Table 3

Basilar artery occlusion and branch infarction—anatomy and clinical features

Affected vessel	Affected structure	Clinical 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.