What tests should be ordered for a patient with suspected neurological and vascular issues?

Diagnostic Testing for Suspected Neurological and Vascular Issues

For patients with suspected neurological and vascular issues, a comprehensive diagnostic approach should begin with brain imaging (non-contrast CT or MRI) followed by vascular imaging (CTA or MRA from aortic arch to vertex), essential blood work, and cardiac evaluation. 1, 2

Initial Brain Imaging

• Non-contrast brain CT or MRI should be performed immediately to distinguish between ischemic stroke and intracranial hemorrhage 1
  • Must be interpreted within 45 minutes of patient arrival by a physician with expertise in reading these studies 2
  • Critical for determining eligibility for thrombolytic therapy

Vascular Imaging

• CT angiography (CTA) or MR angiography (MRA) from aortic arch to vertex should be performed simultaneously with initial brain imaging 2
  • Recommended to identify extracranial carotid stenosis requiring potential revascularization 1
  • Essential for detecting large vessel occlusions eligible for endovascular thrombectomy 2
  • Duplex ultrasonography is recommended for patients with focal neurological symptoms corresponding to carotid artery territory 1

Essential Blood Work

• Complete blood count with platelets
• Coagulation studies (PT/INR, aPTT)
• Electrolytes and renal function tests
• Blood glucose
• Cardiac markers (troponin)
• Oxygen saturation 1, 2

Cardiac Evaluation

• 12-lead ECG should be performed immediately to identify atrial fibrillation or evidence of structural heart disease 1
• Cardiac monitoring should be continuous for at least the first 24 hours to detect arrhythmias 2
• Echocardiography should be performed when cerebrovascular disease is not severe enough to account for neurological symptoms of suspected ischemic origin 1

Additional Testing Based on Clinical Presentation

For Suspected Stroke/TIA

• National Institutes of Health Stroke Scale (NIHSS) assessment to quantify stroke severity 1
• Estimated cardiac event risk assessment using Framingham criteria 1
• For patients with transient, fluctuating, or persistent unilateral weakness or speech disturbance:
  • Complete evaluation within 24 hours of first contact with healthcare system 1

For Suspected Cerebrovascular Disease

• Lumbar puncture with CSF analysis if subarachnoid hemorrhage is suspected and CT is negative for blood 1
• Electroencephalogram (EEG) if seizures are suspected 1
• Toxicology screen and blood alcohol level in selected patients 1

For Suspected Immune-Mediated Neurological Issues

• MRI brain with contrast may reveal T2/FLAIR changes typical of autoimmune encephalopathies 1
• Lumbar puncture with CSF analysis including cell count, protein, glucose, viral PCRs, oligoclonal bands, and autoimmune panels 1
• Serum studies including ESR, CRP, thyroid panel, autoimmune encephalitis panels 1

Testing Algorithm Based on Presentation

1. Acute focal neurological deficits (≤24 hours):

   • Immediate non-contrast brain CT/MRI
   • CTA/MRA from aortic arch to vertex
   • Complete blood work and 12-lead ECG
   • Continuous cardiac monitoring

2. Transient neurological symptoms (24-48 hours):

   • Brain imaging within 24 hours
   • Vascular imaging (CTA/MRA or carotid ultrasound)
   • Complete blood work and ECG
   • Consider echocardiography

3. Subacute neurological symptoms (>48 hours to 2 weeks):

   • Brain and vascular imaging within 2 weeks
   • Complete blood work and ECG
   • Consider additional testing based on symptoms

Common Pitfalls to Avoid

1. Delaying neuroimaging - This can lead to missed treatment windows for thrombolysis or thrombectomy 2

2. Incomplete vascular assessment - Failing to image both extracranial and intracranial vessels can miss significant stenosis or occlusions 1

3. Overlooking cardiac sources - Missing paroxysmal atrial fibrillation or other cardiac sources of embolism 2

4. Inadequate laboratory testing - While treatment decisions should not be delayed awaiting results, complete blood work is essential for identifying underlying conditions 2

5. Failing to correlate findings - Correlation of findings obtained by several carotid imaging modalities should be part of quality assurance 1

By following this systematic approach to diagnostic testing, clinicians can efficiently identify neurological and vascular issues, determine appropriate treatments, and improve patient outcomes.