Pain in the Face and the Cranium, anatomical Landmarks, pain mechanisms

1. Diagnosis and
Management of
Craniofacial Pain
TARIQ FARIDI M. Ed, Ph D (c)
Director, PATIENT EDUCATION
COMPLETE BRAIN CARE INSTITUTE

2. Key Points
 All facial pain IS NOT trigeminal neuralgia
 There are no tests for trigeminal neuralgia or for that
matter most causes of facial pain
 The wrong diagnosis can lead to the wrong treatment
 Despite all the advancements in medicine, it is not
possible to cure all pain problems

3.  Approach to the patient with craniofacial pain
 Specific pain syndromes
 Pharmacological Management
 Surgical Treatments

4. Approach to the Patient with
Craniofacial Pain
 Single most important aspect is to ESTABLISH THE CORRECT DIAGNOSIS
 Careful detailed pain history
 Location
 Duration
 Temporal characteristics
 Quality
 Severity
 Circumstances of onset
 Influencing factors
 Neurological symptoms
 Response to medications
 The more paroxysmal the pain, the more likely that surgery may be
beneficial

5. Neuropathic Craniofacial Pain
Syndromes
 Trigeminal neuralgia
 Trigeminal neuropathic
 Postherpetic trigeminal pain
 Glossopharyngeal neuralgia
 Geniculate neuralgia
 Occipital neuralgia
 Sphenopalatine neuralgia
 Vidian neuralgia
 Superior laryngeal neuralgia
 Carotidynia

6. Headache Syndromes
 Classic migraine
 Common migraine
 Migraine variants
 Chronic daily headache
 Cluster headache
 Muscle tension headache
 Post-traumatic headache
 Chronic paroxysmal hemicrania
 Headache caused by other disorders
 Eg. Brain tumor, hydrocephalus, etc.

7. Ocular and Periocular Disorders
 Tolosa-Hunt Syndrome
 Raeder’s paratrigeminal syndrome
 Orbital apex syndrome
 Cavernous sinus syndrome
 Parasellar syndrome
 Corneal pathology
 Angle closure glaucoma
 Optic neuritis
 Orbital cellulits

8. Otologic Problems
 Otitis externa and interna
 Ramsey-Hunt Syndrome
 Bullous myringitis
 Tumors
 Mastoiditis

9. Dental and Periodontal
Pathology
 Periodontal abscess
 Bruxism
 Burning mouth syndrome
 Temporomandibular joint disorders

10. What’s The Point?
SUCCESSFUL
TREATMENT DEPENDS
ON MAKING THE
CORRECT DIAGNOSIS

11. Classification of Facial Pain
 Trigeminal neuralgia, type 1, (TN1): facial pain of spontaneous onset with greater than 50% limited to
the duration of an episode of pain (temporary pain).
 Trigeminal neuralgia, type 2, (TN2): facial pain of spontaneous onset with greater than 50% as a
constant pain.
 Trigeminal neuropathic pain, (TNP): facial pain resulting from unintentional injury to the trigeminal
system from facial trauma, oral surgery, ear, nose and throat (ENT) surgery, root injury from posterior
fossa or skull base surgery, stroke, etc.
 Trigeminal deafferentation pain, (TDP): facial pain in a region of trigeminal numbness resulting from
intentional injury to the trigeminal system from neurectomy, gangliolysis, rhizotomy, nucleotomy,
tractotomy, or other denervating procedures.
 Symptomatic trigeminal neuralgia, (STN): pain resulting from multiple sclerosis.
 Postherpetic neuralgia, (PHN): pain resulting from trigeminal Herpes zoster outbreak.
 Atypical facial pain, (AFP): pain predominantly having a psychological rather than a physiological origin

12. Pharmacological Therapy
 Anti-epileptics drugs (AEDs)
 Antidepressant medications
 Opiates
 Neuroleptics
 Antispasmodics
 Miscellaneous drugs
 Botox

13. General Principles of Pharmacological
Management
 Rule out surgical lesions (tumor, etc.)
 Neuropathic vs. nociceptive?
 Develop a strategy
 Lay out a plan
 Conservative initial dosing to avoid side effects
 Monotherapy is preferable if possible
 Escalate dose to effect or toxicity
 If second drug needed, choose agent in different class
 Na+ channel blcoker, GABA agonist, etc.

