Stroke/TIA 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 disease4. ↑ PCV/Hct5. 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 infarctconfirmed
TACS PACS POCS LACS
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 DM2.
BP: <185/110 for thrombolysis(Rx of HTN can → ↓ cerebral perfusion)
Imaging of acute stroke?
Urgent CT/MRII.
Diffusion-weighted MRI is most sensitive for acute infarctII.
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 48hII. 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 AFb.
Start from 2wks post-stroke (INR 2-3)
IV. Carotid endarterectomy if good recovery + ipsilat stenosis ≥70%
Rehabilitation for stroke?
MENDSI.
MDT: SALT (Speech and Lang Therapist) , dietician, OT, PTII.
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
RFs for impaired swallowing
Reduced consciousness Inability to sit upright/ to hold head upright Impaired or absent communication Neglect or visual feed defect Acute confusion or dementia Facial weakness Poor/absent voluntary cough
Investigations of swallowing
- gold standard = video fluoroscopy.
- also Fibreoptic Endoscopic examination of the Swallow (FEES).
FEES test
An ENT endoscope is put through the nose into the upper airway to examine whether food (which can be coloured with blue dye pre-swallowing) is visible where it should not be.
Definition of TIA?
- Sudden onset focal neurology lasting 24h due to temporary occlusion of part of the cerebral circulation
- ~15% of 1st strokes are preceded by TIAs.
Causes of TIA?
I. Atherothromboembolism from carotids (MAINLY)II. Cardioembolism: post-MI, AF, valve diseaseIII. Hyperviscosity: polycythaemia, SCD, myeloma
Investigations for TIA?
- Aim to find cause and define vascular risk
I. Bloods: FBC, U + Es , ESR glucose, lipids
II. CXR
III. ECG
IV. Echo
V. Carotid doppler ± angiography
VI. Consider Diffusion weighted MRI
Timing of management of TIA and risk of another stroke?
- Intervention w/i 72hrs → 2% strokes @ 90d - Intervention w/i 3wks → 10% strokes @ 90d
Management of TIA?
ACAS
- Antiplatelet/coagulate:
- aspirin/clop 300mg/d for 2 wks, then 75mg/d
- or warfarin if AF, MI - Cadiac RFs control
- Assess risk of future stroke (ABCD2 score)
- specialist referral
- ABCD2 ≥4: w/i 24hrs
- ABCD2 <4: w/i 1wk
Prognosis for TIA patients?
3x ↑ in mortality cf TIA-free populations
ABCD2 score components
Predicts stroke risk following TIA 1. Age≥60 2. BP ≥ 140/90 3. Clinical features a. Unilateral weakness (2 points) b. Speech disturbance w/o weakness 4. Duration a. ≥ 1h (2 points) b. 10-59min 5. DM Max score: 7
What is ABCD2 score used for?
Predicts stroke risk following TIA
- Score ≥6 = 8% risk w/i 2d, 35% risk w/i 1wk
