Differentiating Trigeminal Differentiating Trigeminal Neuropathy From Neuropathy From

Trigeminal NeuralgiaTrigeminal Neuralgia

Does It Even Matter?Does It Even Matter?

Justin Sandall, D.O.Justin Sandall, D.O.Vanderbilt University Medical CenterVanderbilt University Medical CenterDepartment of Anesthesiology, CA-2Department of Anesthesiology, CA-2

Case PresentationCase Presentation 26 y/o female w/a history of chronic migraine HA, depression and 26 y/o female w/a history of chronic migraine HA, depression and

hypothyroidism presents for evaluation of L sided facial pain. hypothyroidism presents for evaluation of L sided facial pain.  She relates a history of migraines since the age of 11; occurred She relates a history of migraines since the age of 11; occurred

infrequently until beginning college in 2001 at which time they infrequently until beginning college in 2001 at which time they increased in frequency to 2-3x/month.  increased in frequency to 2-3x/month. 

~1 year ago she had her typical migraine which "didn't go away."  ~1 year ago she had her typical migraine which "didn't go away."  She now has a constant, throbbing/boring pain in her L She now has a constant, throbbing/boring pain in her L periorbital/frontal area with occ. radiation to the L maxilla.  periorbital/frontal area with occ. radiation to the L maxilla. 

She also has intermittent sharp, lancinating pains in thoseShe also has intermittent sharp, lancinating pains in thosesame areas.  same areas. 

Her pain is worsened with anxiety, working out, loud noises, heat and Her pain is worsened with anxiety, working out, loud noises, heat and alleviated with application of cold, migraine medications and Lyrica. alleviated with application of cold, migraine medications and Lyrica. Mother has noticed L sided facial swelling.Mother has noticed L sided facial swelling.

There is no association with brushing teeth, putting on makeup or There is no association with brushing teeth, putting on makeup or wind on the face.  She denies changes in hearing, balance or wind on the face.  She denies changes in hearing, balance or coordination.  She also denies sensory changes, tearing, conjunctival coordination.  She also denies sensory changes, tearing, conjunctival effusion and ataxia.  effusion and ataxia. 

No h/o trauma or HSV. No h/o trauma or HSV.

Case PresentationCase Presentation

MEDICATIONS:MEDICATIONS:    - Synthroid Oral Tablet 75 mcg 1 tablet by mouth daily - Synthroid Oral Tablet 75 mcg 1 tablet by mouth daily - Betaxolol 10mg PO twice daily - Betaxolol 10mg PO twice daily - Zoloft 150mg PO daily - Zoloft 150mg PO daily - Migrelief 2 tabs PO - Migrelief 2 tabs PO - Topamax 300mg OP daily - Topamax 300mg OP daily - Ondansetron tab PO PRN - Ondansetron tab PO PRN - Indomethacin 25mg PO twice daily - Indomethacin 25mg PO twice daily - Zomig Zmt 5mg PO twice daily - Zomig Zmt 5mg PO twice daily - Lyrica 300mg - Lyrica 300mg - Kariva BC - Kariva BC - Zyrtec 10mg - Zyrtec 10mg

Case PresentationCase Presentation

Relevant Physical ExamRelevant Physical Exam PERRL, CN II-XII intact b/l, NTTP along PERRL, CN II-XII intact b/l, NTTP along

trigeminal distribution w/o allodynia or trigeminal distribution w/o allodynia or hyperesthesia, no sensory deficits, TMJ NTTP hyperesthesia, no sensory deficits, TMJ NTTP b/lb/l

Relevant ImagingRelevant Imaging Previous work-up including CT and MRI Previous work-up including CT and MRI

unrevealingunrevealing

Trigeminal NeuralgiaTrigeminal Neuralgia Most common pain syndrome referable to a cranial nerve.Most common pain syndrome referable to a cranial nerve.11

Most common in adults > 50 y/o, women slightly more than menMost common in adults > 50 y/o, women slightly more than men22

Classically, pain is described as an electric shock–like, stabbing, Classically, pain is described as an electric shock–like, stabbing, unilateral pain with abrupt onset and termination in distribution of unilateral pain with abrupt onset and termination in distribution of trigeminal nerve – usually V2/3.trigeminal nerve – usually V2/3.2,32,3

Intervals between attacks are pain freeIntervals between attacks are pain free Minimal or no sensory loss in the region of pain Minimal or no sensory loss in the region of pain

Precipitation from trigger areas or by certain daily activities, such as Precipitation from trigger areas or by certain daily activities, such as eating, talking, washing the face, or cleaning the teetheating, talking, washing the face, or cleaning the teeth33

Diagnosis is typically made by the historyDiagnosis is typically made by the history Imaging is often pursued to r/o other causes of facial pain &/or to Imaging is often pursued to r/o other causes of facial pain &/or to

evaluate for MS, vascular compression of the trigeminal nerve etc.evaluate for MS, vascular compression of the trigeminal nerve etc. Typically, 80% of patients respond to medical therapyTypically, 80% of patients respond to medical therapy33

