What is Anton-Babinski syndrome (cortical blindness) and how should it be diagnosed and managed?

Anton-Babinski Syndrome: Cortical Blindness with Denial

Anton-Babinski syndrome is a rare neuropsychiatric condition characterized by cortical blindness (bilateral vision loss from occipital lobe damage), visual anosognosia (denial of blindness), and confabulation, most commonly caused by bilateral posterior cerebral artery strokes affecting the occipital lobes.

Clinical Presentation

The syndrome presents with a characteristic triad 1, 2:

• Cortical blindness (bilateral vision loss with intact anterior visual pathways)
• Visual anosognosia (denial of blindness, present in 90.3% of cases)
• Visual confabulation (fabricating visual experiences)

Patients behave as if sighted despite complete or near-complete vision loss, often bumping into objects while insisting they can see 3. The median age of presentation is 55 years (range 6-96 years) with no gender preference 1.

Etiology

Stroke accounts for 40.3% of cases and is the leading cause 1. The pathophysiology involves:

• Bilateral occipital lobe damage (most common)
• Posterior cerebral artery territory infarction
• Less common causes include cerebral venous thrombosis, multiple sclerosis exacerbation, and rare conditions like sirolimus-induced thrombotic microangiopathy 4

Hypertension is present in 34.7% of cases 1.

Diagnosis

Diagnosis requires clinical recognition of the triad combined with neuroimaging confirmation of bilateral occipital lobe injury 2, 4:

Clinical Assessment

• Document complete or near-complete vision loss on examination
• Observe patient behavior showing denial of blindness
• Note confabulatory responses when asked about visual stimuli
• Verify intact pupillary light reflexes (anterior visual pathways preserved)

Neuroimaging

• MRI is superior to CT for distinguishing bilateral occipital infarction from posterior reversible encephalopathy syndrome (PRES) 4
• CT may show bilateral occipital hypodensities but can miss early ischemic changes
• Visual evoked potentials show P100 latency abnormalities 5

Key Diagnostic Pitfall

Do not confuse Anton-Babinski syndrome with functional blindness or malingering—the denial is genuine anosognosia, not willful deception.

Management

Management depends on the underlying cause and timing of presentation:

Acute Phase (if presenting within thrombolysis window)

For acute bilateral PCA stroke, combined systemic thrombolysis and mechanical thrombectomy with stent-retriever can achieve complete resolution 6. This represents the only intervention with documented complete reversal of the syndrome.

Subacute/Chronic Phase

When acute intervention is not possible, the approach includes:

1. Causal treatment (30.6% of cases): Address the underlying etiology

   • Stroke: Standard secondary prevention (antiplatelet therapy, risk factor modification)
   • Avoid blanket anticoagulation—it correlates with higher mortality 1

2. Supportive care (30.6% of cases): Safety measures and rehabilitation

   • Environmental modifications to prevent injury
   • Visual stimulation therapy using color looming discs shows promise: 30 minutes daily, 5 times weekly for 4 weeks improved reading ability, visual evoked potentials, and functional scores 5

3. Rehabilitation focus: Modify goals to accommodate cortical blindness rather than expecting vision recovery 2

Prognosis

Outcomes from the largest systematic review 1:

• Improvement: 45.8% (partial recovery of insight or visual function)
• Unchanged: 22.2%
• Deterioration: 11.1%

The critical determinant of outcome is whether acute revascularization is achievable—the single case with complete resolution received combined thrombolysis and thrombectomy 6.

Clinical Algorithm

1. Recognize the syndrome: Patient with vision loss who denies blindness and confabulates
2. Emergency imaging: Obtain MRI brain (or CT if MRI unavailable) immediately
3. If acute bilateral PCA stroke (<4.5 hours): Activate stroke protocol for thrombolysis ± thrombectomy 6
4. If beyond acute window: Implement causal treatment based on etiology, avoid routine anticoagulation 1
5. Initiate visual stimulation therapy at 5 months post-onset if no spontaneous recovery 5
6. Adjust rehabilitation expectations: Focus on adaptive strategies rather than vision restoration 2

The syndrome shares features with Dide-Botcazo syndrome and requires distinguishing from other causes of cortical blindness without anosognosia 1.