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

Abstract

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 T2/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.He was diagnosed with Behçet's 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).