1、Infections of the Central Nervous SystemPathogen all kinds of pathogens,such as virus,bacteria,Rickettsia,Spirochaeta,parasite,prion protein,etc.Category Encephalitis:brain parenchyma Meningitis:meninges Meningoencephalitis Hematogenous disemination Neuronal spread of the virus Direct infectionHerpe
2、s simplex virus encephalitisHSE The most common type viral encephalitis.Etiology and Pathogenisis HSV-I:90%(70%)trigeminal ganglia HSV(DNA)HSV-II:neunatal Pathology An acute necrotic,asymmetric hemorrhagic process with lymphotic and plasma cell reaction.Usually involves the medial temporal and infer
3、ior frontal lobe.Clinical manifestaion Prodromal infection:fever,headache,muscle pain,diarrhea.Acute onset.last for several days 1 or 2 months unacceptably high mortality(2030%with acyclovir)1 focal or generalized seizure2 behavioral disorders;cognitive function impaired,memory loss3 hemiparesis,aph
4、asia,ataxia,ophthalmoplegia,stiff neck,etc.4disorder of consciousness.somnolent coma5 intracranial pressure deathLaboratory findings CT,MRI:MRI:the most sensitive method of detecting early lesions focal oedema in the medial region of the temporal and orbital surface of the frontal lobes.Meningeal an
5、d gyral enhancement,CT usually shows reduced attenuation in one or both frontal or temporal lobes and sometimes small haemorrhages and with midline shift.Laboratory findings EEG:slow-wave,from one or two temporal or frontal lobes.CSF:BiopsyPressure:normal or increasedcell:lymphocyte and monocyte inc
6、reased,RBC.protein:increased mildglucose and CL-:normalpathogen:antigen,antibody,DNA.Diagnosis The diagnosis of HSE is usually established from the combination of the clinical and investigative features.definitive diagnosis:find hsv in brain or CSF by all methods.Differential Diagnosis Varicella-zoster encephalitis cytomegalovirus encephalitis gastrointestinal viral encephalitis ADEMTreatment Antiviral therapy:Acyclovir 1530mg/kg.d 1421 days Ganciclovir immune therapy symptomatic therapyHigh feverseizurehigh intracranial pressureinfections
