contre coup injury,Concussion,DAI, EDH- forensic aspects

forensic medicine, regional injuries, head

1. Regional injuries - head concussion, DAI, EDH Dr m balaji singh Courtesy; Dr Gautam Biswas, Dr Krishen Vij KNIGHT’S FORENSIC PATHOLOGY

2. Topics to be discussed Classification of head & brain injuries Scalp injuries Coup and contre coup injuries Concussion Diffuse axonal injury Extra dural hemorrhage

3. Severity of brain injury

4. SCALP - layers S - skin C - connective tissue A - galea aponeurotica L - loose areolar tissue P - peri osteum

5. Layers of coverings of brain galea aponeurotica periosteum Loose areolar tissue

6. Scalp injuries Scalp abrasion Scalp laceration, avulsion Scalp contusion Scalp incised wound (1) Bruising of scalp is better detected by touch than by sight . (2) Multiple contusions of the scalp may fuse together, and often it is difficult to determine the number of blows inflicted. (3) wound by blunt weapon on scalp resembles an incised wound- incised like laceration (split laceration)

7. Scalp contusion Blood collection superficial to the galea aponeurotica – is localized collection Bleeding underneath the galea aponeurotica – spreads over peri osteum of cranium

8. Scalp contusion- stripping the scalp layers in the plane of loose areolar tissue- contusion is superficial to galea aponeurotica .

9. Scalp injuries Scalp laceration -bleed profusely, and dangerous. - fatal blood loss may possible. -avulsion of a large area of scalp – in factory accidental trap of scalp hair and in RTA

10. Scalp injuries Incised like Scalp laceration -Hit by blunt and hard object ( metal rod) will crush the scalp against the underlying skull, -This will split the skin and underlying tissues in a sharply demarcated fashion, -which may appear remarkably like a slash from a sharp instrument.

11. Scalp injuries Scalp incised wound- cut by sharp weapon -Less painful than laceration.

12. Complication of scalp injuries - Emissary veins Dural venous sinuses are communicating with scalp through emissary veins -Infection port to brain from scalp

13. Coup and contre coup frontal lobes are commonly involved in contre coup injuries – in fall on occipital lobes- due to irregular base of anterior cranial fossa

14. Contre coup injuries (1) Coup (blow/ impact) injury: means that the injury is located under the area of impact . (2 ) Contrecoup means that the lesion is present in an area opposite the side of impact .

15. Contre coup injuries….. (3) due to local distortion of the skull and sudden rotation of the head, which causes shear strains due to pulling apart of constituent particles of the brain . (4) A certain amount of shear may occur below the point of impact, particularly if the skull is fractured, which causes coup .

16. Contre coup injuries Fontal lobe contusions and sub dural hemorrhages at the base, as a result of contre coup injury due to fall on the back of the head.

17. Head rotational injury- contre coup

18. Contre coup injury Mechanism (French - coup : blow , contre : opposite ,) means that the lesion is present in the brain opposite to the site of impact. It is caused when the moving head is suddenly decelerated by hitting a firm surface , e.g. striking of the head on the ground during a fall, and in road traffic accidents . when a person falls with his occiput striking the ground, he may sustain injury at the occipital lobes (coup injury) and a more prominent injury to the frontal lobes (contre coup injury )

19. Mechanism- theories Skull deformation/Struck hoop theory - When head strikes the ground, a transient deformation of the skull occurs with increase in pressure which may impinge on the underlying brain causing compression— coup injury „ - Simultaneously , opposite area of the skull will bulge outward to accommodate the deformation—the so-called ‘ struck-hoop ’ action . Stuck hoop theory –in younger age- skull in more elastic

20. Contre coup mechanism rarefaction= reduction in density Pressure gradient ( vacuum ) theory : There is formation of vacuum or rarefaction (due to negative pressure gradient) as brain lags behind the moving skull The vacuum exerts a suction effect – stretching and tearing of the blood vessels and brain at opposite side.

21. other theories – mechanism contre coup Brain displacement theory : . The reverse impact of the brain to the internal surface when it returns to its primary position results in contre coup damage . Rotational shear force theory : shear strains produced by rotational forces , either deceleration or acceleration) in the direction of the force applied . pulling apart and stretching the constituent particle of brain and blood vessels that are roughly opposite to the original site of impact .

22. Other theories – contre coup Bony irregularities theory : Most contre coup injuries occur in frontal, temporal and parietal lobes of the brain but very rare in the occipital lobes frontal and temporal poles of brain hitting against the irregular floors and sharp borders of the anterior and middle cranial fossae . Irregular surface of base at frontal lobes

23. Mechanism of contre coup Transmitted wave theory : Energy of impact in a hollow organ propagates by radiating waves , these waves leave the site of impact and converges as they approach the opposite side- damage on opposite side. .

