HEAD INJURY By - Dr. RAJA RUPANI DEFINITION Head injury is a morbid state, resulting from gross or subtle structural changes in the scalp, skull, and/or the contents of the skull, produced by mechanical forces. The blunt force may result in injury to the contents of the skull, either alone or with a fracture of the skull. The extent and degree of an injury is not necessarily proportional to the amount of force applied to the head. SCALP The thickness of scalp in adult is variable, ranging from a few mm to 15 mm. Most wounds are caused by blunt force to the head, like falls or blows Wounds are contusions or lacerations. SCALP CONTUSIONS OF SCALP May occur in the superficial fascia, in the temporalis muscle or loose areolar tissue Contusions in the superficial fascia appears as localized swelling and are limited in size because of dense fibro-fatty tissue of the fascia. Extensive hematoma spreads beneath galea (Sub galeal hemorrhage) Deeper bruising occurs in fibrous galea Infected wounds may result in thrombophlebitis (through emissary veins) Bruising of the scalp is better felt than seen Its firm edge feels like depressed fracture A scalp wound by a blunt weapon frequently resembles an incised wound and as such the edges and ends should be carefully examined with a magnifying lens. LACERATIONS OF SCALP If the scalp is lacerated by a blow, blood is driven out of the vessels due to compression and considerable bleeding occurs With further blows, blood is projected about the scene With repeated blows, blood is splattered over assailant Flat surface or object causes ragged split (linear, stellate or irregular) Temporal arteries spurt freely, as they are firmly bound and unable to contract and a fatal blood loss can occur LACERATION OF SCALP AVULSION OF SCALP Involves large are of scalp Occurs in : - traffic accident - hairs entangled in machinery Avulsion of scalp INJURIES TO FACE Bleeding is more in facial wounds EYES Blunt trauma on the eye causes a) Permanent injury to : - cornea - iris - lens b) Vitreous hemorrhage c) Detachment or rupture of retina d) Traumatic cataract BLACK EYE (PERIORBITAL BRUISING) It is caused by: 1.Direct blow in front of orbits, bruising lids. 2.Injury to the forehead, the blood tracking down under the scalp. 3.Fracture in the anterior cranial fossa, the blood leaking through cracked orbital plates. Black Eye NOSE 1. May be bitten or cut off due to sexual jealousy or enemity. 2. A blow may cause nasal bleeding due to partial detachment of mucous membrane EARS A blow may produce 1.Rupture of the tympanum 2.Deafness 3.Labyrinth may injured FACIAL BONES A blow often fractures the nasal bone and also ethmoid bone with radiating fractures into supraorbital plates, if the force is severe. A blow may fracture maxilla and malar bone. Pulping of face may result from striking with a heavy stone. The mandible is fractured by a blow from a fist, stick or by fall from height. A heavy blow on the jaws drives the condyles against the base of skull producing a fissured fracture. TEETH A fall or a blow with a blunt weapon may cause fracture or dislocation of teeth, with contusion or laceration on lips or gums and bleeding from the sockets. SKULL The outer table is twice the thickness of inner. In young males,the thickness of Frontal and parietal bone = 6 to 10 mm Occipital bone =15 mm. Temporal bone = 4 mm. Skull is thicker in midfrontal, midoccipital, parieto-sphenoid and parieto-petrous buttresses. Force required to fracture a cadaver skull – • Covered by an intact,hair-bearing scalp = 400 to 600 pounds per square inch • Empty human skull = 25 inch-pounds energy is sufficient to MECHANISM OF FRACTURE OF SKULL 1.FRACTURE DUE TO LOCAL DEFORMATION A local impact will drive inwards a piece of bone,shaped a cone like indentation At the apex, the inner table will get streched & fractures first. If the force continue to act,fracture of outer table follows complete fracture line runs from the central point radially. At the periphery of indentation the convexity of the bend is outwards,the outer table fractures first. LOCAL DEFORMATION 2.FRACTURE DUE TO GENERAL DEFORMATION Whenever the skull is compressed laterally, the vertical and longitudinal diameters are increased (and vice versa) due to which parts of skull at distant get bulged and may fracture by bending. The head may be compressed between a) two external objects,such as the ground and a wheel of a car b) an external object and spinal column FRACTURES OF SKULL A. Direct injuries may be caused by: 1. Compression- as midwifery forceps or crushing of head under the wheel of a vehicles. 