1. CENTRAL NERVOUS SYSTEM PATHOLOGY

2. CONGENITAL ANOMALIES OF CNS

3. Anencephaly:
Basically a complete absence of the cerebral hemispheres.

4. Anencephaly

5. Encephalocele and Cranial Meningocele:
Consists of a protrusion of brain or meninges through a cranial defect.
Most frequent in the occipital region.

6. Cranial Meningocele

7. Spinal Meningeocele
Meningeocele consists of herniation of both dura and arachnoid ( layer containing the blood vessels) through a vertebral defect, with the spinal cord remaining in its normal position.

8. Spinal Meningeocele

9. Hydrocephalus Definition:
This is a chronic accumulation of CSF inside the ventricular system leading to its dilatation and consequently atrophy of the brain tissue

10. Hydrocephus

12. Increased CSF production: due to choroids plexus papilloma
Etiology:
Increased CSF production: due to choroids plexus papilloma
Obstruction of CSF flow: due to:
Congenital causes (non-communicating type of obstructive hydrocephalus due to congenital narrowing of ventricular foramina or aqueduct
Acquired causes:
Meningitis
Brain tumor or brain abscess

13. 3. Decreased CSF absorption due to:
Congenital causes: congenital aplasia of the arachnoid villi (lining the ventricles)
Acquired causes: damage of archnoid villi in case of meningitis
Thrombosis of superior sagittal sinus

14. Pathology: There is ventricular dilatation with excess CSF
In infants, hydrocephalus leads to enlargement of the head due to separation of skull sutures
In adults, hydrocephalus leads to increased intracranial tension which may lead → brain herniation → death

15. A hydrocephalus MRI scan and a normal MRI scan

16. Cerbro-vascular disease of CNS

17. Cerebral ischemia
Cerebral infarction
Cerebral hemorrhage

18. Cerebral ischemia: Definition: Decrease in blood flow to the brain
Etiology: shock,
hypotension,
cardiac arrest
Types:
Generalised cerebral ischemia: usually causes irreversible damage of brain tissue
Transient ischemic attack: usually there is reversible symptoms

19. Cerebral infarction: Etiology:
Thrombotic occlusion: due to atherosclerosis and it leads to anemic white infarction
Embolic occlusion: due to thrombo-emboli from cardiac chambers and it leads to hemorrhagic infarction
Small vessel diseases: related to hypertension and arteriosclerosis, it leads to lacunar infarction i.e. lacunae (multiple small infarctions)

21. EMBOLIZATION OF CEREBRAL ARTEY

22. Acute infarction of brain
Lacunar infarction
Intermediate infarction
Old infarction

23. Cerebral hemorrhage: Classified as: Intracerberal hemorrhage
Epidural hemorrhage
Subdural hemorrhage
Subarchnoid hemorrhage

24. Intracerberal hemorrhage (intraparenchymal)
Hypertension is the most frequent predisposing condition.
Other causes as:
vascular malformation especially arteriovenous malformations, cerebral angiopathy, neoplasms, vasculatides, abnormal hemostasis, hematological malignancies and infections

25. Vascular malformations

26. Clinically: Severe headache
Frequent nausea and vomiting and progression of symptoms to coma

27. Intracerberal haemorrhage (intra parenchymal)

28. Epidural hemorrhage Always traumatic
Usually associated with skull fracture
Tear of dural arteries most frequently occurs in the middle meningeal artery
Usually leads to cerebral herniation
Lucid interval before loss of consciousness (short loss of consciousness then patient is well then coma)

29. Epidural hemorrhage

30. Sub-dural hemorrhage Usually traumatic in old age Slow haemorrhage
Gradual symptoms
Caused by rupture of bridging veins (from cerebral to sagittal sinuses)
Predisposing conditions: brain atrophy and abnormal haemostasis
Clinically:
Headache, drowsiness, focal neurological deficits and sometimes dementia

31. Sub-dural hemorrhage

32. Subarachnoid hemorrhage
Most frequent cause is ruptured berry aneurysms as well as trauma, abnormal haemostasis (blood diseases) and tumours
Clinically:
There is sudden thunderclap headache, nuchal rigidity, neurological deficits on one side and stupor

33. Sub arachnoid hemorrhage

34. Diffuse sub-arachnoid haemorrhage

35. BERRY ANEURYSMS Definition:
Thin-walled saccular out-pouchings of blood vessels with thinning of the vessel wall
Most frequent cause of subarchnoid haemorrhage
Most frequent site is the anterior circle of Willis at the branching points

36. BERRY ANEURYSMS

37. Causes of rupture:
1-increased blood pressure
2-trauma
3-spontaneously

38. Complications: Sub arachnoid haemorrhage due to rupture Thrombosis
Pressure on the surrounding structures

39. CNS TRAUMA

40. CNS TRAUMA Trauma of cranial cavity and brain Trauma of spinal cord
Brain Concusion
Brain contusion
Diffuse axonal injury
Trauma of spinal cord
Cerebral herniation
Sub-falcine (cingulated gyrus)
Transtentorial (uncal)
Cerbellar tonsillar

41. A- Trauma of the cranial cavity and brain
Brain concusion:
Change in the momentum of the head (impact against a rigid surface)
Loss of consciousness and reflexes, temporary respiratory arrest and amnesia for the event

43. Brain contusions:
Impact of parts of brain against inner calvarias surfaces
Bruising of the brain resulting from tissue and vessels disruption
Site of injury: crests of orbital gyri in frontal and temporal poles

45. Pathology: Clinically:
Coup: (site of injury) and countercoup: site diametrically opposite
Coup and countercoup develop when the head is mobile
Clinically:
Acute: hemorrhage of brain tissue in a wedge- shaped area
Subacute: necrosis and liquefaction of brain
Remote: depressed area of cortex with yellow discoloration

47. Coup and countercoup

48. OLD BRAIN CONTUSION

49. Diffuse axonal injury:
Injury to the white matter due to acceleration/ deceleration
Damage to the axons
Usually there is coma after the trauma

51. B- Spinal cord injury
Injuries are usually traumatic, due to vertebral displacement
Lesions of thoracic segment → paraplegia
Lesions to cervical segment → quadriplegia
Lesions above C4 → respiratory arrest due to paralysis of diaphragm

52. C- Cerebral herniation
Sub-falcine (cingulated gyrus)
Cingulated gyrus is displaced underneath the falx to the opposite side
Compression of anterior cerebral artery

53. Sub-falcine herniation

54. Cerebellar tonsillar
Displacement of cerebellar tonsils through the foramen magnum
Compression of medulla → cardiorespiratory arrest

55. DIFFERENT FORMS OF BRAIN HERNIATIONS

56. TO BE CONTINUED………….