Clinical features

Occlusion proximal to the anterior communicating artery is often well tolerated because of collateral flow.

Proximal occlusion when both arteries arise from the same anterior cerebral stem usually causes infarction of the medial parts of both hemispheres, producing:

• paraplegia, usually, of the lower limbs
• sensory loss
• incontinence
• mental symptoms
• grasp, snout and pout reflexes
• in extreme cases, akinetic mutism or deteriorating conscious level

Occlusion distal to the anterior communicating artery presents with:

• contralateral hemiplegia and hemisensory loss, usually of the lower limbs with the upper limbs spared
• occasionally, a contralateral grasp reflex

For further detail of frontal lobe signs, see the appropriate section.