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neuro core conditions > Stroke & TIA > Flashcards

Stroke & TIA Flashcards

1
Q

What is stroke?

A

Sudden onset of neurological deficit caused by focal cerebral, spinal or retinal infarction or haemorrhage.

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2
Q

Who does stroke affect?

A

3rd most common cause of death + leading cause of adult disability

Higher in Asians and black African

Stroke risk increases with age

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3
Q

What are the 2 broad categories of strokes?

A 
Ischaemic stroke / infarction (85%)
=> thrombotic
=> large-artery stenosis
=> small-vessel diseases
=> cardio-emboli
=> hypoperfusion

Haemorrhagic (10%)
=> Intracerebral haemorrhage
=> Subarachnoid haemorrhage

Other (5%)
=> arterial dissection
=> venous sinus thrombosis
=> vasculitis

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4
Q

What is the pathology underlying ischaemic stroke?

A

Arterial disease & artherosclerosis => main pathological processes causing stroke

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5
Q

What are the causes of stroke?

A
  1. Small vessel occlusion or thrombosis
    => thrombosis at the site of ruptured mural plaque leads to embolism or occlusion.
  2. Cardiac emboli

=> atrial fibrillation (x5 higher risk)

=> infective endocarditis ; rheumatic & degenerative calcific valve changes

=> congenital valve disorders

=> left ventricular mural thrombus

=> severe hypoperfusion due to MI = infarction in watershed areas especially if there is severe stenosis of proximal carotid vessel

  1. Atherothromboembolism from carotid
  2. CNS bleed due to hypertension, trauma, aneurysm rupture, anticoagulation, thrombolysis
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6
Q

What is the most common cause of stroke?

A

Atrial fibrillation => thrombosis in a dilated left atrium => emboli = the most common cause of stroke

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7
Q

What are other causes of stroke?

A

Other causes:

Consider in younger patients:

=> sudden BP drop >40mmHg

=> carotid artery dissection (spontaneous or from neck trauma)

=> Vasculitis

=> Subarachnoid haemorrhage

=> venous sinus thrombus

=> Anti-phospholipid syndrome

=> Thrombophilia

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8
Q

What are the modifiable risk factors for stroke?

A

Smoking

Diabetes

Hypertension

Dyslipidaemia

Obesity

Alcohol

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9
Q

What are the non-modifiable risk factors of stroke?

A

Age

Men under 65 and Women over 65 years more likely to have stroke (due to loss of E2)

South asian and Afro-carribean

Heart disease (valvular, ischaemic, AF)

Peripheral vascular disease

Carotid bruit

Pregnancy

Combined oral contraceptive pill

Increased clotting i.e. high plasma fibrinogen, low antithrombin III

Polycythaemia vera

Family history

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10
Q

Which main arteries make up the circle of willis to supply the anterior cerebral circulation and the posterior cerebral circulation?

A

Anterior cerebral circulation => two internal carotid arteries

Posterior cerebral circulation => vertebrobasilar arteries

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11
Q

Cerebral infarction

Vessel occlusion => brain ischaemia => neuronal failure => infarction + cell death

The ‘CORE’ is the centre of the stroke - the ischaemic area where hypoxia leads to neuronal damage.
=> Fall in ATM results in release of glutamate => opens calcium channel, releasing free radicals => inflammation, necrosis and apoptotic cell death

A

The ischemic ‘PENUMBRA’ surrounds the ischemic region which is not functioning but is structurally intact.
=> timely revascularisation can help regain function in this area

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12
Q

Where does anterior circulation infarcts take place?

What are the associated symptoms?

A 
Infarcts in territory of: 
=> internal carotid
=> middle cerebral (MCA)
=> anterior cerebral (ACA)
=> ophthalmic arteries

Complete MCA infarct = devastating stroke
=> contralateral hemiplegia
=> facial weakness
=> contralateral sensory loss
=> aphagia / dysphagia
=> hemianopia
=> neglect syndrome / visua-spatial defect
=> initially flaccid limbs (floppy limbs like dead weight) then becomes spastic

Internal carotid strokes = similar picture as MCA strokes

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13
Q

What is lacunar infarction?

A

Lacunes = small infarcts

Hypertension is the major risk factor

Lacunar infarcts often symptomless.

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14
Q

What is lacunar infarction?

What area is affect?

What are the symptoms?

