strokes Flashcards
strokes - anterior circulation - arteries
- middle cerebral artery
- anterior cerebral artery
- lenticulo-striate artery
stroke on middle cerebral artery - area of lesion
motor cortex - upper limb and face sensory cortex - upper limb and face termpal lobe - wernicke area frontal lobe - broca area if in dominant --> aphasia if non dominant --> hemineglect
stroke on anterior cerebral artery - area of lesion
motor cortex - lower limb
sensory cortex - lower limb
stroke on lenticulo-striate artery - area of lesion
- striatum
2. internal capsule
stroke on lenticulo-striate artery - symptoms
Contralateral hemiparesis/hemiplegia (face + body)
absence of cortical signs. eg. neglect, aphasia, visual field loss
a common cause of stroke on lenticulo-striate artery - and why
2ry to unmanaged hypertension because is a common location of lacunar infarcts
strokes - posterior circulation - arteries
- anterior spinal artery
- posterior inferior cerebellar artery
- anterior inferior cerebellar artery
- posterior cerebral artery
- basilar artery
stroke of basilar artery - area of lesion (areas and structures)
- pons, medulla, lower midbrain,
- corticospinal and corticobulbar (UMN)
- ocular cranial nerve nuclei
- paramedian pontine reticular formation
stroke of basilar artery - symptoms
locked-in syndrome :
- preserved consciousness, blinking + vertical eye movement
- quadriplegia
- loss of voluntary facial, mounth and tongue
stroke of anterior spinal artery - area of lesion and symptoms
- lateral corticospinal tract - contralateral hemiparesis (upper and lower limbs)
- medial lemniscus - decreased contralateral proprioception
- Caudal medulla/hypoglossal nerve - ipsilateral hypoglossal dysfunction (tongue deviates ipsilaterally)
medial medullary syndrome is caused by
infarct of paramedian branches of anterior spinal artery and vertebral arteries
stroke of posterior inferior cerebellar artery - area of lesion
lateral medulla (Lateral medullary (wallenberg) syndrome): 1. vestibular nuclei 2. lateral spinothalamic tract 3. spinal trigeminal nucleus 4. nucleus ambiguus (vagus) (μεικτός), 5. sympathetic fibers 6. inferior cerebellar peduncle
stroke of posterior inferior cerebellar artery - symptoms
vomiting, vertigo, nystagmus, decreased pain and Q sensation from ipsilateral face and contralateral body, dysphagia, hoarness, decreased gag reflex, ipsilateral Horner, ataxia, dysmetria
Lateral medullary (wallenberg) syndrome (specific involvement)
POSTERIOR INFERIOR CEREBELLAR ARTERY SYNDROME (STROKE)
nucleus ambiguus effects are specific
stroke of posterior cerebral artery - area of lesion / symptoms
occipital cortex
visual cortex
- contralateral hemianopia with macular sparing
stroke of anterior inferior cerebellar artery - area of lesion
lateral pons: (LATERAL PONTINE SYNDROME)
- cranial nerve nuclei (vestibular, facal, spinal trigeminal, cochlear,)
- sympthathetic fibers
- middle and inferior cerebellar peduncles
- lateral spinothalamic tract
- corticospinal tract
stroke of anterior inferior cerebellar artery - symptoms
LATERAL PONTINE SYNDROME
- vomiting, vertigo, nystagmus
- face paralysis, decreased lacrimation and salivation, decreased taste of the anterior 2/3 of the tongue
- ipsilateral decreased pain and Q of the face and contralateral of the body
- ataxia dysmetria
lateral pontine syndrome - specific lesion
facial nucleus
anterior communicating arteries - lesion
most commonly saccular aneurysm (berry) that can impinge cranial nerves. It can lead to stroke
anterior communicating arteries - symptoms
- visual field defects (bitemporal hemianopia)
- visual acuity defecits
- Rupture –> ischemia in ACA distribution –> contralateral lower extremity hemiparesis, sensory deficits
central post-stroke pain syndrome - definition / course / occurs in
- Neuropathic pain due to thalamic lesions
- initial paresthesias followed in weeks to months by allodynia and dysesthesia
- 10% of stroke patient
common locations of lacunar infarcts
- basal ganglia
- internal capsule
- thalamus
- pons
(Oxford handbook)
stoke - dysphagia and hoarseness - artery?
