To investigate the clinical characteristics of primary Sj-gren's Syndrome （pSS） patients with central nervous system（CNS） damage as the initial manifestation.Methods Fifteen pSS patients with CNS damage as the initial manifestation were recruited.Clinical manifestations，laboratory results and imaging findings were retrospectively analyzed.Descriptive statistics was used for statistical analysis.Results Among the 15 patients，the ratio of male to female was 1∶4，and the first onset age was （45.53±16.19） years old.The diagnosis was confirmed after an average of 32.37 months.The initial symptoms included headache （6.67%），dizziness （20%），vomiting （20%），slurred speech （6.67%），facial paralysis （6.67%），hemilateral limb weakness （26.67%），numbness and weakness of both lower limbs （13.33 %） or the limbs （46.67%），chest and back pain（26.67%），blurred vision （6.67%）.The lesions involved the cerebral hemisphere （33.33%），brain stem （53.33%），cerebellum （6.67%），spinal cord （53.33%），and optic nerve （6.67%），presenting as cerebral infarction（33.33%），SAH（6.67%），transverse myelitis（6.67%），bulbar lesion（6.67%），neuromyelitis optica spectrum disorder （NMOSD）（53.33%） and NMOSD complicated with cerebral infarction in 1 case （6.67%）.CNS symptoms recurred in 3 cases （20%） before pSS was diagnosed.At the time of diagnosis，the positive rate of autoimmune antibodies was anti-SSA antibody 100%，anti-nuclear antibody 100%，anti-SSB antibody 73.33%，anti-R0-52 antibody 80%，anti-ds-DNA antibody 6.67%，respectively.The positive rate of RF was 20%.The increase rate of IgG and IgA were 20%，and the decrease rate of complement C3 was 20%.The cerebrospinal fluid study showed：CSF pressure （80-240） mmH-2O，white blood cells cout （4-130）×106/L，protein （0.27-1.46） g/L；CSF IgG increased in 5 cases，and IgM increased in 2 cases，and IgA increased in 4 cases.Conclusion CNS damage can be the initial manifestation of pSS.The lack of timely screening and monitoring of autoimmune antibody is an important reason for the delayed diagnosis of pSS.For unexplained CNS lesions，especially those presenting as recurrent demyelinating events or cerebral infarction，autoimmune antibodies such as anti-SSA and SSB should be examed actively，while the symptoms such as dry eyes and dry mouth should be questioned.It is important for early diagnosis.

Objective To investigate the clinical and imaging characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease(MOGAD).Methods The clinical symptoms,MRI features,results of laboratory tests and clinical prognosis of 14 MOGAD patients who were hospitalized in our hospital from June 2016 to June 2022 were collected and retrospectively analyzed.Their clinical and imaging characteristics were summarized and discussed.Results Among the 14 enrolled patients,there were 10 males and 4 females,with a male to female ratio of 2.5∶1.Their age of first onset was＜18 years in 3 cases,18～45 years in 8 cases,and＞45 years in 3 cases.Optic neuritis(10/14,71.43％)was the most common clinical type,followed by encephalitis or meningoencephalitis(9/14,64.29％),brainstem encephalitis(5/14,35.71％)and myelitis(5/14,35.71％).Visual impairment(10/14,71.43％)was the most common clinical symptom,followed by headache in 8 cases(8/14,57.14％),fever in 6 cases(6/14,42.86％),dizziness in 6 cases(6/14,42.86％),parethesia in 5 cases(5/14,35.71％),and seizures,limb paralysis,sphincter dysfunction,ataxia,and vomit were all in 4 cases(4/14,28.57％).Four patients(4/14,28.57％)had a history of upper respiratory tract infection before MOGAD onset.There were 10 patients undergoing cerebrospinal fluid(CSF)test,and 8 of them had abnormal results,including 2 patients(2/10,20％)of increased pressure,8 patients(8/10,80％)of larger WBC count in CSF,and 5 patients(5/10,50％)of elevated total protein in CSF.MRI displayed multiple lesion involvement,and there were 7 cases(7/14,50.00％)in cortical/subcortical white matter,6 cases in brainstem(6/14,42.86％),5 cases in optic nerve(5/14,35.71％),4 cases in spinal cord(4/14,28.57％).The hippocampus,thalamus,basal ganglia,and paraventricular white matter were involved in 3 cases(3/14,21.43％),respectively,and the cerebellum and corpus callosum were in 2 cases(2/14,14.29％),respectively.MRI lesions demonstrated patchy hyperintensity on T2 WI and T2 FLAIR,with patchy,nodular and linear enhancement.Among the 10 patients undergoing visual evoked potential(VEP)test,abnormalities were detected in 9 cases(9/10,90％),and 8(8/10,80％)had bilateral visual pathway abnormalities.Eight patients(8/14,57.14％)experienced relapse and remission course.Both methylprednisolone pulse therapy and immunoglobulin modulation therapy were effective in the acute phase.Five patients with relapsed remission presented a significant reduction in recurrence after immunosuppressants.Conclusion MOGAD is manifested with various clinical features,with vision loss,headache,fever and dizziness more common.MRI lesions of MOGAD involve cerebral cortex,subcortical white matter,brainstem,and optic nerve,etc.Patchy hyperintesive signals are observed on T2WI and T2 FLAIR,and some lesions can be enhanced.Corticosteroid pulse therapy and immunoglobulin therapy show effective treatment in the acute phase,and immunosuppressants in the remission phase can reduce relapse.