A

Lacunes = small infarcts in basal ganglia, internal capsule, thalamus and pons

Hypertension is the major risk factor

Lacunar infarcts often symptomless or:
=> Ataxia hemiparesis
=> Pure motor
=> Pure sensory
=> Sensorimotor
=> Dysarthia/clumsy hand

*cognition/consciousness intact

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15
Q

What are the symptoms of a brainstem infarct?

Brainstem infarct is posterior circulation stroke.

A

Quadriplesia

Disturbance of gaze & vision

Locked in syndrome (aware but unable to respond)

*symptoms depended on assoc. with cranial nuclei.

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16
Q

Purpose of investigation in stroke is to confirm clinical diagnosis and differentiate between ischaemic or haemorrhage stroke.

What is the immediate urgent investigation of stroke presenting <1h?

What further investigations are carried out within 24h?

A
  1. CT brain => demonstrate haemorrhage immediately but cerebral infarct not detected in acute phases

=> Repeat CT at 24h for all patients

  • insert cannulas before scan + take bloods
    2. Blood count and glucose (+ clotting study if on anti-coagulation)

Further investigation:

=> Routine blood test (FBC, ESR, glucose, clotting studies, lipids)

=> ECG for AF

=> Carotid doppler studies in patients with anterior circulation stroke fit for surgery

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17
Q

What additional tests may be carried out to find out underlying cause of the stroke?

A
  1. Chest Xray => cardiac source of emboli

2. Carotid doppler ultrasound ± CT/MRI angiography => carotid artery stenosis

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18
Q

What are the differential diagnosis for stroke?

A

Head injury

Hypo/hyperglycaemia

Subdural haemorrhage

Intracranial tumours

Hemiplegic migraine

Post-ictal (Todd’s palsy)

CNS lymphoma

Wernicke’s encephalopathy

Hepatic encephalopathy

Encephalitis

Toxoplasmosis

Cerebral abscess

Mycotic aneurysm

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19
Q

What is the significance of ‘ACT FAST’ is stroke?

A

Public health measure to increase awareness about stroke

F = facial asymmetry 
A = arm/leg weakness
S = speech difficulty
T = time to call 999
20
Q

What is the primary prevention in stroke?

Primary prevention = before stroke onset

A

Control risk factors:

Treat hypertension ; diabetes ; hyperlipidaemia

Manage cardiac disease

Quit smoking

Exercise helps increase HDL and glucose tolerance

Lifelong anticoagulation if AF or prosthetic heart valve i.e. warfarin or DOAC

21
Q

What is the secondary prevention in stroke?

Secondary prevention = preventing further strokes

A

Control risk factors

Control BP and cholesterol

Antiplatelet agents after stroke:
=> if no primary haemorrhage on CT, give 2 weeks of aspirin 300mg
=> then switch to long-term clopidogrel
=> if clopidogrel not tolerated, give low dose aspirin + dipyridamole

Give anti-coagulation if stroke due to AF or cardiac:
=> warfarin
=> or DOAC

22
Q

What is the secondary prevention in stroke?

Secondary prevention = preventing further strokes

A

Control risk factors

Control BP

Control cholesterol (atorvastatin 40mg)

Antiplatelet agents after stroke:
=> if no primary haemorrhage on CT, give 2 weeks of aspirin 300mg
=> then switch to long-term clopidogrel
=> if clopidogrel not tolerated, give low dose aspirin + dipyridamole

Give anti-coagulation if stroke due to AF or cardiac:
=> warfarin
=> or DOAC

23
Q

How do you manage acute stroke?

A

Protect the airway => avoids hypoxia + aspiration

  1. Maintain homeostasis => glucose between 4-11mmol/L
  2. Screen swallow => till then nil by mouth but keep hydrated
  3. CT/MRI within 1h => essential if thrombolysis considered or high risk of haemorrhage
  4. Anti-platelet agents (aspirin 300mg) once haemorrhagic stroke ruled out
  5. Thrombolysis or Thrombectomy
  6. Admit to a high acute stroke unit (HASU) => improves outcomes + saves lives + reduces long-term disability
  7. Rehabilitation => start early post stroke to maximise improvement and prevent complications

Nurse queries:
*in acute initial stage = don’t treat HTN because likely to make ischaemia worse if BP drops
If massively elevated, consultant might suggest IV lobetalol
BP usually drops after alteplase
If BP still high a week or so post stroke then manage

Aspiration common post stroke - aspiration pneumonia
=> if pyrexial give paracetamol but first do a swallow assessment
=> check if can cough, lick lips, head control => then call SALT team

24
Q

When is CT/MRI indicated within 1h in a patient presenting with acute stroke?

