Ischemic Strokes

 
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Associated Articles
Swell Watch (Malignant Cerebral Edema)

FACTS

  • ~85% of strokes are ischemic (~15% hemorrhaghic)
  • Pathology: Arterial occlusion → brain ischemia/infarct; large-vessel occlusion (LVO) may be salvageable with endovascular thrombectomy (EVT).
  • Time is brain: Reperfusion is most effective early; select patients benefit up to 24 h (perfusion mismatch).
  • Neurosurgery roles: (1) Support EVT pathway; (2) Decompressive surgery for malignant edema (MCA, cerebellum); (3) EVD for hydrocephalus; (4) Hemorrhagic transformation management.
  • Thresholds of cerebral ischemia:
    • gray matter: ~100 mL blood/100g tissue
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HPI

  • Onset/Last Known Well (LKW) exact clock time.
  • Symptom evolution: sudden focal deficit (aphasia, hemiparesis, neglect, field cut, dysarthria, ataxia).
  • Anticoagulants/antiplatelets, recent surgery/bleed, prior ICH.
  • Vascular risk: AFib, carotid disease, prior stroke/TIA, MI, diabetes, HTN, smoking.
  • Seizure at onset? (post-ictal Todd’s vs stroke).
    • First seizure-of-life in > 60 year old is most commonly caused by stroke
  • Headache, vomiting, decreased LOC (consider hemorrhage or posterior fossa stroke).

PHYSICAL EXAM

  • NIHSS (document score and key items).
  • Airway/ABCs, GCS, pupils, gaze deviation, fields, facial droop, speech, neglect.
  • Motor/sensory asymmetry; cerebellar signs (for posterior fossa).
  • BP, glucose, temp (treat extremes).
  • Look for malignant edema red flags: worsening mental status, anisocoria, vomiting, bradycardia/HTN (Cushing response).

IMAGING

MRI DWI:
  • mechanism of diffusion restriction in strokes - water moves intracellularly (as opposed to interstitial space) → constrained space → reduced brownian motion → bright on diffusion restriction
  • MR Spectroscopy: lactate and lipid peaks increase
  • Non-contrast head CT (STAT): Rule out hemorrhage; early ischemic change (ASPECTS).
  • CTA head/neck: Identify LVO (ICA/M1/M2, basilar, vertebral) and tandem cervical lesions.
  • CT perfusion (or MR DWI/Perfusion) if beyond early window or unclear onset → core vs penumbra mismatch (for 6–24 h EVT selection).
  • MRI (when available/appropriate): DWI restriction (core), FLAIR mismatch (wake-up stroke), SWI microbleeds/HT.
 

A/P

  • IV tPA within 4.5h LKW

# Notes

Stroke Syndromes

See also
Master Functional Map
 
RIGHT
LEFT
R ACA
L ACA
R MCA
L MCA
R PCA
L PCA Stroke
- RHH (L occ lobe responsible for R field)
- Alexia without agraphia (cannot read but can still write due to splenium extension)
R SCA
L SCA
R AICA
L AICA
R PICA
L PICA

Weber Syndrome

Location: cerebral peduncle, ipsilateral fasicles of oculomotor nerve
Symptoms: diplopia, ptosis, afferent pupillary defect, contralateral hemiplegia/hemiparesis, parkinsonian rigidity
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PICA Infarct: Wallenberg Syndrome (Lateral Medullary Syndrome)

  • supplies lateral medulla, inferior cerebellar peduncle, inferior cerebellar hemisphere
  • vertigo with nystagmus (inferior vestibular nucelus and pathways)
  • Ipsilateral Horner’s (sympathetic fibers)
  • contralateral pain/temperature loss (spinothalamic tract)
  • dysphonia/dysphagia/dysarthria (different nuclei and fibers of CN 9/10)
 

Small Perforator Occlusions

  • these