Stroke Syndromes Lecture Notes

Introduction

• Stroke syndromes are important for understanding clinical manifestations based on affected vascular territories.
• Types of strokes: Ischemic and hemorrhagic strokes.
• Understanding which vessel supplies which brain area helps predict neurodeficits.

Middle Cerebral Artery (MCA) Syndrome

• Supplied Areas: Frontal lobe, lateral parietal lobe, and part of the temporal lobe.
• Clinical Manifestations:
  • Motor Cortex (Frontal Lobe): Affects voluntary skeletal muscle movement.
    • Lesion Effects: Contralateral hemiplegia (face and upper extremities more than lower extremities).
  • Somatosensory Cortex (Parietal Lobe): Sensory loss on contralateral side (face and upper extremities more than lower extremities).
  • Frontal Eye Fields: Ipsilateral gaze deviation if affected.
  • Wernicke’s Area (Temporal Lobe): Receptive aphasia (impaired language comprehension).
  • Broca’s Area (Frontal Lobe): Expressive aphasia (impaired language expression).
  • Optic Radiations: Causes visual field defects (contralateral homonymous hemianopia).
  • Right MCA Effects: May cause apraxia and hemineglect.
    • Apraxia: Difficulty performing motor movements despite intact motor function.
    • Hemineglect: Ignoring sensations on the contralateral side of the body.

Anterior Cerebral Artery (ACA) Syndrome

• Supplied Areas: Medial frontal and parietal lobes.
• Clinical Manifestations:
  • Motor/Sensory Cortex: Contralateral weakness and sensory loss (lower extremities more than upper and face).
  • Paracentral Lobule: Urinary and fecal incontinence.
  • Prefrontal Cortex/Anterior Cingulate Cortex: Abulia and akinetic mutism (loss of motivation and movement).
  • Transcortical Motor Aphasia: Similar to Broca's but with preserved repetition.

Internal Carotid Artery (ICA) Syndrome

• May lead to symptoms of both MCA and ACA syndromes due to its branching.
• Additional Symptoms: Amaurosis fugax (transient monocular vision loss).

Watershed Zones

• MCA-ACA Watershed: Proximal limb weakness and sensory loss, called Man-in-the-Barrel syndrome.
  • Caused by: Global hypoperfusion.
• MCA-PCA Watershed: Visual dysfunctions, including prosopagnosia and Balint's syndrome.

Posterior Cerebral Artery (PCA) Syndrome

• Supplied Areas: Occipital lobe, inferior temporal lobe, thalamus, and midbrain.
• Clinical Manifestations:
  • Visual Cortex Lesions: Contralateral homonymous hemianopia.
  • Midbrain Syndromes: Include Weber's, Claude's, and Benedict's syndromes.
    • Weber's Syndrome: Third nerve palsy and contralateral hemiplegia.
    • Claude's Syndrome: Third nerve palsy and contralateral ataxia.
    • Benedict's Syndrome: Combination of Weber's and Claude's.

Basilar Artery Syndrome

• Supplied Areas: Pons and cerebellum.
• Clinical Manifestations:
  • Medial Pons (paramedian branches): Sixth nerve palsy, internuclear ophthalmoplegia, contralateral hemiplegia.
  • Lateral Pons (AICA): Ipsilateral ataxia, vertigo, hearing loss, facial weakness.
  • Cerebellar Involvement: Ataxia, dysmetria, dysdiadochokinesia.

Vertebral Artery Syndrome

• Supplied Areas: Medulla and posterior inferior cerebellum.
• Clinical Manifestations:
  • Medial Medulla (vertebral and anterior spinal artery): Ipsilateral tongue deviation, contralateral hemiplegia, contralateral sensory loss.
  • Lateral Medulla (PICA): Wallenberg's syndrome, including ipsilateral ataxia, dysphagia, and Horner's syndrome.
  • Cerebellar Involvement: Ipsilateral ataxia.

Conclusion

• Stroke syndromes are complex but understanding vascular supply and associated symptoms is key for diagnosis and treatment.
• Supporting content available through additional resources and practice.