Hamzah's neuro pathology

Question 1

What is an ischaemic stroke?

Answer 1

Blocked artery leads to reduced blood flow to brain –> damage depends on location and time

Question 2

What is a haemorrhagic stroke?

Answer 2

• artery ruptures and bleeds within the brain

- can be secondary after an ischaemic stroke –> if reperfusion occurs, the dead endothelial cells are likely to rupture

Question 3

Aetiology of strokes

Answer 3

• atherothrombosis: damaged tunica intima –> atherosclerosis –> fibrous plaque breaks off –> blood clot formation
• emboli: AF, DVT, prosthetic valves
• CNS bleeds: HTN, trauma
• shock or sepsis - sudden decrease in BP
• vasculitis
• anti-phospholipid syndrome

Question 4

Risk factors for stroke

Answer 4

• FH, HTN, smoking, past TIA, high PCV (haematocrit), high alcohol consumption, increased clotting, PVD, contraceptive pill

Question 5

Pathogenesis of stroke

Answer 5

• no blood means no nutrients to brain cells
• high sodium in brain cells draws water in via osmosis –> cytotoxic oedema
• high calcium in brain cells –> damages lipids in mitochondria and lysosomes –> degenerative enzymes leak out
• 4-6hrs after infarct - inflammation damages the BBB

Question 6

Clinical presentation of stroke

Answer 6

• sudden onset
• focal neurological signs relate to distribution of affected artery
• severe headache and coma within hrs

Question 7

ACA occlusion

Answer 7

limbs affected

Question 8

MCA occlusion

Answer 8

chin to hip affected

Question 9

PCA

Answer 9

peripheral vision lost but not macular vision

Question 10

Cerebral infarcts (50%)

Answer 10

• hemiplegia
• initially flaccid, then spastic muscle
• dysphasia
• homonymous hemianopia

Question 11

Brainstem infarcts (25%)

Answer 11

• quadriplegia
• disturbances of gaze and vision
• locked in syndrome

Question 12

lacunar infarct (25%)

Answer 12

• in basal ganglia, internal capsule, thalamus and pons

- 5 different syndromes: ataxic hemiparesis, pure motor, pure sensory, sensorimotos, dysarthria (clumsy hand)

Question 13

Differential diagnosis of stroke

Answer 13

• Head injury, hypo/hyperglycaemia, subdural haemorrhage, intracranial tumours, hemiplegic migraine, epilepsy, CNS lymphoma

Question 14

Diagnostic tests for stroke

Answer 14

• FAST
• CT/MRI
• Hypertension - retinopathy and CXR –> big heart
• cardiac source of emboli - ECG –> AF
• cardiac doppler IS and CT/MRI angiography
• vasculitis - ANCA positive (IgG autoantibodies)

Question 15

Treatment of stroke

Answer 15

• 1st hr
• protect airway, NBM, check pulse, BP and ECG
• blood glucose
• thrombolysis - IV alteplase must be given within 4.5 hrs
• high dose aspirin (inhibits COX1, suppressing prostaglandins and thromboxane synthesis)
• clopidogrel (inhibits platelet aggregation by modifying platelet ADP receptors)

Question 16

Stroke prevention

Answer 16

Primary prevention

• control risk factors - statins
• exercise
• smoking cessation
• lifelong anticoagulation if left prosthetic heart valves

Secondary prevention

• control risk factors
• antiplatelet agents - clopidogrel
• warfarin if stroke from AF

Question 17

What is a TIA

Answer 17

• sudden onset of focal CNS phenomenon due to temporary occlusion of part of the cerebral circulation
• symptoms last <24hrs

Question 18

Aetiology of TIA

Answer 18

• atherothromboembolism (listen for bruits)
• cardiac embolism - AF, valve disease, prosthetic valve
• hyperviscosity - polycythaemia, leucocytosis, myeloma

Question 19

Carotid territory symptoms of TIA

Answer 19

• amaurosis fugax (painless temporary loss of vision in eye - emboli passes into retinal artery)
• aphasia
• hemiparesis (one sided weakness)
• hemianopic visual loss

Question 20

Vertebrobasilar territory symptoms of TIA

Answer 20

• diplopia (double vision), vertigo, vomiting
• choking and dysarthria (slurred speech)
• ataxia
• bilateral visual loss
• tetraparesis (all 4 limbs weak)

Question 21

What is not typical of a TIA

Answer 21

Global events such as syncope or dizziness

Question 22

Differential diagnosis of TIA

Answer 22

• hypoglycaemia, migraine aura, focal epilepsy, hyperventilation, retinal bleeds

Question 23

Diagnostic tests for TIA

Answer 23

• FBC, ESR, U&Es, glucose, CXR, ECG, carotid doppler and angiography

Question 24

Treatment of TIA

Answer 24

Control cardiovascular risks
- BP <140/85, statins, DM, smoking cessation

Antiplatelet drugs - aspirin 300mg then clopidogrel

Warfarin if cardiac source of emboli

Cardiac endarterectomy - removes plaque from inside of internal carotid arteries

Question 25

ABCD2 score in TIA

Answer 25

• = estimates the risk of a stroke after a TIA
• Age>60 = 1
• BP>140/90 = 1
• clinical features: unilateral weakness=2, speech disturbance without weakness=1
• duration of symptoms: >1hr=2, 10-59mins=1

> 4 - high risk and must be assessed by a specialist within 24 hrs

> 6 = strongly predicts a stroke - 35,5% in next week