Stroke (ischaemic and haemorrhagic)

Question 1

Definition

Answer 1

· Rapid permanent neurological deficit from cerebrovascular insult. Also defined clinically, as focal or global impairment of CNS function developing rapidly and lasting > 24 hrs

· Can be subdivided based on:
o Location - anterior circulation vs posterior circulation
o Pathological Process - infarction vs haemorrhage

Question 2

Aetiology/Risk factors (infarction (80%))

Answer 2

o Thrombosis
· Can occur in small vessels (lacunar infarcts)
· Can occur in larger vessels (e.g. middle cerebral artery)
· Can arise in prothrombotic states (e.g. dehydration, thrombophilia)

o Emboli
· From carotid dissection, carotid atherosclerosis, atrial fibrillation
· NOTE: they can arise from venous blood clots that pass through a septal defect (e.g. VSD) and get lodged in the cerebral circulation

o Hypotension
· If the blood pressure is below the autoregulatory range required to maintain cerebral blood flow, you can get infarction in the watershed zones between different cerebral artery territories

o Others
· Vasculitis
· Cocaine (arterial spasm)

Question 3

Aetiology/Risk factors (haemorrhage (10%))

Answer 3

o Hypertension

o Charcot-Bouchard microaneurysm rupture (DEFINITION: aneurysms within the brain vasculature that occur in small blood vessels)

o Amyloid angiopathy

o Arteriovenous malformations

o Less common: trauma, tumours, vasculitis

Question 4

Epidemiology

Answer 4

· COMMON

· Incidence: 2/1000

· 3rd most common cause of death in industrialised countries

· Usual age of stroke patients: 70+

Question 5

Presenting symptoms

Answer 5

· SUDDEN-ONSET
· Weakness
· Sensory, visual or cognitive impairment
· Impaired coordination
· Impaired consciousness
· Head or neck pain (if carotid or vertebral artery dissection)
· Enquire about time of onset (critical for emergency management if < 4.5 hrs)
· Enquire about history of AF, MI, valvular heart disease, carotid artery stenosis, recent neck trauma or pain

Question 6

Signs on physical examination

Answer 6

· Examine for underlying cause (e.g. atrial fibrillation)

· Infarction - see next 3 flashcards

Question 7

Signs on physical examination (lacunar infarcts)

Answer 7

· Affecting the internal capsule or pons: pure sensory or motor deficit (or both)

· Affecting the thalamus: loss of consciousness, hemisensory deficit

· Affecting the basal ganglia: hemichorea, hemiballismus, parkinsonism

Question 8

Signs on physical examination (anterior circulation)

Answer 8

· Anterior Cerebral
§ Lower limb weakness
§ Confusion

· Middle Cerebral
§ Facial weakness
§ Hemiparesis (motor cortex)
§ Hemisensory loss (sensory cortex)
§ Apraxia
§ Hemineglect (parietal lobe)
§ Receptive or expressive dysphasia (due to involvement of Wernicke's and Broca's areas)
§ Quadrantopia (if superior or inferior optic radiations are affected)

Question 9

Signs on physical examination (posterior circulation)

Answer 9

· Posterior Cerebral - hemianopia

· Anterior Inferior Cerebellar - vertigo, ipsilateral ataxia, ipsilateral deafness, ipsilateral facial weakness

· Posterior Inferior Cerebellar (affected in lateral medullary syndrome) - vertigo, ipsilateral ataxia, ipsilateral Horner’s syndrome, ipsilateral hemisensory loss, dysarthria, contralateral spinothalamic sensory loss

· Basilar Artery - cranial nerve pathology and impaired consciousness

· Multiple Lacunar Infarcts - vascular dementia, urinary incontinence, gait apraxia, shuffling gait, normal or excessive arm-swing

· Intracerebral - headache, meningism, focal neurological signs, nausea/vomiting, signs of raised ICP, seizures

Question 10

Investigations

Answer 10

· Bloods
o Clotting profile - check if thrombophilia (especially in young patients)

· ECG
o Check for arrhythmias that may be the source of the clot

· Echocardiogram
o Identify cardiac thrombus, endocarditis and other cardiac sources of embolism

· Carotid Doppler Ultrasound
o Check for carotid artery disease (e.g. atherosclerosis)

· CT Head Scan
o Rapid detection of haemorrhages

· MRI-Brain
o Higher sensitivity for infarction but less available

· CT Cerebral Angiogram
o Detect dissections or intracranial stenosis

Question 11

Management plan (hyperacute stroke)

Answer 11

o If < 4.5 hrs from onset

o Exclude haemorrhage using CT-head

o If haemorrhage excluded, thrombolysis may be considered

Question 12

Management plan (acute ischaemic stroke)

Answer 12

o Aspirin + Clopidogrel to prevent further thrombosis (once haemorrhage excluded on CT head)

o Heparin anticoagulation considered if there is a high risk of emboli recurrence or stroke progression

o Formal swallow assessment (NG tube may be needed)

o GCS monitoring

o Thromboprophylaxis

Question 13

Management plan (secondary prevention)

Answer 13

o Aspirin and dipyridamole

o Warfarin anticoagulation (atrial fibrillation)

o Control risk factors: hypertension, hyperlipidaemia, treat carotid artery disease

· Surgical Treatment - carotid endarterectomy

Question 14

Possible complications

Answer 14

· Cerebral oedema (increased ICP)
· Immobility
· Infections
· DVT
· Cardiovascular events
· Death

Question 15

Prognosis

Answer 15

· 10% mortality in the first month
· Up to 50% that survive will be dependent on others
· 10% recurrence within 1 year
· Prognosis for haemorrhagic is WORSE than ischaemic

Question 16

Cerebellar stroke triad

Answer 16

Ataxia
Nausea
Headache