25 introduction and types of neuralgias

NEURALGIAS

Dr V.RAMKUMARCONSULTANT DENTAL&FACIOMAXILLARY SURGEONREG NO: 4118-TAMILNADU-INDIA(ASIA)

CLASSIFICATION OF OROFACIAL PAIN

Typical facial pain: dental, ocular, TMJ Primary neuralgias

Trigeminal neuralgia Glosso pharyngeal Geniculate Post-herpetic neuralgia

Secondary neuralgias Atypical neuralgia : Pain of vascular origin

PRIMARY NEURALGIAS

The most common paroxysmal neuralgia arises in the trigeminal nerve. Occasionally, it affects the glossopharyngeal and superior laryngeal branch of vagus nerve.

The aetiology of this pain is unclear. It may be due to viral aetiology within the

ganglion, demyelination of intracranial nerve roots due to compression by small vascular loops, by dural bands or by narrowing of foramina.

Secondary neuralgias

They arise from irritation of the trigeminal ganglion or nerves by some identifiable lesion and may either mimic exactly the primary paroxysmal pain, or present as a less specific disturbance.

Important differentiating features are the associated local sensory or motor impairment which may or may not be present when the patient first presents.

The lesion can be either extracranially or intracranially.

Secondary neuralgias :Extra cranial lesions:

1. Causalgia2. Fray’s syndroma3. Herpes zoster4. Post-herpetic neuralgia5. Nasopharyngeal carcinoma (Trotter’s

syndrome)6. Cranial base lesions

Secondary neuralgias: Intracranial lesions

1. Tumours of posterior cranial fossa

(ex: Schwannoma)

2. Tumors of middle cranial fossa

(Ex: pituitary tumors & aneurysms of

the internal carotid aretry)

3. Multiple sclerosis

TRIGEMINAL NEURALGIA

It is defined as sudden, usually unilateral, severe, brief, stabbing, lancinating, recurring pain in the distribution of one or more branches of fifth cranial nerve.

Introduction

‘Tic Doloureux’ (powerful jerking) coined by Nicholaus Andre.

Also called as Fothergill’s disease.

Etiology

Vascular factorsMechanical factorsAnomaly of superior cerebellar arteryDental etiologyInfections Multiple sclerosis

Etiology –cont….

Post-traumatic neuralgiasIntra-cranial tumorsBasilar compressionsIntra-cranial vascular abnormalitiesViral etiology

General characteristics

Incidence – 4 in 100,000 persons.Age of occurrence: late middle age or

later in life (5th to 6th decade).Sex predilection: female (58%)Affliction of sides: Right side (60%)Division of trigeminal nerve involvement:

V3 is more common than V2. V1 is rarely involved (5%)

Clinical features

It typically manifests as a sudden, unilateral, intermittent paroxysmal, sharp, shooting, lancinating, shock like pain, elicited by slight touching superficial “trigger points” which radiate from that point , across the distribution of the one or more branches of the trigeminal nerve.

CONT…

Pain is usually confined to one part of the one division of TN- mandibular or maxillary, but occasionally spreads to an adjacent division or rarely involve all the three divisions.

Pain is of short duration and lasts for a few seconds, but may recur with variable frequency though there is a refractory period (complete lack of pain) between the attacks, some patients report of dull ache in between the attacks.

Clinical features

Trigger points are stimulated either by touching or chewing, smiling or speaking, brushing or shaving or even washing the face.

Presence of an intraoral or extraoral trigger points provocable by external stimuli is seen in TN.

Location of trigger points depends on the division of the 5th cranial nerve In V1 – supraorbital ridge of the affected side in V2 –skin of the upper lip, ala nasi or cheek

or on the upper gums In V3 - lower lip, teeth or gums of the lower

jaws .

Cont…

Paroxysmal Excruciating pain – stabbing, severe, burning or shocking lasting for several seconds.

Pain is associated with lacrimation, flushing and salivation

Trigger zones (V3)– most common site- mental foramen and maxillary canine region.

Cont….

Effected region is usually hyperkeratinised due to vigorous rubbing

Rarely crosses the midline. Does not occur during sleep Paroxysms occur in cycles, each cycles lasting

for weeks or months. Pain seems to become more intense and unbearable with each attack.

In extreme cases, the patient will have a motionless face – frozen or mask like face.

Diagnosis

History (classic clinical pattern) MRI scanning & CT. Response to carbamazepine is universally

accepted by many clinicians as a step in definitive diagnosis of the codition.

Diagnostic injections of a local anesthetic agent into the patients trigger zone should temporarily eliminate all the pain.

Protocol for diagnostic nerve blocks

Materials required

1cc syringe, 25 gauze needle, normal saline, LA without adrenaline.

Always begin injections at the site of pain and then move proximally.

Inject 0.5 ml of normal saline at test site. wait for 5 min, if pain is relieved then psychogenic pain is likely.

Cont….

If pain persists, the inject 0.5 ml of 2 % lignocaine without adrenaline at surface site and wait for 5 min, if pain is relieved then direct therapy at small nociceptor fibres.

If pain persists, inject little deeper and wait for 5 min, if pain is relieved then consider musculoskeletal origin of pain.

If pain is not relieved, inject more proximal portion of nerve, if pain is relieved, direct therapy at site.

Glossopharyngeal Neuralgia

Similar to trigeminal neuralgia RarePain related to sensory areas supplied

by pharyngeal and auricular branch of vagus ( vagoglossopharyngeal neuralgia)

Cause unknown

Clinical features :

Age : 15 – 85 (average 50)No sex predilectionParoxysmal pain in ear , infra auricular area,

tonsil , posterior mandible, lateral wall of pharynx.

Difficulty in locating the painEpisodic pain – unilateral , sharp,

lancinating, extremely intense.

Cont….

Abrupt onsetShort duration (30-60 secs) that repeats

for every 5 – 30 mins.Talking , chewing , swelling, yawning,will

produce painDefinite trigger zone easily identified.

Treatment

Unpredictable remissions and recurrence80% of the patient has immediate pain relief

after the application of topical LA.Drugs like carbemezipine, oxcarbazepine,

baclofen, phenytoin Ressection of glossopharyngeal nerve

Sphenopalatine neuralgia

Otherwise called as Cluster Head achePain affliction to middle face and upper

face.Occurs as temporal groups or clustersCause – vascular (vasodiation) has been

suggested related to abnormal hypothalamic function, head trauma, abnormal release of histamine.

Cont…

Head ache is initiated by alcohol , cocaine and nitroglycerine .

80% of the patients are cigarette smokers.

Clinical featuresoccurs at any age.Sex predilection Male> Female

Cont…..

Pain is unilateral and follows the distribution of ophthalmic division of trigeminal nerve.

Pain felt behind the orbit , radiating to temporal and upper cheek region.

Simulates tooth ache.Pain is abrupt in onset , burning and

lancinating without trigger zones.

Cont…..

Pain lasts for 15 mins to 3 hrs. Eight times daily or alternate days. And lasts for week.

Pain often begins at same time at given 24 hr (alarm clock headache).

Treatment

Prednisone, ergotamine, lithium carbonate, Indomethacin, verapamil.

Sumatriptan New surgical tecniques have been

proposed.

(Gamma Knife Radiosurgery)

Thank you