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(Cerebellar Stroke)
(Evaluation)
 
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==Background==
 
==Background==
*Vascular injury that reduces CBF to specific region of brain causing neuro impairment
+
*Vascular injury that reduces cerebral blood flow to specific region of brain causing neuro impairment
*Accurate determination of last known time when pt was at baseline is essential
+
*Accurate determination of last known time when patient was at baseline is essential
 +
*In-hospital mortality of 5-10% for ischemic stroke and 40-60% for hemorrhagic stroke
 +
*Only 10% of stroke survivors will recover completely
 +
[[File:23-Sensory-Homonculus.png|thumb|Sensory Homonculus - courtesy AnatomyZone.com]]
  
===Stroke Syndromes===
+
{{Ischemic Stroke Cause}}
#Anterior Circulation (internal carotid system)
+
{{Hemorrhagic Stroke Cause}}
##ACA
+
{{Stroke types}}
###Contralateral sensory and motor symptoms in the lower extremity (sparing hands/face)
 
###Left sided lesion: akinetic mutism, transcortical motor aphasia
 
###Right sided lesion: Confusion, motor hemineglect
 
##MCA
 
###Hemiparesis, facial plegia, sensory loss contralateral to affected cortex
 
###Motor deficits found more commonly in face and upper extremity than lower extremity
 
###Dominant hemisphere involved: aphasia
 
###Nondominant hemisphere involved: inattention, neglect, dysarthria without aphasia
 
###Homonymous hemianopsia and gaze preference toward side of infarct may also be seen
 
#Posterior circulation (vertebral system)
 
##Vertebral artery
 
###Crossed neuro deficits (i.e., ipsilateral CN deficits w/ contralateral motor weakness)
 
###Multiple, simultaneous complaints are the rule
 
####Vertigo, headache, nausea, visual disturbances, oculomotor palsies, ataxia
 
###Isolated events are not attributable to vertebral occlusive disease:
 
####E.g. Isolated lightheadedness, vertigo, transient ALOC, drop attacks
 
##Basilar artery
 
###Quadriplegia, coma, locked-in syndrome
 
##Posterior cerebral
 
###Unilateral headache (most common presenting complaint)
 
###Visual field defects (contralateral homonymous hemianopsia, unilateral blindness)
 
###Motor function is typically minimally affected
 
##Posteroinferior cerebellar
 
###Vertigo, gait instability, limb ataxia, HA, dysarthria, N/V, CN abnormalities
 
 
 
===Causes===
 
#Ischemic (87%)
 
##Thrombotic (80% of ischemic CVA)
 
###Atherosclerosis
 
###Vasculitis
 
###Arterial dissection
 
###Polycythemia
 
###Hypercoagulable state
 
###Infection
 
##Embolic (20% of ischemic CVA)
 
###Valvular vegetations
 
###Mural thrombi
 
###Arterial-arterial emboli from proximal source
 
###Fat emboli
 
###Septic emboli
 
##Hypoperfusion
 
###Cardiac failure resulting in systemic hypotension
 
#Hemorrhagic (13%)
 
##Intracerebral
 
###HTN
 
###Amyloidosis
 
###Anticoagulation
 
###Vascular malformations
 
###Cocaine use
 
##SAH
 
###Berry aneurysm rupture
 
###Vascular malformation rupture
 
  
 
==Clinical Features==
 
==Clinical Features==
*Thrombotic
+
{{Stroke Syndromes}}
**Stuttering or waxing and waning
 
**TIA involving same vascular distribution
 
*Embolic
 
**Sudden onset of symptoms
 
**TIAs involving different vascular distributions
 
**A-fib
 
**Valvular replacement
 
**Recent MI
 
*Hemorrhagic
 
**Sudden onset of symptoms
 
**Preceded by severe headache
 
**Recent neck trauma/manipulation
 
 
 
==Cerebellar Stroke==
 
*Sudden inability to walk is common finding
 
*Can be confused w/ acute vestibular syndrome (e.g. labyrinthitis)
 
*HINTS Exam can reliably distinguish the two (more effective than early DWI MRI)
 