14. Antiepileptic Agents
 Tegretol (carbamazepine)
 Trileptal (oxcarbazepine)
 Neurontin (gabpentin)
 Lyrica (pregabalin)
 Dilantin (phenytoin)
 Depakote (valproic acid)
 Topamax (topirimate)
 Lamictal (lamotrigene)
 Keppra (levateracitam)
 Gabatril
 Benzodiazepines

15. Antiepileptic Drugs (AEDS)
 Similarities in pathophysiology of neuropathic pain and
epilepsy
 All AEDS ultimately act on ion channels
 Efficacy of AEDS most clearly established for neuropathic
conditions characterized by episodic lancinating pain
 Most clinical studies have focused on DPN and PHN
 Use of AEDS in patients with FBSS is nearly entirely empiric

16. AEDS Studied in Neuropathic Pain

17. Mechanisms of Selected AEDS
 Carbamazepine (Tegretol)
 Modulates voltage-gated Na+ channels
 Reduces spontaneous activity in experimental neuromas
 Inhibits NE uptake; promotes endogenous descending inhibitory mechanisms
 Oxcarbazepine (Trileptal)
 Modulates Na+ and Ca+2 channels, incease K+ conductance
 Lacks toxicity of epoxide metabolites
 Lamotrigine
 Blocks voltage-gated Na+ channels
 Inhibits glutamate release from pre-synaptic neurons
 Gabapentin (Neurontin)
 Structural analog of GABA
 Binds to voltage-dependent calcium channels
 Inhibits EAA release; Interacts with NMDA receptor at glycine site
 Pregabalin (Lyrica)
 Binds to voltage-gated calcium channels

18. Adverse Effects of AEDs
 Allergic reaction
Up to 7% with CBZ
Some cross-reactivity between CBZ and
PHT
 Cognitive changes
 Sedation
 Nystagmus, ataxia, diplopia, dizziness
 Nausea, vomiting, headache

19. Adverse Effects of 2nd Generation
AEDS

20. Antidepressant Analgesics
“The results suggest to us that
antidepressants may have an analgesic
action which is independent of their mood-
altering effects”
Merskey & Hester 1972

21. Descending Pain Modulation
 Endorphin link from PAG to pontine
raphe nuclei
 Serotonergic conection to spinal
dorsal horn
 Noradrenergic pathway from locus
ceruleus to dorsal horn

22. Antidepressant Analgesics
Current Evidence
 Relieves all components of neuropathic pain
 RCT - clear separation of analgesic and
antidepressant effects
 Although other agents (eg anti-epileptics)) may be
regarded as 1st line therapy over antidepressants,
there is no good evidence for this practice
 More selective agents are either less effective or not
useful (serotonergic, noradrenergic)
 Because of incomplete efficacy, combination therapy
may be needed
 Comparative data regarding other drugs using NNT
figures now exists

23. Antidepressants in Neuropathic Pain-RCT
 Watson et al.: reviewed 29 randomized
clinical trials
 16 involved PHN or PDN
 Mixed SN agents – 18/21 + effects
 Amitriptyline 10/13, Imipramine
5/5,Doxepin 1/1, Venlafexline 2/2
 NA – 10/12 + effects
 Nortriptyline 3/4, desipramine 4/5,
maprotiline 2/2, bupropion 1/1
 Serotonergic agents – 4/5 + effects
 Paroxetine 1/2, clomipramine 2/2,
citalopram 1/1
86 83
80
0
20
40
60
80
100
Mixed NS NA Ser

