A Comparative Study On The Clinical,Imaging And Pathological Features Of Primary Angiitis Of The Central Nervous System And Tumefactive Demyelinating Lesions

BacgroundPrimary angiitis of the central nervous system(PACNS)is an inflammatory disease with unknown etiology,and it mainly involves the small blood vessels and pial microvessel wall in central nervous system.Due to lack of specificity clinically and in auxiliary examinations,and especially the mass effect on neuroimaging,the disorder is easily misdiagnosed as tumor like demyelinating lesions(TDLs).TDLs is a special type of inflammatory demyelinating disease of the central nervous system,often involving the cortex and subcortical area.The lesions of TDLs are irregular,and the patients with TDLs often present with headache as the initial symptom,which is difficult to be distinguished from PACNS.In particular,the histopathological results of the two diseases are also affected by the samples from biopsy,and thus,sometimes it is difficult for the differential diagnosis even with pathological study.Because there is not enough research on the clinical,imaging and pathological similarities and differences about two disorders,a further study is needed.ObjectiveTo compare the clinical,imaging and pathological features of PACNS and TDLs in order to provide an important reference for clinical diagnosis.To improve the ability of diagnosis and differential diagnosis of PACNS and TDLs,to reduce the misdiagnosis and missed diagnosis.MethodsThe clinical data of 19 cases with PACNS and 17 cases with TDLs were retrospectively analyzed.All the diagnoses were confirmed by using pathological studies in Navy General HospitalResults1.The demographic data and the characteristics of onset are as follows:the average age of onset of PACNS was 32 ± 13.7 years old,and the average age of onset of TDLs was 39.3 ± 12.8 years old.There was no significant difference between the two groups.13 males and 6 females with PACNS,and 7 males and 10 females with TDLs were included,and no statistical difference was found between the two groups.The mean duration of PACNS was 42.2 ± 70.7W,the average duration of TDLs was 2.7 weeks,and the course of PACNS was obviously longer than that of TDLs,and the difference was statistically significant(P=0.033)between the two groups.More patients with PACNS had chronic onset(P=0.001),and subacute onset were common in TDLs(P=0.010),and the difference is statistical significant.2.The initial symptom and the main clinical symptoms of PACNS and TDLs are as follows:the initial symptoms of PACNS included headache(5 cases),dizziness(4 cases),and epilepsy(3 cases),and the initial symptoms of TDLs included dizziness(4 cases),headache(3 cases),and limb weakness(3 cases).There was no statistical difference between the two groups.The main clinical manifestations of PACNS were headache(52.6%,10/19),limb weakness(47.3%,9/19),seizures(31.5%,6/19)and cognitive impairment(21.1%,4/19),dizziness(21.1%,4/19)and sensory disorders(21.1%,4/19),visual decline(15.8%,3/19)and hydroposia in(10.5%,2/19),aphasia(5.2%,1/19),5.2%(1/19),disturbance of consciousness(5.2%,1/19),central tongue paralysis(5.2%,1/19),exophthalmos(5.2%,1/19).The major clinical manifestations of TDLs were limb weakness(29.4%,5/17),dizziness(23.5%,4/17),central surface tongue paralysis(17.6%,3/17),headache(17.6%,3/17),cognitive decline(17.6%,3/17),sensory disturbance(17.6%,3/17),visual decline by(17.6%,3/17),seizures(5.9%,1/17),aphasia(5.9%,1/17),dysarthria(5.9%,1/17).the difference was statistically significant(P=0.041)between the two groups on the headache.3.Comparison of the features of PACNS and TDLs on imaging:(1)63.2%of the lesions of PACNS and 29.4%of the lesions of TDLs in cortical or subcortical area.Statistically difference was found between the two groups(P=0.041).The brainstem involvement accounted for 15.8%of the patients with PACNS and 52.9%of patients with TDLs,and the difference between the two groups was statistically significant(P=0.033).Temporal lobe involvement occurred in 42.1%of the patients with PACNS,5.9%of the patients with TDLs,and there was difference between the two groups(P=0.020);parietal lobe involvement happened in 47.4%of the patients PACNS and 11.8%of the patients with TDLs,and there was difference(P=0.017);occipital lobe was involved in 26.3%of the patients with PACNS,and no patients with TDLs,and there were differences(P=0.017).There was no statistical differences between the two groups for the involvement of the lateral ventricle,thalamus,basal ganglia area,centrum ovale,corpus callosum and cerebellum.(2)The average number of PACNS were 2 ±1,and TDLs was 5±4,and no significant difference was identified.PACNS with multiple lesions occurred in 16 cases,single lesion in 3 cases.11 cases with TDLs had multiple lesions and 6 cases had single lesion,no significant difference.15 cases with PACNS had supratentorial lesions,only 2 cases had subtentorial lesions,and 2 cases had both.9 cases with TDLs had supratentorial lesions,6 case had subtentorial lesions,and 2 cases had both.