🎯 Pathology

• a disorder that causes recurrent episodes of unilateral electric shock-like pains in the face along the dermatomes of the trigeminal nerve (usually the V2 and V3 dermatomes) that last for a few seconds

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⚡️ Trigeminal nerve

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Roots

• the trigeminal nerve gives off two roots:

  • ​a large sensory root

  • a small motor root (travels with the mandibular division)

 

Divisions

• ophthalmic nerve (CN V1)

  • ​general somatic sensory fibres

  • passes through the superior orbital fissure

  • participates in the corneal reflex

• maxillary nerve (CN V2)

  • general somatic sensory fibres

  • passes through foramen rotundum

• mandibular nerve (CN V3)

  • general somatic sensory and somatic (branchial) motor fibres

  • passes through foramen ovale

  • provide motor supply to the muscles of mastication

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💡 Causes​

• compression of the trigeminal nerve

  • usually compressed by an artery (most commonly by the superior cerebellar artery)

  • vein

  • acoustic neuroma

  • multiple sclerosis

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Triggers

• shaving

• washing

• brushing teeth

• chewing

• talking

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🩺 Clinical features

• unilateral electric shock-like pains usually the V2 and V3 dermatomes are affected that last for a few seconds

  • if the V1 dermatome is affected, autonomic features such as lacrimation and rhinorrhoea are seen

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🕵️‍♂️ Investigations

• clinical

• neuroimaging (CT/MRI)

  • to exclude lesions such as tumours

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💆‍♂️ Management

• carbamazepine