Stroke recognition and initial assessment

Stroke Recognition - FAST & Furious Onset

• Sudden onset of a focal neurologic deficit. Ascertaining "last known normal" time is critical.
• 📌 Use the FAST mnemonic for rapid prehospital and ED screening:
  • Face: Unilateral drooping (ask patient to smile).
  • Arm: Unilateral weakness or drift (ask to hold arms out).
  • Speech: Slurred (dysarthria) or abnormal language (aphasia).
  • Time: Time is brain! Immediate transport.

⭐ Stroke mimics are frequent. Hypoglycemia can perfectly replicate focal stroke signs; always perform a fingerstick glucose test immediately on arrival.

ED Arrival & Triage - Door to Needle Dash

Immediate goal: Rapidly assess for thrombolysis eligibility. The clock starts from symptom onset or the patient's last known well time.

• Door to Physician (<10 min)
  • Assess ABCs, vitals, establish IV access.
  • Perform NIH Stroke Scale (NIHSS).
  • Check finger-stick glucose to rule out hypoglycemia.
• Door to Stroke Team (<15 min)
  • Activate stroke team for parallel processing.
• Door to CT Scan (<25 min)
  • Immediate non-contrast head CT is crucial.
• Door to Needle (<60 min)

⭐ The single most important initial test is a non-contrast head CT. It is essential to differentiate between ischemic and hemorrhagic stroke, as this fundamentally dictates all subsequent management decisions.

Clinical Evaluation - Scoring the Deficit

• NIH Stroke Scale (NIHSS): Standardized tool to quantify stroke-related neurological deficits.
  • Assesses 11 items including consciousness, language, motor strength, and sensation.
  • Score ranges from 0 (no deficit) to 42 (most severe).
  • Guides treatment decisions (e.g., tPA, thrombectomy).
  • Severity:
    • <5: Mild
    • 5-14: Moderate
    • 15-24: Severe
    • >24: Very Severe

⭐ An NIHSS score >22 is strongly associated with a high likelihood of death or severe disability and may predict malignant cerebral edema and hemorrhagic transformation.

• Modified Rankin Scale (mRS): Measures degree of disability in daily activities post-stroke, from 0 (no symptoms) to 6 (dead). Assesses long-term outcome.

Initial Imaging - Code Gray Matter

• Primary Goal: Immediate non-contrast CT (NCCT) to rapidly exclude intracranial hemorrhage (ICH) before thrombolysis. Ischemic changes may not be visible in the first few hours.

• Key NCCT Findings:

  • Hemorrhage: Appears hyperdense (bright).
  • Early Ischemia: Subtle signs like loss of grey-white differentiation, the insular ribbon sign, or a hyperdense MCA sign.

• Advanced Imaging:

  • CTA (Angiography): Identifies large vessel occlusion (LVO).
  • CTP (Perfusion): Differentiates infarct core from the penumbra (salvageable tissue).

⭐ The ASPECTS score on NCCT quantifies early ischemic changes in the MCA territory. A score < 6 suggests a large, established infarct and may be a relative contraindication for thrombectomy.

Stroke Mimics - The Great Pretenders

• Conditions presenting with focal neurologic deficits that are not due to cerebral ischemia.
• Rapid identification is key to avoid misdiagnosis and inappropriate tPA administration.
• Common mimics include:
  • Seizures (post-ictal Todd's paralysis)
  • Hypoglycemia (< 50 mg/dL)
  • Migraine with aura
  • CNS tumor or abscess
  • Conversion disorder
  • Hypertensive encephalopathy

⭐ Hypoglycemia is a critical mimic. Always check a finger-stick glucose on arrival; it's rapidly reversible.

• BE-FAST (Balance, Eyes, Face, Arm, Speech, Time) is the key to rapid stroke recognition.
• Immediate non-contrast head CT is essential to distinguish ischemic vs. hemorrhagic stroke.
• Always check blood glucose to rule out hypoglycemia, a common stroke mimic.
• The NIH Stroke Scale (NIHSS) is the standard for quantifying neurological deficit.
• "Time is brain" - the therapeutic window for tPA is extremely limited, typically <4.5 hours.
• Suspect hemorrhagic stroke with a "thunderclap" headache and early vomiting.