Cerebral Vascular Disease Flashcards
Definition of cerebral ischemia
inadequate blood or oxygen to brain
mild or acute ischemia
syncope
severe or long-standing ischemia
whole brain = hypoxic-ischemia encephalopathy
focal region = stroke
systemic causes of short-lived cerebral ischemia
hypotension, vasovagal reaction, arrhythmia, MI
PE of stroke/TIA work up
BP, RR, pulse
Fundoscopy
Listen for bruits, murmurs, abnormal rhythms
Careful neuro exam
Labs to work up stroke/TIA
CBC, ESR, CMP, Lipid profile, Clotting studies (PT/PTT), serologic test for syphilis
Imaging to eval for possible embolic cause of stroke
carotid U/S, ECG, Holter monitor, ECHO, TEE, angiogram
Why is getting a CT/MRI important in work up of stroke?
only way to differentiate ischemic and hemorrhagic stroke
Difference in causes of ischemic and hemorrhagic strokes?
ischemic - thrombosis or embolic blockage of blood flow to brain
hemorrhagic - bleeding inside or around brain tissue
Non-modifiable RF for stroke
age, male, African American, hypercoaguable state
Modifiable RF for stroke
- stop smoking and drinking
- control DM, HTN
- treat hyperlipidemia, hyper coagulability, sleep apnea
- convert A-fib to sinus rhythm
- reduce obesity
How to decrease risk of A-fib?
anti-coags
How are mitral valve defects and A fib ruled out as causes of stroke?
TEE r/o mitral defect
ECHO r/o A-fib
What are two types of stroke and which is more likely?
Ischemic (85%)
Hemorrhage (15%)
What is most likely cause of hemorrhagic stoke?
HTN
In a stroke, if blood quickly restored then it is a ______. But if prolonged ischemia _______.
TIA
tissue necrosis -> hemorrhagic stroke
RF specific to ischemic stroke
atherosclerosis, AGE, fhx, HTN, DM, tobacco, high lipids, A-fib, recent MI, valvular disease, patent foramen ovale, hypercoaguable states, systemic vascular disease, HIV/AIDS
What are some hypercoaguable states?
cancer, thrombocytosis, factor V Leiden, oral contraceptives
When is tPA not appropriate for stroke treatment?
hemorrhagic strokes (or other bleeds) acute stroke tx after 4.5 hours of sx onset thrombolysis (on blood thinner) uncontrolled HTN pregnancy
How/when does tPA work?
= tissue plasminogen activator
breaks up clots; used in immediate treatment of stroke (within 4.5 hrs) or MI (within 12 hrs)
What tx is used for acute stroke symptoms and prevention?
anti-platelet tx: Aspirin/Clopidogrel
Medical management to reduce complications and prevent secondary stroke?
- reduce RFs
- take Aspirin
- Save ischemic penumbra region
- Rehab: PT/OT, speech pathologist, respiratory therapist, social worker, psychologist
What is major risk of having TIA?
15% risk of full stroke after TIA, esp first 2 days
amaurosis fagux
TIA with transient monocular blindness from emboli to central retinal artery of one eye (branch of internal carotid artery); high correlation with ipsilateral carotid stenosis
How is TIA defined?
stroke that resolves within 24 hours; usually less than 1 hr
Major causes of TIA
- stenosis of major artery (carotid, vertebral)
- embolic phenomena (A-fib)
- thrombosis of smaller BV in brain
What is an important part of PE for TIA?
Listen to carotid arteries
What drug can reduce ICP?
Mannitol
TIA treatement
Urgent eval and tx!
Aspirin
Avoid tPA
Hospitalization for acute workup and availability of tPA if stroke occurs
________ are 20% of ischemic strokes.
small vessel strokes (Lacunar stroke)
5 classic signs of lacunar stroke?
1) Pure motor hemiparesis (hyperreflexia, +Babinski)
2) Pure sensory stroke (unilateral sensory loss)
3) Ataxia hemiparesis (pyramid signs, cerebellar ataxia)
4) Dysarthria & clumsy hand (unilat facial weakness, dysarthric speech, tongue deviation)
5) Mixed sensorimotor stroke (pyramid signs, sensory loss)
Where do small vessel strokes occur?
brainstem, thalamus, pons
What are the effects of a middle cerebral artery stroke?
- contralateral hemiplegia (motor)
- contralateral hemianesthesia (sensory)
- ipsilateral gaze preference
- dysarthria due to facial weakness
- aphasia if L side
What are the effects of a posterior cerebral artery stroke?
3rd nerve palsy (eye down & out, dilated pupil)
Ataxia
Cortical blindness
Hemianopia
What part of brain is affected by posterior cerebral artery stroke?
midbrain, subthalamic, thalamic, cerebellum
Signs/sx of hemmorhagic stroke
ELEVATED ICP -> HA, altered mentation, confusion, coma, vomiting (no nausea), seizures, papilledema, Cushing’s triad, irregular respirations, arrhythmias
Cushing’s triad
high BP, low pulse, widening pulse pressure
Where is intraparenchymal bleeding?
bleeding into substance of brain
Where is subarachnoid bleeding?
bleeding between arachnoid and pia mater
RFs and causes of intraparenchymal bleeding?
