Unilateral cerebral cortical encephalitis with epilepsy: a possible special phenotype of MOG antibody-associated disorders

Myelin oligodendrocyte glycoprotein (MOG) antibody-related encephalomyelitis is an increasingly recognized entity with heterogeneity in phenotype. Among all clinical phenotypes, encephalitis restricted to cerebral cortex might be most easily ignored and under-estimated type. Here, we described two cases of cerebral cortical encephalitis with MOG seropositivity to facilitate the awareness of the manifestations of the disease. In case 1, the patient presented with headaches and fevers turned out to have elevated CSF cells and cerebral cortical FLAIR hyperintense lesions in brain MRI. He was treated as intracranial infection during his first and second admission and fully resolved when discharged. During the patient’s third admission, the patient experienced a seizure, and we found cerebral cortical FLAIR hyperintensity again and MOG antibody was positive in the serum. Therefore, we considered the patient suffered from MOG antibody encephalitis. In case 2, the patient also had headache, fever, and experienced a seizure. MOG antibody was positive in the serum and brain MRI showed cortical hyperintense lesions. Both the patients were young man, response well to corticosteroids and recovered completely. The two cases suggested that encephalitis, especially benign recurrent unilateral cerebral cortical encephalitis with epilepsy, might be a special phenotype of MOG antibody-associated disorders.