In a patient with a positive Romberg test, what type of cerebrovascular accident (CVA) is most likely?

Posterior Circulation Stroke (Brainstem or Cerebellar Infarct)

A positive Romberg test in a CVA patient most strongly suggests a posterior circulation stroke affecting the brainstem or cerebellum, particularly involving structures responsible for proprioception and balance.

Understanding the Clinical Context

A positive Romberg test indicates impaired proprioceptive pathways or vestibular dysfunction. In the context of cerebrovascular accidents, this finding points toward:

Primary CVA Location: Posterior Circulation Territory

The posterior circulation (vertebrobasilar system) supplies:

• Brainstem structures including the medial lemniscus (proprioceptive pathways)
• Cerebellum (coordination and balance)
• Vestibular nuclei in the pons and medulla

When these areas are affected by ischemic stroke, patients develop:

• Ataxia and gait instability
• Positive Romberg sign (inability to maintain balance with eyes closed)
• Vertigo (if vestibular structures involved)
• Nystagmus

1 emphasizes that posterior circulation infarcts involving the brainstem or cerebellum are the most worrisome causes of acute vestibular syndrome with ataxia, with prevalence reaching 25% in patients presenting with acute persistent vertigo and up to 75% in high vascular risk cohorts.

Critical Diagnostic Considerations

Why Posterior Circulation?

The Romberg test specifically assesses proprioceptive pathways that travel through the dorsal columns and medial lemniscus—structures that course through the brainstem. A positive test with CVA indicates:

1. Medullary or pontine infarction affecting the medial lemniscus
2. Cerebellar infarction causing truncal ataxia
3. Lateral medullary syndrome (Wallenberg syndrome) affecting vestibular nuclei

2 illustrates this principle with a case where sudden onset ataxia with positive Romberg and tandem gait tests initially suggested acute cerebrovascular disease in the posterior fossa, highlighting how these clinical signs direct attention to this anatomical region.

Important Clinical Pitfall

Up to 75-80% of patients with posterior circulation strokes may lack focal neurologic deficits initially 1. This means a positive Romberg test might be the only objective finding, making it particularly valuable for localization. Do not dismiss posterior circulation stroke simply because other "classic" stroke signs are absent.

Imaging Approach

For a patient with positive Romberg test and suspected CVA:

1. Immediate non-contrast CT head - to exclude hemorrhage 3
2. MRI with DWI sequences - most sensitive for posterior circulation infarcts, particularly small brainstem or cerebellar strokes that CT often misses 1
3. Vascular imaging (CTA or MRA) - to identify vertebrobasilar occlusion or stenosis 3

MRI is superior to CT for posterior fossa evaluation because CT has limited sensitivity for acute brainstem and cerebellar infarcts due to beam-hardening artifact from the skull base.

Differential Anatomical Locations

While posterior circulation is most likely, specific Romberg-positive CVA patterns include:

• Lateral medullary infarct (most common posterior circulation stroke)
• Cerebellar infarct (vermis or hemispheric)
• Pontine infarct affecting medial lemniscus
• Thalamic infarct (less common, but can affect sensory pathways)

The absence of cortical signs (aphasia, neglect, visual field cuts) and presence of ataxia/balance impairment strongly favor infratentorial (posterior circulation) over supratentorial (anterior circulation) stroke.