24. Contre coup – most supported theories. Skull deformation/Struck hoop theory Pressure gradient theory Rotational shear force theory : Bony irregularities theory :

25. Concussion- head concussion

26. Definition Concussion (Latin concutere : to shake ) - physiological disruption of brain function as a result of a traumatic event - which is manifested by loss of memory or focal neurological deficit , - most of the time it will be transient.

27. Concussion of Brain it’s a state of temporary unconsciousness due to head injury. complete or partial paralysis of cerebral function with spontaneous recovery immediately after injury, recovery is a rule.

28. Concussion…….. followed by amnesia - The person is not able to recollect the events what happened few seconds just before the accident and few minutes there after. The person behaves automatically, but not rationally or responsibly

29. Concussion in contact sports

30. Mechanism of concussion It occurs due to sudden acceleration / deceleration of head. The violent head movement causes shearing or stretching of nerve fibres, but no major axonal damage. A post-traumatic amnesia from few minutes to days is seen. Blows to neck or cervico -cranial junction produce brainstem concussion

31. In foot ball players

32. Concussion grades coup or contre coup effects may lead concussion.

33. Concussion -Signs and Symptoms Unconsciousness, bradycardia, hypotension and sweating, and is always followed by retrograde or posttraumatic ( anterograde ) amnesia , temporary lethargy, irritability and cognitive dysfunction . Muscles are flaccid , pupils are dilated and unreacting , pulse is weak and slow, and respiration is shallow .

34. Post-concussion syndrome Seen in patients who returned to work too early after head injury. It consists of headache, vertigo, lassitude, irritability and depression which may persist for month

35. Concussion -grading

36. Alcohol effect - concussion Breath smells alcoholic odor

37. Concussion - Penalty to the sportsmen Concussion is common among contact and collision sports participants. Football, rugby players and boxers are particularly exposed to repetitive concussions, leading to the condition known as chronic traumatic encephalopathy syndrome.

38. Punch drunk syndrome ( PDS ) A condition occurring late in boxer’s career or years after retirement which is the cumulative result of recurrent cerebral concussions . Signs and symptoms : There may be deterioration of speed and reflexes , and incoordination along with personality change associated with social instability and sometimes paranoia and delusions

39. PDS- dementia pugilistica or boxer’s encephalopathy Later , memory loss progresses to full dementia , often associated with Parkinsonian signs, ataxia or intention tremors , shuffling, broad-based gait and dysarthria . Autopsy : Chronic SDH, attenuation of corpus callosum , DAI and cortical atrophy may be seen. Muhammad Ali a popular boxer suuffered with PDS at his old age.

40. Diffuse axonal injury D A I

41. D A I- Definition Diffuse axonal injury (DAI) is a condition representing a spectrum of severity in which the victim is unconscious from the time of injury, and then either remains in a coma or enters a persistent vegetative state.

42. D A I

43. Concussion leads to DAI concussion some times may progress to DAI functional abnormality of nerve cells and of their connections - Death may occur without the patient regaining consciousness, or he may recover partially and then die suddenly . the victim may exhibit automatism and may commit some violent or criminal act.

44. D A I - grading Upper Brain stem Upper brain stem

45. TBI traumatic brain injury

46. D A I - Diagnosis Symptoms are confused with condition of drunkenness CT scan : Characteristic CT findings may be absent but in severe DAI focal lesions are seen as petechial hemorrhages in the corpus callosum , cerebellar peduncle and evidence of diffuse injury to axons . MRI with its high sensitivity may show some parenchymal injury,

47. DAI

48. D A I – diagnosis- Seen in the internal capsule, corpus callosum and superior cerebellar peduncle. Immuno histo chemistry – used to detect axonal swellings .

49. Histologically , - scattered microglial accumulates -and debris-laden macrophages

50. Histology - DAI numerous axonal swellings ( ‘retraction balls / bulbs’ ) retraction balls seen as eosinophilic -pink swellings , but a survival of 15–18 h is required to demonstrate

51. Autopsy Findings - D A I i . Contact injuries to the scalp and skull may be absent. ii. Thin subarachnoid haemorrhage may be seen. iii. Brain: Cut sections may be normal to the naked eye or there may be minimal gross alterations— focal lesions in the dorso lateral aspect of the rostral brainstem

52. Autopsy findings …..DAI focal necrosis or petechial hemorrhages in the corpus callosum

53. Diffuse axonal injury (D A I) Gliding contusions are common and hemorrhages in the thalamus and basal ganglia are frequent . autopsy is usually negative , but in some cases petechial haemorrhages may be found in the brain.

