How should a focal neurological deficit be evaluated and managed emergently?

Emergency Evaluation and Management of Focal Neurological Deficit

A patient presenting with focal neurological deficit must be treated as a stroke until proven otherwise, with immediate activation of stroke protocols, non-contrast CT brain within ≤25 minutes of arrival, and simultaneous assessment for thrombolysis eligibility—all while stabilizing airway, breathing, and circulation. 1, 2

Immediate Triage and Stabilization (First 10 Minutes)

Prioritize stroke patients with the same urgency as acute myocardial infarction or major trauma, regardless of symptom severity. 2

Airway, Breathing, Circulation

• Assess and secure airway immediately; intubate if Glasgow Coma Scale ≤8 or inability to protect airway 1, 2
• Use rapid sequence intubation with attention to preoxygenation and avoidance of blood pressure fluctuations 1
• Provide supplemental oxygen only if SpO₂ <94%; routine oxygen in non-hypoxic patients shows no benefit 2
• Place nasogastric or orogastric tube after intubation to reduce aspiration risk 1

Critical Time Documentation

Record the exact "last known well" time immediately on arrival—this single datum determines all reperfusion therapy eligibility 2

Neurological Assessment

Standardized Stroke Scale

Perform the NIH Stroke Scale (NIHSS) or Canadian Neurological Scale (CNS) immediately to quantify severity, guide treatment decisions, and provide prognostic information 1, 2

Vital Signs Assessment

• Measure blood pressure, heart rate, temperature, and SpO₂ 1
• Obtain finger-stick glucose immediately—hypoglycemia (<50-60 mg/dL) mimics stroke and contraindicates thrombolysis 1, 2
• Assess hydration status and presence of seizure activity 1

Stroke Team Activation

Activate the multidisciplinary stroke team or expert consultation without delay while the neurological exam is underway 2

Laboratory Evaluation (Do Not Delay Imaging)

Obtain core labs but proceed with imaging and treatment without waiting for results: 1, 2

• Complete blood count
• Electrolytes, creatinine, estimated glomerular filtration rate
• Random glucose (if not already obtained by finger-stick)
• Coagulation profile (INR, aPTT)
• Cardiac troponin

Exception: For patients on warfarin, INR level is required before thrombolysis 1

Pitfall to avoid: Awaiting renal function results should not delay CT angiography in most patients with disabling symptoms—"neurons over nephrons" 1

Emergent Brain Imaging

Non-Contrast CT Brain

Order non-contrast CT brain immediately—it is the single most critical diagnostic test and must be completed within ≤25 minutes of arrival for thrombolysis candidates 2, 3, 4

Interpretation Requirements

• Must be performed by a physician skilled in CT reading to exclude intracerebral hemorrhage and assess early ischemic changes 2
• Even extensive early ischemic changes involving >1/3 of a hemisphere do NOT preclude rtPA administration within the 3-hour window 2

Vascular Imaging Timing

Do not postpone IV thrombolysis to obtain CT angiography; imaging for large-vessel occlusion should follow, not delay, thrombolytic therapy 2

Blood Pressure Management

For Thrombolysis Candidates (≤4.5 hours from onset)

Target BP <185/110 mmHg before administering rtPA to reduce hemorrhagic risk 2

Medication options: 2

• Labetalol 10-20 mg IV over 1-2 minutes; may repeat once
• Nicardipine infusion starting at 5 mg/hr, titrated by 2.5 mg/hr every 5-15 minutes to maximum 15 mg/hr

For Non-Thrombolysis Candidates

Treat severe hypertension only if SBP >220 mmHg or DBP >120 mmHg—aggressive lowering may worsen cerebral perfusion 2

Cardiac Evaluation

ECG and Monitoring

• Obtain 12-lead ECG promptly to identify acute MI or atrial fibrillation as potential stroke etiologies 1, 2
• ECG should not delay CT or thrombolysis assessment unless patient is hemodynamically unstable 1
• Initiate continuous cardiac monitoring for the first 24 hours to detect atrial fibrillation and other arrhythmias 2

Stroke Mimic Evaluation

High-Priority Mimics to Exclude

The most critical mimics accounting for ~19% of suspected strokes are: 2

• Hypoglycemia (immediate finger-stick required)
• Seizure with Todd's paralysis (inquire about witnessed seizure activity)
• Hypertensive encephalopathy (severe BP >220/120 mmHg with headache, delirium)
• Brain tumor or subdural hematoma (gradual progression, known malignancy, remote head trauma)
• Toxic-metabolic disturbances (diabetes, alcohol use, lithium/phenytoin/carbamazepine use)

Physical Examination Clues

Lack of focal cranial-nerve deficits and non-vascular patterns of weakness are indicative of non-stroke mimics 2

Tests NOT Routinely Required

Chest X-ray, lumbar puncture, and toxicology screens are not needed in most acute stroke presentations unless specific clinical indications exist (e.g., suspected cardiac/pulmonary disease, unclear history) 1, 2

Chest X-ray should be completed only when patient has evidence of acute heart or pulmonary disease and can be deferred until after acute treatment decision 1

Critical Treatment Pitfalls to Avoid

• Do not delay treatment for "mild" or rapidly improving symptoms—large-vessel occlusions can present with fluctuating deficits 2
• Do not postpone imaging or thrombolysis to obtain MRI, echocardiography, or extensive vascular imaging—these may be performed after the acute treatment decision 2
• Do not withhold rtPA solely because of early ischemic changes on CT within the 3-hour window 2
• Do not discharge patients from the ED without diagnostic evaluations, consideration of functional impairments, initiation of secondary prevention, and ongoing management plan 1

Seizure Management

• Treat active seizures with short-acting benzodiazepine (e.g., IV lorazepam) if not self-limited 2
• Do not give prophylactic anticonvulsants for a single seizure at stroke onset—no evidence of benefit and potential for harm 2

Grading and Documentation

The degree of neurological impairment using an accepted grading system (Hunt and Hess Scale, Fisher Scale, Glasgow Coma Scale, World Federation of Neurological Surgeons Scale) is useful for prognosis and triage in patients with subarachnoid hemorrhage 1

Transfer Considerations

If definitive stroke expertise is not directly available, expedient transfer to an appropriate referral center should be considered 1