Symptoms of TIA in the Anterior Circulation

The symptoms of TIA in the anterior circulation (carotid/ACA/MCA) are:

• Weakness or sensory loss affecting the contra-lateral arm, leg or one side of the face

• Dysphasia or dysarthria (dysphasia usually indicates left sided cerebral hemisphere ischaemia)

• Monocular visual loss (amaurosis fugax) usually lasting a few minutes only (ophthalmic branch of internal carotid)

In differentiating between anterior and middle cerebral artery occlusions, it should be noted that:

• Middle cerebral artery occlusion affects the contra-lateral face and arm more than the leg. See homunculus diagram to the right.

• Anterior cerebral artery occlusion affects the contra-lateral leg more than the face or arm

• In lesions affecting the internal capsule (i.e. small vessel disease), the face, arm and leg may be equally affected as the relevant nerve fibres lie close together.