**1. Head Impulse Testing
 
***Tests vestibulo-ocular reflex
 
***Have pt fix their eyes on your nose
 
***Move their head in the horizontal plane to the left and right
 
***If reflex is intact their eyes will stay fixed on your nose
 
***If reflex is abnormal eyes will move with their head and won't stay fixed on your nose
 
***It is reassuring if the reflex is abnormal!(due to dysfunction of the nerve)
 
**2. Nystagmus
 
***Benign nystagmus only beats in one direction no matter which direction their eyes look
 
***Bad nystagums beats in every direction their eyes look
 
****If pt looks left, get left nystagmus, if looks right, get right-beating nystagmus
 
**3. Test of Skew
 
***Vertical dysconjugate gaze is bad
 
***Alternating cover test
 
****Have pt look at your nose w/ their eyes and then cover one eye
 
*****When rapidly uncover the eye look to see if the eye quickly moves to re-align
 
****If any of the above 3 tests are consistent w/ CVA obtain full work-up (including MRI)
 
 
 
==DDX==
 
#Seizures/postictal paralysis (Todd paralysis)
 
##Transient paralysis following a seizure which typically disappears quickly
 
##Note: seizures can be secondary to a CVA
 
#Syncope
 
##No persistent or associated neurologic symptoms
 
#Brain neoplasm or abscess
 
##Focal neurologic findings, signs of infection, detectable by imaging
 
#Epidural/subdural hematoma
 
##History of trauma, ETOH, anticoagulant use, bleeding disorder; detectable by imaging
 
#Hypoglycemia
 
##Can be detected by bedside glucose measurement, history of DM
 
#Hyponatremia
 
##History of diuretic use, neoplasm, excessive free water intake
 
#Hypertensive encephalopathy
 
##Gradual onset; global cerebral dysfunction, HA, delirium, HTN, cerebral edema
 
#Meningitis/encephalitis
 
##Fever, immunocompromise may be present, meningismus, detectable on LP
 
#Hyperosmotic coma
 
##Extremely high glucose levels, history of DM
 
#Wernicke encephalopathy
 
##History of ETOH or malnutrition; triad of ataxia, ophthalmoplegia, and confusion
 
#Labyrinthitis
 
##Predominantly vestibular symptoms; pt should have no other focal findings
 
#Drug toxicity
 
##Lithium, phenytoin, carbamazepine
 
#Bell's palsy
 
##Neuro deficit confined to isolated peripheral 7th nerve palsy; often a/w younger age
 
#Complicated migraine
 
##History of similar episodes, preceding aura, HA
 
#Meniere disease
 
##History of recurrent episodes dominated by vertigo symptoms, tinnitus, deafness
 
#Demyelinating disease (MS)
 
##Gradual onset, may have hx of multiple episodes of findings in multiple distributions
 
#Conversion disorder
 
##No cranial nerve findings, nonanatomic distribution of findings
 
  
==Work-Up==
+
==Differential Diagnosis==
#Bedside glucose
+
{{Stroke DDX}}
#Bedside Hb (polycythemia)
+
{{Weakness DDX}}
#CBC
 
#Chemistry
 
#Coags
 
#Troponin
 
#ECG (esp A-fib)
 
#[[Head CT]]
 
##Primarily used to exclude intracranial bleeding, abscess, tumor, other stroke mimics
 
#Also consider:
 
##Pregnancy test
 
##CXR (if infection suspected)
 
##UA (if infection suspected)
 
##Utox (if ingestion suspected
 
  
==Treatment==
+
==Evaluation==
===Ischemic===
+
[[File:StrokeMCA overlay.png|thumb|[[Ischemic stroke]] with CT showing early signs of a middle cerebral artery stroke with loss of definition of the gyri and grey white boundary.]]
*tPA AND non-tPA candidates:
+
[[File:Intracerebral heamorrage.jpg|thumb|[[Hemorrhagic stroke]] (i.e. spontaneous intracranial hemorrhage).]]
**Dehydration
+
[[File:Posterior fossa hemorrhage.jpg|thumb|[[Hemorrhagic stroke]] in the posterior fossa.]]
***Normalize volume status w/ IVF
+
[[File:Left MCA Stroke.png|thumb|12-lead ECG of a patient with acute stroke, showing large deeply inverted T-waves.]]
**Hypoxia
+
'''Always obtain blood glucose, which is commonly overlooked (more embarrassing if you give tPA)'''
***Maintain SpO2 >92%
+
Find out last known normal of affected deficit and write it down in chart
**Hyperpyrexia
+
{{Stroke workup}}
***Search for cause
 