24. Adverse Effect of Antidepressants
 Anti-cholinergic autonomic effects (TCAs)
 Allergic and hypresensitivity reactions
 Cardiovascular effects
 Orthostatic hypotension (avoid imipramine in
elderly)
 Quinidine-like cardiac effects
 CNS effects
 Sedation, tremor, seizures, atropine-like delerium,
exacerbation of schizophrenia/mania
 Acute overdose may be fatal (>2000mg)
 Withdrawal reactions

25. Guidelines for Use of Antidepressants
in Pain Management
 Eliminate all other ineffective analgesics
 Start low and titrate slowly to effect or toxicity
 Nortriptyline or amitriptyline for initial treatment
 Move to agents with more noradrenergic effects
 Consider trazadone in patients with poor sleep pattern
 Try more selective agents if mixed agents ineffective
 Do NOT prescribe monoamine oxidase inhibitors
 Tolerance to anti-muscarinic side effects usually takes
weeks to develop
 Withdraw therapy gradually to avoid withdrawal
syndrome

26. Opioids for Chronic Non-Malignant
Pain
 Well-established and accepted for acute/cancer pain
 Extrapolation of outcomes to non-malignant pain
flawed
 Information is more anecdotal, contradictory,
philosophical, and/or emotional than scientific
 Limited number of well-designed RCT with
inconclusive results
 Reduction in pain scores of around 20% without major
benefits on function or psychological outcomes

27. Principles of Opioid Therapy in
Chronic Non-Malignant Pain
 Opioids provide analgesic benefit for a selected
subpopulation of patients
 Less evidence exists regarding improvement in
function
 Benefits outweigh risks in well-selected patients
 Most benefit in patients with pain from established
nociceptive/neuropathic conditions
 Identification of other appropriate patients is
problematic, and valid diagnostic criteria do not
exist

28. Implementation of Opioid Therapy
Prerequisites
 Failure of pain management alternatives; but not a last resort
 Opioids should only be use as part of a multimodality approach
 Identification of realistic goals of treatment
 Physical and psychosocial assessment by multidisciplinary team
 Consider history of substance abuse as a relative contraindication
 Decision to prescribe by multidisciplinary team or at least two practitioners
 Informed written consent
 Best practice – prescribe a trial of opioids and withdraw use if the provision of
analgesia does not result in functional improvement

29. Implementation of Opioid Therapy
Therapeutic Trial Period
 Appropriate oral or transdermal drug selection
 Defined trial period with regular assessment and review
 Opioid dose adjustment or rotation as needed
 Decision for long-term treatment predicated upon
demonstration of pain relief and/or functional
improvement

30. Implementation of Opioid Therapy
Long-Term Therapy
 Opioid contract
 Single defined prescriber
 Regular assessment and review
 Routine urine and serum drug screen
 Ongoing effort to improve physical, psychological,
and social function as a result of pain relief
 Continued multidisciplinary approach to pain
 Defined responses to psychosocial or behavioral
problems (addiction, diversion, etc)

31. Opioid Therapy - RCT
Pain Type Study Control Results
Nociceptive Arner & Meyerson, 1988 Placebo Pos
Kjaersgaard-Anderson, 1990 Paracetamol Pos***
Neuropathic Arner & Meyerson, 1988 Placebo Neg
Dellemijn & Vanneste, 1997 Placebo/Valium Pos
Kupers, et al., 1991 Placebo Pos
Rowbotham et al., 1991 Placebo Pos
Idiopathic Arner & Meyerson, 1988 Placebo Neg
Kupers, et al., 1991 Placebo Neg
Moulin et al., 1996 Benztropine Pos***
Unspecified Arkinstall et al., 1995 Placebo Pos***
Mays et al., 1987 Placebo/Bupiv Pos

32. Opioid Therapy – Prospective
Uncontrolled Studies
Pain Type Reference Results
Nociceptive McQuay et al., 1992 Pos
Neuropathic Fenollosa et al., 1992 Pos
McQuay et al., 1992 Mixed
Urban et al., 1986 Pos
Idiopathic McQuay et al., 1992 Neg
Mixed/Unspecified Auld et al. 1985 Pos
Gilmann & Lichtigfeld, 1981 Pos
Penn and Paice, 1987 Pos
Plummer et al., 1991 Mixed

