外科学课件：颅内压增高和脑疝

1、颅内压增高和脑疝Intracranial Hypertension,Intracranial Pressure，ICP,定义Definition 颅腔内容物对颅腔壁所产生的压力 侧卧位腰穿脑脊液压为代表 正常颅内压 80-180mmH2O 50-100mmH2O(儿童) 高颅内压持续 200mmH2O,病因和发病机理Etiology and Mechanism,颅腔容积intracranial volume 14001500ml 颅腔内容物components 脑组织 brain 11501350cm3 颅内血容量blood 2%-11% 脑脊液 c.s.f 10%,病因和发病机理Etiolo

2、gy and Mechanism,脑体积增加 ：脑水肿 ，弥漫性/局限性， 血管源性/细胞毒性 颅内血容量增加 ： 缺氧 ，CO2蓄积 ， 脑血管扩张 颅内脑脊液增加：分泌过多，吸收障碍，循环障碍 颅内占位性病变：肿瘤，血肿，脓肿等,正常脑室,脑室扩大,丘脑松果体区肿瘤并积水,左侧额颞肿瘤,右侧颞叶肿瘤,右侧颞叶肿瘤、转移瘤,外伤硬模外血肿,颅内压增高的病理生理Pathophysiology,脑脊液的调节：CSF挤入椎管，CSF吸收加快，CSF分泌减少10% 脑血流量的调节： 脑灌注压(CPP) 脑血流量(CBF)=- 脑血管阻力(CVR) CPP=平均动脉压(mAP)-颅内压(ICP),颅内

3、压增高分期和临床表现Clinical manifestation,代偿期：时间长短取决病变性质、部位和发展的速度 早期：脑轻度缺氧，头痛呕吐，解除病因预后良好 高峰期：脑重度缺氧，“三主症”，自动调节丧失，脑干功能衰竭 衰竭期：脑疝发生，脑无灌注，脑细胞活动停止,颅内压增高的诊断Diagnosis,病史和临床表现：History and clinical manifestation 辅助检查：Accessorytest X-ray，腰穿，颅内压监护 特别： CT，MRI，DSA,颅内压增高的治疗Treatment,病因治疗：最根本和最有效的治疗 Specific treatment 对症治疗：

4、降低颅内压 Nonspecific treatment 脱水限制入量，渗透性脱水，利尿性脱水 激素 冬眠 过度换气 手术,脑 疝 BRAIN HERNIATION,脑疝的机理Mechanism of herniation,高压区的脑组织 相邻的孔隙 低压区 压迫重要结构/生命中 枢 死亡 Brain creeping out of adjacent foramina displaced along the brain the least resistant Toward the tentorial incision or great occipital foramen Compress bra

5、in stem around nerve ,vessels To death,脑疝的分类,按部位及疝出内容 小脑幕切迹疝 (颞叶钩回疝) Transtentorial herniation 枕骨大孔疝 (小脑扁桃体疝) Tonsillar herniation 大脑镰下疝 (扣带回疝) Inferior cerebral falx herniation 小脑幕上疝 (小脑蚓疝),Transtentorial herniation,Supratentorial mass making pressure difference cerebral tissue(temporal lobe uncus/

6、hippocampal)displacementtentorial incisurecompressionupper brain stem(midbrain) ,around cranial nerve (oculomotor),artery(posterior cerebral a.),小脑幕切迹疝Transtentorial Herniation,病理生理变化 动眼神经损害 脑干受压变化 脑脊液循环障碍 疝出组织变化 枕叶梗死,Clinical Manifestation,Severe headache and vomiting Disturbance of consciousness (

7、compressed reticular formation of midbrain) Ipsilateral platycoria (compressed oculomotor nerve) Contralateral palsy (compressed pyramidal system) Change in vital sign (BP,heart rate,respiration),小脑幕切迹疝的临床表现clinical manifestation,颅内压增高症状加剧 意识障碍 瞳孔变化 锥体束征 生命体征改变,小脑幕切迹疝的治疗Treatment,早期明确诊断，病因处理 具体： 维持呼

8、吸道的通畅 甘露醇的应用 病因处理-手术或姑息手术 脑室穿刺,枕骨大孔疝Transforamen Magna Herniation,病理生理 延髓受压 脑脊液循环障碍 疝出组织的变化,Tonsillar Herniation,Posterior fossa space-occupying lesions tonsil of cerebellum displacement great occipital foramen compression medulla oblongata ,around cervical spinal nerves Respiration center in medull

9、a oblongata,枕骨大孔疝的临床表现,枕下疼痛、项强或强迫头位 颅内压增高症状加剧 后组颅神经受累 生命体征改变,Clinical manifestation,Respiratory changes Compressed respiration center Neck rigidity Compressed and pulled cervical spinal nerves Other vital sign changes Later stage mydriasis,apnea,Treatment of Herniation,Diagnosis clear and definite O

10、smotic diuretics mannitol Ventricular puncture ,v-p shunt Operation removal mass,枕骨大孔疝的处理,早期明确诊断、病因处理,Treatment of Herniation,Diagnosis clear and definite Osmotic diuretics mannitol Ventricular puncture ,v-p shunt Operation removal mass,枕骨大孔疝与小脑幕切迹疝临床表现的比较,生命体征变化较早 瞳孔变化、意识障碍出现晚,本次课的思考题,颅内压增高的常见病因? 颅内压