To report a perplexing case of Behcet disease (BD) presenting as a focal parenchymal lesion that reached a diagnosis after noting a prominent retinal vasculopathy, highlighting the importance of ophthalmologic evaluation in undifferentiated CNS disease.

BD can have variable systemic manifestations driven by a vasculitis, including oral or genital ulcers, pulmonary aneurysms, and uveitis. Neurologic involvement is present in less than 10% of patients, most commonly as a meningoencephalitis. 

 We present the case of a woman who developed asymmetric sub-acute sensorineural hearing loss at age 31 followed by transient right facial weakness at age 40, and most recently presented with right facial numbness and arm weakness at age 47. Brain MRI revealed a left frontal enhancing lesion with associated T2/FLAIR hyperintensity extending from the periventricular to the juxtacortical area with a thin rim of a reduced diffusion. CSF and serum studies were negative for inflammation, infection and malignancy except for elevated ESR and CRP. Brain biopsy revealed non-specific gliosis. Persistent enhancement on MRI was noted over 3 months, with spontaneous clinical improvement. Patient endorsed insidious vision changes over recent years, and visual testing was performed.  

Dilated ophthalmic examination demonstrated striking peripheral attenuation and sclerosis of retinal vasculature, with evidence of nonperfusion and skip lesions on retinal fluorescein angiography (FA). Findings of occlusive retinal peripheral vasculopathy suggested an underlying vasculitis as the etiology of the brain lesion and prior deficits, raising the likelihood of BD. Patient was homozygous for HLA-B*51, further supporting this diagnosis even with lack of mucosal ulcers and negative history of pathergy.

Neurologic manifestations of BD can be diverse including retinal occlusive vasculopathy; ulcers are not universally present. Ophthalmologic examination, even when minimally symptomatic, can inform the diagnosis of CNS lesions. Patient was started on Prednisone, Infliximab and Methotrexate, achieving disease remission.