neurologic disorders
Neuromyelitis Optica Spectrum Disorder (NMOSD)
Diagnosis of NMOSD
Brain and spinal cord MRI Visual evoked potentials Diagnosis of neuromyelitis optica spectrum disorder usually includes brain and spinal cord MRI and visual evoked potentials ( Diagnosis reference ). The following features help distinguish neuromyelitis optica from multiple sclerosis (MS): Neuromyelitis optica affects several (typically ≥ 3) contiguous spinal segments of the spinal cord, whereas MS typically affects a single segment. On MRI, cerebral white matter lesions are uncommon in neuromyelitis optica, unlike in MS. On MRI, morphology and distribution of the lesions differ from those in MS. Measurement of Evoked Responses can help differentiate neuromyelitis optica from other optic neuropathies. Findings in neuromyelitis optica spectrum disorder include reduced amplitudes or prolonged latencies. This test is also useful for detecting clinically inapparent damage before symptoms develop. Blood tests to measure an IgG antibody specific for neuromyelitis optica spectrum disorder (aquaporin-4 antibody [also known as NMO-IgG]) may be done to differentiate it from MS. Anti-MOG (myelin oligodendrocyte glycoprotein) antibodies identify a subset of patients who have neuromyelitis optica spectrum disorder and who appear to have different clinical features, fewer exacerbations, and better recovery than patients with aquaporin-4 antibodies or with neither antibody. Some patients with clinical evidence of neuromyelitis optical spectrum disorder do not have either antibody and are classified as having double antibody negative neuromyelitis optica spectrum disorder. 1.Wingerchuk DM, Banwell B, Bennett JL, et al: International consensus diagnostic criteria for neuromyelitis optica spectrum disorders.Neurology85 (2):177–189, 2015. doi: 10.1212/WNL.0000000000001729 Epub 2015 Jun 19 