What is the diagnostic approach for a suspected cerebrovascular accident (CVA) or stroke in an adult patient?

Diagnosis of Cerebrovascular Accident (Stroke)

Immediate brain imaging with non-contrast CT is the essential first step to differentiate ischemic from hemorrhagic stroke, and this must be completed within 25 minutes of emergency department arrival with interpretation within 45 minutes. 1, 2

Initial Clinical Assessment

Establish an organized protocol with a designated acute stroke team to complete the entire evaluation and treatment decision within 60 minutes of ED arrival. 3

Neurological Examination

• Apply the National Institutes of Health Stroke Scale (NIHSS) to quantify stroke severity, provide prognostic information, and guide treatment decisions. 3, 4
• Document the exact time the patient was last known to be at baseline—this is critical for determining thrombolytic therapy eligibility. 5
• Perform a focused neurological examination looking specifically for: focal weakness (hemiparesis), facial droop, speech disturbance (dysarthria/aphasia), visual field defects, sensory deficits, and ataxia. 6, 4

Prehospital Recognition

• Use the FAST scale (Face-Arms-Speech-Time) or Cincinnati Prehospital Stroke Scale for rapid stroke identification before hospital arrival. 3
• These scales assess three key physical findings: facial droop, arm weakness, and speech abnormalities. 3

Mandatory Imaging Studies

Brain Imaging (First Priority)

• Non-contrast CT or MRI of the brain is required immediately to exclude hemorrhage before any antithrombotic therapy can be administered. 1, 2
• CT remains the most practical initial imaging modality at most institutions due to speed and availability. 3
• Complete CT within 25 minutes of arrival and interpret within 45 minutes (door-to-interpretation time of 45 minutes total). 3, 2
• MRI is superior for detecting small cortical infarcts, posterior fossa lesions, and distinguishing acute from chronic ischemia, but logistical constraints often limit its use acutely. 3

Vascular Imaging (Second Priority)

• Perform CT angiography from aortic arch to vertex immediately to identify large vessel occlusions that may benefit from endovascular therapy. 1
• This should not delay IV thrombolytic therapy but is necessary for patients being considered for endovascular interventions (treatment window extends up to 24 hours). 1, 4
• CT perfusion and multiphase CTA can assess cerebral blood flow and collateral vessels but must not delay thrombolytic therapy. 1

Essential Laboratory Tests

Obtain these tests immediately but do not delay thrombolytic therapy while awaiting results unless there is clinical suspicion of bleeding abnormality, thrombocytopenia, or known anticoagulant use. 5, 2

Core Laboratory Panel

• Blood glucose: Must be checked immediately to exclude hypoglycemia as a stroke mimic—this is the only mimic requiring immediate exclusion. 1, 2
• Complete blood count with platelets: Detects thrombocytopenia, anemia, or polycythemia affecting treatment decisions. 1, 2
• Coagulation studies (PT/INR, aPTT): Critical before thrombolytic therapy to identify coagulopathies. 1, 2
• Electrolytes and renal function (creatinine, eGFR): Identifies metabolic derangements and guides medication dosing. 1, 2
• Troponin: Identifies concurrent myocardial infarction or ischemia. 1, 2

Cardiac Evaluation

• 12-lead ECG is mandatory due to the high incidence of cardiac disease in stroke patients, particularly to detect atrial fibrillation. 3, 1, 2
• Extended cardiac monitoring up to 30 days is recommended when initial ECG shows no atrial fibrillation but cardioembolic mechanism is suspected. 1
• Echocardiography should be performed when a cardiac source is suspected, particularly in young adults, when infectious endocarditis is suspected, or when stroke mechanism remains unidentified. 1

Tests NOT Routinely Required

• Chest x-ray is not needed for most stroke patients unless there is clinical evidence of acute cardiac or pulmonary disease. 3
• Lumbar puncture is not indicated for most stroke patients—brain imaging has very high yield for detecting hemorrhage. 3
• Exception: Consider lumbar puncture only if subarachnoid hemorrhage is suspected and CT is negative for blood. 2

Critical Timing Considerations

The entire diagnostic evaluation should be completed within specific timeframes based on risk stratification:

• Highest risk patients: comprehensive evaluation within 24 hours 1
• Moderate risk patients: within 2 weeks 1
• Lower risk patients: within 1 month 1

Common Pitfalls to Avoid

• Never delay acute treatment to obtain multimodal imaging studies beyond the basic non-contrast CT. 3
• Do not skip vascular imaging (CTA) as it identifies large vessel occlusions amenable to endovascular therapy up to 24 hours from symptom onset. 1
• Do not forget glucose testing—hypoglycemia is a critical stroke mimic requiring immediate exclusion. 1
• Do not routinely obtain chest x-ray—this represents a change from older guidelines and wastes valuable time. 3
• Be aware that common stroke mimics include: seizures (11%), metabolic/electrolyte disturbances (12%), vertigo (19%), cardiovascular disorders (10%), and brain tumors (5%). 7
• Without brain imaging, you cannot safely administer rtPA, antiplatelet therapy, or anticoagulation because you cannot differentiate ischemic from hemorrhagic stroke. 5