中枢神经系统感染2ppt课件

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 worldwide. 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, alcoholism, 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 of: AIDS Excessive alcohol use Pulmonary tuberculosis Weakened immune system Pathogenesis it should not be withheld while awaiting 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 therapy, 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 4-10 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 weeks Corticosteroids are indicated as adjunctive 辅助的 therapy in patients with spinal subarachnoid 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 fungal 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 predictor 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. Pathology 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 cysticercosis result from 1. the mass effect占位效应 of intraparenchymal脑实质 内 cysts 2. obstruction of CSF flow by intraventricular cysts 3. 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 eosinophilia 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 block; 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 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 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 vesicular 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 of 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 treatment Calcified cysts do not require treatment. Albendazole, 阿苯达唑15mg/kg/d in three doses taken with meals, and continued for