What is the initial evaluation and treatment approach for a patient with suspected stroke, including tests to rule out stroke and management of stroke mimics?

Initial Evaluation and Treatment Approach for Suspected Stroke

The initial evaluation of a patient with suspected stroke must include an immediate clinical assessment to establish diagnosis, rule out stroke mimics, determine eligibility for time-sensitive treatments, and develop a management plan, with rapid brain imaging (CT or MRI) being the most critical diagnostic test to differentiate between ischemic stroke, hemorrhagic stroke, and stroke mimics. 1, 2

Immediate Assessment

Initial Evaluation

• Rapid assessment of airway, breathing, and circulation (ABC) 1, 2
• Standardized neurological examination using validated stroke scale (NIHSS preferred) 1, 2
• Vital signs: heart rate and rhythm, blood pressure, temperature, oxygen saturation 1, 2
• Determine time of symptom onset (critical for treatment decisions) 2

Stroke Scale Assessment

The NIHSS evaluates:

• Level of consciousness
• Orientation and ability to follow commands
• Gaze and visual fields
• Facial movement
• Motor function (arms and legs)
• Limb ataxia
• Sensory function
• Language and articulation
• Extinction/inattention 1

Diagnostic Testing

Immediate Brain Imaging

• Non-contrast CT or MRI should be performed as soon as possible 1, 2
• Primary purpose: rule out hemorrhage and stroke mimics 2
• MRI with diffusion-weighted imaging is more sensitive than CT for detecting acute ischemia (83% vs 26% sensitivity) 3
• Consider vascular imaging (CTA or MRA) from aortic arch to vertex to identify large vessel occlusions 2

Essential Laboratory Tests

• Blood glucose (hypoglycemia can mimic stroke symptoms) 1
• Complete blood count with platelet count 1
• Coagulation studies (PT/INR, aPTT) - especially important in patients on anticoagulants 1
• Serum electrolytes and renal function 1
• Cardiac markers 1, 2

Cardiac Assessment

• 12-lead ECG (to identify arrhythmias, particularly atrial fibrillation) 1, 2
• Cardiac monitoring to detect arrhythmias 1

Additional Tests for Selected Patients

• Toxicology screen (if drug use suspected) 1
• Blood alcohol level (if alcohol intoxication suspected) 1
• Arterial blood gases (if hypoxia suspected) 1
• Chest radiography (if lung disease suspected) 1
• Lumbar puncture (if subarachnoid hemorrhage suspected and CT negative) 1
• Electroencephalogram (if seizures suspected) 1

Common Stroke Mimics to Rule Out

• Hypoglycemia (check blood glucose immediately) 1
• Seizures with post-ictal Todd's paralysis 1, 2
• Complicated migraine 2
• Conversion disorder 2
• Brain tumors 2
• Toxic-metabolic encephalopathy 2
• Infections (meningitis, encephalitis) 2

Management Approach

Time-Critical Actions

• "Time is brain" - do not delay imaging or treatment decisions while waiting for laboratory results 2, 4
• Establish eligibility for intravenous thrombolysis (rtPA) within 3-4.5 hours of symptom onset 2
• Assess for large vessel occlusion that may benefit from endovascular therapy 2

Blood Pressure Management

• For patients not eligible for thrombolysis: treat only if SBP >220 mmHg or DBP >120 mmHg 1, 2
• For thrombolysis candidates: ensure BP <185/110 mmHg before treatment 2

Seizure Management

• New-onset seizures occurring at stroke onset or within 24 hours should be treated with short-acting medications (e.g., lorazepam IV) if not self-limited 1
• Single, self-limiting seizures at stroke onset do not require long-term anticonvulsant treatment 1

Pitfalls to Avoid

• Delaying brain imaging in patients with suspected stroke 2, 5
• Missing atypical stroke presentations (altered mental status, dizziness, generalized weakness) 2
• Overlooking stroke mimics, particularly hypoglycemia 1
• Dismissing resolved symptoms (TIAs), which still require urgent evaluation 2
• Aggressively lowering blood pressure in acute ischemic stroke patients not receiving thrombolysis 1, 2

Systems-Based Approach

Implementing an organized stroke protocol can significantly reduce door-to-treatment times 4:

• Establish stroke teams with clear communication protocols
• Develop streamlined pathways for rapid imaging
• Create standardized order sets and protocols
• Coordinate with emergency medical services for pre-notification
• Ensure 24/7 availability of stroke expertise (in person or via telemedicine)

By following this structured approach to evaluation and management, healthcare providers can rapidly identify stroke patients, distinguish them from stroke mimics, and initiate appropriate time-sensitive treatments to improve outcomes.