***Antipyretics
 
**Glycemic control
 
***Controversial
 
  
====tPA Candidate====
+
===Large Vessel Occlusion - Thrombectomy===
#Hypertension
+
*"Cortical strokes" of ICA, MCA, and some ACA occlusions are most likely to benefit from thrombectomy
##Lower SBP to <185, DBP to <110
+
*CT perfusion study is the key factor in determining brain tissue salvageability from symptom onset to thrombectomy of 6-24 hours<ref>Albers GW, Marks MP, Kemp S, et al. Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging. N Engl J Med. 2018;378(8):708-718.</ref>
##Options:
+
*If CT perfusion unavailable, use ASPECT score<ref>Barber PA, Demchuk AM, Zhang J, Buchan AM. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet. 2000;355(9216):1670-4.</ref>
###Labetalol 10–20mg IV over 1–2 min; may repeat x1 OR
 
###Nitroglycerin paste, 1–2 in. to skin OR
 
###Nicardipine 5mg/hr, titrate up by 2.5mg/hr at 5-15min intervals; max dose 15mg/hr
 
####When desired blood pressure attained reduce to 3mg/hr
 
#tPA
 
##See [[CVA (tPA)]]
 
  
====Non-tPA Candidate====
+
====VAN Score====
#Hypertension
+
*NIHSS score ≥ 6 is nearly 100% sensitive for emergent large vessel occlusion, which may be amenable to thrombectomy<ref>Teleb MS, Ver Hage A, Carter J, et al Stroke vision, aphasia, neglect (VAN) assessment—a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices Journal of NeuroInterventional Surgery 2017;9:122-126.</ref>
##Allow permissive HTN unless SBP >220 or DBP >120 (lower by 10-25%)
+
*'''VAN''' score is just as sensitive, but also may be more specific (~90%)
#Aspirin 325mg (within 24-48hr)
+
**Weakness must be present, plus one or all of the VAN to be VAN positive
#Anticoagulation not recommended for acute stroke (even for A-fib)
+
***Weakness qualifying findings -- if no weakness, the pt is VAN negative
 +
****Mild (minor drift)
 +
****Moderate (severe drift—touches or nearly touches ground)
 +
****Severe (flaccid or no antigravity)
 +
***'''V'''isual disturbance qualifying findings
 +
****Field cut (which side) (4 quadrants)
 +
****Double vision (ask patient to look to right then left; evaluate for uneven eyes)
 +
****Blind new onset
 +
***'''A'''phasia qualifying findings
 +
****Expressive (inability to speak or paraphasic errors); do not count slurring of words (repeat and name 2 objects)
 +
****Receptive (not understanding or following commands) (close eyes, make fist)
 +
****Mixed
 +
***'''N'''eglect qualifying findings
 +
****Forced gaze or inability to track to one side
 +
****Unable to feel both sides at the same time, or unable to identify own arm
 +
****Ignoring one side
 +
**If VAN positive, CT and CTA of the head should be ordered for consideration of thrombectomy plus/minus tPA
  
===Hemorrhagic===
+
==Management==
*See [[Intracerebral Hemorrhage (ICH)]]
+
*Depends on type
 +
**[[Ischemic stroke|Ischemic]] vs [[Hemorrhagic stroke|Hemorrhagic]]
 +
**Acute vs subacute vs old
 +
**Due to risk for hemorrhagic transformation, there is no role in acute completed stroke for:
 +
***Dual antiplatelet therapy (as opposed in select cases of [[TIA]])
 +
***Anticoagulation, with or without atrial fibrillation
  
===Cerebellar===
+
==Disposition==
*Early neurosurgical consultation is needed (herniation may lead to rapid deterioration)
+
*Admit for acute or subacute stroke
  
 
==See Also==
 
==See Also==
 
*[[Transient Ischemic Attack (TIA)]]
 
*[[Transient Ischemic Attack (TIA)]]
*[[CVA (tPA)]]
+
*[[Thrombolysis in Acute Ischemic Stroke (tPA)]]
 
*[[CVA (Post-tPA Hemorrhage)]]
 
*[[CVA (Post-tPA Hemorrhage)]]
*[[Intracranial Hemorrhage (ICH)]]
+
*[[Intracerebral Hemorrhage]]
 
*[[Subarachnoid Hemorrhage (SAH)]]
 
