Diagnosis of MOGAD

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)

Overview

  • Definition: MOGAD is associated with serum antibodies against myelin oligodendrocyte glycoprotein (MOG), differentiating it from multiple sclerosis (MS) and aquaporin-4 (AQP4)-seropositive neuromyelitis optica spectrum disorder.

  • Diagnosis: A core criterion is the presence of MOG-IgG. Diagnostic criteria need validation to improve identification and management of MOGAD.

Clinical Presentation

  • Common Symptoms:

    • Acute disseminated encephalomyelitis (ADEM)

    • Optic neuritis (uni- or bilateral)

    • Transverse myelitis

  • Less Common Symptoms:

    • Cerebral cortical encephalitis

    • Brainstem and cerebellar presentations

    • Tumefactive brain lesions

  • Disease Course:

    • Can be monophasic or relapsing; diagnosis of MS must be excluded.

Incidence and Demographics

  • Incidence: 1.6-3.4 per million annually; prevalence is estimated at 20 per million.

  • Sex/Race: No marked sex or racial predominance; patients affected range across all ages.

Diagnostic Process

  • Cell-Based Assays: Essential for accurate diagnosis; MOG-IgG titers are crucial for distinguishing MOGAD from other demyelinating disorders.

  • MRI Imaging Characteristics: Imaging usually shows bilateral, ill-defined lesions and lacks the typical small ovoid lesions seen in MS.

  • CSF Analysis: Oligoclonal bands may be present, but their presence is not diagnostic of MOGAD.

Proposed Diagnostic Criteria

  1. Core Clinical Attacks:

    • Optic neuritis

    • Myelitis

    • ADEM

    • Cerebral/multifocal deficits

    • Brainstem/cerebellar deficits

    • Cerebral cortical encephalitis with seizures

  2. Positive MOG-IgG Testing:

    • Clear positive results from cell-based assays in serum

    • Requires supporting clinical or MRI features for low positives or CSF positives

  3. Exclusion of Other Diagnoses:

    • Must rule out conditions like MS or AQP4-IgG seropositivity

Prognostic Considerations

  • Patients with MOGAD have varying outcomes, with many showing substantial recovery after attacks. However, there is a risk of relapse similar to other demyelinating diseases.

  • Understanding the long-term clinical implications of MOGAD is crucial for managing therapy and monitoring disease progression.

Future Directions

  • Further studies are needed to validate the proposed criteria, explore the pathogenesis, and investigate therapeutic approaches, especially those targeting cytokines such as IL-6.