Lec 60 Clinical Aspects of Stroke Flashcards
What is mortality from stroke?
20%
What is definition stroke?
acute neuro dysfunction of vascular origin with sudden [seconds] or rapid [hrs] occurence of symptoms and signs coresponding to involvement of focal areas of brain
What are two main types of stroke?
ischemic and hemorrhagic
What are risk factors for stroke?
- HTN
- heart disease
- previous stroke
- diabetes
- carotid bruit
- smoking
- oral contraceptives
What are non-modifiable risk factors for stroke?
hispanic and african american
diabetes
male gender
over age 55
What diseases should you think if you see sudden onset persistent focal deficit?
- ischemic stroke
- intracerebral hemorrhage
- partial seizure
- tumor or abscess with bleed
- hypoglycemia
- MS
- migraine
What is ischemic stroke?
blood supply to focal part of brain interrupted, brain cells deprived of glucose and oxygen
What are major causes of ischemic stroke?
- small or large artery thrombus
- embolus
What is acute treatment for ischemic stroke?
thrombolysis
What are the 5 categories of ischemic stroke?
- large artery atherosclerosis
- embolism
- small vessel disease
- stroke of other determined etiology
- stroke of undetermined etiology
What are lacunar infarcts?
small infarcts defined by small size, typically in deep structure such as internal capsule, basal ganglia, thalamus, brainstem
secondary to chronic hypertension
What happens if you have lesion of either frontal lobe?
intellectual impairment
personality change
urinary incontinence
hemiparesis
if left = broca’s aphasia
What is effect of lesion to left temporo-parietal?
alexia agraphia wernicke's aphasia right-left disorientation homonymous field defect
What is effect of lesion to right temporal?
confusional state
failure to recognize faces
homonymous field defect
What is effect of lesion to either parietal?
contralateral sensory loss or neglet
agraphaesthesia
homonymous field defect
if right:
- dressing apraxia
- failure to recognize faces
if left:
limb apraxia
What is effect of lesion to occipital?
visual field defects
visuospatial defects
disturbance of visual recognition
What areas of brain affected by MCA [middle cerebral artery] stroke?
motor cortex of upper limb and face
sensory cortex of upper limb and face
temporal lobe [wernicke]; frontal lobe [broca]
What are symptoms of MCA stroke?
contralateral paralysis - upper limb and face
contralateral loss of sensation – upper and lower limb and face
aphasia – if in left hem [dominant]
hemi- neglect – if in right hem
– posterior frontal, temporal, parietal lobes
What are symptoms of ACA stroke?
contralateral paralysis – lower limb
contralateral loss of sensation – lower limb
[sensory + motor cortex involved]
– frontal pole, mesial frontal lobe
Between ACA and MCA stroke which has more leg paralysis/sensation loss?
MCA!
Arm = ACA leg = MCA
What are symptoms of lenticulo-striate artery stroke?
contralateral hemiparesis/ hemiplegia
= common location of lacunar infarcts secondary to chronic HTN
What are signs of left [dominant] cerebral hemisphere stroke?
aphasia left gaze preference right visual field deficit right hemiparesis right hemisensory loss
What are signs of right [non-dominant] cerebral hemisphere stroke?
neglect = left hemi-inattention right gaze preference left visual field deficit left hemiparesis left hemisensory loss
What are symptoms of internal carotid artery occlusion?
- produces ACA and MCA symptoms
- preceded by amarosis fugax = monocular visual loss due to temporary reduction in retinal artery/opthalmic artery/ciliary artery blood flow = curtain coming down on vision
What are symptoms of posterior cerebral artery stroke?
contralateral homonymous hemianopia with macular sparing
if dominant = get alexia without agraphia
What is alexia?
acquired dyslexia = cant understand writing
What happens if stroke affecting PCA bilaterally?
anton’s syndrome = cortical blindness = pt blind but unaware of deficit
What part of brain is affected if PCA stroke?
occipital lobe
What are symptoms of basilar artery stroke?
have: preserved consciousness and blinking, quadriplegia, loss of voluntary facial, mouth, tongue movements
== locked-in syndrome
Do emboli more frequently cause stroke in posterior or anterior circulation?
anterior circulation
thus –> most posterior circulation strokes due to thrombi
What are symptoms of PICA stroke?
wallenberg [lateral medullary] syndrome –> N/V, headache ataxia, ipsilateral paralysis of tongue, dysphagia, hoarseness, decreased gag reflex, ipsilateral horner syndrome, lost pain and temp sensation from ipsilateral face and contralateral body
don’t pick a [PICA] horse [hoarseness] that can’t eat [dysphagia]
Nucelus ambiguus effects are specific to which artery lesion?
