Can right-sided head pain be a presenting symptom in patients with Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD)?

Right-Sided Head Pain in MOGAD

Yes, headache including right-sided head pain can be a presenting symptom in MOGAD, particularly in the context of cortical encephalitis, optic neuritis with perioptic inflammation, or acute disseminated encephalomyelitis (ADEM). While headache is not the primary defining feature of MOGAD, it occurs as part of several characteristic clinical phenotypes.

Clinical Contexts Where Headache Occurs in MOGAD

Cortical Encephalitis Presentation

• Headache is a prominent feature of MOG antibody-associated cerebral cortical encephalitis (CCE), typically presenting alongside fever and seizures 1
• In systematic reviews of MOG-positive CCE cases, most patients presented with the triad of seizures, headache, and fever, which can initially be misdiagnosed as viral encephalitis 1
• Cortical encephalitis in MOGAD is characterized by cortical/subcortical white matter lesions and can present with seizures 2

Optic Neuritis with Perioptic Inflammation

• Optic neuritis in MOGAD frequently demonstrates perioptic gadolinium enhancement (optic nerve sheath involvement), which can cause periorbital or hemicranial pain 2
• The optic nerve involvement is often longitudinally extensive with prominent papilledema, papillitis, or optic disc swelling, all of which can generate headache 3

ADEM Presentation

• ADEM in MOGAD presents with large, confluent T2 brain lesions, disturbance of consciousness, behavioral changes, or epileptic seizures, and headache can accompany these presentations 3, 2
• This is the most common presentation in children but also occurs in adults 4

Important Clinical Caveats

Distinguishing Features

• Headache in MOGAD is typically accompanied by other neurological deficits such as visual loss, seizures, altered consciousness, or myelopathic symptoms, rather than occurring as an isolated symptom 1
• The presence of fever with headache should raise suspicion for cortical encephalitis phenotype, particularly if seizures develop 1

Diagnostic Considerations

• CSF analysis often shows neutrophilic pleocytosis or white cell count >50/μl, which can help distinguish MOGAD from other causes of headache with neurological symptoms 3, 2
• The absence of CSF-restricted oligoclonal bands is typical in MOGAD (particularly in continental European patients), unlike multiple sclerosis 3, 4

Lateralization

• While the question specifically asks about right-sided pain, MOGAD lesions can be unilateral or bilateral, and cortical lesions are often unilateral on brain MRI 1
• The laterality of headache would correspond to the side of cortical involvement or optic nerve inflammation

Clinical Pitfall to Avoid

• Do not dismiss MOGAD based solely on headache as a presenting symptom, especially in younger patients with fever and seizures, as this combination strongly suggests MOG-associated cortical encephalitis that requires urgent immunotherapy 1
• Early recognition is critical because MOGAD generally responds very well to high-dose intravenous methylprednisolone, with most patients achieving complete symptom relief after immunotherapy 1, 5