Stroke patho-physiology

Question 1

Ischaemic Stroke (Most common – ~85% of cases)

Answer 1

*Occurs when a blood clot or narrowing of arteries blocks blood flow to the brain.
*Cause:
- Atherosclerosis (fatty plaque buildup)
- Thrombus (blood clot formed in brain vessels)
- Embolus (clot travels from heart or elsewhere to brain)
*Example in practice:
Simon (in your case study) had an ischaemic stroke, likely due to his history of cardiac arrhythmia, which can cause emboli.
*Results in:
Tissue death in the area of the brain affected
Common symptoms: weakness, speech problems, vision changes

Question 2

Haemorrhagic Stroke (~15% of cases)

Answer 2

*Occurs when a blood vessel ruptures, causing bleeding into or around the brain.
*Types:
- Intracerebral haemorrhage: bleeding into brain tissue
- Subarachnoid haemorrhage: bleeding into the space around the brain (often due to an aneurysm)
*Cause:
- High blood pressure
- Aneurysms
- Trauma
- Blood-thinning medications
*Symptoms:
- Sudden, severe headache
- Nausea/vomiting
- Loss of consciousness

Question 3

Transient Ischaemic Attack (TIA) – “Mini-stroke”

Answer 3

*Temporary blockage of blood flow to the brain that resolves within 24 hours and does not cause permanent damage.
*Important warning sign for future stroke
*Needs immediate medical evaluation

Question 4

Primary Motor Cortex (Right Hemisphere – Frontal Lobe)

Answer 4

*Main pathology:
Infarction of the primary motor cortex leads to contralateral (left-sided) hemiparesis, due to interruption of voluntary motor pathways (corticospinal tract).
*Relevant symptoms in Simon:
- Left-sided weakness (hemiparesis), especially in upper limb
- Clumsiness and reduced fine motor control
- Difficulty using his left arm for dressing, washing
- Reliance on his wife for upper body activities

Question 5

Internal Capsule (Right Side)

Answer 5

*Main pathology:
This is a key area where motor and sensory fibres converge. A stroke here can result in dense hemiparesis and sensory loss on the opposite side of the body.
*Relevant symptoms in Simon:
- Significant weakness and poor coordination on the left
- Circumduction gait due to inability to lift and control the left leg
- Foot drop on the left side
- Sensory loss in the left arm and swelling in the left foot (likely due to lack of movement and awareness)

Question 6

Primary Somatosensory Cortex (Right Parietal Lobe)

Answer 6

*Main pathology:
Damage here impairs perception of touch, position, and pressure on the opposite side of the body.
*Relevant symptoms in Simon:
- Numbness and reduced sensation in the left upper limb
- Poor proprioception (body awareness), affecting balance and limb use
- Possibly contributes to arm being unsupported, causing shoulder subluxation

Question 7

Premotor Cortex & Supplementary Motor Area (Right Hemisphere)

Answer 7

*Main pathology:
These areas help plan and coordinate movements. Damage here causes poor initiation and sequencing of movement, especially for more complex actions.
*Relevant symptoms in Simon:
- Clumsiness when walking
- Effortful transfers and mobility tasks
- Need for external support (stick, furniture) to steady himself
- Difficulty coordinating sit-to-stand movement

Question 8

Cerebellar Connections or Brainstem Pathways (Possibly Affected)

Answer 8

*Main pathology:
If the stroke affects connections between the cortex and cerebellum or brainstem, it can impair balance, coordination, and posture.
*Relevant symptoms in Simon:
- Fatigue and postural instability
- Reliance on walls and furniture for balance
- Poor standing stability, especially during fatigue
- Heavily weight-bearing through the right side

Question 9

Which artery is blocked in simons case?

Answer 9

*Right Middle Cerebral Artery (MCA)
*Why?
Simon has left-sided weakness and sensory loss, especially in his arm and hand, which are classic signs of a right MCA stroke.