posterior inferior cerebellar artery
stroke - paralysis of face and loss of lacrimation - artery
Anterior inferior cerebellar artery
intracranial hemorrhage - types
- epidural hematoma
- subdural hematoma
- subarachnoid hemorrhage
- intraparenchymal (hypertensive) hemorrhage
epidural hemorrhage - mechanism
rupture of middle meningeal artery (branch of maxillary) often often 2ry to fracture of temporal bone –> rapid expansion (artery)
epidural hemorrhage - course
- Lucid interval (a temporary improvement in a patient’s condition after a traumatic brain injury)
- rapid expansion under systemic arterial pressure
epidural hemorrhage - complications
- transtentorial herniation
2. CN III
epidural hematoma - CT
- biconvex (lentiform), hyperdense blood collection
- not crossing suture lines
- can cross falx, tentorium
subdural hematoma - mechanism
rupture of bridging veins –> slow venous bleeding
(less pressure because of veins= hematoma develops over time). Can be acute or chronic
subdural hematoma - CT
- Crescent-shaped hemorrhage
- crosses sature lines
- Midline shift
- Cannot cross falx, tentorium
- findings of “acute on chronic” haemorrhage
- if acute –> hyperdense, if chronic –> hypodense
causes of subarachnoid hemorrhage
- rupture of an aneurysm (such as berry)
2. arteriovenous malformations
Saccular (berry) aneurysm - associations and risk factors
- ADPKD
- Ehlers-Danlos syndrome
- advanced age
- hypertension
- smoking
- race (increased risk with black)
subarachnoid hemorrhage - complications after 4-10 days
visible on CT
- vasospasm due to blood breakdown –> ischemic infract (not visible in CT)
- rebleed (visible in CT)
- high risk of developing communicating and/or obstructive hydrocephalus
intraparenchymal (hypertensive) hemorrhage - is caused by
- hypertension (MCC)
- amyloid angiopathy
- vasculitis
- neoplasm
(can cause Charcot-Bouchard)
intraparenchymal (hypertensive) hemorrhage - area
typically occurs in basal ganglia and internal capsule (Charcot-Bouchard aneurysm of leniculostriate vessels)
can be lobar
cns aneurysms - types
- Saccular (berry) aneurysm
2. Charcot-Bouchard microaneurysm
Charcot-Bouchard microaneurysm is associated with … / area / important
chronic hypertension
- it affects small vessels (eg. in basal ganglia, thalamus)
- not seen in angiogram
Saccular (berry) aneurysm - area
bifurcations in the circle of Willis
MC site is junction of anterior communicating artery and anterior cerebral artery
Saccular (berry) aneurysm - complications
- rupture (–> subarachnoid hemorrhage or hemorrhagic stroke)
- bitetemporal hemianopia (via compression of optic chiasm) (anterior comm)
- visual acuity deficits (anterior comm)
- CN III palsy (posterior comm)
aneurysm associated with hypertension - saccular or Charcot Bouchard?
both
MCC and 2nd MCC of subarachnoid hemorrhage (and proportion)
- rupture of an aneurysm (such as berry) (80%)
2. arteriovenous malformations (15%)
most vulnerable areas of ischemic brain disease (which is the most)
- hipocampus (MOST) 2. neocortex 3. cerebellum
4. watershed areas
images can detect ischemic changes in (time)
- CT–> 6-24h (but can show almost imminently hemorrhage)
- diffusion-weighted MRI –> 3-30 min
Hemorrhagic stroke is often due to
- hypertension
- anticoagulation
- cancer
- 2ry to ischemic stroke
MC side of Hemorrhagic stroke
basal ganglia
transient ischemic attack - definition
Brief, reversible episode of focal neurologic dysfunction without acute infraction (-MRI), with the majority resolving in less than 15 mins
hypoxic ischemic stroke is due to / area / common during
hypoperfusion or hypoxemia / warershed areas
common during cardiovascular surgeries
thrombotic ischemic stroke is due to / MC area
a clot forming directly at site of infarction usually over an atherosclerotic plague. commonly the MCA
ischemic stroke - treatment
- tPA (if within if 3-4,5 h of onset
no hemmorrhage/risk of hemorrhage) 2. Reduce risk with medical therapy - optimum control of BP, blood sugar, lipids
- treat conditions that increase risk (eg. aspirin, clopidogrel)
blood - cortical distribution - arteries and what the supply
- anterior cerebral artery –> anteriomedial surface of the cortex
- middle cerebral artery –> lateral surface of the cortex
- posterior cerebral artery –> posterior and inferior surface
watershed zone are in danger to be damaged under / lesions
severe hypotension –> 1. upper leg/upper arm weakness 2. defects kn higher order visual processes
auto-regulation - Cerebral perfusion is primarily driven by
- PCO2 (primarily)
2. PO2 (in severe hypoxia)
autoregulation - relationship between PO2 and cerebral blood flow
P02 increases cerebral blood flow (until P02=50 mmHg)
PO2>50 –> plateau of cerebral blood flow
autoregulation - relationship between PCO2 and cerebral blood flow
cerebral perfusion pressure increases with PCO2 until PCO2=90 mmHg
at PCO2>90 –> plateau of cerebral blood flow
