Vertebral Artery Dissection

Vertebral artery dissection affects the posterior circulation, and most often presents as a lateral medullary syndrome due to emboli in the posterior inferior cerebellar artery (Fig 1).

This causes:

• Ipsilateral facial pain and loss of temperature sensation (spinal trigeminal nucleus – Fig 2)
• Contralateral pain and loss of temperature sensation from the body (lateral spinothalamic tract after decussation – Fig 3)
• Dysphagia and dysarthria (nucleus ambiguus motor fibres of CN IX and X – Fig 4)
• Ataxia (cerebellar peduncle – Fig 5)
• Vertigo (vestibular nuclei – Fig 6)

These patients may also have a Horners syndrome caused by ischaemia of descending sympathetic fibres (Fig 7).