Stroke/TIA Flashcards
What is the definition of a stroke?
Sudden onset of focal neurological deficits that have a vascular origin and that last longer than 2 hours or use death
Is ‘stroke’ a diagnosis and why?
No - it is the experience of persisting neurological complications of cardiovascular disease
What is the distribution of the anterior cerebral artery?
Superior and medial cerebrum
What is the distribution of the middle cerebral artery?
Bulk of the lateral surface of the cerebrum
What is the distribution of the posterior cerebral artery?
Occipital lobe
What are the problems associated with the anterior cerebral artery?
Contralateral weakness and sensory loss in the legs
Loss of voluntary control of urination
Visual disturbance
What are the problems associated with the middle cerebral artery?
Contralateral weakness and sensory loss, especially of arm and face
Homonymous hemianopia
Aphasia
Visuospatial problems
What are the problems associated with the posterior cerebral artery?
Macular sparing homonymous hemianopia
What are the types of stroke and the proportion of those?
Ischaemic stroke - 80%
Haemorrhagic stroke - 17%
Other - 3%
What is an ischaemic stroke?
Cerebral vessel occlusion and subsequent infarction
What are the types of ischaemic stroke, and what are they?
Thrombotic - blockage of vessels at the site of clot development
Embolic stroke - clots that arise distally, break off from site of origin and block downstream
Where can embolic strokes come from?
Break off from atherosclerotic plaques at for example the carotid arteries or the heart in MI/AF/endocarditis
What are haemorrhage strokes?
Consequence of intracerebral haemorrhage reducing blood supply to certain areas of the brain
or mass effect of the clot
What are the causes of haemorrhagic strokes?
Uncontrolled hypertension Trauma Aneurysm Clotting disorders Tumours
What are causes of strokes other than ischaemic and haemorrhagic?
Antiphospholipid syndrome, vasculitis
Septic
Carotid artery dissection
How does sepsis cause a stroke?
Sudden drop in BP can result in hypoperfusion of areas of the brain that are the border zones between 2 artery territories
What causes carotid artery dissection?
Hypertension
Whiplash-like trauma
Who are strokes caused by carotid artery dissection more likely in?
People under 40 - account for 20%
What are the presenting features of a stroke caused by carotid artery dissection?
Focal neurological deficits
Pain in the neck or face
Horner’s syndrome - dilated pupil and droopy eyelid
Lower cranial nerve symptoms - facial weakness, vision loss, dysarthria
What are conditions that can mimic a stroke?
SOL Hypoglycaemia Epilepsy and Todd's palsy Delirium Syncope
What are the risk factors for a stroke?
CVD such as angina, MI, peripheral vascular disease Previous stoke or TIA AF Carotid artery disease HTN Diabetes Smoking Vasculitis Thrombophilia Combined contraceptive pill
What are the types of stroke under the Oxford Classification?
Total anterior circulation stroke (TACS)
Partial anterior circulation stroke (PACS)
Posterior circulation syndrome (POCS)
Lacunar stroke (LACS)
What arteries are affected in a total anterior circulation stroke?
Blockage of both anterior and middle cerebral arteries
What arteries are affected in a partial anterior circulation stroke?
Blockage of one of anterior or middle cerebral arteries
What arteries are affected in a posterior circulation syndrome?
Vertebral basilar arteries
What arteries are affected in a lacunar stroke?
Multiple small vessel infarcts in basal ganglia an thalamus
What is the diagnostic criteria for a total anterior circulation stroke?
All 3 of:
- Unilateral weakness +/- sensory loss of face, arm or leg
- Homonymous hemianopia
- Higher cerebral dysfunction: dysphasia, visuospatial problems
What is the diagnostic criteria for a partial anterior circulation stroke?
2 of:
- Unilateral weakness +/- sensory loss of face, arm or leg
- Homonymous hemianopia
- Higher cerebral dysfunction: dysphasia, visuospatial problems
What is the diagnostic criteria for posterior circulation syndrome?
1 of:
- Isolated homonymous hemianopia
- Cerebellar or brainstem syndromes (dysarthria, ataxia, hiccups, vomiting)
- Ataxia, facial weakness, nystagmus, diplopia
+/- confusion or mood changes
What is the diagnostic criteria for a lacunar stroke?
1 of:
- Purely sensory stroke
- Ataxic hemiparesis
- Unilateral weakness +/- sensory symptoms in face, arms or legs
What is the criteria in a ROSIER score?
Loss of consciousness (-1) Seizure activity (-1) New acute onset (or on awakening from sleep): - Asymmetric facial weakness (+1) - Asymmetric arm weakness (+1) - Asymmetric lek weakness (+1) - Speech disturbance (+1) - Visual field defect (+1) Score >0 stroke is likely = does not rule out stroke completely
What is the acute management of a stroke?