11stst line therapy is carbamazepine line therapy is carbamazepine2,3,52,3,5

Trigeminal NeuralgiaTrigeminal Neuralgia May target trigeminal nerve at various sites with nerve blocks if May target trigeminal nerve at various sites with nerve blocks if

unresponsive to medical therapyunresponsive to medical therapy Superficial V1/V2, gasserian ganglionSuperficial V1/V2, gasserian ganglion

If responsive to local anesthetic block, may pursue trigeminal neurolysisIf responsive to local anesthetic block, may pursue trigeminal neurolysis Most common target is the gasserian ganglion via the foramen ovaleMost common target is the gasserian ganglion via the foramen ovale11

Studies have all used patients w/classic trigeminal neuralgiaStudies have all used patients w/classic trigeminal neuralgia• Less premorbid depression/anxiety, more satisfied w/outcome, fewer side effect Less premorbid depression/anxiety, more satisfied w/outcome, fewer side effect

complaints, more willing to repeat procedurecomplaints, more willing to repeat procedure11

Study by Taha and Tew in 1996 evaluated RF rhizotomy w/curved electrode, Study by Taha and Tew in 1996 evaluated RF rhizotomy w/curved electrode, RF rhizotomy, glycerol rhizotomy, balloon compression, and posterior fossa RF rhizotomy, glycerol rhizotomy, balloon compression, and posterior fossa exploration (microvascular decompression, partial trigeminal rhizotomy)exploration (microvascular decompression, partial trigeminal rhizotomy)44

• Showed initial pain relief to be 91-98% with success of procedure in 85-98% and Showed initial pain relief to be 91-98% with success of procedure in 85-98% and pain recurrence in 15-54%pain recurrence in 15-54%

Glycerol rhizotomy had lowest initial pain relief, lowest procedure success and highest Glycerol rhizotomy had lowest initial pain relief, lowest procedure success and highest pain recurrencepain recurrence

Complications of trigeminal neurolysis can be devastating and include Complications of trigeminal neurolysis can be devastating and include anesthesia dolorosa, loss of corneal sensation, keratitis, dysesthesiaanesthesia dolorosa, loss of corneal sensation, keratitis, dysesthesia11

Trigeminal Neuropathy (included Trigeminal Neuropathy (included atypical trigeminal neuralgia and atypical trigeminal neuralgia and

atypical facial pain)atypical facial pain) Chronic or recurrent pain in the area of previous nerve injury, Chronic or recurrent pain in the area of previous nerve injury,

numbness, dysesthesias, and chronic burning sensations. numbness, dysesthesias, and chronic burning sensations. Diagnostic evaluations rule out any other cause of pain.Diagnostic evaluations rule out any other cause of pain.22

More likely to have sensory loss or allodyniaMore likely to have sensory loss or allodynia55

Doesn’t meet White and Sweet criteria:Doesn’t meet White and Sweet criteria:22     The pain is paroxysmal.The pain is paroxysmal. The pain is confined to the trigeminal distribution.The pain is confined to the trigeminal distribution. The pain is unilateral.The pain is unilateral. The bedside clinical sensory examination is normal.The bedside clinical sensory examination is normal. The pain may be provoked by light touch to the face (trigger zones)The pain may be provoked by light touch to the face (trigger zones)

Significant clinical challenge because the symptoms of PTN Significant clinical challenge because the symptoms of PTN respond poorly, if at all, to AED or surgical therapies commonly respond poorly, if at all, to AED or surgical therapies commonly used in TN.used in TN.1,21,2

Neurolytic treatment may actually worsen pain in this subgroupNeurolytic treatment may actually worsen pain in this subgroup More often associated with young, middle aged women and feelings More often associated with young, middle aged women and feelings

of depressionof depression Motor cortex stimulation for trigeminal neuralgia seems promising – Motor cortex stimulation for trigeminal neuralgia seems promising –

70% success rate compared to 50% for central pain70% success rate compared to 50% for central pain55

Classic Classic trigeminal trigeminal neuralgianeuralgia

RareRare Intraoral or Intraoral or extraoral in extraoral in trigeminal trigeminal regionregion

Each episode Each episode of pain lasts of pain lasts for seconds to for seconds to minutes; minutes; refractory refractory periods, and periods, and long periods long periods of no pain of no pain

Sharp, Sharp, shooting, shooting, moderate to moderate to very severe very severe

Light touch Light touch provoked provoked (e.g., eating, (e.g., eating, washing, washing, talking) talking)

Discrete Discrete trigger zones trigger zones

Atypical Atypical trigeminal trigeminal neuralgia neuralgia

RareRare Intraoral or Intraoral or extraoral in extraoral in trigeminal trigeminal regionregion

Sharp attacks Sharp attacks lasting lasting seconds to seconds to minutes, more minutes, more continuous-continuous-type type background background painpain, less , less likely to have likely to have complete pain complete pain remission remission

Sharp, Sharp, shootingshooting, , moderate to moderate to severe but severe but also also dull, dull, burning, burning, continuouscontinuous mild mild background background pain pain

