Table 3

Basilar artery occlusion and branch infarction—anatomy and clinical features

Affected vesselAffected structureClinical presentation
Lower and middle basilar artery
 Pontine paramedian perforators, short cirumferential branches
  • Corticospinal tracts

  • Unilateral or bilateral limb weakness

  • Corticobulbar tracts

  • Bulbar symptoms: dysarthria, dysphonia, dysphagia

  • Paramedian pontine reticular formation

  • Eye movement abnormalities: horizontal gaze palsy, internuclear ophthalmoplegia, nystagmus, pinpoint pupils

  • Medial lemniscus

  • Sensory deficits

Top of the basilar syndrome
 Midbrain perforating branches
  • Midbrain/pretectal region

  • Reticular activating system

  • Vertical eye movement abnormalities

  • Hyperconvergence

  • Hypersomnolence

  • Peduncular hallucinations

 Superior cerebellar artery
  • See below

  • See below

 Posterior cerebral arteries
  • Thalamus

  • Medial temporal lobe

  • Occipital cortex

  • Sensory deficits

  • Anterograde and retrograde amnesia

  • Visual field defects

Anterior inferior cerebellar artery
  • Lateral pons

  • Hemifacial sensory loss, 7th nerve palsy, Horner's syndrome, limb ataxia

  • Anterior inferior cerebellum

  • Labyrinth, cochlea

  • Acute vestibular syndrome with hearing loss

Superior cerebellar artery
  • Lateral midbrain

  • 4th nerve palsy, ipsilateral hemifacial sensory loss, contralateral body hemisensory loss, Horner's syndrome, limb ataxia, dysmetria

  • Superior cerebellum (superior vermis, dentate nucleus)

  • Truncal and gait ataxia, dysarthria, nausea and vomiting (pseudo-gastroenteritis)

Locked-in syndrome
 Pontine perforators, poor collateral supply
  • Extensive pontine infarction

  • Loss of all limb and bulbar motor function. Only vertical eye movements maintained. Consciousness and cognition preserved.