- ABCDE
- Monitor BP, allow to be increased as decrease may compromise cerebral perfusion
- Urgent imaging - CT or MRI brain
- Determine ischaemic or haemorrhagic
- Admit to stroke uniting rehabilitation
When are CTs done and when are MRIs done in a stroke presentation?
CT brain first line in acute phase of stroke
MRI brain first line if presenting after 1 week or with mild deficits suggesting a small lesion
How does imaging help in differentiating between ischamic and haemorrhagic stroke?
CT shows haemorrhagic well until about a week - then MRI is better
MRI shows infarct better as it takes a while to show up on CT, by which time the damage has been done
What is the management of ischaemic stroke?
If presented <4.5 hours ago - thrombolysis with IV Alteplase
If presented >4.5 hours ago and within 48 hours - 300mg aspirin continued for at least 14 days
Clot retrieval with thrombectomy as an addition or alternative to thrombolysis if confirmed large vessel occlusion (unless >24 hours)
What is Alteplase?
A tissue plasminogen activator
What are the contraindications for thombolysis with alteplase?
Seizures Recent surgery Prolonged CPR Major infarct haemorrhagic stroke Mild non-disabling symptoms Currently on anticoagulant therapy Previous ischaemic stroke in last 3 months BP >180/110 (reduce before thrombolysis)
What investigations is done to try to determine the cause of a stroke?
Bloods: glucose, lipids, immunology screen
24 hour ECG and BP monitoring
Imaging: echo, carotid artery ultrasound
What management is done for secondary prevention of a stroke?
Lifestyle modification - diet, smoking etc. Anticoagulation if thromboembolic stroke Medication - antihypertensives if HTN - anti-platelet (aspirin, clopidogrel) - statin
What is a transient ischaemic attack (TIA)?
Sudden onset of focal neurological deficit due to temporary artery occlusion with symptoms lasting <24 hours
What is a crescendo TIA?
2 or more TIAs within a week - high risk of developing into a stroke
What is the presentation of a TIA?
The same as a stroke
Amaurosis fugax - temporary loss of vision that lasts <5 minutes and described as a curtain coming down over one eye
What assessment is done in TIA?
ABCD2 score
What is involved in the assessment of TIA?
Age (>60 = 1)
BP (>140/90 = 1)
Unilateral weakness = 2, speech disturbance (no weekness) = 1
Duration (>1 hour = 2, 10-59mins = 1, symptoms <10 mins = 0)
Diabetes = 1
Score out of 7
- 0-3 is low risk
- 4-5 is intermediate risk
- 6-7 is high risk
If <4 refer for investigation and management within 7 days
If >4 refer within 1 day
What investigations should be done in TIA?
Bloods - FBC, U&E, glucose, lipids
ECG, CXR, carotid doppler,
CT brain
What is the management for TIA?
Aspirin 300mg for 14 days
Don’t drink for 1 month
Lifestyle modification and secondary prevention as with stroke
Carotid endarterectomy if carotid atherosclerosis found
Where can intracranial venous thrombosis occur?
Any dural venous sinus - most commonly in sagittal or transverse sinus
What are risk factors for intracranial venous thrombosis?
Pregnancy
Dehydration
Head injury
Drugs: OC, tranexamic acid
Malignancy: intracranial and extracranial
Systemic disease: hyperthyroidism, antiphospholipid, SLE, nephrotic syndrome, heart failure, Crohn’s/UC
What is the presentation of intracranial venous thrombosis in the sagittal sinus?
Headache Vomiting Seizures Reduced vision Papilloedema
What is the presentation of intracranial venous thrombosis in the transverse sinus?
Headache \+/- Mastoid pain Seizures Focal signs Papilloedema
What is the presentation of intracranial venous thrombosis in the cavernous sinus?
Ophthalmoplegia Swollen conjunctiva/eyelids Proptosis Photophobia Fever Focal/raised ICP symptoms
What structures pass through the cavernous sinus?
CN III, IV, V1 and V2, VI, internal carotid, sympathetic fibres
Where does thrombosis in cavernous sinus usually spread from?
Infection from the face
What are differential diagnoses for intracranial venous thrombosis?
Meningitis
Tumour
Subarachnoid haemorrhage
What investigation is done for intracranial venous thrombosis?
Bloods
Lumbar puncture
CT/MRI - delta sign in superior sagittal thrombosis
What is the management for intracranial venous thrombosis?
Anti-coagulation: heparin + warfarin +/- streptokinase
Manage symptoms of raised ICP
What are intracranial haemorrhages?
Bleeding within the skull
What are the subtypes of intracranial haemorrhages?
