Brain and its blood supply
The body supplies blood to the brain via the internal carotid and vertebral arteries. These vessels come together to form a ring called the circle of Willis. The function of the circle of Willis is to provide a shunt system should any of the vessels become damaged.
Arising from the circle are the three main vessels that supply the brain with blood; the anterior cerebral artery, middle cerebral artery, and the posterior cerebral artery.
It is important to be able to recognise the consequences of the occlusion of the three main vessels supplying the brain.
Anterior cerebral artery (ACA) occlusion
Occlusion of the anterior cerebral artery may result in the following defects
If stroke occurs prior to the anterior communicating artery it is usually well tolerated secondary to collateral circulation
Middle cerebral artery (MCA) occlusion
Occlusion of the middle cerebral artery may result in the following defects
Posterior cerebral artery (PCA) occlusion
Occlusion of the posterior cerebral artery may result in the following defects
Arising from the circle are the three main vessels that supply the brain with blood; the anterior cerebral artery, middle cerebral artery, and the posterior cerebral artery.
It is important to be able to recognise the consequences of the occlusion of the three main vessels supplying the brain.
Anterior cerebral artery (ACA) occlusion
Occlusion of the anterior cerebral artery may result in the following defects
- Hemiparesis of the contralateral foot and leg (more severely than the arm)
- Sensory loss of the contralateral foot and leg
- Motor dysphasia
If stroke occurs prior to the anterior communicating artery it is usually well tolerated secondary to collateral circulation
Middle cerebral artery (MCA) occlusion
Occlusion of the middle cerebral artery may result in the following defects
- Hemiparesis of the contralateral face and limbs
- Sensory loss of contralateral face and limbs
- Dysphasia (when dominant hemisphere affected)
- Contralateral neglect
- Homonymous hemianopia or quadrantanopia
- Dorsolateral prefrontal dysfunction
Posterior cerebral artery (PCA) occlusion
Occlusion of the posterior cerebral artery may result in the following defects
- Alexia without agraphia (left PCA)
- Contralateral loss of pain and temperature sensation
- Contralateral hemianopia
- Prosopagnosia
- Ipsilateral cranial nerve defects (V, VIII, IX, X, & XI)
- Horner's syndrome
