Overview of stroke Flashcards
WHO definition of a stroke is what?
“Clinical syndrome consisting of rapidly developing clinical signs of focal [or global in case of coma] disturbance of cerebral function lasting more than 24 hours or leading to death with no other apparent cause other than vascular origin.” WHO
Common Sx of carotid territory stroke
Weakness of face, leg, arm
Amaurosis fugax
Impaired language
Common Sx of posterior circulation problems
Dysarthria, dysphagia, diplopia, dizziness, ataxia, diplegia
Three main types of stroke
ischemic [clots], hemorrhagic [bleeds], TIA
Which most common, ischaemic or hemorrhagic?
Ischaemic in 85%, hemorrhagic in 15%
Causes of ischemic stroke and interruption cerebral blood supply
embolism, thrombosis, systemic hypoperfusion
Early signs of a stroke
Face, Arms, Speech, Time to call 999
Vascular supply and Circle of Willis summarise
slide
What are the cerebral vascular territories?
slide
What is the Oxford Stroke [Bamford] classification for strokes?
Clinical classification of patterns of neurological deficit in acute ischaemic stroke
- anterior circulation infarction [partial and total]
- posterior circulation infarction
lacurnar infarction
What is anterior circulation infarction?
Anterior and middle cerebral arteries
Sx of anterior circulation infarction?
Contralateral weakness Contralateral sensory loss/sensory inattnetion Dysarthria Dysphasia [receptive, expressive] Homonymous hemianopia/visual inattnetion higher cortical dysfunction
posterior circulation infarction
- Cranial nerve palsy and a contralteral motor/sensory deficit [‘crossed signs’]
- Conjugate eye movement disorder [e.g. horizontal gaze palsy]
- Cerebellar dysfunnction [e.g. vertigo, nystagmus, ataxia, dysarhria]
isolated homonymous hemianopia - bilateral events can cause reduced GCS
What is a lacunar infarction?
Occlusion of deep penetrating arteries
Affects small volume of subcortical white matter [therefore do not present with cortical features e.g. dysphasia, apraxia, neglect, visual field loss]
Underlying process is often referred to as small vessel disease [arterial wall, disorganisatioin, microatheroma, lipohyalinosis]
Give examples of Lacunar syndromes
- Pure motor hemiparesis
- Ataxic hemiparesis
- ‘Clumsy hand’ and dysarthria
- Pure hemisensory
- Mixed sensorimotor
Go through Bamford stroke classification of each main type of stroke [TACS, PACS, LACS, POCS]
see slides
After recognition of stroke [FAST], what should be done immediately?
ABCDE assessment + bloods, BM
brief Hx and exam [time of onset, RFs, CI to thrombolysis], BP [permit moderate HTN], NIHSS [grade severity of the stroke]
What is the second stage of stroke Mx
urgent head CT [+/- CT angiography]
What is the third stage of stroke Mx?
Thromblysis +/- mechanical thrombectomy if indicted or aspirin 300mg
What is the final stage in stroke Mx?
investigate the cause [history, examination, bloods, imaging]
screen and prevent Cx [dehydration, aspiration, VTEs, pressure sores, infection, depression]
Establish secondary prevnetion [lifestyle, medical, surgical]
Rehabilitation [physio, OT, SALT]
What is the NIHSS?
Grade and track the severity of stroke
Monitor response to acute Tx
Utility of CT in acute stroke pros and cons
pros
- quick
- readily available 24/7
- sensitive for haemorrhage
- may see a ‘hyperdense vessel’
cons
- cannot usually Dx an infarct in the acute phase
- less sensitive than MRI for picking up other abnormalities [demyelination, mass lesions, microhaemorrhages] and for lacunar and posterior circulation infarcts
What is thrombolysis?
breaking down acute clot
how is thrombolysis given?
IV plasminogen activator e.g. altepase 0.9mg/kg
Given within 4.5hrs of Sx onset [or time they were ‘last seen well’]
Diagnostic uncertainty
Potentially life-saving
What are the contraindications for thrombylsis?
slides
post thrombolysis care
- more aggressive BP - monitoring
- vigilance for Cx [bleeding]
- 24 hour CT head [haemorrhagic transformation]
What is mechanical thrombectomy and when is it used?
Mechanical recanilsation of the culprit vessel
Proximal stenosis
6 hour time-window for anterior circulation stroke [later for basilar thrombosis]
can be used alongside IV thrombolysis
Limited resource
What is the time window for mechanical thrombectomy?