A

CT/MRI within 1h => essential if thrombolysis considered or high risk of haemorrhage.

High risk haemorrhage signs: 
=> low GCS, 
=> signs of increased intracranial pressure, 
=> severe headache, 
=> meningism, 
=> bleeding tendency, 
=> anti-coagulated

Less urgent imaging <24h
=> MRI is most sensitive for acute infarct but CT helps rule our primary haemorrhage

25
Q

What anti-platelet agent is initiated once haemorrhage has been ruled out?

A

=> High dose aspirin 300mg as soon as haemorrhage is excluded and if thrombolysis contraindicated
OR
=> On day 2 after a second CT scan post thrombolysis

=> Continue high dose aspirin 300mg for 2 weeks

=> Then switch to long term anti-thrombotic treatment i.e. clopidogrel

26
Q

When is thrombolysis considered in acute stroke?

A

Thrombolysis considered as soon as haemorrhagic stroke ruled out

Onset of symptoms <4.5h
=> benefits of thrombolysis in this window > risks
=> best results in first 90mins

IV Alteplase 0.9mg/kg to a max of 90mg => agent of choice
=> 10% of total given as bolus and 90% given as an infusion
=> monitor v closely - as high risk of bleeding

Always do CT/MRI 24h post-lysis to monitor for bleeds

27
Q

What are the contraindications for thrombolysis?

A

Contraindications to thrombolysis:

=> Major infarct or haemorrhage on CT

=> Mild / non-disabling deficit

=> Recent surgery, trauma, artery or vein puncture

=> Previous CNS bleed

=> Arteriovenous malformation / aneurysm

=> Severe liver disease, varices, portal hypertension

=> Seizure on presentation

=> Blood glucose <3 or >22

=> Stroke or serious head injury in last 3 months

=> Known clotting disorder

=> Anticoagulant or INR >1.7

=> BP >180/105mmHg

28
Q

When is thrombectomy considered in acute stroke?

A

Intracranial thrombectomy within 6 hours and will consider it within 24h post stroke => additional benefit for large artery occlusion in the proximal anterior circulation

29
Q

What is a transient ischaemic attack (TIA)?

A

Brief episode of neurological dysfunction due to temporary focal cerebral or retinal ischaemia without infarction i.e. weak limb, aphasia or loss of vision lasting seconds or minutes with complete recovery. Mostly unilateral

*<24h time limit no longer used

30
Q

What are the signs of TIA?

A

Signs specific to artery territory

Amaurosis fugax
=> sudden transient loss in vision in one eye
=> due to emboli passing through retinal artery
=> often 1st clinical sign of internal carotid artery stenosis

*Global events i.e. syncope or dizziness not characteristic of TIA

31
Q

What signs are present if TIA occurs in the anterior circulation (carotid system)?

A

Amaurosis fugax

Aphasia

Hemiparesis

Hemisensory loss

Hemianopic visual loss

32
Q

What signs are present if TIA occurs in the posterior circulation (verterbrobasilar system)?

A

Diplopia

Vertigo & vomiting

Choking & dysarthria

Ataxia

Hemisensory loss ; Hemianopic visual loss ; Bilateral visual loss

Tetraparesis

Loss of consciousness (rare)

33
Q

What are the causes of TIA?

A

Atherothromboembolism from carotid = main cause
=> listen for bruits

Cardioembolism
=> mural thrombus post MI
=> AF, valve disease, prosthetic valve 
=> Hyperviscosity i.e. polycythaemia, sickle cell anaemia 
=> Vasculitis (rare)
Non-embolic cause of TIA:
=> Cranial arteritis
=> SLE
=> Syhillis 
=> Polyarteritis nodosa
34
Q

How do you diagnose TIA?

A

Clinical diagnosis

Consciousness usually preserved

35
Q

What are the differential diagnosis for TIA?

A

Hypoglycaemia

Migraine aura

Focal epilepsy

Hyperventilations

Retinal bleeds

Rare mimics of TIA:
=> Malignant hypertension 
=> Intracranial tumours
=> Peripheral neuropathy
=> Phaeocromocytoma 
=> Somatisation 
=> MS (paroxysmal dysarthria)
36
Q

What tests are carried out for TIA?

