Makindo Medical Notes

🧠 Vascular Territories of the Brain

🔴 Internal Carotid Artery (ICA)

• Supplies ipsilateral frontal, parietal, temporal, and occipital lobes.
• Clinical: Infarcts often mimic MCA strokes, though ACA territory may be spared due to collateral flow via the anterior communicating artery.

👁 Ophthalmic Artery

• Central retinal artery occlusion → sudden monocular blindness.

🔗 Posterior Communicating Artery

• Links anterior & posterior circulation; aneurysms here may compress CN III.
• Contributes to thalamus, hypothalamus, and caudate tail perfusion.

🟡 Anterior Choroidal Artery

• Supplies:
  • Posterior limb of internal capsule → contralateral motor/sensory loss.
  • Optic tract & lateral geniculate body → homonymous hemianopia.
  • Choroid plexus of lateral ventricle, globus pallidus, substantia nigra.

🟥 Anterior Cerebral Artery (ACA)

• Deficits: Contralateral weakness & sensory loss, leg > arm.
• No hemianopia; gaze preference to lesion side.
• Dominant hemisphere → expressive dysphasia, dyspraxia.
• Nondominant hemisphere → neglect, visuospatial deficits.
• Behavioural changes: apathy, abulia, disinhibition.
• Paracentral lobule infarction → urinary incontinence.

🟦 Middle Cerebral Artery (MCA)

• Proximal M1 occlusion: Involves basal ganglia & cortex → severe hemiparesis (arm > leg), sensory loss, hemianopia, gaze palsy, aphasia (D), neglect (ND).
• Distal branches spared lenticulostriates: Cortical signs predominate.
• Superior division: Frontal lobe → contralateral face/arm weakness, gaze paresis, expressive dysphasia (D).
• Inferior division: Parietotemporal cortex → sensory loss, hemianopia, receptive dysphasia (D) or neglect (ND).
• Lenticulostriates: Small penetrating arteries → lacunar infarcts of basal ganglia/internal capsule.

🟣 Posterior Cerebral Artery (PCA)

• Proximal P1 occlusion: Infarcts in thalamus, midbrain, mediobasal temporal lobes, occipital cortex → hemiparesis, sensory loss, hemianopia.
• Distal occlusion: Contralateral homonymous hemianopia ± neglect, prosopagnosia (ND).
• Bilateral PCA occlusion: Cortical blindness with preserved pupillary reflexes (Anton’s syndrome), bilateral thalamic infarction → amnesia.

🟤 Basilar Artery

• Occlusion → headache, vertigo, quadriplegia, seizures, coma.
• Locked-in syndrome: preserved vertical gaze & blinking only.
• Top of the basilar: infarcts of midbrain, thalamus, hypothalamus, temporal & occipital lobes → CN III palsy, vertical gaze palsy, ataxia, memory disturbance.

🌐 Midbrain Syndromes

• Weber: Ipsilateral CN III palsy + contralateral hemiparesis.
• Benedikt: Ipsilateral CN III palsy + contralateral ataxia/tremor (red nucleus).
• Nothnagel: Ipsilateral CN III palsy + cerebellar signs + Horner’s syndrome.

🔵 Pons Syndromes

• Millard–Gubler: Ipsilateral CN VI & VII palsy + contralateral hemiparesis.
• Basilar perforator lesions → “crossed” brainstem signs.

🟢 Medullary Syndromes

• Lateral Medullary (Wallenberg, PICA/Vertebral): Horner’s, IX–X palsy (dysphagia, hoarseness), ipsilateral ataxia, contralateral sensory loss.
• Medial Medullary (ASA): Ipsilateral tongue weakness + contralateral hemiparesis & hemisensory loss.