Clinical Characteristics Of Neuromyelitis Optica Spectrum Disorder(NMOSD)

ObjectiveTo analyse systematically the clinical and paraclinical features associated with neuromyelitis optica spectrum disorder(NMOSD)and compare our data with other studies in the meantime in order to summary the characteristics in the diagnosis and treatment process.MethodsWe assessed the medical records and followed up patients of NMOSD,which were confirmed according to the 2015 International Panel for NMO Diagnosis(IPND)criteria for NMOSD.Data collected included year of onset,sex,disease duration,initial presentation,the occurrence of any relapse,laboratory results including aquaporin-4 immunoglobulin G(Ig G)/ myelin oligodendrocyte glycoprotein Ig G / autoantibodies / cerebrospinal fluid protein and white cell count,magnetic resonance imaging findings,treatment profile and disability details.All statistical analyses were performed using SPSS for Windows version 25.0.Results1.Demographic data: The mean onset age was 37.7 years.The peak ages of disease onset were 20-29 and 40-49 years.The age of first attack of patients were generally less than 50 years,which were defined as early onset.Disease duration was shorter in the late onset group.The female to male rate was 4:1.The mean age at last follow up was 45.1 years.2.First attack: Optic neuritis(ON)and acute myelitis(AM)were the most seen.3.Diagnosis at disease onset:14.3% of patients were confirmed as NMOSD.The percentage of first attack after 2015 were remarkably higher in patients definitely diagnosed at onset.4.Recurrence: The monophasic to relapsing ratio was 3:32.The annualized relapse rate was 0.5.The majority of patients recurred within 1 years.ON and AM were the most common,followed by area postrema syndrome.The percentage of involvement of different central nervous system(CNS)regions at second attack and development into neuromyelitis optica(NMO)were significantly higher in patients with isolated ON at onset compared to those with isolated AM at onset.The median relapse frequency was 2.5.57.1% of patients were ultimately developed into NMO.The median time to development into NMO was 17.5months.5.Disease course and clinical symptoms: The mean of the disease duration at last follow up was 89.7 months.Most of patients affected both the right and the left eyes.Among myelitis related symptoms,paresthesia was the most frequently seen during the whole course.Numbness of limb and body,pain,zonesthesia were the most common forms of paresthesia,whereas a certain portion of patients complained of painful tonic and itching.6.AQP4 Ig G and MOG Ig G testing: The median time to testing was 13 months.Serum AQP4 Ig G positive was found in 27 patients,8 patients simultaneously had AQP4 Ig G positive in cerebrospinal fluid(CSF)among them.Serum MOG Ig G positive was found in only one patient.Both serum AQP4 Ig G and serum MOG Ig G positive were not observed in our study.Seroconversion from seropositive to seronegative AQP4 Ig G or MOG Ig G were seen in two patients.7.Autoantibodies: The majority of patients had anti-nuclear antibody and anti-SSA antibody.Sjogren′s syndrome was the most common concomitant autoimmune disease.8.CSF abnormity of the acute phase:45.2% of patients had elevated CSF protein and 64.5% had CSF pleocytosis.9.MRI findings:33.3% of patients had brain lesions.Medulla oblongata was the frequently involved.Spinal cord lesion over 3 vertebral segments was seen in most cases.However,two patients showed short segmental lesion.The median length of spinal cord lesion was 7 segments.Finally,the majority of patients had cervical and thoracic cord lesion.10.Prodromic infection:17.1% of patients definitely had infections prior to disease onset.11.Diagnosis definitely: The median time to make a definitely diagnose was 6months.Most of patients were confirmed within 1 year.The percentage of first attack after 2015 were remarkably higher in patients definitely diagnosed within 1year.The median year to make a definitely diagnose was 2016.Comfirmed cases increased by year.The median relapse frequency at the time of diagnosis definitely was 1.The interval between AQP4 Ig G testing and disease onset positively correlated with time to definitely diagnosis.The interval between AQP4 Ig G testing and disease onset of confirmed cases was shorter than undetermined cases.12.Therapy: 51.4% of patients received acutely treatment at disease onset.The percentage of acutely treatment were remarkably higher in patients definitely diagnosed at disease onset.Whereas,the percentage of cases misdiagnosed with MS were remarkably higher in patients acutely treated,and even worse,the percentage of cases unclearly diagnosed were higher in patients without acutely treatment.The annualized relapse rate positively correlated with untreated frequency during the whole course.The median time to oral low-dose glucocorticoid regularly was 3 months.And the median time to regular immunosuppressants therapy was 13.5 months.13.Expanded disability status scale(EDSS)at last follow up and disability details: The median EDSS at last follow up was 2.8.The majority of patients had no disability.Relapse frequency positively correlated with EDSS at last follow up.The percentage of initial visual acuity ≤0.1 were remarkably higher in patients with visual acuity ≤0.1 at last follow up than visual acuity >0.1.Logistic regression analysis suggested that poorer initial visual acuity were the risk factors for worse visual outcome.ConclusionMiddle-young aged females were susceptible to suffer NMOSD.It was a kind of disease tended to misdiagnosis.The majority of patients were not confirmed at disease onset and may be diagnose definitely undergone several recurrences.The poor knowledge of NMOSD may attribute to misdiagnosis.Also,NMOSD was prone to relapse easily.ON was liable to delay diagnose and treatment because of referring to ophthalmologist initially.Initial visual acuity were associated with final visual outcome.Bilateral optic neuritis,itching,painful tonic,medulla oblongata lesion and acute myelitis with preceding infection highly suggested NMOSD.Short segmental myelitis may not be the exclusion criteria for NMOSD.The confirmed cases increased by the coming of the 2015 International Panel for NMO Diagnosis(IPND)criteria for NMOSD.It was heavily important to test AQP4 Ig G using the best available detection method.Early diagnosis and timely treatment were the most effective way to prevent recurrence and disability.