Subarachnoid
Subdural
Extradural
Intracerebral
What is a haematoma?
Collection of blood within the skull
What is a subarachnoid haemorrhage?
Spontaneous bleeding into the subarachnoid space from any of the cerebral arteries
What are causes of subarachnoid haemorrhage?
Arteriovenous malformation
Rupture of Berry aneurysms (most common)
What conditions are associated with Berry aneurysms?
Polycystic kidney disease
Coarction of the aorta
Ehlers Danlos
What are common signs of development of Berry aneurysms?
Bifurcation of internal carotid into anterior and middle cerebral arteries
Junction of the posterior communicating and internal carotid
Junction between anterior communicating and anterior cerebral arteries
What is the presentation of subarachnoid haemorrhage?
Sudden onset thunderclap headache (occipital, develops within seconds, worst headache ever)
Collapse
Decreased or loss of consciousness
Meningism: photophobia o, neck stiffness
Focal neurological signs - 3rd nerve palsy
What investigations are done for subarachnoid haemorrhage?
CT brain (1st line)
Lumbar puncture if CT negative - positive if Xanthochromatic CSF (yellow)
Angiography to assess vasculature and identify any AVM/aneurysm
What is the management of subarachnoid haemorrhage?
Maintain cerebral perfusion - induce HTN with IV saline
Nimodipine
Refer to neurosurgery for aneurysm clipping, endovascular coiling
What is nimodipine?
Calcium channel antagonist that reduces chance of cerebral artery spasm and ischaemia
What are possible complications of subarachnoid haemorrhage?
Re-bleeding (50% chance in first 6 months)
Delayed ischaemic neurological deficits
Hydrocephalus
Hyponatraemia
How can delayed ischaemic neurological deficits be prevented?
Nimodipine
Hypertension, hypervolemia, haemodilution
Why does hydrocephalus occur in subarachnoid haemorrhage?
Due to blockage of the arachnoid granulations with blood
Usually transient and non-symptomatic but will require a shunt if it becomes symptomatic
Why does hyponatremia occur in subarachnoid haemorrhage?
Develops due to the release of salt wasting compounds from the cerebrum
Common and transient
What is the management of hyponatremia as a complications of subarachnoid haemorrhage?
Sodium supplements
Fludrocortisone
Not fluid restriction
What is a subdural haemorrhage?
Venous haemorrhage from the veins that connect the cortex to the dural venous sinus, with the blood accumulating between the dura and arachnoid matter
What are risk factors for subdural haemorrhage?
Increased age
Alcoholism
Epilepsy
Anti coagulation
What are causes of subdural haemorrhage?
Trauma, especially deceleration injury
Associated trauma may be minor, with patient often not remembering any distinct event
What is the presentation of subdural haemorrhage?
Fluctuations in consciousness
Insidious physical or mental slowing (confusion)
Sleepiness
Dull headache
Unsteadiness
Focal neurological symptoms + symptoms of raised ICP
Symptom development can be over weeks to months as blood can slowly accumulate
What investigation is done for subdural haemorrhage?
CT brain: crescent shaped haematoma
What is the management of subdural haemorrhage?
Medical: - Correction of coagulopathy - Prophylactic anti epileptics: Phenytoin for 7 days - Maintenance of ICP within normal range - Follow up CT scan and review Surgical: - 1st line: burr hole craniotomy - 2nd line: craniotomy
What is an extradural haemorrhage?
Arterial bleed from the middle meningeal artery, with blood collecting between the temporal bone and dura
What are the causes of an extradural haemorrhage?
Temporal bone fracture is most common)
Recent head injury will be apparent
What is the presentation of an extradural haemorrhage?
Head injury, followed by a lucid period that can last from hours to days
Increasingly severe headache associated with a sudden decline in level of consciousness
Confusion
Seizures
Vomiting
Hemiparesis
Focal neurological symptoms and signs of raised ICP
What investigation is done for extradural haemorrhage?
CT brain: lens shaped (biconvex) haematoma
LP is contraindicated due to apparent increased in ICP
What is the management of extradural haemorrhage?
Surgical: clot evacuation and ligation of middle meningeal artery
What is an intracerebral haemorrhage?
Bleeding within the brain parenchyma
What are the causes of an intracerebral haemorrhage?
HTN
Bleeding from tumours
Blood vessel abnormalities: AVM, vasculitis
What is the presentation of an intracerebral haemorrhage?
Quick onset headache
Focal neurological deficits
Decreased level of consciousness
What investigation is done for intracerebral haemorrhage?
CT: variable shaped clots within the cerebral cortex
Angiography: to assess the vasculature
What is the management of intracerebral haemorrhage?
Surgical: clot evacuation
Medical: treat underlying cause
