ROCHESTER, Minn. — Mayo Clinic has launched a first-in-the-U.S. clinical test that will help patients who recently have been diagnosed with an inflammatory demyelinating disease (IDD) but may be unsure of the exact disorder. Neurologic-related diseases commonly affect the brain, optic nerves and the spinal cord, and this new test can distinguish other IDDs such as neuromyelitis optica (NMO), acute disseminated encephalomyelitis, optic neuritis, and transverse myelitis from multiple sclerosis (MS).