The Middle Cerebral Artery (MCA) is the most common site of stroke. MCA infarcts occur in two general regions:  superficial divisions and lenticulostriate branches.

MOTOR CORTEX

Movement of right head, neck, trunk and arm.

SENSORY CORTEX

Sensation from right head, neck, trunk and arm.

BROCA'S AREA

Expressive speech area.
Integration with other language areas.

WERNICKE'S AREA

Receptive speech area.
Integration with other language areas.

MOTOR CORTEX

Movement of left head, neck, trunk and arm.

SENSORY CORTEX

Sensation from left head, neck, trunk and arm.

STRIATUM
(Caudate and Putamen)

Receives cortical inputs relayed to basal ganglia.
Functions in direct and indirect pathways for initiation and control of movement.

INTERNAL CAPSULE
(Anterior Limb)

Contains corticopontine and thalamocortical fibers.

INTERNAL CAPSULE
(Genu)

Contains descending fibers of the corticobulbar tract.

GLOBUS PALLIDUS

Site of origin of output from the basal ganglia to substantia nigra and thalamus.
Functions in direct and indirect pathways for initiation and control of movement.

CORONAL SECTIONS

HORIZONTAL SECTIONS

LOCATION OF INFARCT DEFICIT
Left MCA
Superficial Division		 Right face and arm upper motor weakness due to damage to motor cortex, expressive (Broca’s) aphasia due to damage to Broca’s area. There may also be right face and arm cortical-type sensory loss if the infarct involves the sensory cortex. Other deficits include receptive (Wernicke’s) aphasia due to damage to Wernicke’s area.
Right MCA
Superficial Division		 Left face and arm upper motor weakness due to damage to motor cortex. Left hemineglect (variable) due to damage to non-dominant association areas. There may also be left face and arm cortical type sensory loss if the infarct involves the sensory cortex.
Left MCA
Lenticulostriate Branches		 Right pure upper motor hemiparesis due to damage to the basal ganglia (globus pallidus and striatum) and the genu of the internal capsule on the left side. Larger infarcts extending to the cortex may produce cortical deficits such as aphasia.
Right MCA
Lenticulostriate Branches		 Left pure upper motor hemiparesis due to damage to the basal ganglia (globus pallidus and striatum) and the genu of the internal capsule on the right side. Larger infarcts extending to the cortex may produce cortical deficits such as aphasia.