Neurology - Stroke Flashcards
List the causes of Ischemic and Hemorrhagic Stroke
Thrombosis
- obstruction of large or small vessel
- large vessel commonly carotid due to arthersclerosis
- small vessel commonly lacunar stroke (small cerebral artery) due to hypertension causing lipohyalinosis
Embolism
- Clot from elsewhere that traveled in blood vessel to brain
- commonly from heart due to AF, rheumatic heart disease, prosthetic valve
Systemic Hypoperfusion
- global decreased blood flow to the brain causing global damage
- common in watershed area
- commonly due to cardiogenic shock
Hemorrhagic
- 20% of stroke and due to bleeding
- intracerebral hemorrhage when have bleeding from small arteries in brain from rupture of microaneurysm from hypertension, trauma, amyloid, vascular malformation or drugs
- sub-arachnoid hemorrhage
Discuss the difference between TIA and stroke and common presentation
Definition
- TIA: focal cerebral ischemic event lasting <24hrs followed by full recovery
- usually resolve in minutes to few hours
- Reversible ischemic neurologic deficit: focal cerebral ischemic event with neurological deficit >24hrs followed by full recovery (usually within few weeks)
- Stroke: permanent neurological deficit
Symptoms
- sudden onset focal neurological deficit
- dizziness, n/v
- loss of vision, diplopia
- aphasia, dysarhria
- unilateral weakness/paralysis
- incoordination
- altered LOC, confusion
- dysphasia, aphasia
- facial droop
Discuss presentation of stroke by vascular territory
Anterior Cerebral Artery
- frontal lobe affected
- contralateral leg paresis and sensory loss
- gait disturbance
- urinary incontinence
Middle Cerebral Artery
- posterior frontal lobe, temporal lobe, parietal lobe
- contralateral weakness and sensory loss of face and arm
- contralateral homonymous hemianopia or quadantanopia
- left hemipshere: aphasia
- right hemisphere: visual-spatial neglect
Posterior Cerebral Artery
- occipital lobe
- contralateral homonymous hemianopia
- left hemisphere: alexia with agraphia (cannot read but can write)
- right hemisphere: sensory loss, decreased LOC
Basilar Artery
- brainstem
- locked-in syndrome: quadraparesis/quadraplegia, anarthria/dysarthria, impaired horizontal eye movement
Lacunar Infarct
- Deep brain structures
- Pure contralateral hemiparesis or hemisensory loss
- ataxia
- dysarthria-clumsy hand syndrome: dysarthria, facial weakness, dysphagia, mild hand weakness and clumsiness
Discuss the acute management of stroke
Stabilize
- ABC
Initial Assessment
- onset of symptoms since last awake and free of symptoms
- rule out differential: hypoglycemia, seizure, migraine, syncope
- hemorrhagic strong headache and vomiting
- NIH Stroke Scale exam
Investigations
- Non-contrast brain CT
- ECG
- CBC, electrolytes, blood glucose, INR/PTT, creatinine, BUN, troponin
Address Underlying Cause
- if hemorrhagic then decrease BP to <140mmHg with IV labetalol and immediate interventional radiology or neurosurgery
Discuss the management for an ischemic stroke
- if within 4.5 hours of symptom onset then candidate for IV rTPA
- if contraindication then asparin 325mg or clopidrogrel
Absolute Contraindication - hemorrhagic stroke on CT
- head trauma or prior stroke within last 3 months
- Arterial puncture at non-compressible site in last 7 days
- Any previus intracranial hemorrhage
- Evidence of active bleeding
- Hypertension >185/110 (must lower with IV labetalol first)
- Blood dyscrasia
- platelet <100
- heparin use and PTT above normal limit
- anticoagulant use and INR >1.7 - blood glucose <5
- multilobar infarction >1/3 cerebral hemisphere
Relative Contraindications - Minor or rapidly improving stroke symptoms
- Seizure at onset
- Major surgery or serious surgery within previous 2 weeks
- Recent GI or urinary tract hemorrhage in previous 3 weeks
- recent MI in previous 3 months
Discuss the risk stratification for a TIA
ABCD2 Score
- Age >60 (1 point)
- Blood pressure >=140/90 (1 point)
- Clinical features of TIA
- speech impairement without weakness (1 point)
- unilateral weakness (2 points)
- Duration of TIA
- 10-59 min (1 point)
- >60 min (2 points)
- Diabetes (1 point)
Risk Stratification
- <=3 have 1% risk of stroke in following 2 days so can discharge
- >=4 have 4-8% risk of stroke in following 2 days so hospital observationDiscuss the secondary prevention for stroke
Anti-Platelet
- aspirin
- aspirin + dipyridamole
- clopidogrel
Symptomatic Carotid Stenosis
- >70% then carotid endarterectomy
- 50-70% then carotid endarterectomy considered
- <50% then not indicated
- best if done within 2 weeks
Atrial Fibrilation
- CHADSVAS
- Congestive Heart Failure
- Hypertension
- Age >=75
- Diabetes
- Previous stroke or TIA
- Vascular disease
- Age 65-74
- Sex (female)
Hypertension
- reduce risk of stroke y 40%
Dyslipideia
- target LDL <2
Lifestyle
- reduce alcohol, quit smoking
- stop hormone therapy
- increase physical activity and healthy dietDiscuss the presentation and management of subarachnoid hemorrhage
Pathophysiology
- rupture of intracranial aneurysm bleeding into subarachnoid space
Presentation
- Sudden onset, no prodrome
- Thunderclap headache
- Loss of consciousness
- Nausea/Vomiting
- Irritation of meninges so can have meningitis signs
Investigation
- CT head showing diffuse blood in subarachnoid space
- Lumbar puncture if CT negative but high clinical suspicion
- high RBC count in first and last tube
- xanthochromia
Management
- Surgical clipping or endovascular coiling
- Lower blood pressure with IV labetalol
- monitor in hospital for 1-2 weeks for any complications
- rebleeding
- hydrocephalus
- vasospasm leading to ischemic stroke
Differentiate ischemic and compression causes of CN III palsies
Ischemic
- have a reactive pupil with ptosis, depressed and abducted eye
- as pupillary constrictor fibers run along outside of nerve and vasculature is within nerve
Compressive
- have dilated pupil with ptosis, depressed and abducted eye
Differentiate upper motor lesion and lower motor lesion for CN VII
UMN
- contralateral facial weakness with forehead sparing
- due to bilateral frontalis innervation
LMN
- ipsilateral facial weakness (facial droop, flattening of forehead, inability to close eye)
Discuss abnormalities in visual field
Right Optic Nerve Lesion - right anopsia (no vision from right eye) Right Junctional Scotoma - right anopsia and left upper quadrantonopsia Chiasmial Lesion - Bitemporal heminanopsia (outside) Right Optic Tract Lesion - left homonymous hemianopsia Right Temporal Lesion - left upper quadrantopsia Right Parietal Quadrantanopsia - left lower quadrantanopsia
Discuss the presentation, and tracts involved in a lateral medullary stroke (Wallenburg)
- involvement of the posterior inferior cerebellar artery
Presentation - ataxia with loss of sensation on contralateral side
- loss of pin prick to ipsilateral face and contralateral body
- Ipsilateral Horners (miosis, ptosis)
Tract - spinothalamic tract
- descending sympathetic tract
- inferior cerebellar peduncle
Discuss the presentation and tracts involved in a medial midbrain stroke (Weber’s)
- posterior cerebral artery Presentation - Diplopia - loss of elevation, depression and abduction of eye - contralateral hyperreflexia Tract - CNIII - Contralateral corticospinal tract
