Trigeminal neuralgia/TN/ NEURALGIA

The International Association for the Study of Pain (IASP)1 defines trigeminal neuralgia (TN) as a sudden, usually unilateral, severe brief stabbing recurrent pain in one or more branches of the fifth cranial nerve

synonyms
Idiopathic trigeminal neuralgia / Tic Doulourex.
Trifacial Neuralgia.
Fothergell’s disease.
In 1677 John Locke, a American physician and philosopher, accurately identified the major clinical features of TN

In 1756 the French physician Nicolaus Andre coined the term “Tic douloureux” to the condition.

The English physician John Fothergill in 1773 published detailed description of TN, since then, it has been referred to as ‘Fothergill’s disease’.
Peripheral injections
Long acting LA
Alcohol
Glycerol
Peripheral neurectomy/ nerve avulsion
Cryotherapy
Gasserian ganglion procedures
Percutaneous stereotactic radiofrequency thermal lesioning of the trigeminal ganglion and/or root (rfl)
percutaneous glycerol gangliolysis of the trigeminal ganglion
percutaneous balloon microcompression of the trigeminal ganglion
Intracranial procedures
MVD
Partial sensory rhizotomy
Gamma knife radiation to the trigeminal root entry zone GKR

1. Good morning

2. Trigeminal Neuralgia Presented by: Dr. Kamini Dadsena

3. Outline: Introduction History Aetiology Clinical feature Diagnosis Management Summary References

4. Introduction The International Association for the Study of Pain (IASP)1 defines trigeminal neuralgia (TN) as a sudden, usually unilateral, severe brief stabbing recurrent pain in one or more branches of the fifth cranial nerve synonyms Idiopathic trigeminal neuralgia / Tic Doulourex . Trifacial Neuralgia. Fothergell’s disease.

5. History In 1677 John Locke , a American physician and philosopher, accurately identified the major clinical features of TN In 1756 the French physician Nicolaus Andre coined the term “ Tic douloureux ” to the condition. The English physician John Fothergill in 1773 published detailed description of TN, since then, it has been referred to as ‘ Fothergill’s disease’.

6. Etiology and Pathogenesis Condition known for centuries, but pathogenesis has remained ENIGMA Vascular factors transient ischemia, autoimmune hypersensitivity Mechanical factors : pressure from aneurysms of ICA → erode intra cranial fossa → pulsatile irritation of trigeminal ganglion → demyelenation → pain

7. Etiology Anomaly of superior cerebellar artery : lies in contact with sensory root of trigeminal ganglion → anomaly → demyelenation Dental etiology : Westrum and Black , 1976 differentiation from loss of teeth & degeneration of nerve → proceeds proximally to involve nucleus Infections : various granulomatous & nongranulomatous infections invoving 5 th nr

8. Etiology Ratner’s jaw bone cavities (1979 ): Cavities in the alveolar and jaw bones are the causative factor . Multiple sclerosis : Olfson (1966), sclerotic plaque located at root entry zone of TNr Petrous ridge compression : Lee (1937), compression of nerve at dural foramen Post traumatic neuralgia : traumatic neuromas following injury

9. ‘Ignition Hypothesis’ proposed by Devor et al In this model , a trigeminal injury induces physiologic changes that result in a population of hyper excitable and functionally linked primary sensory neurons . The discharge of any individual neuron in this group can quickly spread to activate the entire population. Such a sudden synchronous discharge could underlie the sudden jolt of pain characteristic of a TN pain attack.

10. Etiology Intracranial tumours : epidermoid tumors, meningiomas of cerebellopontine angle & meckel’s cave, arteriovenous malformations, aneurysms, vascular compressions & trigeminal neuromas may impinge on the nerve Intracranial vascular abnormality: Viral etiology : post herpetic neuralgia is seen in elderly patients. Viral lesions of the ganglion can be etiologic factor

11. General characteristics Incidence: 4:1,00,000 Occurs at middle age or later (5 th or 6 th decade) Female predisposition (58%) Predilection for RT side V3 > V2 > V1

12. Clinical features Sudden, unilateral, intermittent paroxysmal, sharp, shooting, stabbing, lancinating, recurring pain, elicited by slight touching superficial “trigger points”. Pain radiates from that point, across the distribution of one more branches Pain usually confined to 1 branch

13. Clinical features Rarely crosses the mid line Pain is of short duration, lasts for few seconds " tic douloureux " because of a characteristic muscle spasm that accompanies the pain.

