Presentations

Abstract

Introduction:

Myelin oligodendrocyte glycoprotein antibody-associated disease, also known as MOGAD, is an inflammatory demyelinating disorder of the central nervous system (CNS) with a phenotypic presentation similar to multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMSOD). MOGAD is associated with a spectrum of disease including variations of transverse myelitis, optic neuritis, and acute disseminated encephalomyelitis (ADEM), with a tendency to present in pediatric patients. Disease course may be monophasic or associated with acute relapsing and remitting episodes. Pathogenesis is thought to be due to IgG antibodies against myelin oligodendrocyte glycoprotein (MOG), a component of the outer myelin sheath present on the cell surface of oligodendrocytes. Antibodies against MOG cause local areas of demyelination and inflammation, creating characteristic brain lesions. Demyelination leads to characteristic acute attacks of central vision loss, altered mental status, limb weakness, sensory loss, and incontinence and/or erectile dysfunction. Attacks are typically limited in course and may be associated with a preceding illness or vaccination. Diagnosis of MOGAD typically requires a positive result on anti-MOG-IgG titer. However, in this case, we present a patient with clinical and radiologic findings suggestive of MOGAD despite repeated negative anti-MOG-IgG titers.

Case Information:

The patient is a 21 year-old female who initially presented with complaints of vision and balance issues following a case of pneumonia. During her hospital stay, the patient experienced paresthesias and loss of control in her right upper and lower extremities, suggesting transverse myelitis. MRI and biopsy of the brainstem showed a lesion with local inflammation. The patient received a course of high-dose steroids and plasma exchange (PLEX) before being discharged. Following discharge, the patient saw a complete resolution of symptoms. Since this initial episode, the patient has experienced multiple similar episodes with symptoms including headache, loss of function in the right upper and lower extremities, incontinence, altered mental status, and gait instability. These symptoms have regressed after each episode with a course of high-dose steroids. Repeated MRIs have shown brainstem lesions as well as cervical and thoracic spinal cord lesions that regress following each attack. Over the course of each of these episodes, the patient has repeatedly tested negative for the anti-MOG-IgG antibodies that would confirm the diagnosis of MOGAD.

Discussion/Clinical Findings:

In evaluation of patients with symptoms suggestive of MOGAD, MS and NMSOD should be included in the differential due to overlapping phenotypic presentations. A combined approach using clinical, radiologic, and laboratory biomarkers should be used to make the distinction between these three diseases. Patients with MOGAD tend to have a relapsing and remitting illness, with complete or nearly complete return to function after each episode. This is in contrast to NMSOD or MS, which typically show a progression in disease and accumulated disability after each attack. Spinal cord lesions associated with MOGAD also typically resolve completely over the course of months to years, while those associated with MS or NMOSD tend to leave residual hyperintensities. This patient presents with repeated episodes of transverse myelitis that improve with high-dose steroids as well as spinal cord lesions that regress and return, findings that support a diagnosis of MOGAD despite the lack of positive anti-MOG-IgG titers.

Conclusion:

MOGAD should be considered in patients presenting with acute attacks of bilateral optic neuritis, ADEM, transverse myelitis, and/or bowel/bladder/erectile dysfunction. While current guidelines suggest the need for positive anti-MOG-IgG titers to make a diagnosis of MOGAD, we present a patient with clinical and radiologic findings suggestive of MOGAD despite repeatedly testing seronegative for the confirmatory antibodies. This patient's atypical presentation suggests a need for a greater understanding and characterization of the spectrum of demyelinating illnesses. This case stresses the importance of using a combined approach, including both clinical and radiologic diagnostic criteria, to guide diagnosis and treatment in patients with atypical presentations.