Neuralgias

Question 1

where is the V1, V2, V3 first order neurons located?

Answer 1

V1, V2, V3 first order neurons converge at trigeminal ganglion (Gasserian or semilunar) at apex of petrous temporal bonein a depression (Meckel’s Cave) lateral to the cavernous sinus in middle crania fossa.

Question 2

Second order neurons located where and how many pathway?

Answer 2

2 pathways from 2 brainstem nuclei converge in thalamus.
Main sensory nucleus (mid pons) mediates fine touch .
Pain and temperature fibers descend in the Spinal Tract V and terminate on (caudal, lower brainstem) Spinal Trigeminal Nucleus.

Question 3

Third order neurons

Answer 3

in thalamus ascend carry sensory signals to primary somatosensory cortex.

Question 4

Neuralgia

Answer 4

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

Question 5

Trigeminal Neuralgia

Answer 5

Onset >50yo
If age male
Familial predilection maybe

Question 6

Trigeminal Neuralgia Key Features

Answer 6

Paroxysmal (sudden, brief, recurrent) pain is excruciating
Typically lasting seconds
Commonly pain triggered 
Hemifacial: V2 most common, 
Without significant sensory loss

Question 7

Trigeminal Neuralgia Treatment

Answer 7

Medication is First line of treatment
Carbamazepine (Tegretol) (up to 1600mg)
Surgical – Craniotomy (Microvascular decompression )

Question 8

Raeder’s Paratrigeminal Syndrome

Answer 8

Severe unilateral ocular (V1) pain
Typical is single episode lasting hours to weeks
Pain exacerbate with touch (get worse)
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

Question 9

Raeder’s Paratrigemina classes

Answer 9

Three classes
V1 pain + Horner’s + other CN involvement require w/u for mass lesion
V1 pain + Horner’s w/ cluster HA - benign course
V1 pain + Horner’s w/o cluster HA - benign course

Question 10

Raeder’s Etiology & Management

Answer 10

MRI/MRA and CBC, physical exam indicated to rule out:
Internal carotid artery dissection
Trauma
Vasculitis
Parasellar, maxillary sinus mass
Hypertension

Question 11

Postherpetic Neuralgia (PHN)

Answer 11

Distribution unilateral, typically V1
Paresthesia can be present: prickly, crawling sensation or even numbness
Risk increase with age

Question 12

Postherpetic Neuralgia Prognosis & Tx

Answer 12

Risk reduced by early intervention w/ HZV infection

Question 13

Ramsay Hunt syndrome

Answer 13

HZV infection (rash sometimes absent) of external ear
Involving CN VII and sometimes CN VIII
Pain (acutely)
Ipsilateral facial paresis (w/ loss of taste, secretory function)
Decreased and hypersensitive hearing; tinnitus
Vertigo, nystagmus