2. An object in motion striking the head e.g. bullet, bricks, masonary, machinery, dagger, etc. 3. Head in motion striking an object, as in falls and traffic injuries. B. Indirect injury occurs from fall from height and landing on feet or buttocks. Types of Fractures of Skull 1.Fissured Fracture 2.Depressed Fracture 3.Comminuted Fracture 4.Ponds or Indented Fracture 5.Gutter Fracture 6.Ring or Foramen Fracture 7.Perforating Fracture 8.Diastatic or Sutural Fracture FISSURED FRACTURE These are linear fractures as cracks in the bone Involving the inner table or outer table or both. They are caused by forcible contact with a broad resisting surface like – • the ground • an agent having a broad striking surface • fall on the feet or buttocks. • Runs parrallel to the direction of force . • May start at the counter pressure, e.g., in the bilateral compression. • The line of fracture runs parallel to the axis of compression. • Fracture line tends to follow an irregular course and is usually no more than hair's breadth. • Linear fractures do not tend to cross bony buttresses, such as glabella, frontal and parietal eminance, petrous temporal bone, and occipital protuberance. • They tend to cross points of weakness, such as frontal sinuses, orbital roof, parietal and occipital squama. • Fracture lines stop when the energy dissipates or when they meet a foramen, a suture or a preexisting fracture. OSSA TRIQUETRA : In skull, small portion of brim ossify from irregular independent centres and remain for variable period of time as small bone know as OSSA TRIQUETRA FISSURED FRACTURE FISSURED FRACTURE FISSURED FRACTURE DEPRESSED FRACTURE • They are produced by local deformation of the skull. • The outer table table is driven into diploe, the inner table is fractured irregularly. • Also called “fracture a ala signature” (Signature fracture) as their pattern often resembles the causing weapon or agent . • Caused by blows from heavy weapon with small striking surface e.g. stone, sticks, axe, chopper, hammer etc.. • When a hammer is used ,the fracture is circular or an arc of a circle, having the same diameter as the striking surface. DEPRESSED FRACTURE DEPRESSED FRACTURE COMMINUTED FRACTURE • It has two or more intersecting lines of fracture which divide the bone into three or more fragments. • They are caused by fall from height on hard surface, vehicles accidents and from blows from weapons with broad striking surface, e.g. heavy iron bar, thick sticks, etc. • When there is no displacement of the fragment of fragments, it resembles a spider's web or mosaic. COMMINUTED FRACTURE COMMINUTED FRACTURE POND OR INDENTED FRACTURE This is simple dent of the skull – d/t - an obstetrics forceps blade, - a blow from a blunt object or - forcible impact against protruding object. They occur only in skulls which are elastic i.e, skull of infants. Fissured fractures may occur in outer table around the periphery of the dent. POND FRACTURE POND FRACTURE GUTTER FRACTURE They are formed when part of thickness of bone is removed so as to form a gutter, e.g, in oblique bullet wounds. GUTTER FRACTURE RING FRACTURE It occurs in the base of skull The anterior 1/3 is separated at its junction with the posterior 2/3. It runs at about 3 to 5 cm. outside foramen magnum and passes forward through the middle ears and roof of the nose The skull is separated from the spine. It occurs due to : 1.Fall from height 2.Blow to the vertex 3.Blow on the chin 4.Sudden violent turn of head PERFORATING FRACTURE These are caused by firearms and pointed sharp weapons like - daggers knives or axe. The weapon passes through both the table of skull leaving a clear-cut opening, the size and shape of which corresponds o the cross-section of the weapon used. PERFORATING FRACTURE PERFORATING FRACTURE DIASTATIC OR SUTURAL FRACTURE Seperation of sutures, due to a blow on head with blunt weapon. Occurs only in young persons • ELEVATED FRACTURE • BLOW OUT FRACTURE FRACTURE BASE OF SKULL May be produced by 1. Force applied directly at the level of the base 2. General deformation of the skull 3. Extention from the vault 4. Through spinal column or face Most basal fracture tend to meet at and overrun the pitutary fossa Fracture line usually opens into basal foramina Sphenoidal fissure is most commonly affected Blow on the chin or mandible produces: - fracture of glenoid fossa - fracture of cribriform plate of ethmoid Fracture of roof of orbit occurs due to : - Fall on back of the head - Blow on top of head - Sudden violent increase in internal pressure FRACTURES OF BASE OF SKULL 1.Longitudinal May results from a) Blunt impact on face and forehead or back of head b) In front-to-back or back-to-front compression 2.Transverse Results from an impact on either side of head or side to side compression 3.Ring fracture Anterior fossa fracture are due to direct impact on chin. Middle fossa fractures are due to direct impact behind ear. Posterior fossa fractures are due to direct impact on back of head COMPLICATIONS 1.Fracture of anterior cranial fossa may involve frontal, ethmoidal and sphenoidal sinuses with loss of blood from nose or mouth 2. In cribriform fracture, CSF and even brain tissue can leak into nose (CSF Rhinorrhoea) 3. Leptomeningitis 4. Cranial