Trigeminal neuralgia

Question 1

Define trigeminal neuralgia

Answer 1

Facial pain syndrome in the distribution of >1 divisions of the trigeminal nerve

Question 1

Aetiology of trigeminal neuralgia

Answer 1

Associated with trigeminal nerve compression in majority of patients (80-90%) at the root entry zone by an aberrant vascular loop, typically the superior cerbellar artery.
(Many patients have similar compression on the asymptomatic, contra-lateral side, and asymptomatic patients without TN may demonstrate vascular compression)
Demyelinating disease: 20x more prevalence in MS sufferers compared to general population
Brainstem infarcts and amyloid or calcium deposition (rare)

Question 2

Risk factors for trigeminal neuralgia

Answer 2

Increasing age
Multiple sclerosis
Female
Hyeprtension

Question 3

Symptoms of trigeminal neuralgia

Answer 3

Facial pain
- In trigeminal nerve distributions
- Bilateral
- Stabbing/shock
- May be preceded by oropharyngeal/facial trauma or herpetic outbreak
Sensory changes

Question 4

Investigations for trigeminal neuralgia

Answer 4

Clinical diagnosis

Intra-oral XR: exclude dental cause
MRI: if exam suggests other pathology
Trigeminal reflex testing: early blink, early masseter inhibitory reflex

Question 5

Management for trigeminal neuralgia

Answer 5

First line: carbamazepine 200mg/day PO
Second line: gabapentin, pregabalin, lamotrigine, baclofen

Refractory:
- Microvascular decompression
- Ablative surgery