Clinical Characteristic Of Early-Onset And Late-Onset Neuromyelitis Optica Spectrum Disorder

Background and objective:Neuromyelitis optica spectrum disorder(NMOSD)is a spectrum of neuroinflammatory disorder that predominantly involves the optic nerve and the spinal cord.Aquaporin-4 immunoglobulin G(AQP4-Ig G)is the major autoimmune antibody that contributes to the pathogenesis of NMOSD.Median age at onset at the follow-up were higher in the NMOSD group than that in the MS group,that is 35-45 years.Furthermore,NMOSD patients often present as severe sensory impairment and sleep disorder,which can cause anxiety and depression and further affect the quality of life of these patients.It is reported that age of onset is one key factor that influence the prognosis of NMOSD.However,this result was based on studies that only included AQP4-Ig G seropositive NMOSD patients,or studies using 2006 NMOSD diagnosis criteria.This study aimed to describe the clinical and magnetic resonance imaging(MRI)differences between early-onset neuromyelitis optica spectrum disorder(EO-NMOSD)and late-onset(LO)-NMOSD patients.Methods:Medical records from patients who were diagnosed with myelitis or neuromyelitis optica from department of neurology from the First hospital.Fifty patients who fulfilled the 2015 NMOSD diagnosis criteria were followed up.Patients were divided into early-onset group(≤49 years)and late-onset group(≥50 years)according to the age of onset.Twenty-two patients were in the LO-NMOSD group,and 28 were in the EO-NMOSD group.The serum AQP4-Ig G titer was measured,the brain and spinal cord MRI examination were performed at the follow up time.Besides,a number of questionnaires including Expanded Disability Status Scale(EDSS),Hamilton Anxiety Rating Scale(HAMA),the Hamilton Depression Rating Scale(HADA),the Activity of Daily Living Scale(ADL),California Verbal Learning Test Second Edition(CVLT-Ⅱ),Pittsburgh Sleep Quality Index(PSQI),Brief Pain Inventory(BPI),Fatigue Scale-14(FS-14)and Clinical Dementia Rating(CDR)were collected as well.Results:A total of 50 patients with NMOSD,with a male to female ratio of 1:5.25,were collected for this study.Higher AQP4-Ig G seropositivity,higher AQP4-Ig G titer,frequency of thoracic myelitis,and white matter hyperintensities(WMH),as well as greater severity of disability,greater severity of sleep disorders,higher anxiety,poorer cognitive function,and higher clinical dementia rating(CDR)-community affairs scores were observed in late-onset(LO)-NMOSD patients than those in early-onset(EO)-NMOSD.AQP4-Ig G titer positively correlated with age,annual relapse rate,Expanded Disability Status Scale(EDSS)sensory scores,Activity of Daily Living Scale(ADL)scores,and Pittsburgh Sleep Quality Index(PSQI)scores.The EDSSsensory scores positively correlated with age,relapse time,HADA,HAMA,PSQI,ADL,and CDR.WMH was positively correlated with age,EDSS-sensory scores,PSQI scores,and CDR scores and negatively correlated with the California Verbal Learning Test scores.Conclusion:LO-NMOSD patients have worse prognoses than those of EO-NMOSD patients.Higher AQP4-Ig G titers,more WMHs,thoracic myelitis,and severe sensory symptoms are associated with cognition,depression,anxiety,and sleep disorders.