Teaching NeuroImage: Mobile Hypopyon as a Clinical Clue for the Diagnosis of Behçet Disease

A 29-year-old man presented with subacute new-onset headache, confusion, and hallucinations. On examination, he had obtundation and bilateral decreased visual acuity. Brain MRI revealed a T2/fluid-attenuated inversion recovery (FLAIR) hyperintense signal of the diencephalon and basal ganglia. Subsequently, he developed anterior uveitis with mobile hypopyon (Figure). Further questioning of his wife disclosed previous episodes of “red eyes,” acne-like skin lesions, and oral ulcers.

Figure. Ocular Findings and Neuroimaging.

External eye photograph depicts the mobile hypopyon (black arrow) and its movement within the anterior chamber right after the patient changed the position from standing to right lateral decubitus (curved arrow) (A). Brain MRI axial FLAIR-weighted image shows confluent hyperintense lesions in the diencephalon (B).

He was diagnosed with Behçet disease (BD) and fully recovered after a methylprednisolone pulse. The hallmarks of BD are oral and genital ulcers and uveitis. Neuro-BD often presents with cerebral venous thrombosis, aseptic meningitis, or mesodiencephalic venulitis. Although confluent diencephalic lesions on neuroimaging strongly indicate Neuro-BD, the diagnosis also relies on clinical findings.¹ Hypopyon is the sedimentation of leukocytes in the anterior chamber of the eye, which manifests as a whitish fluid level. Mobile hypopyon is typical of NB and a relevant diagnostic clue.²

Appendix. Authors

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