Neurovascular Anatomy: Internal Carotid Artery: Middle Cerebral Artery: Sylvian Segment

Middle Cerebral Artery

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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)
Inferolateral frontal lobe.

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.