(3)12 patients with PACNS showed short T1 signals,and the corresponding area showed short T2 signals.No short T1 and short T2 signals were detected in TDLs.The difference was statistically significant(P=0.000);all the lesions of PACNS were uneven on T1WI andT2WI,all TDLs are not homogeneous lesions,there was significant difference(P=0.000);both PACNS and TDLs lesions showed high signal.on T2FLAIR.(4)68.4%of the patients with PACNS patients showed the the lesions with central low signals surrounded by high signals,and no lesions of TDLs presented this way,and there was significant difference(P=0.000);15.8%of the PACNS lesions showed uneven high signal,and 10.5%showed low signal lesions,within which hyperintense signals were dotted,and 5.2%PACNS lesions showed low signal,and no case of TDLs showed the pattern,but no significant difference was found.17 cases of TDLs showed uniform high or slightly high signal on DWI,and no PACNS showed this pattern of signals,and the statistical difference was significant(P=0.000).(5)there was 15 of the 19 cases with PACNS showed irregular,discontinuous,inhomogeneous enhancement,some of which can be manifested as irregular luminal shaped enhancement and irregular uneven diffused enhancement,irregular discontinuous and inhomogeneous wall thickness enhancement;1 cases showed nodular enhancement,1 cases showed patchy enhancement,1 cases of meningeal like enhancement,1 cases of milliary enhancement.Patients with TDLs showed diverse pattern of enhancement,including 4 cases with comb sign enhancement,4 cases with patchy enhancement,3 cases with C shaped enhancement,2 cases with ring shaped enhancement,1 cases of linear enhancement,1 cases of dot shaped enhancement,1 cases of patchy shaped enhancement.(6)The degree of edema:for PACNS,no edema in 3 cases,mild edema in 8 cases,moderate in 7 cases,severe in 1 cases;for TDLs,there was 6 cases no edema,mild in 10 cases,moderate in 5 cases,severe in 0 cases,mass effect:for PACNS,no mass effect in 6 cases,mild in 7 cases,moderate in 4 cases,significant in 2 cases;for TDLs,no mass effect in 4 cases,mild in 9 cases,moderate in 3 cases,severe in 2 cases.There was no statistical difference.(7)3 patients with PACNS were examined by using SWI,and all of them had low signals indicating remote hemorrhage.3 cases of TDLs were examined with SWI,and no signal of bleeds was observed.MRS examination was done in 3 cases of PACNS and 10 cases of TDLs,the results showed that Ch0/Cr,Cho/NAA,as well as lipid and lactate peaks were elevated,and there was no specificity.4.Comparison of PACNS and TDLs in pathology:1 case of granulomatous PACNS(5.2%),zero with TDLs,there was no significant difference.there are lymphocyte infiltration in 13 cases(68.4%),6 cases with TDLs,there was no significant difference.fibrinoid necrotic type in 5 cases(26.3%)of PACNS,there no one cases in TDLs,The difference was statistically significant(P=0.047);vascular wall inflammatory infiltration:13 cases(68.4%)with PACNS,1 cases with TDLs(5.9%),there was significant difference(P=0.002).there are 2(10.5%)cases of PACNS and 17(100%)cases TDLs was amyelinationed,there was significant difference(P=0.000).There were no differences in nonspecific inflammation,necrosis,axonal staining,immunohistochemistry(CD3,CD20,CD68,LCA,GFAP)between the two disorder groups.Conclusion1.The onset of PACNS was more common in chronic onset,and TDLs was common in subacute onset;PACNS treatment course longer than TDLs.2.PACNS headache is more common than TDLs.3.PACNS and TDLs is significantly different in neuroimaging:(1)PACNS is located in cortical and subcortical area,and temporal,parietal,and occipital lobes are often involved,brain stem is often involved in TDLs;(2)The center of lesion showed short T1 and short T2 signal is characteristic forPACNS,and this is not the case for TDLs;(3)PACNS patients with DWI lesions surrounding low signal and high signal based,TDLs showed homogeneous high signal;(4)the PACNS was not uniform,TDLs was relatively uniform;(5)the PACNS with irregular,discontinuous reinforcement are the main features,TDLs with continuous reinforcement(comb sign,shape C,patchy,ring enhancement etc.)(6)PACNS and TDLs were mainly mild to moderate edema and mild mass effect;4.There are distinguish betweenc and TDLs:(1)there are three types in PACNS is mainly granulomatous,lymphocyte infiltration,fibrinoid necrotic type,which TDLs o:ften have one type is lymphocyte infiltration.(2)the PACNS in vascular wall inflammatory cell infiltration as its main characteristic;TDLs is relatively mainly characterized by perivascular infiltration of lymphocytes;(3)when PACNS have the little myelinoclasis,TDLs is mainly for myelinoclasis.