Stroke Flashcards
Definition of stroke?
Rapid onset, focal neurological deficit due to a vascular lesion lasting >24h
Pathogenesis of stroke
- Infarction due ischaemia (80%)
- intracerebral haemorrhage (20%).
Causes of ischaemic strokes?
I. Atheroma
- Large (e.g. MCA)
- Small vessel perforators (lacunar)
II. Embolism
- Cardiac (30% of strokes):AF, endocarditis, MI
- Atherothromboembolism: e.g. from carotids
Causes of haemorrhagic stroke?
- ↑BP
- Trauma
- Aneurysm rupture
- Anticoagulation
- Thrombolysis
Watershed stroke
sudden ↓ in BP (e.g. in sepsis)
Risk factors for stroke?
- IHD RFs: ↑BP, Smoking, DM, ↑ lipids
- Cardiac: AF, valve disease
- Peripheral vascular disease
- ↑ PCV/Hct
- OCP
Which ethnicity is more prone to strokes?
↑ in Blacks and Asians
Overview of Oxford (/Bamford) classification of stroke?
- Based on clinical localisation of infarct
- S=syndrome: prior to imaging
- I=infarct: after imaging when atheroembolic infarct
confirmed
4 oxford classifications of stroke?
TACS- Total Anterior Circulation Stroke
PACS- Partial Anterior Circulation Stroke
POCS- Posterior Circulation Stroke
LACS- Lacunar Stroke
TACS stroke: mortality?
Highest mortality (60% @ 1yr) + poor independence
Site of TACS stroke?
Large infarct in carotid / MCA, ACA territory
Signs of TACS stroke?
All 3 of:
- Hemiparesis (contralateral) and/or sensory deficit (≥2 of face, arm and leg)
- Homonymous hemianopia (contralateral)
- Higher cortical dysfunction
- Dominant (L usually): dysphasia
- Non-dominant: hemispatial neglect
PACS stroke site?
Carotid / MCA and ACA territory
PACS stroke signs?
2/3 of TACS criteria, usually:
- Hemiparesis (contralateral) and/or sensory deficit (≥2 of face, arm and leg)
- Higher cortical dysfunction
- Dominant: dysphasia
- Non-dom: neglect, constructional apraxia
constructional apraxia
an inability or difficulty to build, assemble, or draw objects.
Site of POCS stroke?
Infarct in vertebrobasilar territory
Signs of POCS stroke?
Any of
- Cerebellar syndrome (DANISH P)
- Brainstem syndrome
- Contralateral homonymous hemianopia
Site of LACS stroke?
- basal ganglia
- internal capsule
- thalamus
- pons
Absence of which signs makes the diagnosis LACS stroke more likely?
Absence of
- Higher cortical dysfunction
- Homonymous hemianopia
- Drowsiness
- Brainstem signs
Potential syndromes of LACS?
- Pure motor: posterior limb of internal capsule (Commonest)
- Pure sensory: posterior thalamus (VPL)
- Mixed sensorimotor: internal capsule
- Dysarthria (slurred speech) / clumsy hand
- Ataxic hemiparesis: ant. limb of internal capsule
- Weakness + dysmetria
Dysmetria
- a lack of coordination of movement
- eg dysdiadochokinesis
Signs of brainstem infarct?
Complex signs depending on relationship of infarct to CN nuclei, long tracts and brainstem connections
eg
- facial weakness with CN7 infarct
- Nystagmus and vertigo with CN8, - Horner’s syndrome with sympathetic fibres infarct
Site of lateral medullary syndrome ( Wallenberg Syndrome)
PICA or vertebral artery territory
Features of lateral medullary syndrome ( Wallenberg Syndrome)
DANVAH
- Dysphagia
- Ataxia (ipsilateral)
- Nystagmus (ipsilateral)
- Vertigo
- Anaesthesia (Ipsilateral facial numbness, Contralateral pain loss)
- Horner’s syndrome (ipsilateral)
Locked-in Syndrome features?
Pt. is aware and cognitively intact but completely paralysed except for the eye muscles.
Locked-in Syndrome causes?
- Ventral pons infarction: basilar artery
- Central potine myelinolysis: rapid correction of
hyponatraemia
Overview of Acute management of stroke?
- Resus (NBM)
- Monitor
- Imaging
- Medical
- Surgery
Monitoring of acute stroke?
- Glucose: 4-11mM: sliding scale if DM
- BP: <185/110 for thrombolysis
(Rx of HTN can → ↓ cerebral perfusion)
Imaging of acute stroke?
Urgent CT/MRI
I. Diffusion-weighted MRI is most sensitive for acute infarct
II. CT will exclude primary haemorrhage
Medical management of acute stroke?
I. Thrombolysis
II. Aspirin 300mg PO/PR once haemorrhagic stroke excluded ± PPI
(If CI, give Clopidogrel instead)
Thrombolysis for stroke?
- Consider if 18-80yrs and <4.5hrs since onset of symptoms
- Alteplase (rh-tPA)
- → ↓ death and dependency
- CT 24h post-thrombolysis to look for haemorrhage
Surgical management for stroke?
- May coil bleeding aneurysms
- Decompressive hemicraniectomy for some forms of MCA infarction.
Primary prevention of stroke (before)?
- Control RFs: (HTN, ↑ lipids, DM, smoking, cardiac disease)
- Consider life-long anticoagulation in AF (use CHADS2) - Carotid endarterectomy if symptomatic with 70% stenosis
- Exercise
Secondary prevention of stroke (after)?
I. Start a statin after 48h
II. Aspirin / clopi 300mg for 2wks after stroke then either
a. Clopidogrel 75mg OD (preferred option)
b. Aspirin 75mg OD + dipyridamole MR 200mg BD
III. Warfarin instead of aspirin/clopi if Cardioembolic stroke or chronic AF
b. Start from 2wks post-stroke (INR 2-3)
IV. Carotid endarterectomy if good recovery + ipsilat stenosis ≥70%
Rehabilitation for stroke?
MENDS
I. MDT: SALT (Speech and Lang Therapist) , dietician, OT, PT
II. Eating
a. Screen swallowing: refer to specialist
b. Screen for malnutrition
III. Neurorehab: physio and speech therapy
IV. DVT Prophylaxis
V. Sores: must be avoided @ all costs
PACS stroke mortality?
- 20% mortality at 1 year
- 33% independent at 1 yr