pneumatocele 5.Middle fossa fracture through basioccipit or sphenoid → bleeding from mouth 6.Fracture of sellaturcica communicates with airway via sphenoid sinus → blood passing into bronchial tree 7.Fracture of petrous temporal bone → blood and CSF escape from ear (CSF Otorrhoea) → blood may pass to mouth via eustachian tube → bleeding from ear due to tearing of posterior branch of middle meningeal artery 8. In posterior fossa fracture → bleeding occurs behind mastoid process → large haematoma at the back of neck 9.Fracture foramen magnum → cerebellar contusion & oedema → fatal herniation of cerebellar tonsils - Cranial nerve injury (streched or bruised) 10. Damage to surrounding structures 11. Shock 12. Portal of entry of bacteria 13. Fat and bone marrow embolism 14. Deprssed fracture → severe dysfunction, coma and death Contrecoup fracture • Fracture of skull occuring opposite to site of force is known as contrecoup fracture. • Usually occurs when head is not supported. • There is sudden disturbance in fluid brain content which transmits the force recieved to opposite side & impacts against the cranial wall. THE CIRCUMSTANCES OF FRACTURE OF THE SKULL 1. Accident - Fall or an injury by a motor vehicles 2. Homicide - Multiple localised and depressed fracture 3. Suicide - by insane AGE OF SKULL INJURY Healing occurs without the formation of visible callus, as periosteal blood vessels are damaged 1st week- Edges of fissured fracture stick together 14 days- Edges are slightly eroded - Inner surface of the skull shows pitting or deposition of salt 3-5 week - Edges become slightly smooth and bands of osseous tissue run across the fissure. INJURIES OF BRAIN & MENINGES 1. Open injuries - if dura is lacerated, e.g. by bullet or fragment of bone 2.Closed injuries - if dura remains intact, whether skull is fractured or not :e.g. a)Blunt force to head b)fall c)head striking a flat surface BRAIN INJURY May be caused by: 1. Penetration by a foreign body - knife, bullet or skull fragments etc. 2. By Distortion of skull - a localised segment undergoes deformation → shear strain in the brain tissue → contusion in surface layer - fractured bone may penetrate the dura → laceration. 3 Acceleration / Deceleration injuries: Sudden movement of the head → intracranial pressure gradients → shearing and tensile forces. An impacting force to the head can produce : - linear accleration, - rotational (angular) accleration or - combinition of both Linear acceleration - The force passes through the centre of head, acclerating it in a stright line. - Impact to the front and back of head Rotational or angular accleration - Head will rotate about its centre. Impact to the side → linear + angular acceleration (is more injurious) MECHANISM OF CEREBRAL INJURIES Damage may be caused without actual blow or fall on the head, e.g. by shaking the infant as in child abuse may cause subdural hemorrhage. A blow → linear or rotational change in velocity Forces involved - linear acceleration / deceleration - centrifugal & rotational velocity. Linear accleration forces → compressional or rarefactional forces Acceleration or decelaration + rotational element → brain damage Deceleration or accleration → the head in rotation → transmitted to brain → brain glides within dura → gliding or shear strain → moves adjacent strata of tissue laterally. The area of the skull depressed → compression and typical cone-shaped contusion. Sudden arrest of moving skull → decelaration of the skull first, but momentum of brain causes continuous motion. The skull and brain cannot change their velocities simultaneously The brain is restraint by the falx and tentorium → damage to base of cerebrum, corpus calosum and brain stem. Impact against the wide wall of the skull → diffuse contusion of cortex Cerebellum d/t small size and light weight is less liable to damage from rotatory movement of head Contrecoup lesion • Coup-located beneath the area of impact • Contrecoup-in an area opposite the side of impact • D/t -Local distortion of skull and sudden rotation of head resulting from blow, which causes shear strain - Acceleration or Deccelaration injury - Formation of cavity or vaccum on opposite side Blow on Occipital – injures Frontal lobe & tip of Temporal lobe Blow on Front of head – damages inner & lower part of back of brain or Brain stem Fall on side – contusion of opposite side Fall on top of head – contusion of ventral surface of cerebral hemisphere Blow on parietal area –lesion on opposite hemisphere or medial side of same hemisphere CONCUSSION OF BRAIN Head injury (Blunt trauma) ↓ Partial / complete paralysis of cerebral function ↓ Concussion- State of temporary unconciousness ↓ Tends to spontaneous recovery. ↓ Post-traumatic Retrograde Amnesia MECHANISM Occurs due to acceleration / deceleration of the head The violent head movement causes shearing or streaching of the nerve fibers and axonal damage. Severe injuries occur