Atypical presentation of MOG-related disease: Slowly progressive behavioral and personality changes following a...

Area of Science:

• Pediatric Neurology
• Neuroimmunology
• Autoimmune Encephalitis

Background:

• Myelin Oligodendrocyte Glycoprotein (MOG) antibody disease typically presents as acute disseminated encephalomyelitis (ADEM), optic neuritis, or neuromyelitis optica spectrum disorders (NMOSDs).
• The full clinical spectrum of MOG antibody disease remains incompletely defined, particularly in pediatric populations.
• This case highlights an atypical presentation requiring broader diagnostic considerations.

Observation:

• A 10-year-old girl presented with a focal seizure, initially with normal neurological exams and brain MRI.
• Following the seizure, she developed progressive behavioral and personality changes over 2.5 months, with subtle neurological signs.
• Brain MRI revealed characteristic hazy, enhancing lesions in the basal ganglia, white matter, brainstem, cerebellum, and spinal cord.

Findings:

• Cerebrospinal fluid analysis was unremarkable, with negative tests for N-methyl-d-aspartate receptor and CASPR2 antibodies.
• High serum titers of Myelin Oligodendrocyte Glycoprotein (MOG) antibodies were detected using a cell-based assay.
• The patient experienced a complete clinical recovery within one week after intravenous immunoglobulin (IVIG) therapy.

Implications:

• This case demonstrates that slowly progressive behavioral and personality changes following a seizure can be a presenting manifestation of MOG antibody disease in children.
• Early recognition and diagnosis of atypical MOG antibody disease presentations are crucial for timely and effective treatment.
• The findings expand the known clinical spectrum of MOG antibody disease, emphasizing the need for comprehensive antibody testing in pediatric neurological disorders.