Two Pools of ATP Detected in the Brains of Pediatric Patients with Myelin Oligodendrocyte Glycoprotein Antibody Disorders (MOGAD) by 3D 31P MR Spectroscopic Imaging (MRSI) at 7T

Over the past four decades, ATP, the obligatory energy molecule for keeping all cells alive and functioning, was thought to contribute only one set of 31P MR signals in the human brain. Here we report for the first time the simultaneous detection of two pools of ATP in the human brain by high-resolution 3D 31P MRSI at ultrahigh field 7T. These two ATP pools differ in cytosolic Mg2+ concentration (1:0.5 ratio), with a resonance separation of 0.5 ppm at beta-ATP, a well-established imaging marker of intracellular Mg2+ concentration. Mg2+ is a cofactor of ATPase and its deficiency is associated with immune dysfunction, free radical damage, perturbations in Ca2+ homeostasis, development of atherosclerosis and dyslipidemia, and a number of neurological disorders, such as cerebral vasospasm, stroke, migraine, Alzheimer's disease, and Parkinson's disease. Our study documents reduced Mg levels in the brain of patients with myelin oligodendrocyte glycoprotein antibody disorders (MOGAD), which is an idiopathic, inflammatory, demyelinating condition of the central nervous system (CNS) more common in pediatric patients. Low-Mg2+ ATP signals in MOGAD were detected mostly in the white matter regions, which may suggest Mg2+ deficiency in oligodendrocytes, which are primarily responsible for maintenance and generation of the axonal myelin sheath. This preliminary study demonstrates the utility of the 7T 3D 31P MSRI for revealing altered energy metabolism with reduced Mg availability at a normal ATP level. The potential correlation between [Mg2+] and disease progression over time should be assessed in larger cohorts.

Myelin Oligodendrocyte Glycoprotein Antibody Associated Cerebral Cortical Encephalitis: Case Reports and Review of Literature

Myelin oligodendrocyte glycoprotein antibody-associated disease is an immune-mediated demyelinating disease of the central nervous system that is present in both adults and children. The most common clinical manifestations are optic neuritis, myelitis, acute disseminated encephalomyelitis, and brainstem syndrome. Cerebral cortical encephalitis (CCE) is a rare clinical phenotype of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), which usually begins with seizures, headaches, and fever, and may be misdiagnosed as viral encephalitis in the early stages. Herein, we report two typical MOG antibody (MOG-Ab)-positive patients presenting with CCE, both of whom presented with headache, fever, seizures, and who recovered completely after immunotherapy. In addition, we performed a systematic review of the present literature from the perspectives of population characteristics, clinical symptoms, MRI abnormalities, treatments, and prognosis. Among the patients reported in 25 articles, 33 met our inclusion criteria, with the age of onset ranging from 4 to 52 years. Most of the patients had seizures, headache, fever, and unilateral cortical lesions on brain MRI. For acute CCE, 30 patients were treated with high-dose intravenous methylprednisolone, and the symptoms of most patients were completely relieved after immunotherapy. This study reported our experience and lessons learned in the diagnosis and treatment of MOG-Ab-positive CCE and provides a systematic review of the literature to analyse this rare clinical phenotype.

Absence of attack-independent neuroaxonal injury in MOG antibody-associated disease: Longitudinal assessment of serum neurofilament light chain

To evaluate the occurrence of attack-independent neuroaxonal and astrocytic damage in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) levels were longitudinally measured in 102 sera using a single-molecule array assay. Sera from 15 adults with relapsing MOGAD with available longitudinal samples for the median 24-month follow-up and 26 age-/sex-matched healthy controls were analyzed. sNfL levels were significantly elevated in all clinical attacks, where the levels decreased below or close to cut-off value within 6 months after attacks. sNfL levels were consistently low during inter-attack periods. In contrast, sGFAP levels did not increase in most clinical attacks and remained low during follow-up. Significant neuroaxonal damage was observed at clinical attacks, while attack-independent neuroaxonal and astrocytic injury was absent in MOGAD.

Pediatric Neuromyelitis Optica Spectrum Disorder: Case Series and Literature Review

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a central nervous system (CNS) inflammatory demyelinating disease characterized by recurrent inflammatory events that primarily involve optic nerves and the spinal cord, but also affect other regions of the CNS, including hypothalamus, area postrema and periaqueductal gray matter. The aquaporin-4 antibody (AQP4-IgG) is specific for NMOSD. Recently, myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been found in a group of AQP4-IgG negative patients. NMOSD is rare among children and adolescents, but early diagnosis is important to start adequate therapy. In this report, we present cases of seven pediatric patients with NMOSD and we review the clinical and neuroimaging characteristics, diagnosis, and treatment of NMOSD in children.