A

Bloods: FBC, LFT, glucose, cholesterol, U&E, ESR, TFT if in AF

Chest Xray

ECG if AF

Carotid doppler ± angiography

CT or diffusion-weighted MRI

Echocardiogram (esp if cluster TIA because likelihood of cardiac cause)

37
Q

How do you manage TIA?

You can only treat TIA after doing a full neurological exam and after symptoms have settled.

A 
Control cardiovascular risk factors
=> BP aim <140/85mmHg
=> Hyperlipidaemia => start atorvastatin at night because cholesterol synthesised at night and any weakness of muscles = sleeping
=> Diabetes 
=> Stop smoking

Antiplatelet drugs:
=> Aspirin 300mg for 2 weeks + PPI for gastric cover
=> Then switch to clopidogrel 75mg
=> If clopidogrel not tolerated, give aspirin 75mg with slow-release dipyridamole

Anticoagulation:
=> if cardiac source of emboli

Carotid endarterectomy
=> perform with 2wks of presentation if >55% carotid stenosis and operable risk is low

38
Q

What is the prognosis of TIA?

A

Long term risks of stroke or CVS events following TIA depended on underlying vascular risk factors => calculate using ABCD2 score

30% go on to having a stroke

15% go on to having MI

TIA in anterior cerebral circulation => more serious prognosis than in posterior circulation

39
Q

When should TIA lead to emergency referral?

What is the ACBD2 score?

A

ABCD2 score not used to refer as all TIA are now considered precursor to stroke so ALL patients are referred to TIA clinic and should be seen within 24h.

Cluster TIA or TIA after anti-coagulation => admit them

Patients under 45 years are not referred to TIA clinic. They should be referred to neurology.

40
Q

Does TIA affect ability to drive?

A

Driving prohibited for at least 1 month.

Do not need to inform DVLA.

*if need to inform DVLA = record this in notes!!!

41
Q

What is a Rosier stroke scale?

A
42
Q

Which condition mimic stroke?

A

2 most common stroke mimics:
1. Hypoglycaemia = always check blood glucose with stroke patient

  1. Migraines

Others:

  1. Bell’s palsy
  2. Mass lesions
  3. Syncope
  4. Sepsis
  5. Seizure / epilepsy
  6. Trauma
  7. Overdose
  8. Intoxication
  9. Hepatic encephalopathy
43
Q

Post stroke care

A

Depression

Dietician for help with swallow after SALT team says no swallow

Nurse - ask MUST score

OT - activities of daily living i.e. can they feed, dress, wash themselves

Reduced mobility = VTE assessment to assess risk - LMWH / pneumatic stockings

44
Q

Post stroke care

A

Psychological impact - Depression

Dietician for help with swallow after SALT team says no swallow

Nurse - ask MUST score

OT - activities of daily living i.e. can they feed, dress, wash themselves

Reduced mobility = VTE assessment to assess risk - LMWH / pneumatic stockings

Rehab

Resus decision?

45
Q

What are the signs & symptoms of stroke?

A
  1. Sudden onset, focal neurological deficit longer than 24 hours and cannot be explained by another condition i.e. hypoglycaemia.

The clinical features of stroke vary depending on causative mechanism and the area of the brain affected and may include:

  1. Confusion, altered level of consciousness, and coma.
  2. Headache — usually of insidious onset and gradually increasing intensity in intracranial haemorrhage, and sudden, severe headache in subarachnoid haemorrhage which may be associated with neck stiffness.
    => Sentinel headache(s) may occur in the preceding weeks.
  3. Unilateral weakness or paralysis in the face, arm, or leg.
  4. Sensory loss — paraesthesia or numbness.
  5. Ataxia.
  6. Dysphasia.
  7. Dysarthria.
  8. Visual disturbance — homonymous hemianopia, diplopia.
  9. Gaze paresis — often horizontal and unidirectional.
  10. Photophobia.
  11. Dizziness, vertigo, or loss of balance — isolated dizziness is not usually a symptom of TIA.
  12. Nausea / vomiting.
  13. Specific cranial nerve deficits such as unilateral tongue weakness or Horner’s syndrome (miosis, ptosis, and facial anhidrosis).
  14. Difficulty with fine motor coordination and gait.
  15. Neck of facial pain (assoc. with arterial dissection)
    * Posterior circulation strokes may be difficult to diagnose and should be suspected if the person presents with:

=> Symptoms of acute vestibular syndrome — acute, persistent, continuous vertigo or dizziness with nystagmus, nausea or vomiting, head motion intolerance, and new gait unsteadiness.

neuro core conditions (9 decks)

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