MOGAD

Overview

MOGAD stands for Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease, which is a mouthful. The short version: it's an autoimmune condition where your own IgG antibodies attack a protein on the insulation (myelin) around your nerves. Doctors used to lump it in with multiple sclerosis or AQP4-positive neuromyelitis optica, but we now know it behaves differently, and it finally got its own official diagnostic criteria in 2023.

Impact

Patients often present with sudden, severe attacks of optic neuritis (inflammation of the eye's nerve), transverse myelitis (spinal cord inflammation), or ADEM-like brain inflammation, which can cause vision loss, paralysis, seizures, and trouble thinking clearly. About half of people go on to have a relapsing course that needs long-term immune treatment. The uncertainty about whether you'll relapse, the need for ongoing therapy, and the possibility of cumulative disability put a real emotional and financial weight on patients and families.

Medical Overview

MOGAD is caused by IgG antibodies directed against MOG, and the best way to detect them is with live cell-based assays. Low-positive titers need careful interpretation alongside the clinical picture and MRI findings. Typical presentations include bilateral or longitudinally extensive optic neuritis with swelling of the optic nerve head, longitudinally extensive transverse myelitis (often showing a gray matter "H-sign" on imaging), ADEM (especially in kids), and cortical or brainstem inflammation. One interesting distinguishing feature is that MRI lesions often resolve on follow-up imaging, which is not what we see in MS. Diagnosis follows the 2023 international criteria, which require a core clinical demyelinating event plus MOG-IgG positivity, supportive features, and ruling out better alternatives. Acute attacks are treated with high-dose IV steroids, with plasma exchange or IVIG for steroid-refractory cases, and long oral steroid tapers are commonly used to reduce early relapse risk. Maintenance therapy for relapsing MOGAD usually relies on IVIG, rituximab, mycophenolate, or azathioprine, though we're still waiting on randomized trials, and several targeted therapies are now in formal study.

References

1. Sechi E, et al.. Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD): A Review of Clinical and MRI Features, Diagnosis, and Management . Frontiers in Neurology . 2022.
2. Al-Ani A, Chen JJ, Costello F. Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): current understanding and challenges . Journal of Neurology . 2023.
3. Cacciaguerra L, Flanagan EP. Updates in NMOSD and MOGAD Diagnosis and Treatment: A Tale of Two Central Nervous System Autoimmune Inflammatory Disorders . Neurologic Clinics . 2024.