in coronal head motion only. Sagittal head motion produces mild or moderate injury At low level of accleration / decelaration, there is physiological dysfunction. With increased physical force, there is immediate stuctural damage of axons and immediate stoppage of all activites. Mild concussion - consciousness is not lost - no confusion or disorientation (± amnesia) Severe concussion - amnesia and loss of consciousness Cerebral concussion may be produced by 1. Direct violence to head 2. Indirect violence a) fall upon the feet or buttocks b) an unexpected fall on the ground in traffic or industrial accidents During established concussion:a) muscles - flaccid b) pupils - dilated and unreacting c) pulse - weak and slow d) respiration - shallow As consciousness returns, there is period during which the person appears to be lucid and in touch with surrounding Post traumatic amnesia - ranges from minutes to days - duration is usually proportional to severity of the injury Concussion can be ruled out if : a) unconsciousness is prolonged b) unconciousness does not occur immediately after blow c) If coma develops later COMMOTIO CEREBRI Severe movement of head ↓ Shearing stress in brain ↓ Small or punctate hemorrhages through out the brain (Commotio cerebri ) CAUSE OF CONCUSSION Most acceptable cause is“Diffuse neuronal injury“ - a functional abnormality of nerve cells and of their connection. DIFFUSE AXONAL INJURY Occurs when head acceleration occurs over a long period, as in a traffic accident and fall from a considerable height. Features of DAI 1. Focal lesion in - corpus callosum - the parasagittal white matter - septum - wall of III Ventricle - dorsolateral brainstem 2. Microscopic evidence of numerous axonal swelling and axonal bulbs ON AUTOPSY 1.Petechial hemorrhages in - cortex (at the junction of grey and white matter) - in roof of IV ventricle - piamater of the upper segments of the cervical cord 2.Oedema 3.Foci of myelin degeneration 4.In mild DAI, some axons may be damaged. In severe DAI there is - shearing of axons in white matter of cerebral hemisphere, corpus callosum and upper brainstem - focal hemorrhage in corpus callosum and dorsolateral rostral brain stem Microscopic examination : up to 12 hours - no axonal injuries After 12 hours - the axons appear Dilated ↓ Club shaped ↓ Retraction balls ↓ no. decreases after 2 to 3 weeks ↓ Microglial cells ↓ Astrocytosis ↓ Demyelinisation DAI is clinical condition : - Mild DAI - coma for 6 to 24 hrs - Moderate DAI - coma for > 24 hrs - Severe DAI - coma for > 24 hrs + brain stem dysfunction Occurs due to - vehicles accidents (90%) - falls and assaults (10% ) AMNESIA FOLLOWING HEAD INJURIES Amnesia usually associated with concussion The memory of distant events tends to return before recent events Permanent retrograde amnesia - seconds up to 7 days Person recovering from concussion, events which occured just before the injury are sometimes remembered indistinctly → later complete amnesia occurs Such patients may make false accusation Post traumatic automatism Is intimately associated with amnesia, after accident Is a behaviour in which person is unaware that the act is taking place The patient may speak and act in purposive manner, but does not remembers them afterwards HEAD INJURY AND ACUTE ALCOHOLIC INTOXICATION A person may be confused and disorientated after a head injury simulates acute alchohlic intoxication Intoxicated person sustaining head injury → impossible to assess to what degree his condition is due to head injury or intoxication Such person should be admitted in a hospital for observation. FEATURES DRUNK CONCUSSED Suffused, flushed, warm and Pale, clammy Difference b/w Drunkenness Concussion Face Pulse Fast, bounding Slow, feeble Pupils Contracted in coma, dilate on external stimuli and Contracted or unequal contract again, reaction to light -sluggish Breathing Sighs, puffs, eructates Shallow, irregular, slow Memory Confused Retrograde amnesia unrelieved by time. Behavior Uncooperative, abusive, unresponsive, insolent, talkative Cooperative quiet. Contusion of brain Localised deformation of skull → shear strain develops in the brain tissue → a zone of contusion in the surface layer When head is rotated → layer of brain tissue slide over each other at different depths in cortex → damage to the blood vessles Contusion may occur on surface of cortex or deeper down without tearing of tissue May occur without injury to the skull The period of unconsciousness = 30 minutes to several days CONTUSION Circumscribed area of brain tissue destruction + extravasation of blood into affected tissue. Produced by blunt force Found in grey and white matter Due to injury of blood vessels by mechanical stress. Most often found in frontal and temporal lobes Deeper structures,e.g.,basal ganglia,midbrain,and brain stem may be contused from impact to forehead and vertex Most haemorrhages occur at the crest of convolution