*[[Subarachnoid Hemorrhage (SAH)]]
 +
*[[Cervical Artery Dissection]]
 +
*[[NIH Stroke Scale]]
 +
*[[Cerebellar Stroke]]
 +
*[[Focal neurologic signs]]
 +
 +
==External Links==
 +
*[http://www.mdcalc.com/modified-nih-stroke-scale-score-mnihss/ MDCalc - NIH Stroke Scale/Score]
 +
*[https://emergencymedicinecases.com/ed-stroke-management-endovascular-therapy/ Emergency medicine cases - ED stroke management in the age of endovascular therapy]
  
==Source==
+
==References==
*Tintinalli
+
<references/>
*UpToDate
 
*AHA/ASA Acute Stroke Guidelines
 
*EMCrit
 
  
[[Category:Neuro]]
+
[[Category:Neurology]]

Latest revision as of 00:55, 6 September 2019

Background

  • Vascular injury that reduces cerebral blood flow to specific region of brain causing neuro impairment
  • Accurate determination of last known time when patient was at baseline is essential
  • In-hospital mortality of 5-10% for ischemic stroke and 40-60% for hemorrhagic stroke
  • Only 10% of stroke survivors will recover completely
Sensory Homonculus - courtesy AnatomyZone.com

Ischemic stroke causes (87% of all strokes)

Hemorrhagic stroke causes (13% of all strokes)

Stroke Types

Clinical Features

Anterior Circulation

  • Blood supply via internal carotid system
  • Includes ACA and MCA

Internal Carotid Artery

  • Tonic gaze deviation towards lesion
  • Global aphasia, dysgraphia, dyslexia, dyscalculia, disorientation (dominant lesion)
  • Spatial or visual neglect (non-dominant lesion)

Anterior Cerebral Artery (ACA)

Signs and Symptoms:

  • Contralateral sensory and motor symptoms in the lower extremity (sparing hands/face)
  • Urinary and bowel incontinence
  • Left sided lesion: akinetic mutism, transcortical motor aphasia
  • Right sided lesion: Confusion, motor hemineglect
  • Presence of primitive grasp and suck reflexes
  • May manifest gait apraxia

Middle Cerebral Artery (MCA)

Signs and Symptoms:

  • Hemiparesis, facial plegia, sensory loss contralateral to affected cortex
  • Motor deficits found more commonly in face and upper extremity than lower extremity
  • Dominant hemisphere involved: aphasia
    • Wernicke's aphasia (receptive aphasia) -> patient unable to process sensory input and don't understand verbal communication
    • Broca's aphasia (expressive aphasia) -> patient unable to communicate verbally, even though understanding may be intact
  • Nondominant hemisphere involved: dysarthria (motor deficit of the mouth and speech muscles; understanding intact) w/o aphasia, inattention and neglect side opposite to infarct
  • Contralateral homonymous hemianopsia
  • Gaze preference toward side of infarct
  • Agnosia (inability to recognize previously known subjects)

Posterior circulation

Signs and Symptoms:

Basilar artery

Signs and Symptoms:

  • Quadriplegia, coma, locked-in syndrome
  • "Crossed signs" in which a patient has unilateral cranial nerve deficits but contralateral hemiparesis and hemisensory loss suggest brainstem infarction
    • Millard-Gubler syndrome (ventral pontine syndrome) -- ipsilateral CN VI and VII palsy with contralateral hemiplegia of extremities
  • Sparing of vertical eye movements (CN III exits brainstem just above lesion)
    • Thus, may also have miosis b/l
  • One and a half syndrome (seen in a variety of brainstem infarctions)
    • "Half" - INO (internuclear ophthalmoplegia) in one direction
    • "One" - inability for conjugate gaze in other direction
    • Convergence and vertical EOM intact
  • Medial inferior pontine syndrome (paramedian basilar artery branch)
    • Ipsilateral conjugate gaze towards lesion (PPRF), nystagmus (CN VIII), ataxia, diplopia on lateral gaze (CN VI)
    • Contralateral face/arm/leg paralysis and decreased proprioception
  • Medial midpontine syndrome (paramedian midbasilar artery branch)
    • Ipsilateral ataxia
    • Contralateral face/arm/leg paralysis and decreased proprioception
  • Medial superior pontine syndrome (paramedian upper basilar artery branches)
    • Ipsilateral ataxia, INO, myoclonus of pharynx/vocal cords/face
    • Contralateral face/arm/leg paralysis and decreased proprioception

Superior Cerebellar Artery (SCA)

Posterior Cerebral Artery (PCA)

Signs and Symptoms:

  • Common after CPR, as occipital cortex is a watershed area
  • Unilateral headache (most common presenting complaint)
  • Visual field defects (contralateral homonymous hemianopsia, unilateral blindness)
  • Visual agnosia - can't recognize objects
  • Possible macular sparing if MCA unaffected
  • Motor function is typically minimally affected
  • Lateral midbrain syndrome (penetrating arteries from PCA)
    • Ipsilateral CN III - eye down and out, pupil dilated
    • Contralateral hemiataxia, tremor, hyperkinesis (red nucleus)
  • Medial midbrain syndrome (upper basilar and proximal PCA)
    • Ipsilateral CN III - eye down and out, pupil dilated
    • Contralateral paralysis of face, arm, leg (corticospinal)

Anterior Inferior Cerebellar Artery (AICA)

Posterior Inferior Cerebellar Artery (PICA)

Signs and Symptoms:

  • Lateral medullary/Wallenberg syndrome
  • Ipsilateral cerebellar signs, ipsilateral loss of pain/temperature of face, ipsilateral Horner syndrome, ipsilateral dysphagia and hoarseness, dysarthria, vertigo/nystagmus
  • Contralateral loss of pain/temp over body
  • Also caused by vertebral artery occlusion (most cases)

Internal Capsule and Lacunar Infarcts

  • May present with either lacunar c/l pure motor or c/l pure sensory (of face and body)[4]
    • Pure c/l motor - posterior limb of internal capsule infarct
    • Pure c/l sensory - thalamic infarct (Dejerine and Roussy syndrome)
  • C/l motor plus sensory if large enough
  • Clinically to cortical large ACA + MCA stroke - the following signs suggest cortical rather than internal capsule[5]:
    • Gaze preference
    • Visual field defects
    • Aphasia (dominant lesion, MCA)
    • Spatial neglect (non-dominant lesion)
  • Others
    • Ipsilateral ataxic hemiparesis, with legs worse than arms - posterior limb of internal capsule infarct
    • Dysarthria/Clumsy Hand Syndrome - basilar pons or anterior limb of internal capsule infarct

Anterior Spinal Artery (ASA)

Superior ASA

  • Medial medullary syndrome - displays alternating pattern of sidedness of symptoms below
  • Contralateral arm/leg weakness and proprioception/vibration
  • Tongue deviation towards lesion

Inferior ASA

  • ASA syndrome
  • Watershed area of hypoperfusion in T4-T8
  • Bilateral pain/temp loss in trunk and extremities (spinothalamic)
  • Bilateral weakness in trunk and extremities (corticospinal)
  • Preservation of dorsal columns

Differential Diagnosis

Stroke-like Symptoms

Weakness

Evaluation

Ischemic stroke with CT showing early signs of a middle cerebral artery stroke with loss of definition of the gyri and grey white boundary.
Hemorrhagic stroke (i.e. spontaneous intracranial hemorrhage).
Hemorrhagic stroke in the posterior fossa.
12-lead ECG of a patient with acute stroke, showing large deeply inverted T-waves.

Always obtain blood glucose, which is commonly overlooked (more embarrassing if you give tPA) Find out last known normal of affected deficit and write it down in chart

Stroke Work-Up

  • Labs
    • POC glucose
    • CBC
    • Chemistry
    • Coags
    • Troponin
    • T&S
  • ECG
    • In large ICH or stroke, may see deep TWI and prolong QT, occ ST changes
  • Head CT (non-contrast)
    • In ischemia stroke CT has sensitivity 42%, specificity 91%[6]
    • In acute ICH the sensitivity is 95-100%[7]
    • The goal of CTH is to identify stroke mimics (ICH, mass lesions, etc .)[8]
  • Also consider:
    • CTA brain and neck
      • To check for large vessel occlusion for potential thrombectomy
      • Determine if there is carotid stenosis that warrants endarterectomy urgently
    • Pregnancy test
    • CXR (if infection suspected)
    • UA (if infection suspected)
    • Utox (if ingestion suspected)

MR Imaging (for Rule-Out CVA or TIA)

  • MRI Brain with DWI, ADC (without contrast) AND
  • Cervical vascular imaging (ACEP Level B in patients with high short-term risk for stroke):[9]
    • MRA brain (without contrast) AND
    • MRA neck (without contrast)
      • May instead use Carotid CTA or US (Carotid US slightly less sensitive than MRA)[10] (ACEP Level C)

