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Mechanical Injuries Of Brain and Meniges.

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Presentation on theme: "Mechanical Injuries Of Brain and Meniges."— Presentation transcript:

1 Mechanical Injuries Of Brain and Meniges

2 1๐ Traumatic Lesions 2๐ Alterations

3 1๐ Traumatic Lesions Extracerebral lesions Intracerebral lesions

4 1๐ Traumatic Lesions Close injury Open injury

5 Extracerebral Lesions
Epidural bleeding Subdural bleeding Subaracnoid bleeding Intraventricular bleeding


7 Intracerebral Lesions
Contusions Lacerations (or Wounds)

8 2๐ Alterations Circulatory disorder Necroses and hemorrhages
Post-traumatic hydrocephalus Secondary infections Fat and air embolism


10 Epidural Bleeding


12 Epidural Bleeding Epidural / Extradural Hemorrhage / Hematoma

13 Causes Skull fracture Separation of dura and skull bone
Tear of a dural artery ,its branches and/or occasionally of a vein

14 Most common site: lateral convexity of a cerebral hemisphere
Location: it almost always at the site of a skull fracture

15 Uncommon occur in the elderly
Children: skull deformation with separation of the dura from the bone without skull fracture

16 Acute hematoma: artery bleeding
Delayed hematoma: venous bleeding, transient arterial spasm

17 Progression of the bleeding
Space occupying hematoma Increase intracranial pressure Confusion Alteration of consciousness Pupillary dilatation: on the hematoma side Central respiratory failure

18 If venous bleeding ,or transient arterial spasm: Lucid interval
Consciousness (may be) ,no signs of confusion: occipital poles and/or cerebellum

19 Chronic Epidural Hematoma
The hematoma spontaneously shrinks and becomes encapsulated by fibrous connective tissue.

20 Subdural Bleeding


22 Subdural bleeding Trauma Rupture of aneurysm
Arteriovenous malformation

23 Vein: - Tearing of one or - Several bridging vein
- Insignificant trauma (sometime): abnormally located blood vessels

24 Artery: - particularly in branches of the middle cerebral artery
- severe cortical contusions and bleeding into subarachnoid space: (usually) tears of arachnoid membrane

25 Artery: - More frequently on the side opposite the impact - (May) without brain contusions or significant subarachnoid hemorrhage

26 Time of onset Acute: within 12 to 24 hr. Subacute: from 24 hr. to 7 d.
Chronic: more than 7 d.

27 Most Location: over the convexities and the lateral aspects of the cerebral hemisphere
Often: extend over the base of frontal and temporal lobes Occasionally: between the hemisphere

28 In skull intact: occur as often as with skull fracture
Rare in the posterior cranial fossa , around the brain stem and cerebellum

29 Chronic Subdural Hematoma
Enlargement if untreat Isotonicity Local presence of fibrinolytic enzymes: bleeding tendency

30 Subaracnoid Bleeding


32 Subaracnoid bleeding Trauma / Nontrauma
Extension of intraventricular hemorrhage

33 Moderately severe blow to the face or forehead
Sudden ,usually severe hyperextension of the head , as from a fall onto the forehead

34 Subarachnoid over the brain stem and basal cisterns = hydrocephalus
Forgetfulness , confusion , psychotic state Spasticity of the lower extremities

35 Intraventricular bleeding

36 Intraventricular bleeding
Most often arterial in origin Trauma Non-trauma: such as rupture AVM or Aneurysms

37 Intracerebral Lesions

38 Contusions Lacerations (Wounds)

39 Contusions Contusion hemorrhage Contusion necrosis Contusion tear

40 Intracerebral Hematoma
In the deeper portions of contusions More frequent in the frontal and /or temporal lobes Location: white matter > grey matter

41 Intracerebral Hematoma
Secondary rupture into the ventricular system and/or the subarachnoid space usually does not occur.

42 Lacerations Stab wounds Gunshot wounds

43 Gunshot wounds Shearing forces within brain tissue
Expansile cavitation Distant contusions (hemorrhages)



46 Contusions According to causative mechanism
Classification of Contusions According to causative mechanism

47 Depending on site and direction of impact
: Coup , Intermediary coup , Contrecoup Independent of site and direction of impact : Fracture contusion , Gliding contusion , Herniation contusion





52 Axonal injury Shearing forces due to blunt head injuries
Focal , diffuse Early ,the areas: little or no change on gross examination of the white matter Older lesions: slightly gray pallor

53 2๐ Alterations

54 2๐ Alterations Circulatory disorder Necroses and hemorrhages
Post-traumatic hydrocephalus Secondary infections Fat and air embolism

55 Circulatory disorder Swelling of the brain: edema and cell necrosis
Usually reversible Perifocal: surrounding a 1๐ brain lesion Generalize: a primary lesion , shock

56 Other rare causes Obstruction of the superior sagittal sinus
Traumatic thrombus or obstruction in internal carotid artery

57 Necroses/Hemorrhages
Vascular compression Shearing lesions

58 Necroses/Hemorrhages
Many lesion are large: such as midbrain and pons If rapidly progressing space occupying lesion: secondary lesion may appear within 30 mins. After injury Hemorrhage : sometimes small or absent

59 Hydrocephalus Traumatic or Non-traumatic cause
White matter loss following a shearing lesion and degeneration of myelinated axons Distension of ventricles by elevated pressure of the CSF

60 Secondary infections Meningitis Intracerebral abscesses

61 Meningitis An infected open injury caused by a foreign body
A fracture in the wall of one of the cranial sinuses associated with a tear in the dura and arachnoid

62 Intracerebral abscesses
In the vicinity of the primary lesion Complication: rupture into the underlying ventricle (Pyocephalus)

63 Fat and air embolism Primary or Secondary lesions
Fat embolism: fractures , stab wound at neck Air embolism: stab wound at neck , a skull fracture lacerating a paranasal dural sinus

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