Trigeminal Neuralgia

Causes

• Vascular Compression of the trigeminal nerve root (most common)

• Tumour or Mass effect on the nerve

• Multiple Sclerosis (demyelination near nerve entry zone)

History

• Severe, sharp, stabbing pain in V2 (maxillary) or V3 (mandibular) divisions of CN V

• Attacks last seconds to minutes with refractory periods

• Triggers: Cold/hot drinks, brushing teeth, shaving, gentle facial touch, wind

• Can mimic migraine but typically short, intense bursts of pain

• More common in older adults, slight female predominance

Examination

• Trigger zones (e.g., nasolabial fold, cheek) → light touch can provoke pain

• Tic Douloureux: Brief facial twitch with severe pain

• Allodynia/Hyperalgesia in the affected dermatomes

• Otherwise normal neuro exam

Investigations

• MRI Brain (focus on trigeminal nerve) to rule out:

  • Vascular loops compressing nerve

  • Tumours, demyelinating plaques (MS)

• Neurophysiological Studies if atypical features

Management

1. Education

   • Explain nerve irritation, advise on trigger avoidance

2. Pharmacotherapy

   • Carbamazepine: First-line (start 100 mg BD, titrate gradually)

   • Oxcarbazepine if carbamazepine intolerance

   • Monitor for side effects (hyponatraemia, dizziness, mood changes)

   • Baclofen: Adjunct or alternative in refractory cases

3. Surgical Decompression

   • Microvascular decompression if severe and recurrent or confirmed neurovascular conflict

4. Referral

   • Non-urgent neurology referral for ongoing management, possible imaging to exclude secondary causes