Large Vessel Occlusion - Thrombectomy

  • "Cortical strokes" of ICA, MCA, and some ACA occlusions are most likely to benefit from thrombectomy
  • CT perfusion study is the key factor in determining brain tissue salvageability from symptom onset to thrombectomy of 6-24 hours[11]
  • If CT perfusion unavailable, use ASPECT score[12]

VAN Score

  • NIHSS score ≥ 6 is nearly 100% sensitive for emergent large vessel occlusion, which may be amenable to thrombectomy[13]
  • VAN score is just as sensitive, but also may be more specific (~90%)
    • Weakness must be present, plus one or all of the VAN to be VAN positive
      • Weakness qualifying findings -- if no weakness, the pt is VAN negative
        • Mild (minor drift)
        • Moderate (severe drift—touches or nearly touches ground)
        • Severe (flaccid or no antigravity)
      • Visual disturbance qualifying findings
        • Field cut (which side) (4 quadrants)
        • Double vision (ask patient to look to right then left; evaluate for uneven eyes)
        • Blind new onset
      • Aphasia qualifying findings
        • Expressive (inability to speak or paraphasic errors); do not count slurring of words (repeat and name 2 objects)
        • Receptive (not understanding or following commands) (close eyes, make fist)
        • Mixed
      • Neglect qualifying findings
        • Forced gaze or inability to track to one side
        • Unable to feel both sides at the same time, or unable to identify own arm
        • Ignoring one side
    • If VAN positive, CT and CTA of the head should be ordered for consideration of thrombectomy plus/minus tPA

Management

  • Depends on type
    • Ischemic vs Hemorrhagic
    • Acute vs subacute vs old
    • Due to risk for hemorrhagic transformation, there is no role in acute completed stroke for:
      • Dual antiplatelet therapy (as opposed in select cases of TIA)
      • Anticoagulation, with or without atrial fibrillation

Disposition

  • Admit for acute or subacute stroke

See Also

External Links

References

  1. Itoh Y, Yamada M, Hayakawa M, Otomo E, Miyatake T. Cerebral amyloid angiopathy: a significant cause of cerebellar as well as lobar cerebral hemorrhage in the elderly. J Neurol Sci. 1993 Jun;116(2):135-41.
  2. Macdonell RA, Kalnins RM, Donnan GA. Cerebellar infarction: natural history, prognosis, and pathology. Stroke. 18 (5): 849-55.
  3. Lee H, Kim HA. Nystagmus in SCA territory cerebellar infarction: pattern and a possible mechanism. J Neurol Neurosurg Psychiatry. 2013 Apr;84(4):446-51.
  4. Rezaee A and Jones J et al. Lacunar stroke syndrome. Radiopaedia. http://radiopaedia.org/articles/lacunar-stroke-syndrome.
  5. Internal Capsule Stroke. Stanford Medicine Guide. http://stanfordmedicine25.stanford.edu/the25/ics.html
  6. Mullins ME, Schaefer PW, Sorensen AG, Halpern EF, Ay H, He J, Koroshetz WJ, Gonzalez RG. CT and conventional and diffusion-weighted MR imaging in acute stroke: study in 691 patients at presentation to the emergency department. Radiology. 2002 Aug;224(2):353-60.
  7. Suarez JI, Tarr RW, Selman WR. Aneurysmal subarachnoid hemorrhage. N Engl J Med. 2006; 354(4):387–396.
  8. Douglas VC, Johnston CM, Elkins J, et al. Head computed tomography findings predict short-term stroke risk after transient ischemic attack. Stroke. 2003;34:2894-2899.
  9. ACEP Clinical Policy: Suspected Transient Ischemic Attackfull text
  10. Nederkoorn PJ, Mali WP, Eikelboom BC, et al. Preoperative diagnosis of carotid artery stenosis. Accuracy of noninvasive testing. Stroke. 2002;33:2003-2008.
  11. Albers GW, Marks MP, Kemp S, et al. Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging. N Engl J Med. 2018;378(8):708-718.
  12. Barber PA, Demchuk AM, Zhang J, Buchan AM. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet. 2000;355(9216):1670-4.
  13. Teleb MS, Ver Hage A, Carter J, et al Stroke vision, aphasia, neglect (VAN) assessment—a novel emergent large vessel occlusion screening tool: pilot study and comparison with current clinical severity indices Journal of NeuroInterventional Surgery 2017;9:122-126.