What is the appropriate protocol for localizing a stroke in a pediatric patient?

Algorithm for Stroke Localization in Children

When a child presents with suspected stroke, immediately activate EMS for transport to an emergency department with pediatric neurology expertise, then systematically assess for focal neurological deficits and general symptoms to localize the stroke, recognizing that pediatric stroke presents differently than adult stroke and requires emergent neuroimaging within 1 hour of arrival. 1

Step 1: Initial Recognition and Activation

• Do not use adult stroke screening tools (FAST, Cincinnati Prehospital Stroke Scale) as the sole method to identify pediatric stroke, as these are not validated in children and miss the broad presentation spectrum 1
• Activate emergency response immediately if pediatric stroke is suspected, as early identification reduces mortality and permanent disability 1
• Transport to an ED with pediatric neurology and stroke expertise whenever possible 1

Step 2: Systematic Clinical Assessment for Localization

Assess for Focal Neurological Signs (Localizing Features):

• Hemiparesis or limb weakness - suggests contralateral hemispheric involvement 1
• Facial droop - indicates facial nerve pathway involvement 1
• Altered sensation - localizes to sensory pathways 1
• Visual disturbance - suggests occipital or optic pathway involvement 1
• Speech disturbance (dysarthria or aphasia) - indicates dominant hemisphere or brainstem involvement 1, 2

Assess for General Neurological Signs:

• Altered mental status or altered consciousness - suggests diffuse involvement or large territory stroke 1, 2
• Seizure - may indicate cortical irritation 1
• Headache - common but nonspecific 1
• Ataxia - suggests cerebellar or brainstem involvement 1
• Vertigo/dizziness - may indicate posterior circulation stroke 1
• Nausea/vomiting - associated with increased intracranial pressure or posterior fossa involvement 1

Step 3: Critical Pitfalls to Avoid

• Recognize stroke mimics are extremely common (44% in one trial), including migraine (38%), seizures with postictal paralysis (15%), and Bell's palsy (10%) 1
• Symptoms may present gradually rather than suddenly in children, making identification more difficult than in adults 1
• Infants and young children may have nonspecific presentations, leading to diagnostic delays 1
• Do not delay imaging if stroke is suspected - the high rate of stroke mimics does not justify withholding urgent evaluation 1

Step 4: Emergent Neuroimaging Protocol (Within 1 Hour of Arrival)

Preferred Imaging Strategy:

• MRI with diffusion-weighted imaging (DWI) is the imaging procedure of choice for acute pediatric stroke detection, with 77% sensitivity in the first 3 hours versus 16% for CT 1
• Rapid MRI stroke protocols should be used to overcome challenges with traditional protocols in pediatric patients 1
• MRI also aids in identifying stroke mimics, which is critical given the 44% mimic rate 1

Alternative if MRI Unavailable:

• Noncontrast CT is acceptable if MRI is not readily available or the child is unstable 1
• However, if CT is negative in a child with stroke-like symptoms, do not initiate antithrombotic therapy given the high rate of stroke mimics 1

Additional Vascular Imaging:

• MRA of intracranial and cervical vessels should be obtained to identify vascular abnormalities and guide potential intervention 1
• Perfusion imaging (MR perfusion preferred over CT perfusion) can provide information on cerebral blood flow adequacy but is not necessary to proceed with acute intervention 1

Step 5: Time-Sensitive Considerations

• The therapeutic window for potential intervention is up to 24 hours from last seen normal in pediatric stroke, though this is not FDA-approved 1
• Consultation with pediatric stroke specialists should occur immediately to determine optimal imaging and treatment strategies 1
• Median time from ED arrival to MRI should be under 94 minutes based on quality improvement data 3
• Mechanical thrombectomy may be considered up to 6 hours or longer on a case-by-case basis, though systematic pediatric data are lacking 1

Step 6: Differential Localization by Syndrome

Anterior Circulation (Carotid Territory):

• Contralateral hemiparesis, facial droop, aphasia (if dominant hemisphere), visual field defects 1, 2

Posterior Circulation (Vertebrobasilar):

• Ataxia, vertigo, cranial nerve deficits, bilateral motor/sensory findings 1

Lacunar (Small Vessel):

• Pure motor or sensory deficits without cortical signs 4

Hemorrhagic:

• Severe headache, vomiting, altered consciousness, seizures more common than ischemic 1

Key Clinical Pearls

• 40% of pediatric "brain attacks" represent either stroke or other neurological emergencies (meningitis/encephalitis, intracranial neoplasm), underscoring the need for prompt evaluation 3
• Dysarthria, altered consciousness, hemiplegia, and hemiparesis are the most predictive clinical warning signs for actual stroke versus mimics 2
• Healthy children without significant medical history represent 37% of stroke alerts, so do not be falsely reassured by lack of risk factors 3