33. Adverse Effects of Opioids
Common Occasional Rare
Nausea/vomiting Hallucinations Respiratory dep.
Constipation Myoclonus Seizures
Urinary retention Mood changes Delerium
Sedation Anxiety Hyperalgesia
Cognitive impairment Rigidity Allodynia
Pruritis Dry mouth
Gastric stasis
Bronchoconstriction
Tolerance, Physical Dependence, Addiction

34. Miscellaneous Agents
 Antiarrhythmics - Mexilitene
 Na+ channel blockade
 Reduce neuronal hyperexcitability
 Possible predictive effect of IV lidocaine challenge
 May worsen AV conduction block
 Monitor EKG, LFT, renal fxn
 Significant incidence of treatment-limiting side effects
 Baclofen
 GABAB receptor antagonist
 Efficacious in TN
 Start 10mg QD and titrate until effect or sedation
 Cannot abruptly withdraw drug!

35. Trigeminal Branch
Stimulation

36. Trigeminal Branch Stimulation
 Stimulation of supraorbital, infraorbital nerves
 Indications
 Trigeminal neuropathic pain
 Trigeminal deafferentation pain
 Post-herpetic neuralgia
 Chronic daily headache

37. Peripheral Trigeminal Branch Stimulation
for Neuropathic Pain
Johnson M, Burchiel K, Neurosurgery, 2004
0
2
4
6
0 25 50 75 100
0
2
4
6
8
Increase No Change Reduced
0
1
2
3
4
5
Slightly Somewhat Mostly Completely
Pain Relief
Medication Use Patient Satisfaction

38. Peripheral Trigeminal Branch
Stimulation for Neuropathic Pain
 Effective for trigeminal
neuropathic pain
 Less effective for PHN
 Simple, low morbidity
 Pain relief seems
relatively durable
 Major problem is erosion
of connector

39. Motor Cortex Stimulation
Motor cortex stimulation is NOT FDA approved and represents an
off-label use of the implanted device

40. History of MCS
 Developed by Tsubokawa and colleagues during 1980s
 Treatment of central deafferentation pain
 Poststroke pain
 Thalamic pain
 Bulbar pain
 Alternative to other methods of neuromodulation for
 SCS
 DBS
 Discovered that stimulation of motor rather than
sensory cortex produced better pain relief

41. Nociceptive Input
(Spinothalamic System)
Non-noxious Input
(DCML System)
Dorsal
Horn
Sensory
Cortex
Thalamus
DCN
Thalamus
Sensory
Cortex
Motor
Cortex
InInhibitory
Inhibitory
Inhibitory
Relationship Between Spinothalamic and DCML System - Normal

42. PNS A
A, C-fiber
Thalamic Pain

43. Motor Cortex Stimulation
Clinical Indications
 Post-stroke pain
 Post-herpetic neuralgia
 Trigeminal neuropathic pain
 Trigeminal deafferentation pain

44. Transcranial Magnetic Stimulation
VAPSPre VAPSPost
Sham 7.0 + 0.6 6.5 + 0.6
0.5 Hz TMS 6.4 + 0.7 5.5 + 0.7
10 Hz TMS 7.3 + 0.5 4.8 + 0.8

45. Localization of Motor Cortex

46. Complications
 Stimulation-induced seizures
 Pain at stimulation site
 Epidural hematoma
 CSF leak
 Electrode fracture or migration
 Infection

47. Results of MCS
Nguyen et. al.: Arch Med Res, 2000
 32 patients with central or peripheral neuropathic
pain
 Mean follow-up 27 months
 Substantial pain relief achieved in:
 77% (10/13) with central pain
 83% (10/12) with neuropathic facial pain
 Satisfactory results in 1/3 patient with SCI pain, 1
patient with PHN, 1 patient with plexus avulsion
 No patient developed seizures

