HEAD TRAUMA

1. HEAD TRAUMA • Presented by Dr.Omar Alsherif • Moderator: Dr.Tareq Alshaikh

2. epidemiology

3. Each year more than 1.4 million patient sustain head trauma in the US ➞ 1.1 million present to ER ➞ 235’000 hospital admissions • TBI is the most common cause of death in people < 45 yrs • Annual mortality from TBI is approximately 50’000 patient • >90’000 suffer from permanent disability • Closed head injury causes immediate death in 25% of acute traumatic injuries • TBI results in more deaths than does trauma to other specific body regions • The financial burden of head injury in the US is estimated to be $75-100 bilion annually

4. anatomy & physiology

5. BONES • The skull is divided into: • Neurocranium • Frontal • Temporal • Sphenoid • Occipital • Parietal • Ethmoid • Viscerocranium • Nasal • Zygomatic • Maxilla • Mandible • Lacrimal • Vomer • Palatine

6. MAJOR REGIONS OF THE BRAIN • Cerebral hemispheres • Diencephalon • Brain stem • Cerebellum

7. CEREBRAL HEMISPHERES • Located on the most superior part of the brain • Together they are called the cerebrum • They make approximately 83% of total brain mass • Each hemisphere consists of four lobes which are the frontal, parietal, temporal & occipital • The cerebrum is responsible for three different functions which are motor, sensory & cognition • Its cortex constitutes of gray matter which are responsible for the cerebrum action • Located internally are the white matter which are responsible for communications b/w cerebral areas & other parts of CNS

8. DIENCEPHALON • Located centrally within the forebrain • Consists of the thalamus, hypothalamus & epithalamus • The thalamus acts as a relay station for sensory inputs ascending to the sensory cortex and association areas.it also mediates motor activities, cortical arousal & memories • The hypothalamus maintains the body’s homeostasis by controlling the autonomic nervous system. It also forms a part of the limbic system • The epithalamus consists of the pineal gland & the choroid plexus

9. BRAIN STEM • Its is consists of: • Midbrain which provides pathways higher & lower brain centers and contains the visual reflex & subcortical motor centers • Pons is mainly a conduction region, but its nuclei also contribute to the regulation of respiration & cranial nerves • Medulla oblongata acts as an autonomic reflex center involved in maintaing body homeostasis. nuclei in the medulla regulate the respiratory rhythm, heart rate, blood pressure & several cranial nerves. Moreover, it provides conduction pathways b/w the brain & the spinal cord

10. CEREBELLUM • Located dorsal to the pons & medulla • Like cerebrum it has outer cortex of gray matter & internal white matter with small deeply situated paired nuclei • Its main function is to give smooth coordination of movements

11. MENINGES • Dura Mater (outer): • Thick double membranous fibrous tissue • It surrounds & supports the large venous channels that carry blood from the brain (sinuses) • Supplied by meningeal arteries which lie b/w the outer surface of the dura & the inner surface of the skull

12. MENINGES • Arachnoid Mater (middle): • Thin layer • Surounds the brain & spinal cord, but does not line it • Pia Mater (inner): • Thin layer • envelops the brain & spinal cord

13. SPACES • Epidural Space: • B/W the inner surface of the skull & the outer surface of the dura mater • Bleeding occur due to: • Supplying blood vessels to the meninges e.g the middle meningeal a. ➢ Rapid level of consciousness deterioration due to expanding hematoma • Fractured bone • The sinuses

14. SPACES • Subdural Space: • B/W the inner surface of the dura & the arachnoid mater • Bleeding occur due to injury to the bridging veins • Subarachnoid Space: • B/W the arachnoid & the pia • CSF circulates within the space

15. AUTOREGULATION & MONRO-KELLIE DOCTRINE • Cerebral blood flow CBF is normally kept constant under a range b/w 50- 150 mm Hg of cerebral perfusion pressure CPP by adjusting vascular tone • CPP = MAP - ICP where MAP = (1/3 SBP) + (2/3 DBP) • Intracranial pressure results from the aggregated volumes of brain tissue, CSF and blood from the fixed intracranial compartment. it is kept b/w 7-15 mm Hg in supine position & - (10-15) mm Hg in standing position • The Monro-Kellie doctrine states that the total volume of intracranial contents remains constant because of the incompressibility of the cranium • A slow expansion of one of those compartments can be buffered by compensatory decrease in either CSF or blood compartments • However, when the buffering mechanism is exceeded ICP will increase • Increase ICP can cause either herniation or ischemia or both

