《中枢神经系统感染-2.ppt》由会员分享，可在线阅读，更多相关《中枢神经系统感染-2.ppt（67页珍藏版）》请在三一办公上搜索。
1、TUBERCULOUS MENINGITIS,结核性脑膜炎,Longnan Hospital Chenjing,Tuberculous meningitis is an infection of the membranes 膜covering the brain and spinal cord(meninges).Tuberculosis(TB)is caused by the bacterium Mycobacterium tuberculosis结核分枝杆菌 and is annually responsible for nearly two million deaths worldwid
2、e.A third of the worlds population is currently infected with the TB bacillus,and more than eight million new cases are diagnosed each year.,Tuberculous meningitis must be considered in patients who present with a confusional state,especially if there is a history of pulmonary tuberculosis,alcoholis
3、m,corticosteroid treatment,HIV infection,or other condition associated with impaired immune responses.,It should also be considered in patients form areas(eg,Asia,Africa)or groups(eg,the homeless and inner-city drug users)with a high incidence of tuberculosis.,Causes,Risk factors include a history o
4、f:AIDS Excessive alcohol use Pulmonary tuberculosis Weakened immune system,Pathogenesis&Pathology发病机制&病理,Tuberculous meningitis usually results from reactivation of latent infection with mycobacterium tuberculosis.结核性脑膜炎多是由于潜伏的结核杆菌复发感染引起的。,Primary infection,typically acquired by inhaling bacillus co
5、ntaining droplets,may be associated with metastatic dissemination of blood-borne bacilli from the lungs to the meninges and surface of the brain.Here the organisms remain in a dormant state in tubercles that can rupture into the subarachnoid space at a later time,resulting in tuberculous meningitis.
6、,原发性感染，尤其是通过吸入含菌颗粒引起的感染，可能与血源性细菌从肺部到脑膜及大脑表面的播散有关。此处的致病菌在结核结节中处于休眠状态，后期可破入蛛网膜下腔，并导致结核菌性脑膜炎。,主要发现是含有大量单核细胞的脑基底部脑膜分泌物。脑膜及脑表面可见结核结节。,The main finding is a basal meningeal exudate渗出物containing primarily mononuclear cells.Tubercles may be seen on the meninges and surfaces of the brain.,The ventricle may b
7、e enlarged as a result of hydrocephalus,and their surfaces may show ependymal exudate or granular ependymitis.Arteritis can result in cerebral infarction,and basal inflammation and fibrosis can compress cranial nerves.,脑积水可引起脑室扩大，并且脑室表面可有大量室管膜渗出物或颗粒状室管膜炎。动脉炎可导致脑梗塞，而颅底部炎症反应和纤维化可压迫神经。,Acute tuberculou
8、s meningitis with marked involvement of the vessel walls and occlusion of smaller vessels.The vascular involvement can result in infarction.,Clinical Findings,A.SYMPTOMSSymptoms have usually been present for less than 4 weeks at the time of presentation and include fever,lethargy昏睡 or confusion,and
9、headache.Weight loss,vomiting,neck stiffness,visual impairment,diplopia 复视,focal weakness,and seizures may also occur.A history of contact with known cases of tuberculosis is usually absent.,B.SIGNS,Fever,signs of meningeal irritation脑膜刺激征,and a confusional state are the most common findings on phys
10、ical examination,but all may be absent.Papilledema视乳头水肿,ocular palsies眼肌麻痹,and hemiparesis轻偏瘫 are sometimes seen.,Complications include spinal subarachnoid block脊髓蛛网膜下腔梗阻,hydrocephalus脑积水,brain edema脑水肿,cranial never palsies颅神经麻痹,and stroke caused by vasculitis or compression of blood vessels at the
11、 base of the brain因血管炎或颅底血管受压导致的卒中.,结核球,stroke,hydrocephalus,Laboratory Findings,Only one-half to two-third of patients show a positive skin test for tuberculosis or evidence of active or healed tubercular infection on chest x-ray.,CSF,The diagnosis is established by CSF analysis.CSF pressure is usu