48. Results of MCS
0
10
20
30
40
50
60
70
80
90
100
VAS score
Pre-Op VAS VAS 3 months VAS long-term

49. Unanswered Questions
 What are the best indications for MCS?
 What is the value of preoperative pharmacological
testing?
 Is there a predictive value to TMS?
 What is the optimum electrode location?
 Is there any value to using multiple electrodes?
 Are there optimum stimulation parameters?
 How often should stimulation be applied and for how
long?
 Can long-term reduction in pain be explained by
adaptation of the brain to chronic stimulation?

50. Deep Brain
Stimulation
Deep brain stimulation is NOT FDA approved for pain and
represents an off-label use of the implanted device

51. Stimulation-Produced Analgesia
 Reynolds, 1969: science
Electrical stimulation of rat midbrain results
in profound analgesia without concurrent
administration of analgesic drugs
 Relationship between SPA and endogenous
opioid system
 Richardson, 1973
1st published report of PAG-PVG stimulation
in humans

52. DBS Pain Targets
 PVG AND PAG
 Activation of endogenous opiate systems
 Descending modulatory pathways
 Best for nociceptive pain
 LEMNISCAL SYSTEM
 Vc (VPL,VPm) nucleus, medial lemniscus, IC
 Paresthesia-producing stimulation
 Best for neuropathic pain

53. Results of DBS
 Overall results variable
 30% to 85% excellent/good pain relief
 Richardson (Neurosurgery, 1977)
 85% effective short-term; 65% at 1 year
 Gybels & Kupers (Neurophys Clin, 1990)
 initial 61%; 4 years 30%
 Plotkin (Appl Neurophys, 1982)
 60-65% good results

54. Results of Deep Brain Stimulation
Gybels and Kupers
 Literature review through 1998
 1,863 patients (38 reports)
 Latest results analyzed
 Success defined as:
 Pain relief scores of 50% or more
 Verbal ratings of “good” or “excellent”
 Lack of relief during trial considered failure

55. Deep Brain Stimulation
Deafferentation Pain
Electrode Site No. Long-Term Success %
PAG-PVG 155 35 23
VPL-VPM 409 228 56
Overall 644 349 54

56. Deep Brain Stimulation
Nociceptive Pain
Electrode Site No. Long-Term Success %
PAG-PVG 291 247 59
VPL-VPM 51 0 0
Overall 419 172 59

57. Pain Type vs. Site of Stimulation
0
10
20
30
40
50
60
Success Rate
Nociceptive pain Deafferentation pain
PAG-PVG VPL-VPM Overall

58. Deep Brain Stimulation
Complications
 Neurologic
 Intracranial hemorrhage 1 - 5%
 Infection 3 -14%
 Seizures 3 - 4%
 Device-related 2 - 26%
 Lead fracture
 Lead migration
 Stimulation-related
 Usually transient, resolve with adjustments to stimulation
 Headache, nausea, diplopia, vertica gaze palsy, nystagmus, uncomfortable
paresthesias, unpleasant stimulation side effects

59. Cluster Headache
 Unilateral headache syndrome
 Pain mainly located in orbitotemporal region
 Abrupt onset and cessation
 Pain last 15 – 3 hours (HIS criteria)
 One or multiple attacks per day
 Autonomic symptoms
 “Cluster periods” lasting weeks to months
 Episodic or chronic forms

60. Surgical Treatment for Cluster
Headache
 Microvascular decompression of trigeminal nerve
 Ablative trigeminal procedures
 RF rhizotomy
 Glycerol rhizolysis
 Stereotactic radiosurgery
 Section of nervus intermedius
 Destruction of sphenopalatine ganglion
 Deep brain stimulation