facing the dura of flax and tentorium Haemorrhage is first seen in the perivascular space along the shrivelled and collapsed blood vessles At the crest Columnar arrangement perpendicular to the surface of the convolutions A larger haematoma may be formed by their union Blow to the top of the head → prominent contrecoup subtemporal or uncal contusion. Blow to the side → a lateral coup lesion → prominent contrecoup contusion or laceration (on lateral aspect of opposite hemisphere) Blow to the front of head usually do not produce cerebral contusion or laceration In severe frontal injury → coup laceration Old contusion appear as shrunken yellowishbrown area known as plaque jaures AGE OF CONTUSION • 1hour - Ischaemic changes • 5-10 days - Capillary proliferation • 2 weeks - Macrophage containing fat • Few weeks - Astrocyte proliferation • 2 months - Scar (pale or golden yellow) CONTUSION NECROSIS Found at convolutions Form small clefts, irregularly-shaped holes or trenches with sharply outlined walls Usually brown in colour. They communicate with subarachnoid space and do not contain any blood vessles CONTUSION TYPES OF CONTUSION 1.Fracture contusion 2.Intermediary coup contusion 3.Gliding contusion 4.Herniation contusion CEREBRAL LACERATION There is loss of continuity of the substance of brain. Surface lacerations are accompained by ruptures of pia matter and subarachnoid haemorrhage When parenchyma is completly disorganised it is termed pulpefaction Usually seen underneath skull fractures In depressed fractures the bone fragments tear the brain surface All penetrating injury produce laceration of brain. Blunt trauma, without fracture skull lacerates the corpus callosum or septum pallucidum in younger individual In severe hyperextention of head At pontomedullary junction, there may be → laceration in the pyramid or → avulsion of the brain stem Usually associated with fractures of the base of the skull and upper cervical vertebrae. Slit-like or irregularily shaped Contain very little blood Adhesions may develop between the brain and dura mater due to healing of surface laceration → causing Secondary epilepsy Healing of deep laceration involving ventricles may produce large glial cyst, filled with CSF (Traumatic Porencephalic Cyst) LACERATION CEREBRAL OEDEMA It occurs due to localised or diffuse accumulation of water and sodium → increases the volume of the brain It is caused due to : - ↑ intravascular pressure - ↑ permeability of the cerebral vessels - ↓ plasma colloidal osmotic pressure Contusion and lacerations → Focal oedema OEDEMA OF BRAIN AND SWELLING In brain swelling, oedema is mainly intracellular. The organ is enlarged and firm and has relatively dry cut surface. In oedema of brain, the fluid collection is interstitial. The organ is enlarged and soft and has a very watery cut surface Swelling of brain May occur following significant head injury May be focal or diffuse involving one or both cerebral hemispheres Within 20 minutes Head injury ---------→ Massive cerebral swelling Swelling of one cerebral subdural haematoma hemisphere+Ipsilateral acute Vasodilation → Increase in intravascular cerebral blood volume or an absolute increase in water content of the brain tissue → Brain swelling Cerebral oedema Occurs due to ↑ water content of the brain ↑Intravascular blood volume (for some time) ↓ Brain swelling ↓ ↑ Vascular permeability ↓ Cerebral oedema Severe oedema presses down cerebral hemispheres upon the tentorium The hippocampal gyrus may impact in the opening Herniate through the midbrain opening Grooving of unci. Haemorrhage and Necrosis at site of pressure ↑ Intracranial pressure → ↓VR from intracranial sinuses Arterial flow is not impaired → ↑ swelling Cerebral oedema ↔ Hypoxia AUTOPSY The dura is stretched and tense Brain is bulging with increase in weight Gyri are pale & flattened with thinning of grey matter. Sulci are filled & cerebral surface is smooth. Cerebral hemispheres and uncus may herniate Cerebellar tonsils may be impacted or coned into foramen magnum INCREASED INTRACRANIAL PRESSURE Causes: EDH & SDH Cerebral hemorrhage Infarction of brain Tumour or Abscess Dural Sinus Thrombosis Leptomeningitis Diffuse cerebral oedema CEREBRAL COMPRESSION D/t - ↑Size of brain (Swelling or ICSOL) Compression → ↓CSF amount ↓ Blood supply Types : 1. Supratentorial 2. Infratentorial Supratentorial Squeezing of Uncus or Temporal Lobe (inner margin) through hiatus ↓ Squeezing of Mid brain (A-P lenghthening) ↓ Streching of Paramedian & Nigral blood vessels ↓ Rupture ↓ Hemorrhage in Midline & Substantia Nigra (Fatal) Infratentorial Rise in pressure ↓ Forces cerebellar lobe and tonsils through foramen magnum ↓ Compresses medulla oblongata ↓ Respiratory failure P. M. Findings 1. Uncal grooving 2. Foraminal indentation of cerebellar tonsils DURET HAEMORRHAGE Secondary tear drop haemorrhage of mid brain and pons Ranging from small streaks to massive confluent haemorrhage