MS (multiple sclerosis) is usually diagnosed through neurological examination, magnetic resonance imaging (MRI), analysis of cerebrospinal fluid, and sometimes also functional tests of nerve pathways. The diagnosis is based on findings that show inflammatory changes in the central nervous system at different times and in different places. Magnetic resonance imaging is a key tool in diagnosing MS, as it can reveal inflammatory lesions in the brain and spinal cord that are typical of MS.