P 788. MOG-Ab Positive Acute Disseminated Encephalomyelitis with Asymmetric Lesions in Basal Ganglia and in Thalami

Background: Acute disseminated encephalomyelitis (ADEM) is an acquired inflammatory disease of the central nervous system caused by an immunological reaction to viral infections. Clinical symptoms are variable and include headaches, seizures, fever, vomiting, behavior disturbances, impaired consciousness, weakness, pyramidal and extrapyramidal signs, and visual and sensory disturbances.¹ Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) in serum and in cerebrospinal fluid (CSF) may be present; their prognostic importance however has to be determined.²

Case: A boy presented at the age of 32 months with dystonia of the left upper extremity, intermittent coarse tremor of the right hand, and deviation of the eyes and head toward the left. He hardly reacted to stimuli and was severely apathic. One week earlier, he had suffered from an upper respiratory tract infection. Laboratory examinations were normal for BC, electrolytes, blood gases, glucose, and inflammatory markers. CSF examination showed 149/µL cells were predominantly leucocytes but also lymphocytes and monocytes. The CSF protein was raised, and the CSF glucose was normal. PCRs of a viral and bacteriological panel were normal. Magnetic resonance imaging (MRI) of the brain showed areas of low attenuation with asymmetric gadolinium enhancement in basal ganglia and thalami. An encephalitis was suspected and antiviral and antibacterial agents were started. After obtaining normal results of the PCR panels, a diagnosis of ADEM was made and steroids were introduced. As there was no improvement within 5 days antibodies to neuronal antigens were examined, the results of which however were not available before 16 days thereafter. Despite treatment with anti-infectious agents, steroids and one dose of immunoglobulins, extrapyramidal symptoms with dystonic and choreatic movements, and agitation worsened. When the results of positive MOG-Ab were known, plasmapheresis was installed, accompanied by another course of urbason, followed by rituximab twice. After 5 days of plasmapheresis, there was marked clinical improvement of all symptoms and sequential MRIs of the brain showed reduction of the inflammatory process of the CNS.

Results: Our patient with ADEM showed no improvement on high-dose steroids and on intravenous immunoglobulins. Marked clinical and neuroradiological improvement occurred after plasmapheresis and rituximab.

Discussion: In patients with severe ADEM refractory to steroids, immunotherapy with plasmapheresis and immunosuppressants should be considered early, without awaiting results of MOG-Ab testing.

References

1. Murthy SN, Faden HS, Cohen ME, Bakshi R. Acute disseminated encephalomyelitis in children. Pediatrics 2002;110(2 Pt 1):e21

2. Hennes EM, Baumann M, Lechner C, Rostásy K. MOG spectrum disorders and role of MOG-antibodies in clinical practice. Neuropediatrics 2018;49(1):3–11