According to clinical case records, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in pediatric patients presents with fever, headache, vomiting, and cerebrospinal fluid pleocytosis that can closely mimic central nervous system infections. Diagnosing this inflammatory demyelinating disorder requires a compatible core demyelinating event, a serum MOG-IgG positive result detected via an appropriate live cell-based assay, and the systematic exclusion of alternative diagnoses, as outlined in recent clinical evaluations.
Diagnostic Challenges in Pediatric MOGAD Mimicking Encephalitis
When an adolescent presents with acute neurological symptoms, clinicians often initiate empirical anti-infective treatments while awaiting microbiological results. In a documented case reviewed by medical specialists, a 13-year-old boy developed bilateral temporal headaches, high fever, binocular horizontal diplopia, and vomiting. Initial lumbar puncture results on illness day six revealed an opening pressure of 150 mm H2O and 195 white cells per microliter, predominantly mononuclear cells, alongside a mildly elevated protein level of 0.50 g/L. These findings initially raised strong suspicion for infectious or autoimmune encephalitis.
However, serial reassessment proved critical when microbiological panels—including cerebrospinal fluid metagenomic next-generation sequencing, viral PCR, and bacterial cultures—returned negative. Serum Mycoplasma pneumoniae IgG showed a positive titer of 1:160, but respiratory PCR and paired serology were negative, ruling out acute active infection. According to the case documentation, clinicians relied on dynamic magnetic resonance imaging (MRI) changes and antibody testing to shift the diagnostic focus toward central nervous system inflammatory demyelination.
Pro Tip: When evaluating pediatric patients with infection-like presentations and unrevealing microbiological workups, clinicians should maintain a high index of suspicion for MOGAD, particularly if serial neuroimaging reveals evolving multifocal T2/FLAIR lesions involving deep gray matter structures.
Interpreting Complex MRI Evolution and Radiologic Lag
Neuroimaging plays an indispensable role in confirming MOGAD, yet clinicians must account for complex radiological patterns. Initial brain MRI performed on illness day eight demonstrated swelling of the medial right temporal lobe alongside patchy T2/FLAIR hyperintense lesions in the right temporal lobe, basal ganglia, and periventricular region. Subsequent scans on illness day 19 showed partial improvement of the temporal swelling alongside the emergence of new right frontal lesions, even as the patient clinically improved—a phenomenon known as radiologic lag.
Subsequent imaging on illness day 30 demonstrated slight local improvement, while day 44 scans showed persistent multifocal abnormalities that remained largely unchanged. These evolving radiological features, combined with aquaporin-4 immunoglobulin G (AQP4-IgG) negativity, helped solidify the inflammatory demyelinating diagnosis.
Evaluating Ocular Motor Dysfunction and MOG-IgG Assay Results
Ocular manifestations such as diplopia serve as vital focal clues in central nervous system disorders. During the reported hospitalization, the patient experienced binocular horizontal diplopia and right exotropia with apparent adduction limitation. While brainstem and cerebellar involvement are recognized in MOGAD, specialists noted that the available ophthalmologic examination did not demonstrate abducting nystagmus or slowed horizontal saccades. Therefore, the finding was classified conservatively as transient ocular motor dysfunction rather than confirmed internuclear ophthalmoplegia.
Antibody testing also required careful interpretation. Serum MOG-IgG tested positive at 1:32 via a live cell-based assay on illness day eight—following intravenous immunoglobulin (IVIG) administration—and rose to 1:100 on days 22 and 77. Conversely, fixed-cell assay results yielded discordant outcomes and were negative on follow-up. According to international diagnostic criteria, live cell-based assays are favored, and clinicians must weigh antibody titers alongside the clinical phenotype and pretest probability to avoid false-positive misclassifications.
Did You Know? False-positive MOG-IgG results occur when testing is applied in low-pretest-probability settings, which makes adherence to the 2023 international diagnostic criteria essential for accurate patient management.
Acute Treatment Protocols and Off-Label Relapse Prevention
Management of acute pediatric MOGAD attacks typically involves targeted immunotherapy. In this case, the patient received 80 g of intravenous immunoglobulin across illness days six and seven, followed by high-dose intravenous methylprednisolone at 1,000 mg daily for three days starting on illness day eight. Acyclovir and azithromycin were administered empirically during the initial infection workup but were discontinued as infectious etiologies were excluded.
Due to the persistence of evolving MRI abnormalities, the care team initiated an individualized, off-label relapse-prevention strategy using rituximab. Administered as four 600-mg doses between illness days 20 and 47, the treatment achieved marked B-cell depletion by day 77. Oral prednisone tapering began on day 80. At the last follow-up on illness day 97, the patient remained clinically stable with no recurrence of headache, fever, vomiting, diplopia, or transient right-foot thermal dysesthesia.
Frequently Asked Questions
What are the primary symptoms of pediatric MOGAD?
Pediatric MOGAD presents with fever, headache, vomiting, cerebrospinal fluid pleocytosis, and focal neurological deficits such as binocular diplopia, blurred vision, or motor weakness, often mimicking acute central nervous system infections.
How is MOGAD diagnosed?
Diagnosis requires a compatible core demyelinating clinical event, detection of serum MOG-IgG using an appropriate live cell-based assay, and the systematic exclusion of alternative infectious, vascular, or autoimmune diagnoses.
Why are live cell-based assays preferred for MOG-IgG testing?
Current international diagnostic criteria favor live cell-based assays because fixed-cell assays can produce discordant or false-positive results, particularly in low-pretest-probability clinical scenarios.
Can MOGAD cause transient peripheral symptoms?
While primarily a central nervous system disorder, rare instances of transient peripheral sensations, such as brief thermal dysesthesia, have been documented alongside mild, non-specific neurophysiological findings.