14. Clinical features Male patients avoid shaving, poor oral hygiene Occasionally a cold breeze blowing on the face can be enough to initiate an attack. Paroxysms occur in cycles, each cycle lasting for weeks or months No attacks during sleep Patients lead poor quality of life due to pain

15. Clinical features The condition can lead to Irritability Severe anticipatory anxiety and Depression Life-threatening malnutrition. Suicidal depression is not uncommon

16. Trigger zones

17. Diagnosis White and Sweet - ‘‘Sweet criteria’’ 1. The pain is paroxysmal. 2. The pain may be provoked by light touch to the face (trigger zones). 3. The pain is confined to the trigeminal distribution. 4. The pain is unilateral. 5. The clinical sensory examination is normal.

18. International Classification of Headache Disorders II (ICHD-II) subdivides TN into 1. Classic TN and 2. Symptomatic TN.

19. Classical trigeminal neuralgia : A . Paroxysmal attacks of pain lasting from a fraction of a second to 2 minutes, affecting one or more divisions of the trigeminal nerve and fulfilling criteria B and C: B. Pain has at least one of the following characteristics: 1. intense, sharp, superficial or stabbing 2. Precipitated from trigger areas or by trigger factors C. Attacks are stereotyped in the individual patient. D. There is no clinically evident neurological deficit. E. Not attributed to another disorder.

20. Symptomatic trigeminal neuralgia: A . Paroxysmal attacks of pain lasting from a fraction of a second to 2 minutes, with or without persistence of aching between paroxysms , affecting one or more divisions of the trigeminal nerve and fulfilling criteria B and C B. Pain has at least one of the following characteristics: 1. Intense, sharp, superficial or stabbing 2. Precipitated from trigger areas or by trigger factors C. Attacks are stereotyped in the individual patient D. A causative lesion, other than vascular compression , has been demonstrated by special investigations and/or posterior fossa exploration.

21. Steps in Diagnosis History Diagnostic nerve block Material Required • 3–1 cc syringes • 3–25 gauge needles • Sterile normal saline • Two percent lignocaine without adr • Several alcohol wipes

22. Steps in Diagnosis History Diagnostic nerve block Carbamazepine MRI Material Required • 3–1 cc syringes • 3–25 gauge needles • Sterile normal saline • Two percent lignocaine without adr • Several alcohol wipes

23. Treatment Medicinal surgical

24. Mathews and Scrivani

25. Medicinal carbamazepine phenytoin oxycarbazepine Gabapentin Topiramate Oxcarbazepine Tiagabine Levetiracetam zonisamide

26. Medicinal Phenytoin was first introduced in 1942, and in 1962 carbamazepine became the most commonly used drug. Baclophen may add to the effectiveness of these drugs. Recently - Neurontin has been widely used because of reduced side effects, although is more expensive .

27. Blom (1962), showed a response to anticonvulsants

28. Carbamazepine ( Tegretol ) Dose- initial- 100mg bid Maintainance - 1200 -2400mg Drug dosage should be taken at night, so that adequate serum concentration can be present in early morning , when pain most occurs. Side effects: Visual blurring, dizziness, somnolence, skin rashes and ataxia and in rare cases hepatic dysfunction , leukopenia , thrombocytopenia—aplastic anemia (It is known to suppress the bone marrow. Patients should be monitored to avoid agranulocytosis). Whenever the side effects appear, a reduction of 200 mg of drug will often eliminate them. Once the pain remission has been achieved , the drug dose should be kept at maintenance level or withdrawn and restarted if symptoms appear.

29. Oxcarbazepine Dose- initial-300mg Maintainance-1200 mg/day. Side effects: Hypona tremia , double vision.

30. Clonazepam Dose- initial- 0.5mg maintainance - 4 mg max 20mg Side effects: Drowsiness, fatigue, lethargy.

31. Phenytoin Dose—100 mg three times a day. Side effects: nystagmus , ataxia, dysarthria, ophthalmoplegia (paralysis of eye movements) as well as drowsiness and mental confusion. Gingival hyperplasia (enlargement of the gums in the mouth) and hypertrichosis (excessive hair growth).

