Atypical Multiple Sclerosis with Antibody to MOG

Area of Science:

• Neuroimmunology
• Demyelinating Diseases

Background:

• Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system.
• Diagnosis typically relies on MRI findings, cerebrospinal fluid (CSF) analysis for oligoclonal bands (OCBs), and clinical presentation according to revised McDonald criteria.
• Atypical presentations can complicate diagnosis and management.

Observation:

• A young female presented with MRI brain lesions suggestive of MS, positive CSF OCBs, and definite MS by revised McDonald criteria.
• She exhibited atypical features including mild pleocytosis and involvement of the brainstem, cerebellar peduncles, and opticospinal (OS) regions.
• Testing revealed positivity for anti-myelin oligodendrocyte glycoprotein (MOG) antibody, leading to a diagnosis of atypical MS.

Findings:

• Typical MS is largely anti-MOG antibody negative.
• In studies, a small percentage of MS patients, particularly those with atypical features like OS involvement or pleocytosis, test positive for MOG antibodies.
• MOG antibody-associated CNS demyelination can present with MS-like lesions but may follow a more severe disease course.

Implications:

• Patients with MS-like lesions and OCBs but atypical features (pleocytosis, brainstem/cerebellar/OS involvement) warrant MOG antibody testing.
• A positive MOG antibody test signifies a distinct entity requiring aggressive treatment, such as plasma exchange and immunotherapy (rituximab or natalizumab), rather than standard MS disease-modifying therapies (DMTs).
• This highlights the importance of identifying MOG antibody-associated disorders for appropriate therapeutic strategies.