Myelin oligodendrocyte glycoprotein antibody (MOG-ab) associated diseases are a distinct nosological entity among central nervous system (CNS) inflammatory diseases such as multiple sclerosis and AQP4-ab neuromyelitis optica spectrum disorder(NMOSD). In children, the clinical spectrum encompasses different phenotypes. Acute disseminated encephalomyelitis (ADEM) remains the most common clinical presentation particularly in young children. Optic neuritis, longitudinaly extensive transverse myelitis and brainstem involvment are the other frequent phenotypes.
To report a case of young child with MOG antibodies associated with relapsing disease with syringomyelia and brain MRI lésions mimicking langerhansian histyocytosis.
A 6 year old girl presented with rapidly progressive balance disorder wich occured few days after viral nasopharyngitis. neurological examination found a statokinetic cerebellar syndrom and moderate visual loss in one eye. In her medical history, the mother described the occurence two years ago of acute bilateral legs weakness and bladder dysfunction with viral infection two weeks earlier. The recovery was complete and spontaneous.The child had follow up since there in neurosurgery because MRI showed syringomyelia evocating lesion.
we performed brain MRI, lumbar puncture, serological and immunological assessment.
Brain MRI found bilateral symetrical cerebellar T2/Flair lesions with gadolinium enhancement, periventricular non specific lésions were also found. Aspect of lesion evocated langerhansian neurohystiocytosis. no evidence of cutaneous or viceral hystiocytosis was found. MOG-ab were positive. IgG olioclonal bands were present in cerebrospinal fluid. the patient recovered after metylprednisolone infusions.
Syringomyelia is described in few cases of AQP4-ab NMOSD, but not in MOG-ab associated diseases. Also, in children with MOG ab, brain MRI usually show ADEM like or brainstem lesions. it is to our knowledge the first case of MOG-ab with these two particular MRI presentations (syringomyelia and neurohystiocytosis mimicking lesions).