61. Proposed Eligibilty Criteria for
DBS in Patients with Cluster HA
 Diagnosis of CH according to HIS criteria
 Symptoms present at least 24 months
 CH attacks on daily basis
 Symptoms strictly unilateral
 All state-of-the-art medications have been
tried singly or in combination
 “Normal psychological profile
 No medical/neurological contraindications to
DBS
 Normal neurological exam and imaging studies
 Patient agrees to discontinue smoking and/or
EtOH consumption

62. DBS for Cluster Headache
 “Stimulation of the Posterior Hypothalamus for Treatment of Chronic Intractable
Cluster Headache: First Reported Series” Neurosurgery (2003)
Stim. Parameters: Amp=.7-3V, PW=60, Rate=180 Hz

63. Nucleus Caudalis DREZ
Procedure

64. Indications for Caudalis DREZ
 Trigeminal deafferentation pain (following RF lesion)
 Recurrent refractory trigeminal neuralgia
 Trigeminal neuropathic pain (post-traumatic)
 Post-herpetic neuralgia
 Central pain following brainstem infarction
 Cluster headache
 Intractable migraine headache
 Atypical facial pain
 Cancer pain

65. Anatomical Landmarks

66. Caudalis DREZ Results
VAS Scores
0
1
2
3
4
5
6
7
8
9
10
VAS Score
Pre-op VAS 7.6 9.5 8.7 8.8
Post-op VAS 6.1 6.6 8.4 7.6
AFP PHN TN Overall

67. Caudalis DREZ Results
Percent Improvement
0
10
20
30
40
50
60
70
Immediate 69 42 14 32
Late 48 41 29 30
AFP PHN TN Overall

69. Occipital Neuralgia and
Occipital Headache
Syndromes

70. Occipital Neuralgia
 Pain within the distribution of the greater and/or lesser occipital nerves
 Neuralgic variant
 Sharp, shooting, electric-like pain
 Almost always unilateral
 Bursts of pain lasting for several seconds to few minutes
 Non-neuralgic variant
 Dull, aching, throbbing, pounding pain
 More constant pain
 Often bilateral
 Sensory dysfunction in C2 nerve territory
 Responds to local blockade of occipital nerve

71. Causes of Occipital Neuralgia
 Idiopathic
 Post-traumatic
 Spinal Disorders
 C1 fracture
 C1-2 instability
 RA with cranial settling
 C1-2 arthrosis
syndrome
 Hypertrophic facet
joint
 Inflammatory disorders
 Post-Operative
 VP shunt
 Retromastoid
craniectomy
 Mastoidectomy
 Chiari malformation
 Metabolic disorders
 Vascular lesions
 Tumors
Evaluation: Plain X-rays, CT, MRI

72. Chiari I Malformation

73. Basilar Invagination

74. Schwannoma of GON

75. Intradural Schwannoma

76. Chronic Daily Headache
 Chronic migraine subset
 Headache present at least 15 days per month
 Near daily to continuous pain
 Incidence 4% to 5%
 Up to 50% unresponsive to medication

77. OCCIPITAL NERVE STIMULATION FOR
OCCITAL HEADACHE SYNDROMES

78. Indications for ONS
 Appropriate clinical condition
 Condition refractory to non-operative therapy
 Acceptable psychological profile
 Positive response to local anesthetic block
 Positive response to temporary stimulation trial

79. ONS - Technique

80. ONS – Electrode Position

81. Complications of ONS
 Infection
 Connector erosion
 Electrode migration
 Electrode fracture
 Motor stimulation
 Stimulation tolerance

82. Occipital Nerve Stimulation
Outcome
 130 patients
 Average duration of symptoms – 8 years
 Unilateral – 88; Bilateral – 42
 Mean VAS score – 9.2 (5-10)
Weiner, R

83. Results of ONS
0
5
10
15
20
25
30
35
40
45
50
Excellent Good Fair Poor
0
1
2
3
4
5
6
7
8
9
10
Pre-Op VAS Post-Op VAS

84. Chronic Migraine

85. Cluster Headache
(May, Bahra, Buchel, Frackowiak & Goadsby, Lancet 1998)