12、ally increased,and the fluid is typically clear and colorless but may form a clot upon standing.Lymphocytic and mononuclear cell pleocytosis of 50-500 cells/mL is most often seen,but polymorphonuclear 多形核细胞pleocytosis can occur early and may give an erroneous impression of bacterial meningitis.CSF p
13、rotein is usually more than 100 mg/dL,particularly in patients with spinal subarachnoid block.The glucose level is usually decreased and may be less than 20 mg/dL.,Acid-fast smears抗酸染色涂片 of CSF should be performed in all cases of suspected tuberculous meningitis,but they are positive in only a minor
14、ity of cases.,Definitive diagnosis is most often made by culturing M tuberculosis from the CSF,a process that usually takes several weeks and requires large quantities of spinal fluid for maximum yield.,The polymerase chain reaction(PCR)聚合酶链反应 has also been used for diagnosis.,Finally,the CT scan ma
15、y show contrast enhancement of the basal cisterns and cortical meninges,or hydrocephalus.,MRI appearance of the typical pattern of central nervous system tuberculous meningitis,Differential Diagnosis,Many other conditions can a subacute confusional state with mononuclear cell单核细胞 pleocytosis 脑脊液细胞增多
16、,including syphilitic 梅毒的,fungal,neoplastic 肿瘤的,and partially treated bacterial meningitis.These can be diagnosed by appropriate smears 涂片,cultures,and serologic 血清学的 and cytologic examinations 细胞学检查.,Treatment,Treatment should be started as early as possible;it should not be withheld while awaiting
17、 culture results.The decision to treat is based on the CSF findings described above;lymphocytic pleocytosis and decreased glucose are particularly suggestive,even if acid-fast smears are negative.,综合治疗：药物治疗、全身支持、并发症的预防、耐药与多耐药TB菌感染的治疗、对症治疗。药物治疗原则：早期、联合、足量、长期、顿服,DRUGS,Four drugs are used for initial t
18、herapy,until culture and susceptibility test results are known.四联治疗isoniazid,异烟肼 300mg;rifampin,利福平 600mg;pyrazinamide,吡嗪酰胺 25mg/kg;ethambutol,乙胺丁醇 15mg/kg,each given orally once daily.,For susceptible strains,ethambutol乙胺丁醇can be discontinued,and triple therapy continued for 2 months,followed by 4-
19、10 months of treatment with isoniazid异烟肼and rifampin利福平alone.Pyridoxine,维生素B6 50mg/d,can be used to decrease the likelihood可能性of isoniazid-induced polyneuropathy.,Side effect of drugs,Complications of therapy include：hepatic 肝脏的dysfunction(isoniazid异烟肼,rifampin利福平,and pyrazinamide吡嗪酰胺)polyneuropathy
20、多神经炎(isoniazid)optic neuritis(ethambutol乙胺丁醇)seizures(isoniazid)ototoxicity 耳毒性(streptomycin链霉素),Corticosteroids,Prednisone 泼尼松60mg/d orally in adults or 1-3 mg/kg/d orally in children,tapered gradually over 3-4 weeksCorticosteroids are indicated as adjunctive 辅助的therapy in patients with spinal suba
21、rachnoid block.They may also be indicated in seriously ill patients with focal neurologic signs or with increased intracranial pressure from cerebral edema.,The risk of using corticosteroids may be high,however especially if tuberculous meningitis has been mistakenly diagnosed in a patient with fung
22、al meningitis.Therefore,if fungal meningitis has not been excluded,antifungal therapy should be added along with corticosteroids.,Prognosis,Even with appropriate treatment,about one-third of patients with tuberculous meningitis succumb死.Coma at the time of presentation is the most significant predic