PICA lesion
“Don’t pick a [PICA] horse [hoarseness] that can’t eat [dysphagia]”
What part of brain is affect by PICA stroke?
lateral medullar [vestibular nuclei, lateral spinothalamic tract, spinal trigeminal nucleus, nucleus ambiguus]
What types of artery strokes will cause acute cerebellar infarction?
PICA, AICA, SCA
can develop life-threatening edema
What is a carotid artery dissection?
separation of layers of artery wall supplying blood to head and brain
blood can enter separation between layers –> cause occlusion and ischemia
can be spontaneous or traumatic
What are symptoms of carotid artery dissection?
headache neck pain horners syndrome transient vision loss ischemic stroke
What are signs of anterior inferior cerebellar artery stroke?
lateral pontine syndrome
- N/V, paralysis of face, decreased lacrimation, salivation, taste from anterior 2/3 tongue, corneal reflex, ipsilateral horner syndrome, ipsilateral hearing loss
Facial nucleus effects are specific to which artery lesion?
AICA lesion
“facial droop means AICA’s pooped”
lateral pontine syndrome comes from which type of artery lesion?
AICA
lateral medullary syndrome [wallenberg] occurs with which type of artery lesion?
PICA
medial medullary syndrome occurs with which type of artery lesion?
ASA
What are signs of anterior spinal artery stroke?
medial medullary syndrome - contralateral hemiparesis [upper and lower limbs] - decreased contralateral proprioception ipsilateral hypoglossal dysfunction --> tongue deviates ipsilaterally
What specific lesions in ASA stroke common?
commonly bilateral
- caused by infarct paramedian branches of ASA and vertebral arteries
What part of brain affected by ASA stroke?
lateral corticospinal tract
medial lemniscus
caudal medulla [hypoglossal]
What is a transient ischemic attack [TIA]?
reversible focal dysfunction –> usually lasts minutes but defined as < 24 hrs [stroke = more time]
What usually causes a subarachnoid hemorrhage?
trauma,
ruptured aneurysm [berry, marfans]
arteriovenous malformation
What happens in subarachnoid hemorrhage?
- rapid time course
- “worst headache of life”
- —> neck stiffness, neck pain, light intolerance, N/V
- bloody or yellow spinal tap
- 2-3 days after –> risk of vasopasm due to blood breakdown and rebleed
What do you see with subarachnoid hemorrhage on CT?
subarachnoid blood in sulci
intraventricular blood layering in posterior horn of lateral ventricle
How do you treat subarachnoid hemorrhage?
surgical emergency
- cerebral angiography, aneurysmal clipping/ interventional coiling
What usually causes mycotic aneurysm
infection, bacteremia, septic embolization
What is charcot-bouchard?
microaneurysm
associated with chronic HTN
affects small vessel [lenticulostriates]
Where does berry aneurysm usually occur?
branch point in circle of willis
–> junction anterior communicating artery and anterior cerebral artery
What are risk factors for aneurysm?
chronic HTN, smoking, family history
How do you treat aneurysm?
surgical emergency
What is intracerebral hemorrhage?
occurs when blood vessel in brain parenchyma ruptures –> accumulation blood within brain tissue
WHat are most common sites for intraparenchymal hemorrhage?
thalamus basal ganglia internal capsule pons cerebellum == charcot-bouchard of lenticulostriate vessels
but can also be lobar
What commonly causes lobar hemorrhages [not subcortical]?
amyloid angiopathy
What causes intraparenchymal/intracerebral hemorrhage?
systemic hypertension
amyloid angiopathy
vasculitis
neoplasm
What are complications of reversible cebreal vasoconstriction syndrome [RCVS]?
- TIA
- ischemic stroke
- intracerebral hemorrhage
- berry aneuryism
Does early ischemic infarct show on CT?
may not!
When do you treat stroke with tPA [tissue plasminogen activator]?
- if within 3-4.5 hr of onset and no hemorrhage/risk of hemorrhage
Are most strokes ischemic or hemorrhagic? most common cause?
mostly ischemic
mostly due to clot occluding an artery
What is treatment at < 3 hours after stroke?
IV tPA [tissue plasminogen activator]?
What is treatment at 3-6 hrs after stroke?
IA tPA
combination bridging IV /IA tPA
What is treatment at > 6 hrs after stroke?
mechanical clot extraction
What are potential drawbacks of IV thrombolysis?
- reperfusion injury
- risk of ICH
- low rate recanalization
- high rate reocclusion
What are benefits/drawbacks of IA [intra-arterial] thrombolysis?
benefits: greater freq of recanalization, can use lower dose of thrombolytic, deliver agent directly to site of occlusion
drawbacks: additional risks of angiogram, increased “door to needle” time
