Inclusion Criteria:

All patients living and/or treated in Switzerland with an IBrainD specified in the following list diagnosed from 2005 onward and with a disease onset before the age of 18.

• - Written informed consent by patients (and/or legal representative(s), if applicable) - Optic Neuritis.

• - Transverse Myelitis.

• - Acute disseminated encephalomyelitis.

• - Multiple Sclerosis.

• - Neuromyelitis Optica Spectrum Disorders.

• - Myelin oligodendrocyte glycoprotein antibody-associated disease.

• - Anti-NMDA-R Encephalitis.

• - Anti-GAD65 Associated Autoimmune Encephalitis.

• - Anti-AMPAR-1/2 Associated Autoimmune Encephalitis.

• - Anti-Lgi-1 Associated Autoimmune Encephalitis.

• - Anti-CASPR-2 Associated Autoimmune Encephalitis.

• - Anti-GABAR-1/2 Associated Autoimmune Encephalitis.

• - Onconeuronal Antibody (Hu, Ri, Yo, Amphiphysin, CRMP-5, Ma-1, Ma-2, SOX-1) Associated Autoimmune Encephalitis.

• - Hashimoto Encephalopathy.

• - CNS Vasculitis.

• - CNS Sarcoidosis.

• - CNS Lupus.

• - Rasmussen Encephalitis.

Exclusion Criteria:

• - Neurological symptoms due to infectious diseases of the CNS.

• - Genetic/metabolic causes of central demyelinating diseases.

- Neurological symptoms due to Guillain-Barré-Syndrome

Background: Pediatric onset MS and other inflammatory brain diseases (IBrainDs) are severe diseases affecting children and adolescents in a period of essential brain development. This possibly leads to a variety of focal neurological deficits as well as early cognitive impairment. In turn, the cognitive impairment may impact school performance and vocational achievements. Timely diagnosis and treatment initiation as well as individually tailored management are important for a favorable disease course. However, the diagnosis of the different IBrainDs can be challenging, especially in young children, since their first acute inflammation is often accompanied by unspecific symptoms common to all IBrainDs. A systematic assessment of similarities and differences between clinical signs, symptoms, and diagnostic workup of different IBrainDs will enable faster and more reliable diagnosis. Furthermore, neither epidemiological data nor information on health care management and disease outcome of pediatric IBrainD patients exist in Switzerland. Therefore, a national registry is being established, which will allow a deeper understanding of pediatric IBrainD epidemiology, clinical presentation, and management. Ultimately, the registry will improve the care of children suffering from an IBrainD in Switzerland. The Swiss-Ped-IBrainD Registry (title: "Swiss Pediatric Inflammatory Brain Disease Cohort Study", project number: 2019-00377) has been approved by the ethics committees of Bern, the Ethikkommission Nordwest- und Zentralschweiz (EKNZ), the Ethikkommission Ostschweiz (EKOS), and the ethics committees of Zürich, Lausanne, Geneva, and Bellinzona. Objectives: The registry pursues the following goals: 1. Gathering representative, population-based epidemiological data on pediatric IBrainD in Switzerland. 2. Monitoring treatment, clinical course, education, social aspects, and outcomes of pediatric IBrainD patients. 3. Providing a platform to facilitate research, national and international collaboration and exchange of knowledge between experts. The registry thus addresses the increasing requests for medical trial participation and promotes the exchange with existing adult registries (e.g., Swiss MS Registry). Inclusion/exclusion criteria: All patients living and/or treated in Switzerland with an IBrainD specified in the following list diagnosed from 2005 onward and with a disease onset before the age of 18.

• - Optic neuritis.

• - Transverse myelitis.

• - Acute disseminated encephalomyelitis.

• - Multiple sclerosis.

• - Neuromyelitis optica spectrum disorders.

• - Myelin oligodendrocyte glycoprotein antibody-associated disease.

• - Anti-NMDA-R associated autoimmune encephalitis.

• - Anti-GAD65 associated autoimmune encephalitis.

• - Anti-AMPAR-1/2 associated autoimmune encephalitis.

• - Anti-Lgi-1 associated autoimmune encephalitis.

• - Anti-CASPR-2 associated autoimmune encephalitis.

• - Anti-GABAR-1/2 associated autoimmune encephalitis.

• - Onconeuronal antibody (Hu, Ri, Yo, Amphiphysin, CRMP-5, Ma-1, Ma-2, SOX-1) associated autoimmune encephalitis.

• - Hashimoto encephalopathy.

• - CNS vasculitis.

• - CNS sarcoidosis.

• - CNS Lupus.

• - Rasmussen's encephalitis.

Excluded are patients with: 1. Neurological symptoms due to infectious diseases of the CNS. 2. Genetic/metabolic causes of central demyelinating diseases. 3. Neurological symptoms due to Guillain-Barré-Syndrome.Registration of Patients and Collection of Medical Data: Pediatricians, pediatric neurologists, neurologists, specialists in rehabilitation, and primary care physicians at the participating centers are responsible to identify children with the listed IBrainDs during regular medical consultations. Upon identification, treating physicians inform patients and their parents orally and in writing about the Swiss-Ped-IBrainD. Patients (and their legal representatives if applicable) who want to participate must give their informed consent. Once a patient consents to participate, their medical data will be entered in the registry. The diagnostic workup and treatment of patients continue as usual and are independent from participation; no examination will be carried out specifically for the Swiss-Ped-IBrainD. Medical data is collected through the following sources:

• - Medical records and reports.

• - Oral/written information from treating physician.

• - Oral/written information from patient/family.

• - Routine statistics and other medical registries.

• - Questionnaires for patients and families The data collection focuses on diagnostic, follow-up, and relapse variables.

Routine data and linkages: Communities; Federal Statistical Office (e.g. the birth register, cause of death statistics, hospital statistics) Current status: Since 2020, the investigators have included 128 people diagnosed with an IBrainD. Funding:

• - Schweizerische Multiple Sklerose Gesellschaft.

• - PedNet Bern.

• - SwissPedRegistry, University of Bern.

• - Roche Pharma (Switzerland) Ltd.

• - Novartis Pharma Schweiz AG.

• - Biogen.

• - Sanofi.

• - Anna Mueller Grocholski-Stiftung.

• - Gottfried und Julia Bangerter-Rhyner Stiftung.

- Fondation Johanna Dürmüller-Bol

Arms

: Patient population

Children, adolescents and adults diagnosed with an IBrainD from 2005 onward and with disease onset before age 18, who are born, treated or living in Switzerland

Interventions