Ischemic stroke

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Background

Ischemic stroke causes (87% of all strokes)

  • Thrombotic (80% of ischemic CVA)
  • 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

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 incontinence
  • Left sided lesion: akinetic mutism, transcortical motor aphasia
  • Right sided lesion: Confusion, motor hemineglect

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
  • Nondominant hemisphere involved: dysarthria w/o aphasia, inattention and neglect side opposite to infarct
  • Contralateral homonymous hemianopsia
  • Gaze preference toward side of infarct

Posterior circulation

Signs and Symptoms:

  • Crossed neuro deficits (i.e., ipsilateral CN deficits w/ contralateral motor weakness)
  • Multiple, simultaneous complaints are the rule
  • 5 Ds: Dizziness (Vertigo), Dysarthria, Dystaxia, Diplopia, Dysphagia
  • Isolated events are not attributable to vertebral occlusive disease (e.g. isolated lightheadedness, vertigo, transient ALOC, drop attacks)

Basilar artery

Signs and Symptoms:

  • Quadriplegia, coma, locked-in syndrome
  • 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 opthalmoplegia) 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)

  • ~2% of all cerebral infarctions[1]
  • May present with nonspecific symptoms - N/V, dizziness, ataxia, nystagmus (more commonly horizontal)[2]
  • Lateral superior pontine syndrome
    • Ipsilateral ataxia, n/v, nystagmus, Horner's syndrome, conjugate gaze paresis
    • Contralateral loss of pain/temperature in face/extremities/trunk, and loss of proprioception/vibration in LE > UE

Posterior Cerebral Artery (PCA)

Signs and Symptoms:

  • Common after CPR, as occiptal 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)

  • Lateral inferior pontine syndrome
  • Ipsilateral facial paralysis, loss of corneal reflex (CN VII)
  • Ipsilateral loss of pain/temp (CN V)
  • Nystagmus, N/V, vertigo, ipsilateral hearing loss (CN VIII)
  • Ipsilateral limb and gait ataxia
  • Ipsilateral Horner syndrome
  • Contralateral loss of pain/temp in trunk and extremities (lateral spinothalamic)

Posterior Inferior Cerebellar Artery (PICA)

Signs and Symptoms:

  • Lateral medullary/Wallenberg syndrome
  • Ipsilateral cerebellar signs, ipsilateral loss of pain/temp of face, ipsilateral Horner's 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)[3]
    • 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[4]:
    • Gaze preference
    • Visual field defects
    • Aphasia (dominant lesion, MCA)
    • Spatial neglect (non-dominant lesion)
  • Others
    • I/l ataxic hemiparesis, with legs worse than arms - posterior 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
  • B/l pain/temp loss in trunk and extremities (spinothalamic)
  • B/l weakness in trunk and extremities (corticospinal)
  • Preservation of dorsal columns

Differential Diagnosis

Stroke-like Symptoms

Evaluation

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%[5]
    • In acute ICH the sensitivity is 95-100%[6]
    • The goal of CTH is to identify stroke mimics (ICH, mass lesions, etc .)[7]
  • Also consider:
    • CTA brain and neck (to check for large vessel occlusion for potential thrombectomy)
    • 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 (without contrast) AND
  • Cervical vascular imaging (ACEP Level B in patients with high short-term risk for stroke):[8]
    • MRA brain (without contrast) AND
    • MRA neck (without contrast)
      • May instead use Carotid CTA or US (Carotid US slightly less sensitive than MRA)[9] (ACEP Level C)

Management

To differentiate between tPA and non-tPA candidates see Thrombolysis in Acute Ischemic Stroke (tPA)

Both tPA AND non-tPA candidates

  • Prevent dehydration
  • Maintain SpO2 >92%
  • Maintain blood glucose between 140 and 180mg/dL
  • Prevent fever
  • HOB >30°

tPA Candidate

  • tPA
  • Hypertension
    • Lower SBP to <185, DBP to <110
    • Options:
      • 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

Non-tPA Candidate

  • Hypertension
    • Allow permissive hypertension
    • If SBP >220 or DBP >120, lower by 25% over 24 hrs (drug of choice is Nicardipine)[10]
  • Aspirin 325mg (within 24-48hr)
  • Anticoagulation not recommended for acute stroke (even for A-fib)

Endovascular Therapy

  • Mechanical clot removal for large vessel occlusions (e.g. M1 occlusion, basilar artery occlusion)
  • Early trials MR RESCUE, SYNTHESIS, and IMSIII showed no benefit and potential harm
  • MR CLEAN Trial show promising outcomes[11]
    • Participants had proximal intracranial artery occlusions
    • Intervention was conducted within 6 hrs
    • Functional independence of 32.6% with endovascular treatment and 19.1% with typical therapy
  • Institutional dependent time window for intervention
  • May require careful patient selection based on last known normal and additional diagnostic studies such as CT perfusion study, Rapid MRI, etc

Cerebellar

  • Early neurosurgical consultation is needed (herniation may lead to rapid deterioration)
  • See Cerebellar Stroke

Corticosteroids

  • Cochrane review showed no benefit in mortality or functional outcomes[12]

Disposition

  • Admit all acute and subacute ischemic strokes

See Also

External Links

References

  1. ↑ Macdonell RA, Kalnins RM, Donnan GA. Cerebellar infarction: natural history, prognosis, and pathology. Stroke. 18 (5): 849-55.
  2. ↑ 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.
  3. ↑ Rezaee A and Jones J et al. Lacunar stroke syndrome. Radiopaedia. http://radiopaedia.org/articles/lacunar-stroke-syndrome.
  4. ↑ Internal Capsule Stroke. Stanford Medicine Guide. http://stanfordmedicine25.stanford.edu/the25/ics.html
  5. ↑ 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.
  6. ↑ Suarez JI, Tarr RW, Selman WR. Aneurysmal subarachnoid hemorrhage. N Engl J Med. 2006; 354(4):387–396.
  7. ↑ 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.
  8. ↑ ACEP Clinical Policy: Suspected Transient Ischemic Attackfull text
  9. ↑ Nederkoorn PJ, Mali WP, Eikelboom BC, et al. Preoperative diagnosis of carotid artery stenosis. Accuracy of noninvasive testing. Stroke. 2002;33:2003-2008.
  10. ↑ Zha AM, et al. Recommendations for management of large hemispheric infarction. Curr Opin Crit Care. 2015; 21(2):91-8.
  11. ↑ Berkhemer OA, et al. A randomized trial of intraarterial treatment for acute ischemic stroke. NEJM. 2015; 372(1):11-20.
  12. ↑ Sandercock PA and Soane T. Corticosteroids for acute ischaemic stroke. Cochrane Database Syst Rev. 2011 Sep 7;(9):CD000064.

Authors

Neil Young

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