23、tor of a poor prognosis.,Cerebral Cysticercosis,脑囊虫病,Cysticercosis is common in Mexico,Central and South America,western and southern Africa,India,China,and southeast Asia.,The disease follows ingestion of larvae 幼虫 of the pork tapeworm(taenia solium-猪肉绦虫)and affects the brain in 60-90%of cases.,Pat
24、hology,病理上典型的包囊大小为510mm，可有薄壁，或呈多个囊腔，内有囊尾蚴。囊虫的囊尾蚴囊肿常为圆形或卵圆形，内膜上有一小白色的囊虫结节突起。当虫体死亡或液化时，囊腔内为暗褐色混浊液体，内含大量蛋白质、当虫体液化被吸收后囊腔变小，囊壁增厚，囊虫死后常发生钙化。,Clinical Finding,Larvae undergo hematogenous 血源性dissemination,forming cysts囊肿 in the brain,ventricles脑室,and subarachnoid space.Neurologic manifestations of cysticerc
25、osis result from 1.the mass effect占位效应 of intraparenchymal脑实质内 cysts2.obstruction of CSF flow by intraventricular cysts3.inflammation that cause basilar meningitis.,They include seizures,headache,focal neurologic signs,hydrocephalus脑积水,myelopathy脊髓病,and subacute meningitis.Peripheral blood eosinophi
26、lia 嗜酸性细胞增多症,soft tissue calcifications钙化,or parasites寄生虫 in the stool 粪便suggest the diagnosis.,Laboratory Findings,The CSF typically shows a lymphocytic pleocytosis(100 cells/mL),with eosinophils嗜酸细胞usually present.Opening pressure is often increased but may be decreased with spinal subarachnoid bl
27、ock;if this is suspected myelography椎管造影术should be performed.Protein is increased to 50-100mg/dL,and glucose is 20-50mg/dL in most cases.Complement fixation 补体结合 and hemagglutination红血球凝聚 studies can assist in the diagnosis.,The CT scan or MRI may show contrast-enhanced mass lesions with surrounding
28、 edema,intracerebral calcifications,or ventricular enlargement.,MRI,活动期：T1加权像囊虫呈圆形低信号，头节呈点 状或逗点状高信号，T2加权像囊虫呈圆形高信号，头节呈点状低信号。退变死亡期：T1加权像水肿区低信号内有高信号环或结节，或仅有低信号区；T2加权像水肿区高信号，内有低信号环或结节。非活动期：T1T2加权像上多呈圆形低信号。混杂期：T1T2加权像上均呈混杂密度病灶。,Vesicular囊状的 colloidal胶体的 granular颗粒状的 calcified钙化的,Axial brain MRI.a T1-W,b
29、T2-W,c FLAIR and d contrast-enhanced T1-W sequences.Images reveal innumerable cysts in bilateral basal ganglia(arrows in a and b)and cerebral hemispheres,giving the“starry-sky”pattern.A few lesions demonstrate perifocal oedema and ring-enhancement(arrows in c and d)suggestive of the colloid vesicula
30、r stage,MRI.Sagittal brain T2-W images show cysticerci in the extra-orbital muscles(arrow)(a)and tongue(arrows)(b)as well as in the cranial and cervical muscles.c Sagittal spine T2-W image reveals hyperintense lesions in nearly every paraspinal muscle(arrows),Treatment,The indications of treatment o
31、f cerebral cysticercosis are controversial有争论的.However,patients with symptomatic neurologic involvement(usually seizures)and either meningitis or one or more noncalcified非钙化的intraparenchymal cysts should be treated.Intraventricular,subarachnoid,and racemose cysts respond poorly to treatmentCalcified
32、 cysts do not require treatment.,Albendazole,阿苯达唑15mg/kg/d in three doses taken with meals,and continued for 8 days,is the preferred therapy.Praziquantel,吡喹酮50mg/kg/d in three divided doses,can also be used,but blood levels are reduced by anticonvulsants 抗惊厥药and corticosteroids皮质类固醇,which are often
33、required in these patients.,Patients with seizures should also receive anticonvulsants.Corticosteroids are indicated for increased intracranial pressure or lesions near the cerebral aqueduct中脑导水管or intraventricular foramina室间孔;these may progress to cause obstructive hydrocephalus梗阻性脑积水.Single accessible intraparenchymal 脑实质内lesions can be removed surgically,and shunting分流术 is required for intraventricular lesions causing hydrocephalus.,
