Quantitative MRI analysis of the brain after twenty-two years of neuromyelitis optica indicates focal tissue damage.

BACKGROUND: The long-term effect of neuromyelitis optica (NMO) on the brain is not well established. METHODS: After 22 years of NMO, a patient's brain was examined by quantitative T1- and T2-weighted mono- and biexponential diffusion and proton spectroscopy. It was compared to 3 cases with short-term NMO and 20 healthy subjects. RESULTS: Although routine T1- and T2-weighted images appeared to be normal, quantitative T1-, T2- and diffusion-weighted magnetic resonance imaging identified areas with high diffusivity and altered relaxation time in 'normal appearing white matter' (NAWM). In such abnormal NAWM regions, biexponential diffusion analysis and quantitative spectroscopy indicated extracellular edema and axonal loss, respectively. Repeated analysis 6 months later identified the same alterations. Such patchy alterations were not detectable in the NAWM of the 3 cases with short-term NMO, and they were also not quantitatively different from the controls. CONCLUSION: After NMO of 22-year duration, metabolic changes, altered diffusivity and magnetic resonance relaxation features of patchy brain areas may suggest tissue damage in NAWM that persist for at least 6 months.

[European treatment recommendation of neuromyelitis optica spectrum disorders: critical remarks and case discussion]. / A neuromyelitis optica spektrumbetegségek európai kezelési elveirol egy eset kapcsán.

Neuromyelitis optica is a demyelinating disease of the central nervous system mediated by antibodies against the waterchannel aquaporin4 (AQP4). In a number of cases the clinical manifestation is spatially limited. Such events of separate longitudinally extensive transverse myelitis (LETM) or relapsing/bilateral optic neuritis (RION/BON) are defined as NMO spectrum diseases. The diagnosis is further challenged by anti-AQP4 seronegative cases. While chronic immunosuppressive therapy should be introduced in definitive NMO, treatment strategy of the NMO spectrum is less defined. Recent EFNS guidelines recommend chronic immunosuppressive treatment of NMO spectrum diseases depending on the clinical course even in AQP4-seropositive cases. Presenting a case with relapsing optic neuritis, here we emphasize the importance of early immunosuppressive therapy in all seropositive NMO spectrum diseases regardless of relapse severity, in order to prevent an upcoming devastating relapse, i.e. NMO conversion.