Trigeminal Neuralgia

Question 1

what is trigeminal neuralgia

Answer 1

disorder of trigeminal nerve seeing episodes of unilateral, intense stabbing/ electric - shock like pain.
most common in mandibular and/or maxillary branch(es)

Question 2

discuss the classification of trigeminal neuralgia

Answer 2

classical - caused by neurovascular compression in nerve root entry zone
idiopathic - unknown cause
secondary - caused by underlying disease such as tumours, artery malformations or MS

Question 3

classical trigeminal neuralgia

Answer 3

caused by neurovascular compression in nerve root entry zone. most commonly the superior cerebellar artery compressing the nerve root between itself and the pons leading to to demyelination of nerve fibres which then start firing ectopically

Question 4

discuss the epidemiology of trigeminal neuralgia

Answer 4

rare , 4-8/100000
females more than males, 2:1

Question 5

name 3 clinical features of trigeminal neuralgia

Answer 5

• paroxysmal attacks of pain lasting less than 2 mins
• very rarely occurs bilaterally and rarely affects v1
• presence of trigger zone, usually near centre of face. brought on by innocuous stimuli e.g shaving, talking, toothbrushing
• majority of patients asymptomatic between attacks

Question 6

who sets out the diagnostic criteria for trigeminal neuralgia

Answer 6

ICHD - 3

Question 7

discuss the diagnostic criteria for trigeminal neuralgia (ICHD 3) (4)

Answer 7

1 - recurrent paroxysms of unilateral facial pain in one or more divisions of trigeminal nerve with no radiation beyond
2 - pain with characteristics (lasts up to 2 mins, severe, electric shock like)
3 - triggered by innocuous stimuli
4 - no better ICHD 3 diagnosis

Question 8

name 3 drugs that may be used to treat TN

Answer 8

carbamazepine
lamotrigine
gabapentin

Question 9

carbamazepine as a treatment for TN
- MOA

Answer 9

usually first line drug treatment
an anticonvulsant which blocks VGSCs therefore decreasing nerve activity

Question 10

carbamazepine as a treatment for TN
- dose

Answer 10

starts with 100/200mg day increasing to max dose of 1600mg day

Question 11

carbamazepine as a treatment for TN
- side effects

Answer 11

dizzyness, tiredness, drowsiness, nausea, leukopenia, ataxia

Question 12

what are the non pharmacological treatment options for TN

Answer 12

surgery
non invasive electrical stimulation

Question 13

briefly discuss surgery as an option for TN management

Answer 13

should only be offered if pharmacological methods inadequate
- gamma knife surgery (utilises radiation, risk of sensory complications)
- microvascular decompression surgery (good pain relief but very invasive)

Question 14

what is trigeminal autonomic cephalgias

Answer 14

severe unilateral head pain predominantly affecting V1
usually cranial parasympathetic features on ipsilateral side - nasal congestion, eyelid oedema, ptosis, miosis
various different types (cluster headaches, paroxysmal hemicrania)

Question 15

cluster headache

Answer 15

type of TAC
excruciating unilateral pain lasting 15 mins to 3 hours
attacks present in clusters - bouts for 1-3 months then remission period with no attacks

Question 16

paroxysmal hemicrania

Answer 16

type of TAC
excruciating unilateral pain for 2-30 mins
multiple attacks a day

Question 17

painful trigeminal neuropathy

Answer 17

hybrid of TN and TAC
can be caused by trauma, herpes zoster or be idiopathic
primary pain is continuous or near continuous and may have superimposed paroxysmal attacks