Imaging Characteristics And Comparative Study Of MOGAD And AQP4-IgG-positive NMOSD Patients

Objective:The imaging features of myelin-oligodendrocyte glycoprotein antibody-associated disease(MOGAD)encephalitis and myelitis were analyzed to determine their imaging characteristics and to assess the differences in brain and spinal cord MRI features between MOGAD and autoantibodies to aquaporin 4-IgG(AQP4-IgG)-positive neuromyelitis optic spectrum disorder(NMOSD)to provide a magnetic resonance imaging(MRI)basis for confirming the diagnosis of MOGAD as early as possible.Methods:The study included 51 patients with MOGAD and 96 patients with AQP4-IgG-positive NMOSD(hereinafter referred to as NMOSD),and collected basic clinical information on admission and MRI sequences of head and spinal cord during the acute phase of disease onset or recurrence,including T1-weighted imaging and gadolinium enhancement,T2-weighted imaging,flair,DWI and ADC.Lesions were classified according to the site of lesion involvement as cortical marginal flair high signal,supratentorial lesions(cortical and paracortical white matter,semi-oval center and corona radiata,corpus callosum,internal capsule,deep gray matter),and infratentorial lesions(midbrain,pons,medulla oblongata,cerebellum).The involvement of any site in any patient was counted once,and then the frequency of involvement was calculated for each site,and the site with the highest frequency was considered to be the most specific.The spinal cord was divided into long segmental lesions,short segmental lesions and long combined short segmental lesions according to the number of segments involved,and their frequency was recorded.In addition,comparing MOGAD patients with AQP4-IgG-positive NMOSD in both groups.The P-value was calculated by chi-square test and Fisher exact test of two independent samples to clarify the difference between the two diseases and their lesions,and P≤0.05 was considered statistically significant.Results:Retrospective analysis of MRI of the head in 31 patients with MOGAD encephalitis and 8 patients with NMOSD encephalitis with AQP4-IgG and MRI of the spinal cord in 12 patients with MOGAD and 68 patients with NMOSD myelitis.As a routine diagnostic method,serum MOG-IgG was detected by cell-based assays(CBA),serum AQP4-IgG was detected by CBA or enzyme linked immunosorbent assay(ELISA),and all patients were positive for a single antibody.The results suggest that in 31 patients with MOGAD encephalitis,23 patients(74.2%)involved cortical and subcortical white matter,significantly more than in 1 patient(12.5%)with NMOSD encephalitis(P=0.003).No patient with MOGAD encephalitis involved the area postrema of the medulla oblongata and the region near the midbrain aqueduct,which was significantly different from 6 patients(75%)with NMOSD involving the area postrema and 3 patients(37.5%)with NMOSD involving the midbrain conduit(P<0.05).Therefore,cortical and subcortical white matter lesions were suggestive of MOGAD encephalitis,whereas lesions in the area postrema and around the midbrain aqueduct were exclusionary for MOGAD.The frequency of long-segmental lesions combined with short-segmental lesions,short-segmental lesions,and long-segmental lesions in MOGAD myelitis was less variable.Long-segment lesions were more common(54 patients,79.4%),and long-segment lesions combined with short-segment lesions were the least frequent(2 patients,2.9%)in NMOSD myelitis,and there were 4 patients with MOGAD myelitis(33.3%)with both long and short segment lesions,which were significantly different(P=0.002),so long-segment lesions combined with short-segment lesions were more suggestive of MOGAD myelitis.The frequency of intracranial enhancement foci in MOGAD was high in this study(70.6%)and all patients with enhancement foci had intracranial symptoms,so it was considered that enhancement foci in MOGAD encephalitis were associated with symptoms in the acute phase of the disease attack.Unlike previous studies,the frequency of reinforcing foci in MOGAD myelitis was 62.5%,similar to the frequency in NMOSD myelitis(64.6%),with no statistical difference between the two(P=0.906).Conclusion:In this study,we analyzed intracranial and spinal cord lesions in patients with MOGAD encephalitis and myelitis and found a high frequency of enhancement in head and spinal cord MRI enhancement in the acute phase of MOGAD and a short duration of enhancement.The least involved sites are the area postrema of the medulla and the vicinity of the middle cerebral aqueduct.In addition,we found that long segmental lesions combined with short segmental lesions of the spinal cord were more likely to be associated with MOGAD myelitis.These findings may help to further identify and diagnose MOGAD patients while awaiting serological antibody results.