17. Pathophysiology

18. PATHOPHYSIOLOGY • Skull fracture: • Simple: a linear # of the vault • Compound: when there is a direct communication with the external environment • Laceration over the fractured bone • Base of skull fracture, due to communications with the sinuses • Depressed: when the bone fragments are depressed beneath the vault. It is considered to be significantly depressed if the inner table fragments are depressed by at least the thickness of the skull • Half of the injuries are due to MVA • If it was caused by non-missile injury only causes focal brain damage, thus most of pt will never loss consciousness • If it was compound with dura laceration there is high risk of intracranial infection

19. PATHOPHYSIOLOGY • Primary • Injury to the brain parenchyma • Injury to blood vessels • Secondary • Altered cellular biochemical processes • Brain edema • ↑ICP • Herniation • Ischemia

20. PRIMARY INJURY (CELLULAR) • Concussion ( American academy of neurology) • Grade 1: no LOC; transient confusion with symptoms resolves in <15 min • Grade 2: no LOC; transient confusion with symptoms resolves in >15 min • Grade 3: brief or prolonged LOC • Contusion • Coup • direct trauma that transfers to the brain damage the neurons • Countercoup • the brain is vulnerable to impact with opposite inner table of skull • sometimes it is even more sever than the direct trauma side • Diffused axonal injury • diffused injury from brain distortion can lead to damage to deep brain structures → disruption of axonal white matter

22. PRIMARY INJURY (BLOOD VESSELS) • Epidural hematoma • The incidence is 1% of all head trauma • Laceration of meningeal arteries 85% • Bleeding from # bones • Associated with lucid interval • Subdural hematoma • The most common surgical intracranial lesion 20-40% • Disruption of bridging veins • Not necessarily to have lucid interval • Poor prognisis is associated with midline shift exceeds the hematoma thickness • Intracerebral hemorrhage

24. SECONDARY INJURY • Results from events occurring after the primary insult either by direct consequences of process initiated by the primary injury, or from deleterious outside influences • The magnitude of secondary injury is often the determining factor in outcome from brain injury • Unlike primary injury they are amenable to treatment

25. SECONDARY INJURY • Secondary intracranial insults to the brain: • Edema • ↑ICP • Ischemia • Herniation • Hydrocephalus • Neurochemically • Infection • Epilepsy • Secondary systemic insult to the brain: • Hypotension • Hypoxia • Hypercapnia • Hypocapnia • Hyperglycemia • Fever • Anemia • Hyponatremia

26. SECONDARY INJURY • Brain edema • Vasogenic due to a breach in blood brain barrier that allows water and solutes to diffuse into the brain • Cellular (cytotoxic) less clearly understood

27. SECONDARY INJURY • Ischemia • Cerebral ischemia is defined as inadequate oxygen perfusion to the brain as a result of hypoxia or hypoperfusion • About 1/3 of patient with severe head trauma have been demonstrated to experience ischemic levels of cerebral blood flow • It could be either to: • Respiratory alkalosis which shifts the oxygen hemoglobin curve to the left thereby decreasing the ease of oxygen release • Focal vasospasm with loss of autoregulation in the injured area may lead to uneven CBF

28. SECONDARY INJURY • Hypotension • It is the number one treatable determinant of severe head injury • Studies has shown that a single episode of SBP < 90 mm Hg occurring during the period from injury through resuscitation doubles the mortality and significantly increases the morbidity of any given brain injury. Furthermore, an early hypotensive episode strongly increases the probability later intracranial hypertension • For these reasons, rapid and complete restoration of blood pressure is the most important goal in the resuscitation of the brain injured patients

29. SECONDARY INJURY • Brain Herniation • Subfalcine: the cingulate gyrus of the frontal lobe is pushed beneath the flax cerebra. It is the most common type of herniation • Central: the diencephalon is squeezed through a notch in the tentorium cerebelli • Uncal: the uncus and the hippocampal gyrus are displaced through the tentorium cerebelli foramen causing compression of the midbrain. It is associated with third nerve palsy • Cerebellar: the tonsils of the cerebellum is pushed through the foramen magnum and compresses leading to respiratory arrest

30. PENETRATING HEAD INJURY • Mostly caused by high velocity injury (1200 Km/s) • Most modern rifle bullets have a muzzle velocity of > 3600 Km/s • Injuries could be: • Tangential: the missile does not enters the cranium but causes laceration of the scalp and depressed # with underlying contusion or hematoma • Penetrating: the missile enters the cranium leading to deposition of metal, boney fragments and debris in to the brain • Through & through: the missile enters & exits the cranium, frequently creating more than one tract due to fragmentation

31. MECHANISM OF INJURY • Mechanical laceration of the brain tissue • Shock wave created by the missile • Cavity formation created by the path of the missile

32. CLASSIFICATION OF HEAD INJURIES • Mechanism • Blunt • Penetrating • Severity (GCS) • Mild: 13-15 • Moderate: 9-12 • Severe: <9 • Morphology • Skull fracture • Vault • Open vs close • Depressed vs non depresses • Linear vs fragmented • Single vs multiple • Base • With vs without CSF leak • Intracranial lesion • Focal • Epidural • Subdural • Intracerebral • Diffuse • Edema • Midline shift • Concussion • Multiple contusions

