facial pain and neuralgias

Question 1

functions of cn 5

Answer 1

sensory (main) and motor

Question 2

where does V1 pass

Answer 2

superior orbital fissure

Question 3

where does V2 pass

Answer 3

oramen rotundum deep in skull to pterygopalatine fossa

Question 4

where does v3 pass

Answer 4

! Via foramen ovale into infratemporal fossa

Question 5

what does v3 do?

Answer 5

Non-taste sensation to anterior 2/3 tongue

Question 6

! Does not innervate the angle of the jaw. CN VII innervates some of external ear. (T/F of cn5)

Answer 6

true

Question 7

Axons travel with V3

! Nucleus lies medially to sensory nucleus

Answer 7

! Motor (ipsilateral muscles of mastication)

Question 8

how is ganglion different than nucleus

Answer 8

collection of cell bodies peripherally; if centrally it is nucleus

Question 9

(2 pathways) from 2 brainstem nuclei converge in thalamus

Answer 9

Second order neurons

Question 10

(mid pons) mediates fine touch and two point discrimination, joint position, vibration, sending fibers to thalamus

Answer 10

Main sensory nucleus

Question 11

Pain & temperature fibers descend in the Spinal Tract V and terminate on (caudal, lower brainstem)?

Answer 11

Spinal Trigeminal Nucleus. Axons cross midline and ascend in trigeminothalamic tract (TTT) to the ventral posteromedial (VPM) nucleus in the thalamus.

Question 12

in thalamus ascend carry sensory signals to primary somatosensory cortex

Answer 12

third order neurons

Question 13

tip of nose is innervated by what nerve?

Answer 13

v1

Question 14

! Nuclear/central origin due to ischemia or MS
! Peripheralorigin(V1,V2,V3)
! Band of paresthesia/anesthesia
! Orbital fracture, neoplasm, aneurysm

Answer 14

! Hypesthesia

Question 15

cutting, piercing, burning or stabbing

Answer 15

Intense lancinating pain

Question 16

! Intense lancinating pain: cutting, piercing, burning or stabbing
! Shooting along course of affected nerve
! Often paroxysmal (sudden, brief, recurrent)
! Cause unknown or due to nerve irritation or damage ! Infection, inflammation, compression

Answer 16

neuralgia

Question 17

name 3 primary facial neuralgias (non HA)

Answer 17

! Trigeminal neuralgia

! Raeder’s paratrigeminal syndrome (neuralgia) ! Postherpetic neuralgia

Question 18

Tic Douloureux

Answer 18

Trigeminal Neuralgia

Question 19

! Diagnosed primarily by patient history
! MRI with close attention to posterior fossa to rule out
possible causes of compression CN V roots or MS
! Onset >50yo
! If age male
! Familial predilection maybe

Answer 19

trigeminal neuralgia

Question 20

paroxysmal pain is excruciating
commony pain triggered by: wind, brush, shaving
hemifacial: v2 most common
without significant sensory loss

Answer 20

trigeminal neuralgia

Question 21

! Compression, irritation, inflammation theory
! vessel in posterior circulation comes to lie on CN V roots and
intermittently stimulate it
! Tumor
! Aneurysm
! Chronic meningeal inflammation
! Peripheral CN V injury or failure of central inhibitory mechanisms
! Demyelination zone (MS)
! Often unknown

Answer 21

trigeminal neuralgia etiology

Question 22

! Over long term:
! pain-free intervals diminish
! pain less responsive to medication ! Some sensory loss can occur
! Temporary spontaneous remission possible but never permanent
! Medical management eventually fails to control (25-50%)

Answer 22

prognosis and management of trigeminal neuralgia

Question 23

whats the first line of tx for trigeminal neuralgia

Answer 23

carbamazepine (antiseizure medicines)

Question 24

! Isolate nerve from adjacent vessel (superior cerebellar artery
or branch of petrosal vein) with sponge
! Preferred for younger patients (90% initial success)
! Longest term pain relief ; Lowest recurrence
! Most cost effective
! Preserved facial sensation and low morbidity ! Low risk of hearing loss

Answer 24

! Microvascular decompression (MVD)

