Neurologic Emergencies 2 Flashcards
signs of basilar skull fracture
- raccoon eyes (periorbital hematoma)
- CSF rhinorrhea or otorrhea
- battle sign
- hemotypmanum
battle sign
postauricular hematoma
subdural hematoma
- closed head injruy
- tearing of bridging veins
- acute, subacute, or chronic
epidural hematoma
- skull fracture
- tearing of middle meningeal a.
- concussion, lucid interval
cerebral contusion
traumatic intracerebral hemorrhage
who is more prone to subdural hematomas and why
- elderly
- d/t their brain atrophy pulling on the bridging veins
what is the best initial imaging to detect ACUTE blood and skull fracture?
CT w/o
what imaging modality is best to detect subacute blood?
MRI w/o
-isodense and hard to see on CT
shape of subdural hematoma on CT
concave to the bone (crescent shape)
shape of epidural hematoma on CT
convex to the bone
what are the 2 MC types of cerebral herniation after head trauma?
- subfalcine herniation
2. uncal herniation
subfalcine herniation
- shift across midline
- causes bicerebral dysfunction w/ depressed consiousness
uncal herniation
- unilateral transtentorial
- causes midbrain compression w:
- depressed consciousness (RAS)
- ipsilateral ptosis and ophthalmoplegia
- contralateral decerebrate posturing
management of uncal herniation
- elevate head 30 degrees w/ head straight
- intubate and hyperventilate
- insert cath
- give mannitol 100 g IV rapidly
- give dexamethasone 10-20 mg IV
when do you not use steroids in tx of uncal herniation
if it’s d/t large ischemic stroke
penumbra
zone of reversible ischemia around core of irreversible infarction during first hours to day after ischemic stroke onset
two tx option to try and save penumbra
- IV tPA
2. mechanical thrombectomy
mechanical thrombectomy
- removing certain large clots
- in addition to tPA w/i 6 hrs of onset
- or instead of tPA w/i 6-24 hrs of onset
- may save penumbra neurons and improve outcome
what conditions to avoid when trying to save penumbra
- low BP
- hyperglycemia
- fever
- seizure
goal of primary care providers for stroke
-prevent the first stroke (primary prevention)
or
-prevent a recurrent stroke (secondary prevention)
goal of prehospital and emergency providers for stroke
- preserve penumbra (AIS)
- prevent complications
goal of hospital providers for stroke
- preserve penumbra (AIS)
- prevent complications
- promote recovery
- pinpoint etiology
- prevent recurrent stroke
what complications are important to prevent in stroke?
- aspiration pneumonia: elevate head of bed and keep pt NPO
- UTI
- hematuria
what conditions most commonly fool physician into mistaking for stroke?
- old stroke or lesion w/ either partial seizure / postictal state or reactivated
- partial seizure
- migraine aura
things that cause abnormal CT that mimic stroke
- ICH
- tumor w/ bleed or seizure
- abscess w/ seizure
- subdural hematoma
MC cause of stroke mimic?
ICH
things that mimic stroke that are normal on CT
- hypoglycemia
- somatic sx
stroke reactivation mechanism
- after stroke, new brain cells form and grow around stroke damaged area
- new neurons are less resilient
- a trigger could cause temporary worsening of the old deficit
what are possible triggers that could reactivate old stroke deficit?
- toxic metabolic insults like
- infection
- alcohol
- sedating meds
- fever
- fatigue
important to remember about stroke / TIA
-no one has the same stroke or TIA over and over
if a pt has repeat spell that are always the same, one of what 3 things is happening?
- old stroke temporarily reactivated
- seizures from old stroke
- migraine aura
what is the exception that allows for lowering BP in AIS
- if necessary to give IV tPA
- if pt also has acute MI, CHF or aortic dissection
if you do need to slightly lower BP during AIS to give tPA, what are the tx options?
- nicardipine IV
- clevidipine IV
- lebetalol IV
BP targets pre and post tPA
- pre-tPA: < 185/110
- post-tPA: < 180/105
tPA dose
- 0.9 mg/kg MAX 90 mg
- give 10% via bolus, remaining via 1 hr infusion
absolute contraindications for tPA
- glucose < 50
- BP > 185/110
- took NOAC w/i 48 hrs
- endocarditis
- aortic dissection
- abnl coag panel
-also: head trauma, intracranial or spinal surg, ischemic stroke w/i 3 mos, hx of intracranial hemorrhage
relative contraindications of tPA
- seizure at onset
- glucose > 400
- major surg or trauma w/i 2 weeks
- left anterior STEMI w/i 3 mos
review
- cerebral arterial territories on CT
- slide 92
MCA supplies
- cortex: face and arm
- subcortex: face, arm and leg
blockage of distal end of M1 causes
-only face and arm weakness
blockage of proximal beginning of M1 causes
face, arm and leg weakness (same as distal ICA)
labs to get before tPA admin
- FSBG
- noncontrast CT brain
- contrast CTA
labs to get to determine if thrombectomy candidate > 4.5 hrs
- FSBG
- noncontrast CT brain
- contrast CTA
- CT perfusion
which type of stroke is good for thrombectly b/c often resistant to tPA alone?
large clot blocking MCA
3 MC causes of ischemic stroke
- large artery atherosclerosis
- smalla artery dz
- cardioembolism
3 less common but not rare causes of ischemic stroke
- nonatherosclerotiv vasculopathies
- hypercoagulable state
- hypoperfusion
ICH =
- intracerebral hemorrhage
- bleedin ginto brain tissue d/t nontraumatic vessel rupture
two type of ICH
- hypertensive
- non-hypertensive
hypertensive ICH
- d/t chronic HTN
- damage small penetatory arteries in medial brain:
- basal ganglia, thalamus, pons, cerebellum
non hypertensive ICH
- outer brain (lobar hemorrhage)
- causes: amyloid angiopathy in dementia pts, ruptured AVMs, bleeding tumors, bleeding disorders
MC cause of subarachnoid hemorrhage (SAH)
- trauma
- MC nontraumatic cause: saccular aneurysm rupture
MC locations of cerebral saccular aneurysms
- Ant. communicating
- post. communicating
- MCA
- basilar a.
MC area for saccular aneurysm d/t chronic HTN
tip of basilar a. (very dangerous)
hx and exam of SAH
- sudden severe HA, perhaps after valsalva maneuver (commonly sex)
- stiff and painful neck, photophobia
- depressed consciousness
- n/v
eval of SAH
- find the blood (CT or lumbar puncture)
- find the aneurysm (cath or CTA)
- use Hunt and Hess scale to get prognosis
tx of SAH
- prevent rebleeding w/ clip or coil
- manage complications like vasospasm
vasospasm
- delayed cerebral ischemia
- basically is clamping down of arteries in the brain
- d/t effect on arteries of blood breakdown products
tx of vasospasm
- nimodipine 60 mg PO q 4 hr x 21 days
- maintain high-normal BP
other complications w/ SAH
- seizure
- hyponatremia
- hydrocephalus
- cardiac arrythmias
