Unilateral cortical FLAIR-hyperintense Lesions in Anti-MOG-associated Encephalitis with Seizures (FLAMES): characterization of a distinct clinico-radiographic syndrome

Clinical approach to the diagnosis of autoimmune encephalitis in the pediatric patient

“…44 Children with MOG antibodies are also less likely to have oligoclonal bands than those with MS. 42,44 However, the spectrum of brain disease associated with MOG antibodies in adults and children has broadened to include ADEM, meningoencephalitis, cortical encephalitis with seizures, brainstem encephalitis, and mimics of vasculitis. [45][46][47] Some of these patients will evolve into more typical demyelinating phenotypes, such as ADEM; therefore, MOG antibodies should be considered in pediatric AE presentations beyond ADEM. [45][46][47] MOG autoantibodies are typically transient in monophasic ADEM, but remain positive in relapsing phenotypes.…”

“…[45][46][47] Some of these patients will evolve into more typical demyelinating phenotypes, such as ADEM; therefore, MOG antibodies should be considered in pediatric AE presentations beyond ADEM. [45][46][47] MOG autoantibodies are typically transient in monophasic ADEM, but remain positive in relapsing phenotypes. 8,9,42 Limbic encephalitis The clinical, EEG, and radiologic features of limbic encephalitis are uncommon in children.…”

The Expanding Clinical Spectrum of Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Associated Disease in Children and Adults

“…The most common symptoms were seizures (85%), headache (70%), and fever (55%). CSF pleocytosis and cortical leptomeningeal enhancement ( Figure 1I) were present in a minority of patients (57). All patients with FLAMES responded to high dose steroids with resolution of FLAIR changes.…”

“…Cerebral involvement in adults is both less common and more restricted than in children, though there are exceptions (55). Syndrome of encephalitis with steroid-responsive seizures, also termed FLAMES (FLAIR-hyperintense Lesions and Anti-MOGassociated Encephalitis with Seizures), appears to be specific to MOGAD (20, [56][57][58]. FLAMES patients present with focal-onset, tonic-clonic seizures, and have unilateral FLAIR hyperintensities with edema on MRI ( Figure 1H).…”

Clinical Reasoning: An 11-year-old girl with focal seizures, fevers, and unilateral, enhancing cortical lesions

“…Various case series have described the presentations of pediatric versus adult anti-MOG-associated disorders, revealing some general themes: patients with anti-MOG antibodies tend to be younger than patients with neuromyelitis optica (NMO) or multiple sclerosis (MS); they rarely meet MS diagnostic criteria; they often present with optic neuritis, myelitis, or acute disseminated encephalomyelitis (ADEM); they often have radiographic involvement of supratentorial white matter, brainstem, or spinal cord; and they are rarely simultaneously positive for anti-NMO antibodies. 4,[8][9][10] To avoid "overdiagnosis," an international panel published a consensus guideline for testing and diagnosis, suggesting that criteria for anti-MOG-encephalomyelitis include: 1) monophasic or recurrent optic neuritis, myelitis, encephalitis, or a combination thereof;…”