When It Is Not MS…—Differential Diagnosis of Optic Neuritis and Multifocal Inflammatory Cerebral Lesions in an Adolescent

Background: Morbus Behçet is a systemic inflammatory disease with recurrent aphthous stomatitis and a broad spectrum of systemic manifestations, particularly skin and mucosal lesions (i.e., genital aphthae), ocular symptoms (i.e., Iritis), and vascular disease—and also CNS involvement in up to 10%. Behçet syndrome, being a rare disease in Western Europe, often manifests with severe symptoms in young Turkish men. Aphthous ulcers, arthritis, and cutaneous lesions have a strong effect on quality of life, but ocular and CNS lesions define the prognosis of Bechet’s disease (BD). “Neuro-BD” is typically associated with a subacute course and inherent progressive psychiatric and/or neurologic symptoms corresponding to the location of the multifocal lesions. These can be found in subcortical regions, in the brain stem and spinal cord. On neuroimaging, it is hard to distinguish between Behçet lesions and typical MS lesions. CSF can show a neutrophilic pleocytosis and increased protein levels. Furthermore, there are many potential vascular complications (i.e., CVST or aneurysm).

Methods: Case report with discussion of the current literature.

Results: A 17-year-old adolescent initially presented with recurrent sterile epididymitis, conjunctivitis, and iritis in a pediatric rheumatology clinic. HLA-B27 haplotype was found, and as cutaneous lesions occurred Morbus Behçet was diagnosed. CNS manifestation included optic neuritis and asymptomatic, multifocal, cerebral lesions. There was insufficient benefit from well-established drugs, so that anti-TNF-α therapy was subsequently initiated.

Conclusion: CNS involvement in Bechet’s disease is a rare but important differential diagnosis of MS-like neurologic symptoms in adolescents and young adults, because of the different therapeutic approaches to these diseases.