in the midline Occurs with asymmetrical herniation of brain stem Suggestive evidence of cerebral compression Flattening of gyri Narrowing of sulci Apparent decrease of CSF Deep grooved marking around uncus of temporal lobe and cerebellar pressure cone CEREBRAL OEDEMA CEREBRAL OEDEMA Supratentorial compression of mid brain against the free edge of tentorium may cause unilateral grooving of cerebral peduncle (Kernohan's notch) When symmetrical, the oedema forces against the tentorium, so that hippocampal gyrus is squeezed into the opening LOSS OF CONSCIOUSNESS D/t Destruction of Reticular activating system ↓ Reduced affarent activity ↓Stimuli → Normal sleep ↓Enzyme system → Irresistible sleep Toxic agents BRAIN STEM May be injured by 1.Streching of peduncles 2.Decelaration against basisphenoid & dorsum sellae 3.Lateral shift of peduncle against tentorial margin 4.Strech or avulsion of cranial nerves 5.Traction on its vascular supply PONTINE HAEMORRHAGE 1.Spontaneous - single - 1/3 to 1/2 of pons involved 2.Traumatic - in different foci, which may unite (Both rupture in IVth ventricle) C/F - Pinpoint pupil not reacting to light with Head injury Primary small hemorrhage occur near walls of III or IV ventricles & aquaduct Numerous & severe hemorrhage in rostral brain stem are fatal CAUSE OF DEATH IN HEAD INJURY Damage to vital cerebral centres - posterior hypothalmus - mid brain - medulla Respiratory failure or paralysis Vital centres - compression or concussion or secondary changes Others - Infection, hypostatic pnemonia, pulmonary embolism or renal infarction INTRACRANIAL HAEMORRHAGES INTRACRANIAL HAEMORRHAGES 1.Extradural Haemorrhage 2.Subdural Haemorrhage 3.Subarachnoid Haemorrhage 4.Intracerebral Haemorrhage EXTRADURAL HAEMORRHAGE (EDH) Exclusively due to trauma On impact → skull moves relative to the bone → empty extradural space → blood vessels get injured Emmissary veins pass through Extradural space Vessels injured (depend upon the site of trauma) A blow over 1. Lateral convexity of head may injure : - Middle meningeal artery (Posterior branch) - Meningeal vein - Posterior Meningeal artery - Anterior Meningeal artery 2. Forehead → anterior ethmoidal artery 3. Occiput or low behind the ear → transverse sigmoid sinus → posterior fossa hematoma 4. Vertex → sagittal sinus 5. Venous extradural hemorrhage accompanies fracture of skull and is due to bleeding from the diploic vein. It is least common type of meningeal bleeding Rare below 2 years (d/t greater adherence of dura to the skull) Common in adults between 20-40 years Occurs due to : - fall from height - hit by a moving object - after a minor accident If fracture found - fissured type (90% cases) Coup - Contre-coup in gross deformity - B/L in B/L trauma 50% with 2nd Haemorrhage Blood Clot : Sharply defined Presses the dura inward → localized concavity of external surface of the brain Oval or circular Rubbery in consistency Reddish-purple Size = 10 to 20 cms in diameter & 2 to 6 cms thick Weight = 30 to 300 gms Area -Tempero-parietal - Fronto-temporal - Parieto-occipital 100 ml is fatal EDH EDH EDH EDH C/F History of head injury Temporary unconciousness Followed by Lucid interval of few hrs to a week (in 30 to 40 % cases) C/L Hemiparesis I/L Dilation of Pupil, not reacting to light (Anisocoria) If B/L – Both pupils dilated + Decerebrate rigidity Age of EDH Recent effusion-Bright red 4th day - Bluish black to brown 12 to 25 days - Pale brownish yellow Few months - Coagulum becomes firm and laminated Death d/t – - Respiratory failure - Cerebral oedema - Secondary haemorrhage in pons - Tentorial herniation PM Findings- Fisssured fracture - Break in vessels CHRONIC EDH Rare ± Fracture Commonly seen in older children and young adults Symptoms are noted 2 to 3 days after injury Sudden death may occurs after several days SUBDURAL HEMORRHAGE (SDH) Arachnoid is - thin, vascular meshwork and is intimately applied to the inner surface of the dura - attached to the dura by venous sinuses and arachnoid granulations Subdural space is very narrow and contains fluid The cerebral vein (bridging veins) cross this space to reach the sinuses CAUSES 1. Rupture of bridging or communicating veins. 2. Rupture of inferior cerebral vein entering the sinuses at the base of skull. 3. Rupture of dural venous sinuses. 4. Injury to cortical veins. 