RFs: age, heavy alcohol, anticoags, cocaine, Asians/African Americans
Causes: HTN, trauma, cerebral amyloid angiopathy
Causes of subarachnoid bleeding?
- aneurism (spontaneous rupture of artery)
- occasionally trauma
Most common site for intraparenchymal hemorrhage
basal ganglia
signs/sx of basal ganglia hemorrhage
CONTRALATERAL HEMIPARESIS
mild = face sag, slurred speech, extremity weakness progression = flaccid paralysis, upper brainstem compression (coma, irreg breathing, dilated ipsilateral pupil)
signs/sx of thalamus hemorrhage
Contralateral hemiparesis/hemiparesis
Sensory defect involving all modalities
Aphasia
Anisocoria (different sized pupils) w/o light reflex
signs/sx of cerebellar hemorrhage
Occipital headache
Repeated vomiting
Gait ataxia
Dizziness/vertigo
progression = stuporous, coma, brainstem compression
signs/sx of pontine hemorrhage
Deep coma w/ quadriplegia over minutes
Decerebrate rigidity
Pinpoint pupils which react to light
Doll eye phenomena
occipital lobe hemorrhage ->
hemianopia
L temporal lobe hemorrhage ->
aphasia, delirium
parietal lobe hemorrhage ->
hemisensory loss
frontal lobe hemorrhage ->
arm weakness
Effects of thalamus/midbrain compression
stupor, coma, herniation
saccular aneurism aka _______.
“Berry” aneurism
Chief complaint of saccular aneurism
abrupt onset of “worst headache of my life” = thunderclap HA
Common location of saccular aneurisms
Circle of Willis
RFs of saccular aneurism
congenital arterial wall weakness
Polycystic kidneys
What is major cause of delayed death and morbidity in saccular aneurism?
cerebral vasospasm 4-14 days following initial bleed
- 50-70% mortality, 70% morbidity
Hallmark diagnostic finding of saccular aneurism?
Blood in CSF upon lumbar puncture
Definitive dx of saccular aneurism
angiography (only if patient stable)
What imaging is done for all suspected hemorrhagic strokes?
Head CT - better at viewing bleeding than MRI
saccular aneurism management
- AIRWAY
- Control BP (150 systolic)
Bed rest, head elevation, mild sedation, analgesia, stool softener
Surgery: surgical clipping or endovascular coil
Of those who survive initial bleed of saccular aneurism, _____ rebleed in 1 month.
30%
Which brain bleeds involve venous blood?
subdural hematomas
RF of subdural hemorrhage
alcohol, anti-coags, elderly
Causes of acute subdural bleed
Contusion Shearing injury (e.g. shaken baby syndrome)
BUT trauma not always required if +RFs
Signs of acute subdural hematoma
Rapid ICP increase
Unilateral headache with enlarged pupil on ipsilateral side (“blown pupil”)
Drowsy/comatose
CT scan results of subdural hematoma
hematoma that layers out in crescent shape
Acute vs Chronic Subdural Hematoma treatment
Acute: immediate Burr hole drainage or craniotomy
Chronic: “watchful waiting” (hematoma may reabsorb on its own) or surgical evacuation
Pathophysiology of chronic subdural hematoma development
brain ages and atrophies -> small bridging veins stretch -> increased tear risk
chronic/older collection of blood between dura and brain
Signs of chronic hematoma
headache, slowed thinking, drowsiness, personality changes, depression, dementia, seizures, motor/sensory deficits
How long for chronic hematoma to develop?
variable; days to weeks to months
Layers from skull to brain
skull, epidural space, dura mater, subdural space, arachnoid membrane, subarachnoid space, pia mater, brain
Why is dramatically high BP a sign of saccular hemorrhage?
body’s attempt to profuse brain
Causes of epidural bleeds
TRAUMA - laceration of middle meningeal artery with overlying skull fracture
Compare epidural and acute subdural bleeding
- Epidural more rapid in development
Epidural rounded blood layer, whereas acute subdural blood crescent shaped - Same treatment (Burr hole, rapid evacuation) and presentation (comatose, dilated pupils, headache)
Why is epidural hematoma more rounded on CT?
hematoma can’t expand past skull sutures
Symptoms of AV Malformation
asx until it bleeds
+/- headache, seizures, pulsating noise in head
Where is bleeding of AV Malformation
surface or deep within brain tissue = intraperenchymal
Best imaging for AV Malformation
MRI > CT better to see tissue of vessels
Gold standard of AV Malformation dx
angiography
Treatment of AV Malformation
Surgical tx if accessible
Embolization
Stereotactic radiation (slow sclerosis of vessels over 2-3 yrs)
What age is AV Malformation most common?
10-30 yo