skip to main content

Neuro-Behcet Disease — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

HardVasculitisNeuro-Behcet DiseaseSCE Rheumatology

A 32-year-old man has recurrent oral aphthae, genital ulceration with scarring and previous bilateral posterior uveitis. Over 5 days, he develops progressive dysarthria and right-sided weakness. MRI brain shows an ill-defined T2/FLAIR-hyperintense lesion centred on the left cerebral peduncle and extending into the ipsilateral thalamus, with surrounding oedema and patchy enhancement. It does not conform to an arterial territory and has no central diffusion restriction. MR venography is normal. CSF contains 68 leucocytes/µL, has an elevated protein concentration and normal glucose; microbiological studies are negative and CSF-restricted oligoclonal bands are absent. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Parenchymal neuro-Behçet syndrome

The diagnosis is **parenchymal neuro-Behçet syndrome**. The mucocutaneous and ocular history establishes the underlying Behçet phenotype, while the subacute pyramidal/brainstem syndrome, inflammatory CSF and ill-defined mesodiencephalic lesion are characteristic of parenchymal involvement. Normal MR venography argues against cerebral venous thrombosis, the principal non-parenchymal neurological manifestation. An arterial embolic infarct would usually have abrupt maximal onset, conform to a vascular territory and show diffusion restriction. A cerebral abscess would more often produce systemic infection, ring enhancement and central restricted diffusion. Multiple sclerosis may affect the brainstem, but the lesion distribution, oedematous inflammatory appearance, absent CSF-restricted oligoclonal bands and Behçet phenotype favour neuro-Behçet syndrome. Primary CNS lymphoma remains an imaging mimic but does not explain this characteristic clinicoradiological pattern as well.

Reference: Rochoy M et al. Neuro-Behçet's disease: A review. 2024. https://pubmed.ncbi.nlm.nih.gov/31887565/