32. Valproic acid Dose—600 mg/day. Side effects: irritability, tremors, confusion, hepatoxicity , weight gain.

33. Mephenesin Carbamate ( Tolceram ) Dose-5 to 15 ml / 5 times a day to every 3 hours.

34. Baclofen ( Lioresal ) Dose - initial-5mg tds Maintainence - 80 mg max One tenth of sufferers cannot tolerate baclophen . Should not be discontinued abruptly after prolonged use because hallucinations or seizures may occur. Side effects: drowsiness, dizziness, nausea and leg weakness.

35. Gabapentin An anti-epileptic drug that is structurally related to the neurotransmitter GABA. This drug is almost as effective as carbamazepine but involves fewer side effects.  The starting dose is usually 300mg three times a day and this is increased to a maximal dose.

36. TRILEPTAL: Is a form of Tegretol - more widely prescribed for a variety of conditions. It has recently been found to be effective for some patients with trigeminal neuralgia. Dose usually begins at 300 mg twice a day and is gradually increased to achieve pain control. The maximum dose is 2400-3000 mg per day. Common side effects are nausea, vomiting, dizziness, fatigue and tremors.

37. Multiple drug therapy AED therapy routinely begins with a single agent, given in gradually increasing doses until pain attacks are either suppressed or satisfactorily reduced. When a patient only partially responds to single drug therapy at dosages that evoke side effects, adding a second AED may enhance the therapeutic response . Because AEDs have differing mechanisms of action as well as differing side effect patterns, combining agents is a reasonable approach.

38. Treatment of Acute Exacerbations Peripheral local anesthetic block Intravenous lidocaine . Intravenous AED Role of Analgesic medication Ineffective in TN

39. Surgical managements Peripheral injections Long acting LA Alcohol Glycerol Peripheral neurectomy / nerve avulsion Cryotherapy

40. Surgical managements Gasserian ganglion procedures Percutaneous stereotactic radiofrequency thermal lesioning of the trigeminal ganglion and/or root ( rfl ) percutaneous glycerol gangliolysis of the trigeminal ganglion percutaneous balloon microcompression of the trigeminal ganglion Intracranial procedures MVD Partial sensory rhizotomy Gamma knife radiation to the trigeminal root entry zone GKR

41. Other procedure TENS Deep brain stimulation Biofeedback Hypnosis/ Autosuggestion Psychiatric counselling

42. PERIPHERAL INJECTIONS Produces anesthesia in the trigger zones Care should be taken to avoid IV injections Very effective in relieving pain

43. Long acting anesthetic agents Emergency pain relieving technique Injected proximally to nerve site Pain free period will be very short

44. Alcohol injections 95% alchohol injectionproduces anesthesia of the region May cause local tissue toxicity inflammation and fibrosis. It may also cause alcohol neuritis. Pain relief for 6-12 months may be seen.

45. Peripheral neurectomy Carried out under GA Most effective pain peripheral nerve destructive technique. Pain may return after amputed nerve stump regenerates . Done in patients where craniotomy contraindicated due to age , systemic diseases.

46. Infra orbital neurectomy 1) conventional 2)brauns trans antral

47. Intra oral approach U – shaped caldwell luc incision is made Infra-orbital foramen located. The nerve is located and avulsed from the skin surface. The foramen may be plugged with poly ethylene plug.

48. Brauns trans-antral approach An intra oral incision is made from the maxillary tubarosity to the midline of vestibule. Mucoperiosteal flap is reflected to anterior and lateral maxillary wall. A 3 cm window is created, the lining of the posterior superior portion of the antrum is carefully exised ..

49. Complications ( i ) inadvertent section of the vessels in the pterygopalatine fossa ( ii) inadvertent sectioning of the branches of the sphenopalatine ganglion entering the posterior aspect of the ganglion.

50. THANK YOU

51. Inferior alveolar neurectomy 1) extra oral approach 2) intra oral approach ( Ginwllas incision )

52. Extra-oral approach Risdons incision,where after reflection of masseter , a bony window is created in Outer cortex and nerve is reflected with nerve hook and is avulsed from its superior attatchment . mental nerve is avulsed anteriorly through the same approach

53. Intra-oral apprroach Dr GINWALLAS incision .: incision is made along anterior border of ascending ramus, extending lingualy and buccaly in a fork like an inverted “Y”. The incision is deepend on the medial aspect of ascending ramus . Temporal and medial pterygoid muscles are split and INFERIOR ALVEOLAR NERVE IS LOCATED.