33. evaluation

34. EVALUATION • Primary survey • Airway & C.Spine protection • Breathing • Circulation • Disability • Exposure • Secondary survey

36. WORKUP • Laboratory • CBC including platelet • Coag. profile • CT-scanning • It is helpful in assessing the degree of intracranial injury, in predicting outcome & avoiding unnecessary hospitalization • Sensitive to intracranial hemorrhage, skull #, mass effect and midline shift, obliteration of basal cisterns, herniation and intracranial air • Defines the nature of the ICH and gives anatomical location of the leasion • Poor for diagnosing DAI

37. MANAGEMENT OF MILD TBI • About 85% of all TBI • History • Mechanism of injury • LOC • Change in mental status • Seizures • Headache • Amnesia • Examination • General • Neurological • Investigation • Blood • Radiological • Admission • GCS < 15 • # skull • Focal neurological deficit • Drug or alcohol intoxication • Persistent headache • +ve CT findings • Suspected domestic abuse

38. MANAGEMENT OF MODERATE TBI • About 10% of all TBI • History & examination • Admission to ICU • Frequent neurological examination • Repeat CT scan if the patient deteriorates and consider managing it as severe TBI

39. MANAGEMENT OF SEVERE TBI • Intubate • Ventilate but don’t hyperventilate Pco₂≃ 35 mm Hg • Resuscitate with IVF • Isotonic solutions • Fluid maintenance to be kept about 2/3 • Complete bed rest • Foley’s catheter • Bed elevation 30° • ICP monitoring • Mannitol • Osmotic diuresis • ⇩ ICP • Neutralizes free radicals • Anticonvulsants • Start diet as soon as possible if there is no contraindication

40. SURGICAL INTERVENTION • Depressed fracture • Penetrating brain injuries • Intracranial mass lesion

41. SKULL FRACTURES • Simple linear # • Conservative • Indicates high force mechanism trauma • Should alert the surgeon for the possibility of underlying hematoma • Patient should be admitted CT scan must be performed • Compound # • Lacerated scalp or due to # of the base • Debridement of the wound, closure, antibiotics should be given

42. SKULL FRACTURES • Depressed # • If it was closed, there is no urgency in elevating the bone. The depressed fragment should be elevated if: • CT scan show evidence that the dura might be injured • Significant brain compression • If it was compound then it is an emergency surgery • Prophylactic antibiotics • TT • Debridement of the wound • Bone elevation • If the dura was penetrated then anticonvulsant should be given for one year

43. PENETRATING HEAD INJURIES • Managed as sever head trauma • Antibiotics must be administered ASAP • IV diuretics to reduce ICP • CT scan to determine the position of the intracranial hematoma, depressed bone fragments & metallic fragments • If accessible removal of all necrotic tissue of the brain & boney & metal fragments should be done • Repeated CT scan must be done immediately after surgery to assess any retained boney or metallic fragments

44. INTRACRANIAL HEMORRHAGE • Epidural hematoma: • Emergency surgery • Craniotomy & evacuation of clot must be done over the area of hematoma • Ligation of bleeding vessele • It is advise to place a drain in the epidural space after surgery • Subdural hematoma: • Most of the times will need drainage • It can be evacuated with burr holes and blood could be washed out with saline • If the bleeding did not stop craniotomy is performed and hemostasis is achived

45. REHABILITATION • After severe head trauma patients may suffer from major disabilities in the form of: • Impairment of the motor function; hemiparesis, quadriparesis, ataxia, poor coordination • Speech disturbance; dysphasia, dysarthria • Impairment of special senses; vision, hearing • Cognitive disturbance; memory impairment, intellectual disability, personality change

46. REHABILITATION • Aim to: • Prevent complication such as contractures of the limbs and to provide counseling for the family • Maximize the neurological recovery by restoring old skills and techniques

47. Maxillofacial trauma

48. EPIDEMIOLOGY • F > M. In general,women have a lower impact tolerance than men owing to a lower density and thickness of the facial skeleton • Of the maxillofacial region, the nasal bone has the lowest impact tolerance with the zygomatic arch following close behind • The glabellar region overlying the frontal sinus requires the greatest amount of force amongst the maxillofacial components • The maxilla is typically more sensitive to horizontal forces while the mandible is more susceptible to lateral force

49. SOFT TISSUE anatomy

50. SCALP • It covers the entire cranial vault, extends over the upper face anteriorly up to the superior nuchal line posteriorly, and from one temporal line to the other laterally • It consists of five layers: • Skin • Connective tissue • Aponeurosis • Loose areolar tissue • Pericranium