(Kiosk 6) Acute Central Nervous System (CNS) Demyelination (Mog Antibody Positive) with Magnetic Resonance Imaging (MRI) Findings Consistent with Acute Disseminating Encephalomyelitis (ADEM): A Case Report

Case Diagnosis: Acute central nervous system (CNS) Demyelination (Mog antibody positive) with magnetic resonance imaging (MRI) findings consistent with acute disseminating encephalomyelitis (ADEM): A Case Report

Case Description or Program Description: Previously healthy 3 year-old (yo) boy presenting with fever, abdominal pain, emesis, decreased sensation and progressive weakness in bilateral legs. In the emergency department, he was found to have urinary retention as well and foley catheter was placed. MRI Brain was performed, showing multiple subcortical hyperintense lesions, concerning for acute disseminated encephalomyelopathy (ADEM). MRI Spine showed hyperintense lesions from C3-T2. Lumbar puncture was performed, showing mildly elevated WBC with lymphocytic pleocytosis and normal CSF protein. Mog and AQP4 antibodies (Abs) were sent, with Mog Ab returning positive. ANA was positive as well. Patient was treated with 5-day course of IV methylprednisolone, started on steroid taper, and treated with IVIG 2 gm/kg.

Setting: Quaternary Pediatric Hospital

Assessment/Results: Patient continues to have bilateral lower extremity weakness, with slow return of sensation. He continues to have urinary retention, requiring indwelling foley catheter. When attempting voiding trial, he required catheterization every 3-4 hours, which presented as a challenge for the family to perform. Urology was consulted for further assistance. Neurology is closely following and plans to continue monthly IVIG administration with Mog-IgG level evaluations every 6 months. He remains in inpatient rehabilitation with slow return of lower extremity sensation/function.

Discussion (relevance): Mog Ab+ CNS demyelination may present initially as ADEM which may complicate treatment and prognosis. While ADEM requires a presentation of encephalopathy, ADEM-like Mog Ab+ disease may not show encephalopathy despite MRI findings. Mog Ab+ disease shows a slower progression and may require longer term rehabilitation intervention.

Conclusions: Mog Ab+ related disease is a rare manifestation of CNS demyelinating disease and may present as a spectrum of symptoms. Mog Ab+ related disease has a higher risk for recurrent disease, thus accurate diagnosis is important for the best treatment and outcomes. Long term IVIG and surveillance neuroimaging/ophthalmologic exams may be required for severe disease manifestation.