Multiple Sclerosis Versus Neuromyelitis Optica Spectrum Disorder

Inclusion Criteria:1- Both sex 2- Aged between 18 and 50 years. All included patients were in a clinically stable phase and had not experienced a relapse within at least three months before blood sampling. 3- All patients diagnosed as MS patients either naive or on disease modifying therapies according to The new diagnostic criteria MacDonalds 2024 4- DMT-naïve NMOSD patients: Diagnosed with MS based on the 2017 McDonald Criteria (Thompson et al., 2018) 5- An informed consent will be obtained from all the patients; the study will be approved by ethical committee in faculty of Medicine Assiut University \- 1\_ Presence of other disorder that mimic MS or NMOSD 3\_ Patients failed to commit to the follow up visits and regular MRI scans 4\_ Patients refused to sign the written informed consent Exclusion Criteria: * 1\_ Presence of other disorder that mimic MS or NMOSD 3\_ Patients failed to commit to the follow up visits and regular MRI scans 4\_ Patients refused to sign the written informed consent