Middle Cerebral Artery

Anterior Cerebral Artery - Coronal Plane

Move the cursor along the course of the anterior and middle cerebral artery and its branches to identify individual segments and their perfusion targets.

Supplies most of the temporal lobe, anterolateral frontal lobe, and parietal lobe.
Perforating branches supply the posterior limb of the internal capsule, part of the head and body of the caudate and globus pallidus.
Unilateral occlusion of Middle Cerebral Arteries at the stem (proximal M1 segment) results in:
- Contralateral hemiplegia affecting face, arm, and leg (lesser).
- Homonymous hemianopia - Ipsilateral head/eye deviation.
- If on left: global aphasia.
Usually occlusion is embolic in nature - thrombotic occlusion more common in carotids.

A1 Segment
(Anterior Cerebral Artery)

From Internal Carotid Bifurcation to Anterior Communicating Artery.

A1 Branches:
Anterior Communicating Artery
(connects both sides of anterior circulations).

Medial Lenticulostriate Arteries (supply basal ganglia, anterior limb of internal capsule).

Recurrent Artery of Heubner (supplies head of caudate and anteroinferior internal capsule).

NEUROVASCULAR SYNDROME
Anterior Cerebral Arteries at their stems results in infarction of the anteromedial surface of the cerebral hemispheres:

Paraplegia
Incontinence
Abulic and motor aphasia Personality change
Contralateral grasp reflex.

Penetrating Branches:
Infarction of anterior corpus callosum and basal ganglia structures (caudate, globus pallidus). Transient hemiparesis seen. Individual may become inattentive, forgetful, or agitated and psychotic

Pericallosal Artery

Continuation of the Anterior Cerebral Artery as it arches superiorly and posteriorly.

Supplies the medial surface of the cerebral hemispheres and corpus callosum.

Horizontal (M1) Segment
Middle Cerebral Artery

Branches include lateral lentciulostriate arteries.

NEUROVASCULAR SYNDROME
Unilateral occlusion of
Proximal M1 Segment
results in deficits in:

MOTOR
Contralateral Hemiplega
(face and arm, lower extremity less affected.

SENSORY
Homonoymous Hemianopia + Deviation of head/eyes toward the side of the lesion.

LANGUAGE
LEFT lesions: Global aphasia.
RIGHT lesions: Anosognosia.

Sylvian (M2) Segment
Middle Cerebral Artery

Segment divides into superior and inferior divisions which can be a site for an embolus to lodge.

Branches supply:
Temporal Lobe and Insular Cortex (sensory language area of Wernicke)
Parietal Lobe
(sensory cortical areas)
Inferolateralr frontal lobe.

NEUROVASCULAR SYNDROME
Superior Division Infarction:
"Brachiofacial paralysis"
Sensorimotor deficit involving face and arm, leg to a lesser extent. Foot is spared.
Ipsilateral deviation of head/eyes.
With Left lesion may have initial global aphasia -> motor aphasia.
No impairment of alertness.
(Can be further subdivided if only one branch of division is affected).

Inferior Division Infarction:
Rarer than Superior Division Infarctions.
Superior quadrantanopia / homonymous hemianopia.
LEFT lesion: Wernicke aphasia (deficit in comprehension of spoken/written language)
RIGHT lesion: Left-sided visual neglect.

Cortical (M3) Segment
Middle Cerebral Artery

Distal branches of MCA course laterally to insular cortex and loop around operculum - "Candelabra" effect seen on lateral angiograms.

Embolization of individual cortical branches can produce highly circumscribed infarctions accompanied by specific neurologic deficits.

Lateral
Lenticulostriate Arteries

Branch of M1 Segment of MCA.

Supplies basal ganglia structures: Part of head and body of caudate, globus pallidus, putamen, and the posterior limb of the internal capsule.

NEUROVASCULAR SYNDROME
Lateral Lenticulostriate A.:
Damage to the internal capsule resulting in contralateral hemiparesis and sensory deficit. Speech may be affected (medial tempora lobe) as well as visual function (Meyer's loop: optic radiations affected).