Light touch Light touch provoked, provoked, but but continuous-continuous-type pain not type pain not so clearly so clearly provoked provoked

May have May have small trigger small trigger areas, variable areas, variable pattern pattern

Trigeminal Trigeminal neuropathyneuropathy

Very Very rarerare

Trigeminal Trigeminal areaarea, but may , but may radiate beyond radiate beyond

ContinuousContinuous Dull with Dull with sharp sharp exacerbationexacerbation

Areas of Areas of allodynia, allodynia, light touch light touch

Sensory loss, Sensory loss, subjective-subjective-objective, objective, progressive, progressive, vasodilation vasodilation and and swellingswelling may occur may occur

Adapted from Essentials of physical medicine and rehabilitation: musculoskeletal disorders, pain, and rehabilitation/ Essentials of physical medicine and rehabilitation: musculoskeletal disorders, pain, and rehabilitation/ [edited by] Walter R. Frontera, Julie K. Silver, Thomas D. Rizzo Jr.—2nd ed. Chapter 90.[edited by] Walter R. Frontera, Julie K. Silver, Thomas D. Rizzo Jr.—2nd ed. Chapter 90.

Case ResolutionCase Resolution 26 y/o female with L sided facial pain in the setting of chronic migraine HA, h/o 26 y/o female with L sided facial pain in the setting of chronic migraine HA, h/o

depression and hypothyroidism. Given the nature of her pain, her history of depression and hypothyroidism. Given the nature of her pain, her history of depression and migraine HA, her pain triggers or lack thereof and physical exam depression and migraine HA, her pain triggers or lack thereof and physical exam findings, this most likely is atypical facial pain secondary to trigeminal neuropathic findings, this most likely is atypical facial pain secondary to trigeminal neuropathic pain in the V1/V2 distribution rather than classic trigeminal neuralgia.  It is important pain in the V1/V2 distribution rather than classic trigeminal neuralgia.  It is important to make this distinction given that definitive treatment of trigeminal neuralgia (i.e. to make this distinction given that definitive treatment of trigeminal neuralgia (i.e. neurolytic tx) can actually worsen the pain of trigeminal neuropathy.  In addition, she neurolytic tx) can actually worsen the pain of trigeminal neuropathy.  In addition, she almost certainly has a component of transformed migraine HA that is contributory almost certainly has a component of transformed migraine HA that is contributory thus one of our long-term goals will be to decrease the number of medicines she is thus one of our long-term goals will be to decrease the number of medicines she is on.on.1. Atypical facial pain  1. Atypical facial pain  2. Trigeminal neuropathic pain in the V1V2 distribution  2. Trigeminal neuropathic pain in the V1V2 distribution  3. Transformed migraine headache  3. Transformed migraine headache  4. H/o depression4. H/o depression5. Hypothyroidism  5. Hypothyroidism 

Will schedule for superficial V1/V2 block and TPI and assess response.  Needs to be Will schedule for superficial V1/V2 block and TPI and assess response.  Needs to be off indomethacin x7 days prior to procedure.  May benefit from Gasserian ganglion off indomethacin x7 days prior to procedure.  May benefit from Gasserian ganglion block and/or Stellate ganglion block down the road if not responsive to more block and/or Stellate ganglion block down the road if not responsive to more conservative measures.  If responds well to the peripheral n. blocks, will use Botox for conservative measures.  If responds well to the peripheral n. blocks, will use Botox for long-term control. Meanwhilelong-term control. Meanwhile

ReferencesReferences Jackson T, Gaeta R: Neurolytic blocks revisited. Jackson T, Gaeta R: Neurolytic blocks revisited. Current Current

Pain and Headache ReportsPain and Headache Reports. 2008, 12:7-13.. 2008, 12:7-13. Raj's practical management of pain/editors, Honorio T. Raj's practical management of pain/editors, Honorio T.

Benzon…[et al.].—4th ed. Chapter 25.Benzon…[et al.].—4th ed. Chapter 25. Essentials of physical medicine and rehabilitation: Essentials of physical medicine and rehabilitation:

musculoskeletal disorders, pain, and rehabilitation/ musculoskeletal disorders, pain, and rehabilitation/ [edited by] Walter R. Frontera, Julie K. Silver, Thomas D. [edited by] Walter R. Frontera, Julie K. Silver, Thomas D. Rizzo Jr.—2nd ed. Chapter 90.Rizzo Jr.—2nd ed. Chapter 90.

Taha JM, Tew JM: Comparison of surgical treatments for Taha JM, Tew JM: Comparison of surgical treatments for trigeminal neuralgia: reevaluation of radiofrequency trigeminal neuralgia: reevaluation of radiofrequency rhizotomy. rhizotomy. NeurosurgeryNeurosurgery 1996, 38:865-871 1996, 38:865-871

McMahon: Wall and Melzack's Textbook of Pain, 5th ed. McMahon: Wall and Melzack's Textbook of Pain, 5th ed. Chapter 37Chapter 37