What is the recommended evaluation and management for a patient with two days of dizziness, facial numbness, and drowsiness, and a negative Dix‑Hallpike test?

Urgent MRI Brain Without Contrast is Indicated

This patient requires urgent MRI brain without IV contrast to evaluate for posterior circulation stroke or other central nervous system pathology. The combination of dizziness with facial numbness and drowsiness represents neurologic deficits that substantially elevate stroke risk, and the negative Dix-Hallpike test excludes benign paroxysmal positional vertigo (BPPV), making a central cause more likely 1.

Clinical Reasoning

This presentation does not represent isolated dizziness. The presence of:

• Facial numbness (cranial nerve involvement)
• Drowsiness (altered mental status)
• Negative Dix-Hallpike (excludes BPPV)

These features classify this as acute vestibular syndrome with neurologic symptoms, which carries significantly increased stroke risk 1. When neurologic findings accompany dizziness, the diagnostic yield of MRI increases from 4% (isolated dizziness) to 12% 1.

Imaging Recommendations

First-Line: MRI Brain Without IV Contrast

• Superior sensitivity for posterior fossa lesions (ischemic stroke, hemorrhage, mass lesions, demyelination) 1
• Diffusion-weighted imaging (DWI) detects acute ischemia with approximately 4% yield in isolated dizziness but substantially higher with neurologic deficits 1
• CT has poor sensitivity (20-40%) for posterior circulation pathology and detects acute lesions in only 6% of cases versus 11% with MRI 1

If MRI Unavailable: CT Head Without Contrast

• Less sensitive but acceptable as initial imaging before MRI 1
• Diagnostic yield remains very low (<1%) in isolated dizziness but may detect hemorrhage or large masses 1
• All patients with isolated dizziness who had positive CT findings were suspected to have central causes on bedside evaluation 1

Consider Adding Vascular Imaging

• MRA or CTA head and neck should be considered if stroke is suspected, though there was guideline disagreement on whether these are appropriate as initial imaging 1
• Vertebral artery dissection can present with vertigo and facial symptoms 1

Critical Pitfalls to Avoid

1. Do not dismiss this as "isolated dizziness" - facial numbness and drowsiness are red flags that demand urgent evaluation
2. Do not rely on CT alone - posterior fossa strokes are frequently missed on CT due to beam-hardening artifact 1
3. Do not delay imaging for "clinical observation" - the 2-day duration with persistent neurologic symptoms warrants immediate evaluation
4. Do not assume negative Dix-Hallpike excludes all pathology - it only excludes typical BPPV; central causes can mimic peripheral vertigo 1

Additional Evaluation

While awaiting imaging:

• Vital signs and orthostatic blood pressures - rule out systemic causes (hypotension, dehydration) 1
• Complete neurologic examination - assess for additional brainstem signs (dysarthria, ataxia, limb weakness)
• HINTS examination (if trained examiner available) - can help differentiate peripheral from central causes in acute vestibular syndrome, though neurologic symptoms already suggest central pathology 1
• Cardiovascular assessment - atrial fibrillation is a risk factor for posterior circulation stroke 1

Management Considerations

• Admit for observation given persistent symptoms over 2 days with neurologic deficits
• Stroke protocol activation may be appropriate depending on time of symptom onset and institutional protocols
• If imaging reveals posterior circulation infarct, neurology consultation for acute stroke management
• If imaging negative, consider alternative diagnoses: vestibular migraine (though drowsiness atypical), demyelinating disease, or metabolic/toxic causes

The presence of facial numbness with dizziness fundamentally changes the risk stratification from benign peripheral vertigo to potential life-threatening central pathology requiring urgent neuroimaging 1.