Stroke Syndromes

Introduction

• Importance of understanding stroke syndromes for recognizing neurodeficits in patients with ischemic or hemorrhagic stroke.
• Different vascular territories affect specific areas of the brain and their clinical manifestations.

Middle Cerebral Artery (MCA) Syndrome

Supply Areas

• Supplies: Frontal lobe, parietal lobe (lateral portions), and part of the temporal lobe.

Clinical Manifestations

1. Contralateral Hemiplegia

   • Weakness on the opposite side of the body.
   • More prominently affects face and upper extremities over lower extremities (motor homunculus).

2. Contralateral Sensory Loss

   • Affects all sensations (touch, pain, temperature, vibration) on the opposite side.
   • More severely affects face and upper extremities compared to lower extremities.

3. Frontal Eye Fields

   • Located in the frontal lobe; involved in eye movement.
   • Damage leads to ipsilateral gaze deviation.

4. Wernicke's Area

   • Affects language comprehension; results in Wernicke's aphasia (receptive aphasia).

5. Broca's Area

   • Affects speech production; results in Broca's aphasia (expressive aphasia).

6. Optic Radiations

   • Damage can lead to contralateral homonymous hemianopia.

MCA Divisions

• Superior Division: Supplies primary motor and somatosensory cortex.
• Inferior Division: Supplies Wernicke's area, optic radiations.

Anterior Cerebral Artery (ACA) Syndrome

Supply Areas

• Supplies medial frontal lobe and medial parietal lobe.

Clinical Manifestations

1. Contralateral Weakness

   • More prominent in lower extremities than upper extremities and face.

2. Contralateral Sensory Loss

   • More pronounced in lower extremities than upper extremities and face.

3. Urinary and Fecal Incontinence

   • Due to damage in the paracentral lobule.

4. Behavioral Changes

   • Damage to prefrontal cortex can lead to akinetic mutism or abulia (lack of willpower).

5. Transcortical Motor Aphasia

   • Damage to connections with Broca's area; comprehension intact, difficulty with speech production.

Internal Carotid Artery (ICA) Syndrome

• Occlusion leads to symptoms of both MCA and ACA syndromes due to compromised blood flow to both territories.
• Amaurosis fugax: Transient monocular vision loss due to ICA insufficiency.

Watershed Zones

• Areas between major cerebral arteries; susceptible to ischemia during global hypoperfusion.
• MCA-ACA Watershed Zone: Causes proximal upper and lower extremity weakness (man-in-a-barrel syndrome).
• MCA-PCA Watershed Zone: Can cause visual dysfunctions like prosopagnosia and balance issues.

Posterior Cerebral Artery (PCA) Syndrome

Supply Areas

• Supplies occipital lobe, parts of the thalamus, and midbrain.

Clinical Manifestations

1. Contralateral Homonymous Hemianopia

   • Loss of visual field on the opposite side due to damage in the visual cortex.

2. Midbrain Syndromes

   • Weber's Syndrome: Contralateral hemiplegia and ipsilateral third nerve palsy.
   • Claude's Syndrome: Ipsilateral third nerve palsy and contralateral ataxia.
   • Benedict's Syndrome: Features of both Weber's and Claude's syndromes.

Basilar Artery Syndrome

Supply Areas

• Supplies pons, cerebellum, and brainstem.

Clinical Manifestations

1. Medial Pons Symptoms

   • Ipsilateral sixth nerve palsy, internuclear ophthalmoplegia, contralateral hemiplegia.

2. Lateral Pons Symptoms

   • Loss of coordination, vertigo, nystagmus, Horner's syndrome, facial weakness.

3. Cerebellar Symptoms

   • Ataxia, dysmetria, and dysdiadochokinesia.

Vertebral Artery Syndromes

Supply Areas

• Supplies the medulla and posterior inferior cerebellum.

Clinical Manifestations

1. Medial Medulla Symptoms

   • Ipsilateral tongue weakness (hypoglossal nerve), contralateral hemiplegia, sensory loss.

2. Lateral Medulla Symptoms (Wallenberg's Syndrome)

   • Dysphagia, dysphonia, vertigo, nystagmus, Horner's syndrome, sensory loss from the face and body.

Conclusion

• Understanding stroke syndromes aids in recognizing clinical presentations and managing patient care.
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