5. Laceration or contusion of the brain and dura. 6. Reinjury of old adhesions between brain and the dura. 7. Secondary to disease e.g. cerebral neoplasm, cerebral aneurysm or blood disorder 8. Drugs such as dicoumarol,warfarin and heparin. SDH may occur from relatively slight trauma with unconsciousness or fracture May be associated with contrecoup contusion May occur after fight or falls Found in alcoholics, old persons and children 100 to 150 ml is fatal Rapid SDH causes - compression of brain stem - secondary brain haemorrhage Haematoma causes - displacement of cerebral hemisphere - flattening of the convolutions of the opposite hemisphere Most commonly supratentorial U/L or B/L Fatal with – Contusion / Laceration / # SDH SDH SDH Types of SDH 1.Acute 2.Subacute 3.Chronic ACUTE SDH D/t - rupture of - large bridging veins - cortical artery - laceration Spreads freely in subdural space Blood is usually liquid or semi-liquid Vary from 1mm to 2 to 3 cm thickness Commonly affected area is fronto-tempero-parietal regions Fresh SDH - easily washed off (but not SAH) C/F- resembles EDH - delayed for 24 to 48 hours ± Lucid interval (longer than EDH) Almost always of traumatic origin Initially no cerebral compression, but secondary changes may increase the size Death d/t secondary pressure upon the brain stem Infarction d/t a) SDH - underneath - recent b) Stroke - Not underlies - as old as oldest portion of haemorrhage SUBACUTE SDH D/t bleeding from smaller bridging veins ± Brain injury Blood – thin & watery d/t – haemolysis or - dilution with CSF May appear like that of chronic type AUTOPSY Cerebral oedema Secondary haemorrhage in pons Tentorial herniation d/t pressure of blood clot and brain swelling Break in the vessels and fissured fracture of nearby skull CHRONIC SDH Presents 3 to 6 weeks after the injury Usually seen over - the parietal lobe - near the midline - may be B/L Often spreads over the temporal or frontal lobe and may extend to the base Localised / Deep / Widespread The fluid is reddish brown (often with fibrin clots) ↓ Darker ↓several weeks Brownish Small hematoma replaced by fibrous tissue Hemorrhage gets rapidly sealed off Chemical changes may cause further hemorrhage ↓ Further trauma Second Hemorrhage (Sealed off) ↓ New Blood vessels penetrate for healing ↓ Successive hemorrhage ↓ Increase volume ↓ Unconsciousness or Death (PACHYMENINGITIS HEMORRHAGICA INTERNA CHRONICA) More space in old age d/t atrophy SDH = small to 100 - 150 ml ± Neurologic symptoms Gradually encapsulated Presses on gyri → flattens → deforms brain surface (without shifting) DATING OF SDH 24 Hours - Layer of fibrin is deposited beneath the dura 36 hours - Fibroblastic activity at junction of clot & dura 4-5 days - 2 to 5 cells thick layer of fibroblast (after 4 days - red cells lose their shape) 5-10 days - capillaries & fibroblasts invaded - Haemosiderin-laden macrophages seen At 8 days - A membrane of 12 to 14 cells thick present 14 days -The membrane enclosing the arachnoid begins to form - Dural membrane attain 1/3–1/2 dural thickness 3-4 wks - covered by fibrous membrane (grows inwards) 4-5 wks - Arachnoid membrane has 1/2 dural thickness - Clot is liquified completely - Haemosiderin-laden macrophages 1-3 Months -The membrane is hyalinised on both sides ↓ large capillaries invade → complete resorption ↓ Gold coloured membrane (adherent to the dura) SUBDURAL HYGROMA When arachnoid is torn ↓ CSF may pass into subdural space ↓ large collection of fluid ↓ cerebral compression ↓ Cerebral hygroma SUBARACHNOID HAEMORRAHAGE (SAH) Piamater is a surface feltwork of glial fibres, inseperable from underlying brain Subarachnoid space contains: - blood vessles of the brain - its cranial nerves - a network of connective tissue fibres - It is filled with CSF Causes 1. Rupture of bridging veins near sagittal sinus 2. Laceration and contusion of brain and pia-arachnoid 3. Rupture of saccular berry aneurysm (in 95% of aneurysms) 4. Angiomas and AV malformations 5. Asphyxia 6. Diseases : Blood dyscrasias, leukaemias 7.Tears of the ventricular ependyma 8. Rupture of an intracerebral haemorrhage of non traumatic origin (apoplectic haemorrhage or stroke) 9. A kick or heavy blow on neck beneath the ear → rupture of vertebro - basilar artery Spontaneous Hypertensive SAH D/t - ruptue of microaneurysyms (Charcot-Bouchard aneurysm) ↑ in no. in arteries of brain with age & length of H.T. Major sites are - putamen / internal capsule (55%) - lobar white matter (15%) - thalamus (10%) - pons (10%) - cerebellar cortex (10%) > 50% are d/t Intracranial aneurysms Berry aneurysms are found at - Bifurcation of Middle cerebral Artery (90%) - Anterior cerebral artery - Posterior communicating arteries In acute alchoholic traumatic SAH is more common due to : - loss of muscular coordination → ↑rotational force - ↑bleeding from congested vessels Most common form of traumatic Intracranial haemorrhage U/L or B/L Localised / Diffuse Areas – Frontal, Parietal or Temporal (Ant. 1/3) It is mostly venous Subdural blood washes away under gently running, while subarachnoid blood imparts a red colour to the brain that does not wash AUTOPSY In mild forms - splashes of haemorrhage over the areas of contusion In most cases - diffuse overlying the cerebral hemispheres Rarely causes scarring within SA space (esp. over brain stem and basal cisterns) Yellow discolouration of leptomeninges is seen in older SAH SAH UNRUPTURED BERRY ANEURYSM RUPTURED BERRY ANEURYSM SAH C/F Headache with rapid onset (thunderclap