6 hour time-window for anterior circulation stroke [later fo basilar thromosis]
Describe an ischaemic penumbra
Penumbra: - blood flow: 10-17 ml/100g/min - electrical silence - spreading depression - reversible damage in case of recirculation Ischaemic core: - blood flow permanently under <7-7.14 ml/100g/min - irreversible membrane damage - damaged brain tissue
4 simple stages for the management of stroke
- investigate the cause [history, examination, bloods, imaging]
- Screen and prevent complications [dehydration, aspiration, VTEs, pressure sores, infection, depression]
- Establish secondary prevention [lifestyle, medical, surgical]
- Rehab [physio, OT, SALT]
Purposes of the investigations
- Diagnosis
- R/o ‘stroke mimics’
- identify aetiology
- Guide RF modification
- Prevent and treat complications
Investigations done for a stroke
- Blood tests [look up slides for more detail]: FBC, ESR, U&Es, lipid profile, LFTs, CRP, clotting screen, glucose and HbA1C
- ECG [MI, AF] +/- 72 hour tape
- carotid doppler USS [carotid stenosis]
- ECG [endocarditis/thrombus]
- MRI [confirm Dx, look for multi-territory infarcts]; delayed CT head if MRI is CI
Clues from the MRI:
- acute/subacute infarcts [up to 2 weeks]
- multiple infarcts same territory
- multi-territory infarcts
- absent flow void in vessels
- same territory ?cuplrit vessel
- multiterritory infarcts ? cardioembolic
- absent flow void vessels: arterial occlusion/dissection
In the young patient/atypical stroke patient, what should you consider?
Bloods:
- HIV and vasculitic screen
- Thrombophilia screen
- Homocysteine
Cardiac investigations
- 7 day holter recorder/implantabel loop recorder
- transcranial dopplers
- transoesophageal echo
Vascular imaging
- CT angiography
- MR angiography
MDT approach to treatment of a stroke
Nursing
- analysing clinical status and progress; blood pressure management
- administration of medications
- nasogastric feeding
- preventing pressure sores
Physio
- strength, balancing, function
- preventing spasticity
- chest physiotherapy in infections and sputum clearance
Occupational therapy
- functional assessments and future needs planning
- cognitive and mood screening
Speech and language therapy
- swallowing impairment and prognosis
- communicating rehabilitation in dysphasias
Dieticians
Orthoptics
Lifestyle management of a stroke
Smoking cessation Drug and alcohol cessation Dietary modifications Exercise Driving advice
Medical management [preventing complications]
VTE assessment
- intermittent pneumatic compression devices
Hydration NG feeding +/- PEG feeding Spasticity - physiotherapy - botox Monitoring for infection
Medical management [secondary prevention]
Antiplatelets
- aspirin 300mg PO/PR for 2 weeks [small ARR]; clopidogrel lifelong
Anticoagulation
- if in AF or evidence of pAF, may need to wait up to 2 weeks
- HASBLED and CHADSVASC scores
Hypertension
- acute: risk of hypoperfusion
- chronic: long term blood pressure target of< 130/80
Cholesterol
- statin therapy: aim for 40% reduction in non-HDL cholsterol
Surgical management of stroke
Extra-cranial carotid stenosis
- USS carotid dopplers +/- CTA/MRA
- ipsilateral [symptomatic] carotid stenosis: 70-99% carotid endarterectomy [CEA] recommended, 50-69% consdier CEA
- alternative: carotid artery stenting
Malignant MCA syndrome:
- decompressive hemicraniectomy
Posterior circulation infarct
- risk of hydrocephalus
- EVD/posterior fossa decompression
55-year-old right handed man, sudden severe headache, weakness of right arm and leg, drowsy and confused.
PMHx: HTNB, AF, DM, PKA
DHx: Apixaban, Ramipril, Metformin
Dx, and then Mx?
Management of haemorrhagic stroke 5 aspects:
- ABCDE - monitoring environment, regular neuro-observations [incl. GCS and pupils]
- Blood pressure? [140-160 systolic acutely, <130/80 long term]
- Bleeding tendency? [coagulation/low platelets/medication-related]
- underlying malformation? [tumour aneurysm, amyloid angioapthy, AVM, cavernoma]
- Need for neurosurgery? [useful for superficial clots, CSF obstruction causes, hydrocephalus, posterior fossa decompression]
What is the minimum, and what is the maximum GCS score?
3, 15
What GCS should you strongly consider airway protection at?
At, or below 8
Ways of reversing anticoagulation
Warfarin [beriplex and vitamin K] Heparin [Protamine] LMWH [partially reversed with protamine] Apixaban/Rivaroxaban/Edoxaban [Beriplex is possibly effective] Dabigatran [Idarucizumab]
Name disorders that stroke can mimic
Seizures, tumours/abscess, migraine, metabolic [e.g. hypoglycaemia, hyponatraemia], functional, spinal cord/peripheral nerve/cranial nerve
