MOGAD presenting as fulminant intracranial hypertension

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) has an expanding phenotype. We describe two cases of MOGAD with associated severe intracranial hypertension. Case 1: A 21-year-old male presented with diffuse cortical encephalitis and intracranial hypertension with both serum and CSF MOG antibody positivity. Initial brain CT scan was normal but subsequent demyelination was evident on MRI. Case 2: A 44-year-old female presented with a progressive brainstem encephalitis and intracranial hypertension and normal MRI, with later development of subcortical demyelination which was confirmed on brain biopsy. CSF-restricted MOG antibody was detected following the biopsy results. Both patients presented with clinical features of severe intracranial hypertension requiring surgical management followed by immunosuppressive therapy (methylprednisone and plasma exchange; and intravenous immunoglobulin and plasma exchange) leading to clinical improvement. MOGAD should be in the differential diagnosis of acute severe intracranial hypertension even in the absence of demyelination on initial neuroimaging. Clinicians should be alert of this syndrome that requires combined management of intracranial pressure in addition to early and intensive immunotherapy. •MOGAD causes several demyelinating syndromes with expanding phenotype variability.•MOGAD can be associated with severe intracranial hypertension.•Neuroimaging may be normal in the initial stages.•Later changes may be cortical or extensive subcortical white matter demyelination.•Early management of intracranial hypertension and immunotherapy is crucial.