*surgery for trigeminal neuralgia

Question 25

! Ionizing radiation targets CN V roots
! Response delayed 2-6 months
! “Success” rate vary by definition 50-80%
! Recurrence common; procedure can be repeated
! Complications - increased paresthesia or numbness

Answer 25

! Stereotactic radiosurgery with Gamma Knife

*noninvasive surgery for trigeminal neuralgia

Question 26

! Preferred for elderly patients, MS*, pain persisting after MVD
! Needle through foramen ovale (V3)
! *Surgery less effective in MS patients ! Low risk and avoids general anesthesia
! Percutaneous radiofrequency trigeminal gangliosis ! 3-4 year pain-free typical
! Alcohol injection
! Low success rate; nonselective; high recurrence
! Glycerol rhizotomy
! Balloon microcompression (crush pain fibers)

Answer 26

percutaneous transovale procedures

*surgery for trigeminal neuralgia

Question 27

what is raeders paratrigeminal syndrome accompanied with

Answer 27

horners syndrome without anhydrosis

Question 28

! Severe unilateral ocular (V1) pain
! Typical is single episode lasting hours to weeks ! Pain exacerbate with touch
! Occasionally recurrent
! Self limiting in 2-3 months
! Ipsilateral oculosympathetic palsy or partial Horner’s (miosis, ptosis, preserved hydrosis)
! Can associate with tearing, erythema, decreased IOP
! Middle-aged male almost exclusively (w/ hx of recurrent
AM HA associated w/ nausea/vomiting) ! Uncommon

Answer 28

Raeder’s Paratrigeminal Syndrome

Question 29

allodynia

Answer 29

abnormal response of pain to light touch

Question 30

WHAT ARE THE THREE CLASSES OF raeder’s paratrigeminal syndrome

Answer 30

1. V1 pain + Horner’s + other CN involvement require w/u
   for mass lesion
2. V1 pain + Horner’s w/ cluster HA - benign course
3. V1 pain + Horner’s w/o cluster HA - benign course
   (#2 & #3 require neurological w/u if protracted course
   of pain or other CN involvement, including addition of V2 & v3)

Question 31

! MRI/MRA and CBC, physical exam indicated to rule out:
! Internal carotid artery dissection ! Trauma
! Vasculitis
! Parasellar, maxillary sinus mass
! Hypertension
! Treatment vary depending on cause. Otherwise symptomatic (see Cluster HA below)

Answer 31

raeder’s etiology and management

Question 32

involves pain around one eye, along with drooping of lid, tearing and congestion on same side as pain

Answer 32

cluster headache

Question 33

! Unilateral periorbital severe pain
! ave 45 minutes (15m-3h)
! 1-4 times daily around same time. Nocturnal common
! Recurrences same side in clusters (4-12 wk)
! Male typically
! May have ipsilateral Horner’s, lacrimation, conjunctival injection, nasal congestion, eyelid edema

Answer 33

cluster HA

Question 34

! Symptomatic
! Non-surgical unless cause
! Avoid vasodilation, alcohol
! Oxygen
! Analgesics
! Octreotide (injectable synthetic somatostatin)
! Triptans (injectable sumatriptan (Imitrex))
! Ergotamine (injectable dihydroergotamine)
! Local anesthetics (intranasal lidocaine)
! Prevention:
! Ca++ channel blockers, corticosteroids, nerve block

Answer 34

tx for cluster HA

Question 35

hzv can lead to what?

Answer 35

postherpetic neuralgia

Question 36

! Severe burning, aching, stabbing protracted pain
! Pain can be accompanied or triggered by super-sensitivity
to light touch (allodynia)
! Distribution unilateral, typically V1
! Following HZV infection (shingles)
! Paresthesia can be present: prickly, crawling sensation or even numbness
! Occasionally facial muscle weakness
! Risk increase with age (60% of 60yo w/ shingles; 75% of 70yo w/ shingles develop PHN)

Answer 36

postherpetic neuralgia

Question 37

what do we use to treat hzv

Answer 37

acyclovir

Question 38

! Risk reduced by early intervention w/ HZV infection

Answer 38

postherpetic neuralgia prognosis and tx