Stroke Syndromes Lecture Notes

Introduction

• Importance of understanding stroke syndromes:
  • Stroke results in neurodeficits based on affected vascular territory
  • Understanding the vessel supply helps predict clinical manifestations

Middle Cerebral Artery (MCA) Syndrome

• Supplied Areas:

  • Frontal lobe
  • Parietal lobe (more lateral)
  • Temporal lobe

• Frontal Lobe Impact:

  • Primary Motor Cortex:
    • MCA stroke affects movement on contralateral side
    • Motor homunculus: Face & Upper Extremities > Lower Extremities
    • Results in contralateral hemiplegia (face & upper extremities)
  • Frontal Eye Fields:
    • Affected by superior division of MCA
    • Results in ipsilateral gaze deviation

• Sensory Impact:

  • Primary Somatosensory Cortex:
    • Results in contralateral sensory loss (face & upper extremities)

• Language Areas:

  • Wernicke’s Area:
    • Comprehension of language is affected (receptive aphasia)
    • Involvement with inferior division of MCA
  • Broca's Area:
    • Affected by superior division
    • Results in Broca's aphasia (expressive aphasia)

• Optic Radiations:

  • Affected by inferior division
  • Results in contralateral homonymous hemianopia

• Right MCA Syndrome:

  • Results in apraxia and hemineglect

Anterior Cerebral Artery (ACA) Syndrome

• Supplied Areas:

  • Medial frontal lobe
  • Medial parietal lobe

• Motor & Sensory Impact:

  • Primary Motor & Somatosensory Cortex:
    • Contralateral weakness & sensory loss
    • Lower extremities > Upper extremities

• Paracentral Lobule:

  • Affects urinary & fecal continence

• Behavioral Impact:

  • Prefrontal Cortex & Anterior Cingulate:
    • Leads to abulia and akinetic mutism

• Transcortical Motor Aphasia:

  • Speech production issues distinct from Broca’s

Internal Carotid Artery (ICA) Syndrome

• Can mimic MCA and ACA syndromes depending on area affected
• Ophthalmic Artery Involvement:
  • Can lead to amaurosis fugax (transient monocular vision loss)

Watershed Zones

• MCA-ACA Watershed Zone:

  • Man-in-the-barrel syndrome

• MCA-PCA Watershed Zone:

  • Visual dysfunctions, including prosopagnosia & Balint’s syndrome

Posterior Circulation Strokes

• Posterior Cerebral Artery (PCA) Syndrome:
  • Supplies occipital lobes, thalamus, midbrain
  • Visual Impacts:
    • Contralateral homonymous hemianopia
  • Midbrain Syndromes:
    • Weber Syndrome: Third nerve palsy, contralateral hemiplegia
    • Claude Syndrome: Third nerve palsy, contralateral ataxia
    • Benedikt Syndrome: Combination of Weber and Claude

Basilar Artery Syndrome

• Supplied Areas:
  • Pons and cerebellum
  • Medial Pons:
    • Paramedian branches affect medial pons
    • Lead to loss of conjugate gaze, internuclear ophthalmoplegia, sensory loss
  • Lateral Pons:
    • AICA affects lateral pons & anterior inferior cerebellum
    • Results in ipsilateral ataxia, vertigo, nystagmus, Horner's syndrome

Vertebral Artery Syndrome

• Supplied Areas:
  • Medulla and posterior inferior cerebellum
  • Medial Medulla:
    • Supplied by vertebrals & anterior spinal artery
    • Results in contralateral hemiplegia, tongue deviation
  • Lateral Medulla (Wallenberg Syndrome):
    • Supplied by PICA
    • Results in ipsilateral ataxia, bulbar palsy, Horner's syndrome

Conclusion

• Stroke syndromes are crucial for diagnosing and managing stroke patients
• Understanding vascular territories helps predict clinical outcomes

Understanding these stroke syndromes and their presentations is critical for quick diagnosis and effective management of stroke patients.