Stroke Flashcards
Define Stroke?
Rapid permenant neurological deficit from cerebrovascular insult
How is stroke defined clinically?
Focal or global impairment of CNS function developing rapidly and lasting > 24hrs
How can stroke be subdivided?
Location - anterior circulation vs posterior circulation
Pathological Process - infarction vs haemorrhage
What is the ratio between Infarction and Haemorrhage?
Infarction (80%)
Haemorrhage (10%)
Whatt are some of the causes of Infarction?
Thrombosis Emboli Hypotension Vasculitis Cocaine (arterial spasm)
Where can thrombosis occur?
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)
Where can Emboli occur?
Carotid Dissection
Carotid Atherosclerosis
Atrial Fibrillation
Venous blood clots that pass through a septal defect and get lodged in the cerebral circulation
How can Hypotension cause Infarction?
If the bp is below the autoregulatory range required to maintain cerebral blood flow, you can get infarction in the watershed zones between different cerebral artery territories
What can cause Haemorrhage?
Hypertension Charcot-Bouchard microaneurysm rupture Amyloid Angiopathy Arteriovenous Malformations Trauma Tumours Vasculitis
What is Charcot-Bouchard Microaneurysm Rupture?
Aneurysms within the brain vasculature that occur in small blood vessels
What is the epidemiology of stroke?
COMMON
Incidence: 2/1000
3rd most common cause of death in industrialised countries
Usual age of patients are 70+
What are the presenting symptoms of stroke?
Sudden Onset Weakness Sensory, visual or cognitive impairment Impaired Coordination Impaired Consciousness Head or neck pain
What do we usually enquire about when talking about stroke?
Time of Onset (Critical for emergency management if <4.5 hrs)
History of AF, MI, Valvular Heart Disease, Carotid Artery Stenosis, Recent Neck Trauma or pain
What do we usually do when doing a physical examination for stroke?
Examine for underlying cause (e.g. atrial fibrillation)
What are the signs of Lacunar Infarcts that affect the internal capsule or pons?
Pure sensory or motor Deficit
Occasionally both
What are the signs of Lacunar Infarcts that affect the thalamus?
Loss of consciousness
Hemisensory Deficit
What are the signs of Lacunar Infarcts that affect the basal ganglia?
Hemichorea
Hemiballismus
Parkinsonism
What are the signs of an Anterior Cerebral Infarct?
Lower Limb Weakness
Confusion
What are the signs of a Middle Cerebral Infarct?
Facial Weakness Hemiparesis Hemisensory Loss Apraxia Hemineglect Receptive or expressive dysphasia Quadrantopia
What is Hemiparesis and what part of the brain is it related to?
Weakness on one side of the body
Motor Cortex
What is Hemisensory loss and what part of the brain is it related to?
Loss of Sensation on one side of the body
What is Hemineglect and what part of the brain is it related to?
It is an unawareness or unresponsiveness to things on one side of them
Parietal Lobe
What is receptive and expressive dysphasia due to?
Due to involvement of Wernicke’s and Broca’s Areas
When does Quadrantopia occur?
If superior or inferior optic radiations are affected
What signs do Posterior Cerebral Infarcts present with on physical examination?
Hemianopia
What signs do Anterior Inferior Cerebellar Infarcts present with on physical examination?
Vertigo
Ipsilateral Ataxia
Ipsilateral Deafness
Ipsilateral Facial Weakness
What signs do Posterior Inferior Cerebrallar Infarcts present with on physical examination?
Vertigo Ipsilateral Ataxia Ipsilateral Horner's Syndrome Ipsilateral Hemisensory Loss Dysarthria Contralateral Spinothalamic Sensory Loss
When is the Posterior Inferior Cerebellar artery affected?
Lateral Medullary Syndrome
What signs do Basilar Artery Infarcts present with on physical examination?
Cranial Nerve Pathology and Impaired Consciousness
What signs do Multiple Lacunar Infarcts present with on physical examination?
Vascular Dementia Urinary Incontinence Gait Apraxia Shuffling Gait Normal or Excessive Arm-Swing
What signs do Intracerebral Infarcts present with on physical examination?
Headache Meningism Focal Neurological Signs Nausea/vomiting Signs of raised ICP Seizures
What bloods would you do for a stroke?
Clotting profile -check if thrombophilia (especially in young patients)
Why would you do an ECG in stroke?
Check for arrhythmias that may be the source of the clot
Why would you do an Echocardiogram for stroke?
Identify cardiac thrombus, endocarditis and other cardiac sources of embolism
Why would you do a Carotid Doppler Ultrasound in stroke patients?
Check for carotid artery disease (e.g. atherosclerosis)
Why do we do a CT head scan in stroke patients?
Rapid Detection of haemorrhages
Why do we do an MRI (brain) in stroke patients?
Higher sensitivity for infarction but less available
Why do we do a CT Cerebral Angiogram for stroke patients?
Detect Dissections or intracranial stenosis
What is the management plan for Hyperacute Stroke?
If < 4.5 hours from onset
Exclude haemorrhage using CT-head
If haemorrhage excluded, thrombolysis may be considered
What is the management plan for Acute Ischaemic Stroke?
Aspirin + Clopidogrel to prevent further thrombosis (once haemorrhage excluded on CT head)
Heparin anticoagulation considered if there is a high risk of emboli recurrence or stroke progression
Formal Swallow Assessment (NG tube may be needed)
GCS monitoring
Thromboprophylaxis
What is the secondary prevention for stroke?
Aspirin and dipyridamole
Warfarin anticoagulation (atrial fibrillation)
Control Risk Factors
What are the risk factors for stroke?
Hypertension
Hyperlipidaemia
Treat Carotid Artery Disease
What surgical treatment could we do in stroke patients?
Carotid Endarterectomy
What are the possible complications of stroke?
Cerebral Oedema (increased ICP) Immobility Infections DVT Cardiovascular Events Death