54. Intra cranial hemorrhages

55. Intra cranial Hemorrhages

56. Types of hemorrhages Intra Axial Hemorrage - - Intra Parenchymal - Intra Ventricular Extra Axial Hemorrhage – Epidural Hemorrhage - Subdural Hemorrhage - Subarachniod Hemorrhag

57. Extra dural hemorrhage Collection of blood in a space between dura and skull, mostly due to trauma .

58. EDH

59. EDH

60. Layers of skull and brain coverings

61. EDH

62. EDH & SDH

63. EDH Clot is localised and causes localised concavity of surface of brain, with flattening of the gyri due to pressure effect. Clot is oval or circular, 10 to 20 cm. in diameter, 2 to 6 cm. thick, weighs 30 to 300 g. and is adherent to dura . Usually, 200 ml. of blood collection - minimum to cause death

64. EDH it is the least common type of meningeal bleeding (1 to 3%). It is not common in first 2 yeasrs of age, but may possible between 20 to 40 years. Bleeding may occur due to fall from height or after a vehicular accident. Middle meningeal artery and dura mater

65. EDH Meningeal arteries passing through grooves of the endo -cranium, when ever skull fractures arteries also may get damaged and bleed in to ED space Extra Dural space is a potential space, why because dura mater closely attached inside the cranium.

66. Extra dural haemorrhage- mechanism At the moment of impact the skull moves relative to the dura underneath it, dura is stripped from bone , Meningeal arteries may torn and blood will leak in to the potential space between endo cranium and dura .

67. EDH- mechanism and an potential extra dural space is filled with blood upon the site of trauma . Dura will be further stripped from endocranium due to more collection of arterial blood which leeks with pressure.

68. Meningeal arteries – a source EDH

69. EDH- source of bleed Most common site – tempero -parietal region VESSELS : most common 1. Anterior & Posterior branches of middle meningeal artery 2. Middle meningeal vein

70. EDH - vessels injured . injury to middle meningeal artery- commonest . - due to a blow to the lateral convexity of the head. - Less commonly- - posterior meningeal artery near- foramen magnum -anterior meningeal artery near cribriform plate . -anterior ethmoidal artery- A blow over forehead . -sagittal sinus A blow on vertex .

71. Signs and symptoms- EDH a episode of consciousness in between two bouts of unconsciousness is called lucid interval (Lucid = clear ). Initial loss of conscious ( L O C) due to concussion and the subsequent clear period (lucid interval)- due to recovery from concussion, second time unconsciousness is due to EDH

72. EDH - symptoms lucid interval may extend from few hours to a week Lucid interval more common in adults than in children As pressure on brain increases, patient is first confused and may appear to be drunk

73. Diagnosis -EDH X RAY & CT are diagnostic Hematoma limited by suture line EDH is bi-convex and SDH is banana shape. Death occurs due to respiratory failure due to compression of brain stem. Sub Dural Hematoma Vs EDH

74. EDH- blood is limited at the points of the sutures

75. kernohan’s notch effect EDH – raised ICT coning of supratentorial content through the tentorial hiatus shift of midbrain to the opposite side – injured by sharp end of tentorium cerebelli Kernohans notch

76. EDH & SDH

77. EDH

78. EDH

79. EDH & SDH

80. EDH- complications • Complications – -cerebral oedema, -meningitis, -post traumatic amnesia, -post traumatic epilepsy • Immediate surgical intervention is life saving

81. Cerebral oedema is due to: (a) Increase in intravascular pressure. (b) Increased permeability of cerebral vessels. (c) Decrease in plasma colloid osmotic pressure. There is localised or diffuse abnormal accumulation of water and sodium, which increases the volume of the brain . Focal oedema in the brain stem is usually fatal

82. Pressure effects- Herniation

83. Medico-legal Aspects-EDH EDH is almost always due to trauma , either by means of accident or assault. But very rare due to spontaneous rupture of blood vessels Prognosis is good with proper surgical treatment in time .„ Patient may be discharged from hospital during lucid interval and die at home . doctor may be charged with negligence „ Most complications occur within the first 24 h following the injury.

84. M L I – E D H Patient’s attendants should be instructed on warning signs otherwise it may amount to medical negligence. „ The condition may resemble drunkenness and patient may die in police custody Presence of an EDH alone may or may not cause death— the possibility increasing with increasing blood collection intra cranially, pressure effect , duration of injury and the presence of herniation - this affect the time laps since incident till to death .

85. Non-traumatic spontaneous EDH rare but may be seen in sickle cell anemia , coagulopathies , infectious diseases of the skull like sinusitis, vascular malformations of the dura, metastasis to the dura or skull, and chronic kidney disease. In this category of patients, typically there is no evidence of head trauma, skull fracture or lucid interval

86. EDH- autopsy findings Fissured fracture is seen in 90% cases, but sometimes it is depressed. Haematoma is directly under the site of surface injury, and usually covers motor area of brain and tends to run in middle fossa .

87. M L I of E D H Heat hematoma and EDH

88. Important questions (2 or 4 marks) Lucid interval Concussion EDH DAI Coup and contre coup injuries Punch drunk syndrome

89. Thanking you Be safe