headache) Stiff neck Photophobia Deterioration of consciousness ARTEFACT Produced at autopsy d/t a) damage to cerebral vein and the arachnoid b) decomposition with: - lysis of blood cells - loss of vascular integrity - leakage of blood in SA space INTRACEREBRAL HAEMORRHAGE (ICH) Found on surface or in the substance of the brain Haemorrhage into brain due to trauma usually occurs near surface CAUSES 1.Capillary haemorrhage found in softening of brain d/t: - anoxia or arterial thrombosis - sinus thrombosis - blood dyscrasias - fat embolism - asphxial deaths 2.Spontaneous haemorrhage in region of basal ganglion by rupture of lenticulostriate artery (common in middle aged and elderly) 3. Angioma or malignant tumor of the brain 4. Hypertensive cerebro-vascular disease Haemorrhage occurs in thalmus, external capsule, pons and cerebellum 5. Laceration of brain 6. Blow on head ± fracture of skull → coup-contrecoup mechanism 7. Intraventicular haemorrhage INTRAVENTRICULAR HAEMORRHAGE D/t head striking firm object Bleeds from - choroid plexuses - veins of septum pelucidum - rupture of an AV fistula Also d/t extension of non traumatic ICH Death - rapid or delayed for several days INTRA CEREBRAL HEMORRHAGE INTRACEREBRAL HEMORRHAGE NON TRAUMATIC ICH In hypertensive cerebrovascular disease With physical exercise or excitement D/t rupture of lenticulostriate artery Spontaneous hemorrhage in basal ganglia, thalamus, external capsule, pons or cerebellum Common in middle aged and elderly Difference B/W Post-traumatic ICH & Apoplexy Trait Po st-traumatic haemorrhage Apoplexy 1. Cause Head injury Hypertention, atherosclerosis, aneurysm 2. Age Young individuals Adults past middle age 3. Onset Distinct interval (few min to several hrs) b/w violence and symptoms Sudden 4. Position of head In motion Any position 5. Region White matter of temporooccipital or frontal region Ganglionic region 6. Contrecoup haemorrhage May be present Not present 7. Concussion May be seen, may become conscious before clinical effect appear Not present 8. Coma Spontaneous variation Deep unconciousness Questions 1. Contre coup injuries are seen in : A) Heart B) Brain. C) Lungs D) Uterus 2. Depressed fracture of skull is produced by: A) A light weight blunt object B) A heavy weight blunt object with small striking surface. C) A heavy weight blunt object with big striking surface D) Fall on the road 3. Sutural surface of skull is also known as : A) Diastatic fracture. B) Fissured fracture C) Depressed fracture D) Comminuted fracture 4. Spider web fracture of skull is other name for: A) Diastatic fracture B) Fissured fracture C) Depressed fracture D) Comminuted fracture. 5. Gutter fracture of skull is due to: A) Sharp pointed weapon B) Fire arm injury. C) Blunt weapon D) Heavy cutting weapon 6. Contre coup injuries of the brain are seen at: A) Adjacent to site of impact B) Away from the site of impact C) Anywhere in the brain D) Just opposite to the site of impact. 7. Punch drunk syndrome is commonly seen in : A) Tailors B) Cobblers C) Boxers D) Cricket players 8. Ring fracture is a type of fracture of : A) Mandible B) Skull. C) Humerus D) Femur 9. Fracture of the base of the skull may result from: A) Fall from feet B) Blow over chin C) Blow over vertex D) All of the above. 10. Contre coup injuries are usually seen, when head is : A) Not supported B) Supported. C) Covered with a heavy object D) Moving at a great speed 11. Bevelling of inner table of the skull bone is suggestive of : A) Burr hole B) Penetrating wound C) Fire arm entry wound. D) Perforating wound 12. Commonest type of intracranial haemorrhage is : A) Subarachnoid . B) Subdural C) Intracerebral D) Extradural 13.Rupture of berry aneurysm leads to : A) Subarachnoid haemorrhage. B) Subdural haemorrhage C) Extradural haemorrhage D) All of the above 14. Ring fracture of skull is produced by : A) A blow on the front of head with blunt object B) A blow on the side of head with blunt object C) Fall from height landing on buttocks. D) A hit with a small bullet over the head 15. CHF ottorrhea is caused by: A) Fracture of cribriform plate B) Fracture of parietal bone C) Fracture of petrous temporal bone. D) Fracture of tympanic membrane 16. Most common site for fracture mandible : A) Condyle. B) Angle C) Body D) Symphysis 17. Lucid interval is classically seen in: A) Intracerebral hematoma B) Acute subdural hematoma C) Chronic subdural hematoma D) Extradural hematoma. 18.True about CSF rhinorrhoea: A) Commonly occurs due to break in cribriform plate. B) Contains less amount of proteins C) Decreased glucose content confirms diagnosis D) Immediate surgery is required 19. Characteristic of anterior cranial fossa fracture : A) Black eye. B) Pupillary dilatation C) CSF otorrhea D) Hemotympanum 20.Orbital blow out fracture involves : A) Lateral wall and floor of orbit B) Medial wall and floor of orbit C) Lateral wall and roof of orbit D) Medial wall and roof of orbit