Confusing Onset of MOGAD in the Form of Focal Seizures.

MOGAD is a demyelinating syndrome with the presence of antibodies against myelin oligodendrocyte glycoprotein, which is, next to multiple sclerosis and the neuromyelitis optica spectrum, one of the manifestations of the demyelinating process, more common in the pediatric population. MOGAD can take a variety of clinical forms: acute disseminated encephalomyelitis (ADEM), retrobulbar optic neuritis, often binocular (ON), transverse myelitis (TM), or NMOSD-like course (neuromyelitis optica spectrum disorders), less often encephalopathy. The course may be monophasic (40-50%) or polyphasic (50-60%), especially with persistently positive anti-MOG antibodies. Very rarely, the first manifestation of the disease, preceding the typical symptoms of MOGAD by 8 to 48 months, is focal seizures with secondary generalization, without typical demyelinating changes on MRI of the head. The paper presents a case of a 17-year-old patient whose first symptoms of MOGAD were focal epileptic seizures in the form of turning the head to the right with the elevation of the left upper limb and salivation. Seizures occurred after surgical excision of a tumor of the right adrenal gland (ganglioneuroblastoma). Then, despite a normal MRI of the head and the exclusion of onconeural antibodies in the serum and cerebrospinal fluid after intravenous treatment, a paraneoplastic syndrome was suspected. After intravenous steroid treatment and immunoglobulins, eight plasmapheresis treatments, and the initiation of antiepileptic treatment, the seizures disappeared, and no other neurological symptoms occurred for nine months. Only subsequent relapses of the disease with typical radiological and clinical picture (ADEM, MDEM, recurrent ON) allowed for proper diagnosis and treatment of the patient both during relapses and by initiating supportive treatment. The patient's case allows us to analyze the multi-phase, clinically diverse course of MOGAD and, above all, indicates the need to expand the diagnosis of epilepsy towards demyelinating diseases: determination of anti-MOG and anti-AQP4 antibodies.