What initial workup and management should be ordered for a 54-year-old male presenting with acute onset of right-sided numbness, weakness, and ataxia (loss of coordination)?

Acute Neurological Workup for Suspected Stroke

For this 54-year-old male with acute onset right-sided numbness, subjective weakness, unsteadiness, and dizziness, urgent brain MRI with diffusion-weighted imaging should be performed as the initial diagnostic test, along with MRA of the head and neck to evaluate for vascular pathology. 1

Clinical Presentation Analysis

This patient's presentation strongly suggests a possible posterior circulation stroke:

• Acute onset right-sided numbness and weakness
• Unsteadiness and feeling "drunk" while walking
• Dizziness with position changes
• Preserved sensation despite subjective changes
• No slurred speech or headache
• Normal neurological examination findings

Diagnostic Algorithm

First-Line Imaging

1. Brain MRI with diffusion-weighted imaging (DWI)

   • Superior to CT for detecting early ischemic changes, especially in the posterior fossa 1
   • Can identify small cerebellar infarcts that may be missed by CT 1
   • DWI can detect acute ischemic changes within minutes of onset

2. MRA of head and neck

   • Essential for evaluating vascular pathology that may cause posterior circulation stroke 1
   • Can identify vertebral artery dissection or occlusion 1

If MRI is not immediately available

1. Non-contrast head CT

   • To rapidly exclude hemorrhage 1
   • Limited sensitivity (approximately 10%) for early posterior fossa ischemic changes 1

2. CT angiography (CTA) of head and neck

   • To evaluate for large vessel occlusion that might require thrombectomy 1

Rationale for MRI-First Approach

The American College of Radiology guidelines specifically note:

• CT has low sensitivity (approximately 10%) for posterior fossa ischemic strokes 1
• MRI changes diagnosis in up to 16% of cases of acute dizziness, with acute findings in 8% 1
• Posterior circulation strokes are frequently missed on CT alone 1

Additional Workup

Once imaging is completed, the following should be ordered:

• Complete blood count
• Coagulation studies (PT/INR)
• Basic metabolic panel
• ECG to evaluate for atrial fibrillation
• Lipid panel
• Blood glucose level

Common Pitfalls to Avoid

1. Relying solely on CT imaging

   • CT has poor sensitivity for posterior fossa strokes 1
   • Many posterior circulation strokes are missed on initial CT evaluation

2. Dismissing symptoms due to normal neurological exam

   • Subtle posterior circulation strokes can present with minimal findings on examination
   • Cerebellar strokes may initially present with isolated dizziness or ataxia without other focal deficits

3. Delaying imaging

   • Time-sensitive nature of stroke requires prompt imaging
   • "Time is brain" - earlier diagnosis allows for potential intervention within treatment windows

4. Failing to evaluate vascular structures

   • Vascular imaging (MRA or CTA) is essential to identify the underlying cause
   • Vertebral artery dissection is an important cause of posterior circulation stroke in middle-aged adults 2

This patient's presentation with acute onset of unilateral symptoms, ataxia, and dizziness warrants urgent evaluation for stroke, with MRI being the preferred initial imaging modality due to its superior sensitivity for posterior fossa lesions.