Animal Model Experiment And Clinical Research On Inflammatory Demyelinating Diseases Of Central Nervous System

Background and Purpose Multiple sclerosis(MS) is a common inflammatory demyelinating disease of central nervous system, whose clinical symptoms is repeatly relapse and remitting phase by turns. Demyelinating with relative sparing of axons, associated with a variable degree of inflammation and astrogliosis, is considered the neuropathological hallmark of MS. Disease mechanisma relevant to MS have been studied extensively in experimental autoimmune encephalomyelitis (EAE), which has the same pathology change with MS. By the development of pathological technology, it has become more evident that axonal damage is detected in MS and EAE. And there is a positive correlation between permanent clinical disability and axonal damage. In our study, we established the EAE models and investigated the occurrence of acute axonal damage determined by pathological technology.Methods: Female SJL/J mice immunized with the p139-151 peptide of myelin proteolipid protein(PLP) and bcg vaccine in incomplete Freund's adjuvant developed EAE. These mice were also injected intravenously with Bordetella pertussis bacilli. Mice were weighed and examined daily for neurological signs. Mice were killed when the first neurological attack and their brains and spinal cords were removed. Tissue sections were sliced continuously, which were stained with haematoxylin and eosin (HE), luxol fast blue(LFB), Bodian 's silver stain impregnation. The primary antibodies for immunohistochemical staining were anti-APP, anti-myelin basic protein(MBP) and anti-glial fibrillary acidic protein(GFAP). Results: Seven(23.3%) mice attacked in 15～22days after immunized. Average attack time was 19±2.58days. Average clinical neurological score was 2.14±0.69. The average weight was 21.85±0.94g before immunized and 23.24±1.55g after immunized (no significant difference). There are inflammation cells infiltrate,especially around the small blood vessel to forming cuffing, which found in brain and spinal cord under piamater. The lesions are more common and severity in spinal cord than brain. Demyelinating were found in the lesions with LFB stain, where axon swollen and transection with Bodian's silver stain. APP-positive axons in active demyelinating lesions which MBP-positive and GFAP-negative.Conclusions: The clinical symptoms of SJL/J mice EAE models immunized with the PLP was mild. Whose clinical neurological score were under 3 point by Kono criteria. The typical MS lesions didn't found in the brains but in the spinal cords. Axonal damage begins at disease onset before demyelinating, and not parallel with the clinical symptoms in the early stage. Background and Objective Inflammatory demyelinating diseases of central nervous system occasionally present as a mass lesion that is indistinguishable clinically and radiologically from a brain tumor, while whose histologic examination revealed that the lesion was inflammatory changes as multiple sclerosis or other inflammatory demyelinating diseases.So it was called demyelinating pseudotumors(DPT).It is hard to diagnose DPT with clinical features and neuroimaging findings, because it presented as a mass lesion mimicking brain tumor. Our study summarized the clinical features,neuroimaging findings and pathological characteristics of 35 cases which presented suggestive of brain tumor, and differentiated it from glioma. In order to enhance the cognition of DPT and improve accuracy of diagnose.Methods Summarize the clinical features,neuroimaging findings and pathological characteristics of 35 cases,and 18 of whom have been validated by bioscopy.Results Demyelinating pseudotumors affects adults of both sexes.The onset age of patients ranges from 9 to 69 years. There was no definite antecedent,and the clinical syndromes were atypical. Neuroimaging scans showed multiple lesions in cerebral hemisphere, while in brain stem and spinal cord is single. The symptom and neuroimaging were not parallel. While with many or large lesions, the symptoms and signs were less.The lesions not enhanced on CT scan, but appear ring-like or patch enhance on MRI scan.9 cases with DWI all appeared high density. The myelin basic protein was useful for diagonisis. The typical pathological changes were demyelinating, perivascular inflammatory infiltration and reactive gliosis.The Creutzfeuldt cells were also found in these cases. The lesions may become small or disappear after treatment, but cannot as the criterion to exclude brain neoplasm.Conclusions DPT wais a distinct demyelinating disease entity,which was confusable with brain neoplasm.It was difficult to distinguish DPT from brain neoplasm with the clinical features and conventional neuroimaging scan. But DWI scan was useful. The pathological changes accord with demyelinating, and Creutzfeuldt cells were also found. It was important to apply corticosteroid treatment or biopsy rather than being anxious to excise the lesions.