1. Differentiating TrigeminalDifferentiating Trigeminal
Neuropathy FromNeuropathy 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 Center
Department of Anesthesiology, CA-2Department of Anesthesiology, CA-2

2. Case PresentationCase Presentation
 26 y/o female w/a history of chronic migraine HA, depression and26 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; occurredShe relates a history of migraines since the age of 11; occurred
infrequently until beginning college in 2001 at which time theyinfrequently 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." She~1 year ago she had her typical migraine which "didn't go away." She
now has a constant, throbbing/boring pain in her L periorbital/frontalnow has a constant, throbbing/boring pain in her L periorbital/frontal
area with occ. radiation to the L maxilla.area with occ. radiation to the L maxilla.

She also has intermittent sharp, lancinating pains in thoseShe also has intermittent sharp, lancinating pains in those
same areas.same areas.
 Her pain is worsened with anxiety, working out, loud noises, heat andHer 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 orThere is no association with brushing teeth, putting on makeup or
wind on the face. She denies changes in hearing, balance orwind on the face. She denies changes in hearing, balance or
coordination. She also denies sensory changes, tearing, conjunctivalcoordination. 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.

3. 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

4. Case PresentationCase Presentation
 Relevant Physical ExamRelevant Physical Exam

PERRL, CN II-XII intact b/l, NTTP alongPERRL, CN II-XII intact b/l, NTTP along
trigeminal distribution w/o allodynia ortrigeminal distribution w/o allodynia or
hyperesthesia, no sensory deficits, TMJ NTTPhyperesthesia, no sensory deficits, TMJ NTTP
b/lb/l
 Relevant ImagingRelevant Imaging

Previous work-up including CT and MRIPrevious work-up including CT and MRI
unrevealingunrevealing

5. 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 ofunilateral 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 painMinimal or no sensory loss in the region of pain
 Precipitation from trigger areas or by certain daily activities, such asPrecipitation 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 toImaging 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 carbamazepineline therapy is carbamazepine2,3,52,3,5

6. Trigeminal NeuralgiaTrigeminal Neuralgia
 May target trigeminal nerve at various sites with nerve blocks ifMay 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 effectLess 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 fossaRF 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% andShowed 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 highestGlycerol rhizotomy had lowest initial pain relief, lowest procedure success and highest
pain recurrencepain recurrence

Complications of trigeminal neurolysis can be devastating and includeComplications of trigeminal neurolysis can be devastating and include
anesthesia dolorosa, loss of corneal sensation, keratitis, dysesthesiaanesthesia dolorosa, loss of corneal sensation, keratitis, dysesthesia11

7. Trigeminal Neuropathy (includedTrigeminal Neuropathy (included
atypical trigeminal neuralgia andatypical 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 PTNSignificant clinical challenge because the symptoms of PTN
respond poorly, if at all, to AED or surgical therapies commonlyrespond 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 feelingsMore 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

8. ClassicClassic
trigeminaltrigeminal
neuralgianeuralgia
RareRare Intraoral orIntraoral or
extraoral inextraoral in
trigeminaltrigeminal
regionregion
Each episodeEach episode
of pain lastsof pain lasts
for seconds tofor seconds to
minutes;minutes;
refractoryrefractory
periods, andperiods, and
long periodslong periods
of no painof no pain
Sharp,Sharp,
shooting,shooting,
moderate tomoderate to
very severevery severe
Light touchLight touch
provokedprovoked
(e.g., eating,(e.g., eating,
washing,washing,
talking)talking)
DiscreteDiscrete
trigger zonestrigger zones
AtypicalAtypical
trigeminaltrigeminal
neuralgianeuralgia
RareRare Intraoral orIntraoral or
extraoral inextraoral in
trigeminaltrigeminal
regionregion
Sharp attacksSharp attacks
lastinglasting
seconds toseconds to
minutes, moreminutes, more
continuous-continuous-
typetype
backgroundbackground
painpain, less, less
likely to havelikely to have
complete paincomplete pain
remissionremission
Sharp,Sharp,
shootingshooting,,
moderate tomoderate to
severe butsevere but
alsoalso dull,dull,
burning,burning,
continuouscontinuous
mildmild
backgroundbackground
painpain
Light touchLight touch
provoked,provoked,
butbut
continuous-continuous-
type pain nottype pain not
so clearlyso clearly
provokedprovoked
May haveMay have
small triggersmall trigger
areas, variableareas, variable
patternpattern
TrigeminalTrigeminal
neuropathyneuropathy
VeryVery
rarerare
TrigeminalTrigeminal
areaarea, but may, but may
radiate beyondradiate beyond
ContinuousContinuous Dull withDull with
sharpsharp
exacerbationexacerbation
Areas ofAreas of
allodynia,allodynia,
light touchlight touch
Sensory loss,Sensory loss,
subjective-subjective-
objective,objective,
progressive,progressive,
vasodilationvasodilation
andand swellingswelling
may occurmay 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.

9. Case ResolutionCase Resolution
 26 y/o female with L sided facial pain in the setting of chronic migraine HA, h/o26 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 ofdepression and hypothyroidism. Given the nature of her pain, her history of
depression and migraine HA, her pain triggers or lack thereof and physical examdepression and migraine HA, her pain triggers or lack thereof and physical exam
findings, this most likely is atypical facial pain secondary to trigeminal neuropathicfindings, this most likely is atypical facial pain secondary to trigeminal neuropathic
pain in the V1/V2 distribution rather than classic trigeminal neuralgia. It is importantpain 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, sheneurolytic tx) can actually worsen the pain of trigeminal neuropathy. In addition, she
almost certainly has a component of transformed migraine HA that is contributoryalmost 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 isthus one of our long-term goals will be to decrease the number of medicines she is
on.on.
1. Atypical facial pain1. Atypical facial pain
2. Trigeminal neuropathic pain in the V1V2 distribution2. Trigeminal neuropathic pain in the V1V2 distribution
3. Transformed migraine headache3. Transformed migraine headache
4. H/o depression4. H/o depression
5. Hypothyroidism5. Hypothyroidism
 Will schedule for superficial V1/V2 block and TPI and assess response. Needs to beWill 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 ganglionoff indomethacin x7 days prior to procedure. May benefit from Gasserian ganglion
block and/or Stellate ganglion block down the road if not responsive to moreblock 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 forconservative measures. If responds well to the peripheral n. blocks, will use Botox for
long-term control. Meanwhilelong-term control. Meanwhile

10. ReferencesReferences
 Jackson T, Gaeta R: Neurolytic blocks revisited.Jackson T, Gaeta R: Neurolytic blocks revisited. CurrentCurrent
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 forTaha JM, Tew JM: Comparison of surgical treatments for
trigeminal neuralgia: reevaluation of radiofrequencytrigeminal neuralgia: reevaluation of radiofrequency
rhizotomy.rhizotomy. NeurosurgeryNeurosurgery 1996, 38:865-8711996, 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