLE SCLEROSIS

4. ALTERED PAIN MECHANISMS

5. NEURAL CROSSTALK

6. TUMOURS

CLINICAL FEATURES

• INCIDENCE: 4 CASES PER 100,000 POPULATION.

• AGE: MAINLY 50-70 YEAR AGE GROUP.

• SEX: IT IS SLIGHTLY MORE COMMON IN WOMEN.

• ACCORDING TO THE INTERNATIONAL HEADACHE SOCIETY,

PAROXYSMAL ATTACKS OF PAIN WHICH LASTS A FEW SECONDS TO LESS THAN 2

MINUTES; OCCURRING ESPECIALLY IN THE MORNING AND RARELY AT NIGHT.

NO NEUROLOGICAL DEFICIT.

ATTACKS ARE STEREOTYPED IN THE IN THE INDIVIDUAL.

PAIN HAS AT LEAST FOUR OF THE FOLLOWING CHARACTERISTICS:

A DISTRIBUTION ALONG ONE OR MORE DIVISIONS OF THE TRIGEMINAL NERVE.

A SUDDEN, INTENSE, SHARP, SUPERFICIAL, STABBING OR BURNING FEELING.

THE PAIN IS SEVERE.

IT IS PRECIPITATED FROM TRIGGER AREAS OR WHILE PERFORMING DAILY ACTIVITIES LIKE EATING, TALKING, SHAVING, CLEANING, ETC.

THE PATIENT IS USUALLY ENTIRELY ASYMPTOMATIC BETWEEN EPISODES BUT SOME PATIENTS EXPERIENCE A DULL ACHE AT OTHER TIMES.

TYPES OF TRIGEMINAL NEURALGIA

PROPOSED BY ELLER ET AL

• TRIGEMINAL NEURALGIA TYPE 1 (TN1): THE CLASSIC FORM OF TRIGEMINAL NEURALGIA IN WHICH EPISODIC LANCINATING PAIN PREDOMINATES

• TRIGEMINAL NEURALGIA TYPE 2 (TN2): THE ATYPICAL FORM OF TRIGEMINAL NEURALGIA IN WHICH MORE CONSTANT PAINS (ACHING, THROBBING, BURNING) PREDOMINATE

• TRIGEMINAL NEUROPATHIC PAIN (TNP): PAIN THAT RESULTS FROM INCIDENTAL OR ACCIDENTAL INJURY TO THE TRIGEMINAL NERVE OR THE BRAIN PATHWAYS OF THE TRIGEMINAL SYSTEM

• TRIGEMINAL DEAFFERENTATION PAIN (TDP): PAIN THAT RESULTS FROM INTENTIONAL INJURY TO THE SYSTEM IN AN ATTEMPT TO TREAT TRIGEMINAL NEURALGIA (NUMBNESS OF THE FACE IS A CONSTANT PART OF THIS SYNDROME, WHICH HAS ALSO BEEN REFERRED TO AS ANESTHESIA DOLOROSA OR ONE OF ITS VARIANTS.)

• SYMPTOMATIC TRIGEMINAL NEURALGIA (STN): TRIGEMINAL NEURALGIA ASSOCIATED WITH MULTIPLE SCLEROSIS (MS)

• POSTHERPETIC NEURALGIA (PHN): CHRONIC FACIAL PAIN THAT RESULTS FROM AN OUTBREAK OF HERPES ZOSTER (SHINGLES), USUALLY IN THE OPHTHALMIC DIVISION (V1) OF THE TRIGEMINAL NERVE ON THE FACE AND USUALLY IN ELDERLY PATIENTS

• GENICULATE NEURALGIA (GEN): PAIN TYPIFIED AS EPISODIC AND LANCINATING, FELT DEEP IN THE EAR

• GLOSSOPHARYNGEAL NEURALGIA (GPN): PAIN TYPIFIED IN THE TONSILLAR AREA OR THROAT, USUALLY TRIGGERED BY TALKING OR SWALLOWING

TRIGGER ZONES• TRIGGER ZONES OR POINTS CAN BE EITHER EXTRAORAL OR INTRAORAL.1. EXTRAORAL TRIGGER ZONES:a) NASOLABIAL FOLDb) VERMILION BORDER OF LIPc) MIDFACIAL AND PERIORBITAL SKIN.

2. INTRAORAL TRIGGER ZONES: THEY ARE UNCOMMON BUT DO OCCUR SPECIALLY ON THE ALVEOLUS.

DIAGNOSIS• HISTORY • EXAMINATION, INCLUDING NEUROLOGICAL ASSESSMENT, ESPECIALLY THE

CRANIAL NERVES. • INVESTIGATIONS INCLUDING:oMRI AND CT oESR TO EXCLUDE VASCULOTIDES AND SEROLOGY FOR LYME DISEASE OR

RARELY HIV.

MANAGEMENTMEDICAL

• ANTICONVULSANTSa) CARBAMAZEPINE: 200MG TID

b) PHENYTOIN: 300MG QID

c) GABAPENTIN: 1200-3600MG TID

d) OXCARBAZEPINE: 300MG BID

• GABA ANTAGONISTSa) BACLOFEN: 10MG TID

• TRICYCLIC ANTIDEPRESSANTSa) AMYTRYPILINE: 25-75MG QID

• IT PREVENTS ATTACKS OF NEURALGIA IN 60% OF PATIENTS.

• IT IS NOT AN ANALGESIC, IF GIVEN WHEN AN ATTACK OCCURS, IT WILL NOT RELIVE PAIN

• MUST BE GIVEN PROPHYLACTICALLY FOR LONG PERIODS.

• DOSE CAN BE EFFECTED BY BLOOD MONITORING.

• CONTRAINDICATIONS: PREGNANT PATIENTS

HLA-B1502 PATIENTS

ASIAN OR CHINESE PATIENTS

• SURGICAL

PERIPHERAL NERVE BRANCH PROCEDURES.

OPEN PROCEDURES.

•PERIPHERAL NERVE BRANCH PROCEDURES

a)BLOCKING THE PERIPHERAL NERVE BRANCHES.

b)ALCOHOL BLOCK

c) POST GANGLIONIC SECTIONING.

d)CRYOTHERAPY

•OPEN PROCEDURESa) MICROVASCULAR DECOMPRESSION

b) SUBTEMPORAL EXTRADURAL RETROGASSERIAN RHIZOTOMY

c) INTRADURAL RHIZOTOMY

d) MEDULLARY TRACTOTOMY

CONCLUSION• TRIGEMINAL NEURALGIA (TN) IS NEUROPATHIC FACIAL PAIN ARISING FROM THE

TRIGEMINAL NERVE.

• TREATMENT FOR TN: MEDICATION IS THE INITIAL THERAPY AND IF PHARMACOLOGIC TREATMENT FAILS THEN SURGICAL PROCEDURES ARE UNDERTAKEN.

REFERENCES• ORAL AND MAXILLOFACIAL MEDICINE - 5TH EDITION, CRISPIAN SCULLY• TEXTBOOK OF ORAL & MAXILLOFACIAL SURGERY- 2ND EDITION, CHITRA

CHAKRAVARTHY• HTTP://GOO.GL/PMC75V• HTTP://WWW.IHS-HEADACHE.ORG/• HTTPS://GOO.GL/GOKIXV