54. Lingual neurectomy A vertical incision is made at the inner border of the ascending ramus, extending from the coronoid process down the level of the floor of the mouth. nerve lies even more superficially and it can be easily found between the anterior pillar of the fauces at the root of the tongue . After dissection, the nerve is grasped with a hemostat and is then either avulsed or cauterized and cut.

55. Cryotherapy temperature colder than -60° centigrade. Produce wallerian degeneration. Nitrous oxide cryo probe is used .

56. THERMOCOAGULATION PERIPHERAL RADIOFREQUENCY NEUROLYSIS GREGG AND SMALL in 1986 65° centigrade for 1-2 min. 20% recurrence rate is there. Used in elderly patients

57. Gasserian ganglion procedures Glycerol injection Controlled radio frequency thermocoagulation Balloon compression

58. 1900, first open surgeries done on gasserian ganglion for trigeminal neuralgia. 1910, harris , hartel introduced approaches to ganglion via foramen ovale. 1931, kirschner introduced percutaneous electrocoagulation of gasserian ganglion.

59. Radio frequency thermocoagulation Percutaneous radiofrequency thermal lesioning of the trigeminal nerve was repopularized by Sweet and Wepsic in 1974 It preserves motor function of trigeminal nerve. Lower recurrence rate well tolerated by elderly and medically compromised patients.

60. Principle- This technique is based on the findings that the compound action potentials of nociceptive fibers ( A-d and C fibers ) in nerves are blocked at lower temperatures than those of larger A-a and A-b fibers carrying tactile sensations.

61. A ALTERNATING CURRENT OF HIGH FREQUENCY CAUSES IONISATION OF BIOLOGICAL TISSUES . WHICH FURTHER LEADS TO COAGULATION OF TISSUES.

62. Percutaneous glycerol chemoneurolysis Percutaneous chemoneurolysis with glycerol was introduced in 1981 by Hakanson . Glycerol , a mild neurolytic , provides excellent pain relief while largely sparing trigeminal nerve function in most patients . pure anhydrous (99.5%) glycerol is instilled into the trigeminal cistern .

63. Balloon compression Percutaneous balloon compression of the gasserian ganglion with a balloon catheter was introduced by Mullan and Lichtor in 1983 a technique to traumatize the trigeminal ganglion and preganglionic rootlets mechanically using a percutaneously inserted balloon-tipped catheter . It is then inflated using a radiopaque contrast agent to a predetermined pressure to compress the neural structures . 1.3 – 1.5 atm pressure.

64. OPEN PROCEDURS MICROVASCULAR DECOMPRESSION OF THE SENSORY ROOT Popularized by jannetta in 1967 Open craniotomy approach is used to gain access to the trigeminal root entry zone and adjacent brain stem. Most commonly performed intra cranial procedure done to decompress superior ceribellar artery has mortality rate of 2%

65. TRIGEMINAL ROOT SECTION Extradural sensory root section( fraziers approach1901) Intra dural root section – discribed by wilkins in1966 less chances of damage to sup petrosal n. and facial n. Can cause damage to 5,7,8 cranial nerves.

66. Trigeminal tract totomy or medullary tract totomy – done at the cervico medullary junction Very useful in patients with glossopharyngeal and pharyngeal pain distribution Causes loss of pain and temperature sensation in ipsilateral face and pharynx.

67. Gamma knife radiation to the trigeminal root entry zone GKR Relatively recent procedure, that employs computerized stereotactic methods to concentrate gamma radiation on the trigeminal root entry zone. It has gained wide acceptance, however long term results of GKR in TN remain to be established . Advocated in old, frail patients.

68. Summary An early and accurate diagnosis of TN is important. Patients with TN are usually initially treated pharmacologically. The best treatment for the patient depends on the age of the patient, medical comorbidities, and the risks the patient is willing to assume.

69. Summary Surgical approaches MVD PSR

70. Summary Three percutaneous ablative procedures GKS Partial sectioning of the trigeminal nerve

71. Summary Peripheral procedures stereotactic radiosurgery

72. References Toda K. Operative treatment of trigeminal neuralgia: review of current techniques. Oral Pathol Oral Radiol Endod 2008;106:788-805. Scrivani SJ, Mathews SE, Maciewicz RJ. Trigeminal neuralgia. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:527-38. Liu JK, Apfelbaum RI. Treatment of trigeminal neuralgia. Neurosurg Clin N Am 2004;15: 319–334 Textbook of oral and maxillofacial surgery by Neelima malik .

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