Diseases of the Nervous System

1. Diseases of the Nervous System Kun Mu（牟坤） MD, PhD Department of Pathology School of Medicine, Shandong University

2. Contents • Structure of the NS and basic pathologic changes • Common complications of CNS • Infectious diseases of NS • Neoplasms of NS

3. I. Structure of the CNS and basic pathologic changes Sulci(脑沟) Gyri(脑回) Parietal lobe(顶叶) Occipital lobe(枕叶) Cerebellar peduncles(小脑脚) Fourth ventricle(四脑室) Frontal lobe(额叶) Cerebellum(小脑) Pons(桥脑） Spinal Cord (脊髓)

4. Microscopic structure of theCNS • Neuron（神经元） Cell bodies-- grey matter Cell processes– axons--White matter bundles

5. Staining of neurones in the cerebral cortex

6. Microscopic structure of theCNS • Neuron（神经元） Cell bodies-- grey matter Cell processes– axons--White matter bundles • Glia（胶质细胞） Astrocytes Oligodendrocytes Ependymal cells

7. Staining of astrocyte in the cerebral cortex

8. Glia-oligodendrocytes

9. Ependymal cells

10. Microscopic structure of theCNS • Neuron（神经元） Cell bodies-- grey matter Cell processes– axons--White matter bundles • Glia（胶质细胞） Astrocytes Oligodendrocytes Ependymal cells • Microglia （小胶质细胞） • Meningocyte（脑膜细胞） • Vessel （血管）

11. I. Basic pathology changes of CNS • Neuron • Astrocytes • Oligodendrocytes • Ependymal cells • Microglia

12. 1. Basic pathology changes of the Neuron • Chromatolysis （尼氏体溶解） • Red neuron （红色神经元） • Simple neuronal atrophy（单纯性神经元萎缩） • Cellular inclusion（包含体形成） • Cell Structure protein change（细胞结构蛋白异常） • Waller degeneration（ Waller变性）

13. 1. Basic pathology changes of the Neuron •  1. Chromatolysis （尼氏体溶解） 正常神经细胞 中央型尼氏体溶解

14. 1. Basic pathology changes of the Neuron • 2.Red neuron （红色神经元）---Coagulation necrosis

15. 1. Basic pathology changes of the Neuron • 1. Chromatolysis （尼氏体溶解） • 2. Red neuron （红色神经元） • 3. Simple neuronal atrophy（单纯性神经元萎缩） Common in some chronic degenerative diseases

16. 1. Basic pathology changes of the Neuron • 4. Cellular inclusion（包含体形成） Negri body-rabies（狂犬病）

17. 1. Basic pathology changes of the Neuron • 5. Cell Structure protein change（细胞结构蛋白异常） Neurofibrillary Tangles-AZ Lewy bodies-PD

18. 1. Basic pathology changes of the Neuron • 6. Wallerdegeneration（ Waller变性） • Degeneration • Demyelination（脱髓鞘） • Regeneration Trichrome染色：髓鞘染成红色，胶原纤维染成青色，可见髓鞘缺失、崩解。

19. 2. Basic pathology changes of the astrocytes • 1. Swelling（肿胀） • 2. Reactive astrogliosis（反应性胶质化）

20. 2. Basic pathology changes of the astrocytes • 2. Reactive astrogliosis

21. 2. Basic pathology changes of the astrocytes • 1. Swelling（肿胀） • 2. Reactive astrogliosis（反应性胶质化） • 3. Amyloid body（淀粉样小体)

22. 3. Basic pathology changes of the oligodendrocyte • Satellitosis（卫星现象）

23. 4. Basic pathology changes of the ependymal cell • Ependymal granulation（颗粒状室管膜炎） 正常室管膜细胞 颗粒状室管膜炎

24. 5. Basic pathology changes of the microglia • 1. Neuronophgia（噬神经细胞现象） • 2. Foamy cell(gitter cell)（格子细胞形成） • 3. Microglial nodules（胶质结节）

25. 5. Basic pathology changes of the microglia 噬神经细胞现象neuronophagia 格子细胞 gitter cell

26. 5. Basic pathology changes of the microglia microglial nodules (胶质结节）

27. II.Common Complications of CNS • 1. Brain edema(脑水肿) • 2. Hernia(脑疝) • 3. Hydrocephalus( 脑积水)

28. 1. Brain edema Brain edema (脑水肿) : increased water content within the brain parenchyma Vasogenic edema:A state of increased extracellular fluid volume; Brain tumor, abscess, infarct, hemorrhage Cytotoxic edema:The swelling of cellular elements; Hypoxia, toxication

29. 1. Brain edema

30. 1. Brain edema 脑水肿

31. 2. Herniation Herniation (脑疝形成）: Abnormal protrusion of brain tissue through an opening. Causes : Raised ICP (Intracranial pressure) Intracranial expanding lesions – tumor, haematoma, abscess

32. 2. Herniation Intracranial pressure (ICP) Within the intact skull, there are 3 major components of intracranial pressure: the brain, the CSF and blood. Any increase in volume of one of these 3 components will produce an increase in ICP Normal ICP is 0.6-1.8kPa

33. 2. Herniation-Types Supracallosal hernia（扣带回疝，大脑镰下疝） Tentorial hernia（小脑天幕疝，海马沟回疝） Foramen magnum hernia(枕骨大孔疝，小脑扁桃体疝）

34. 2. Herniation

35. 扣带回疝

36. 海马沟回疝

37. 小脑扁桃体疝

38. 3. Hydrocephalus Hydrocephalus(脑积水) refers to the accumulation of excessive CSF within the ventricular system

39. 3. Hydrocephalus-Types 1. noncommunicating hydrocyphalus (非交通性脑积水) Obstructive hydrocephalus 2. communicating hydrocyphalus(交通性脑积水) Overproduction of CSF Defective absorption of CSF

40. 3. Hydrocephalus-Types Causes: • Increased secration of CSF ：脉络丛肿瘤 • Obstraction to the flow of CSF：肿瘤、粘连性阻塞 • failure of absorption of CSF：蛛网膜粒的闭塞

41. 3. Hydrocephalus-Types Dilated lateral ventricles seen in a coronal section

42. III. Infectious diseases of CNS • Epidemic meningitis • Epidemic Encephalitis B

43. Routes of infection • Hematogenous spread • Direct implantation Trauma, Nasal or paranasal sinuses inflammation • Invasion via the peripheral nerves

44. Structure of menginges

45. Meningitis • Acute suppurative meningitis:bacteria • Acute lymphocytic meningitis:virus • Chronic meningitis:TB

46. 1. Epidemic meningitis • Group A meningococcus accounts for an estimated 80–85% of all cases in the meningitis belt, with epidemics occurring at intervals of 7–14 years. • Suppurative immflamation

47. 1. Epidemic meningitis-Transmission • The bacteria are transmitted from person-to-person through droplets of respiratory or throat secretions from carriers • The bacteria overwhelm the body's defenses allowing infection to spread through the bloodstream to the brain.

48. 1. Epidemic meningitis-Gross • There areabundant creamy, purulent exudate, most prominently over the superior surface of the cerebrum. • The exudation full in sulci. • The gyri are swollen. • The vessels are congested.

49. 1. Epidemic meningitis-Gross

50. 1. Epidemic meningitis-Micro • Neutrophilic exudate, dilated vessels, edema in the subarachnoid space