Traumatic Brain Injury: Causes, Consequences, and Management

1. Disorders of the Central Nervous and Peripheral Nervous Systems and Neuromuscular Junction Chapter 15

2. Traumatic Brain Injury

3. Brain Trauma • Major head trauma • A traumatic insult to the brain possibly producing physical, intellectual, emotional, social, and vocational changes • Transportation accidents • Falls • Sports – related event • Violence

4. Meninges

5. Brain Trauma • Closed(blunt, nonmissile) trauma – more common • Hit a hard surface or rapidly moving object • Dura remains intact and brain tissues are not exposed • Causes focal (local) or diffuse (general) brain injuries

6. Brain Trauma • Diffuse Brain Injury(no major broken blood vessels) DAI-Diffuse axonal injury: concussion • Most common type – 75 to 90% mild • Moderate & severe Table 15-2 • Physical consequences, cognitive deficits, behavioral manifestations: page 381 • diffuse axonal injury accounts for 50% of injuries • Focal injuries >2/3 deathsw

7. Mechanisms of Brain Injury • Primary: neural injury, primary glial injury, and vasculat responses • Secondary: consequence of primary • Altered cerebral blood flow, hypoxia, ischemia, inflammation, cerebral edema, increased ICP, & herniation • Tertiary: days/months later • due to primary/secondary injury • Pneumonia, fever, infection, immobility

8. Maximum Force

9. Concussion “microscopic stretching & tearing at the cellular level” Confusion Amnesia Headache Dizziness Ringing in the ears Nausea or vomiting Slurred speech Fatigue Change in personality

10. Concussion • Grade school • Junior high • High school • College • NFL “brain heals by scaring”

11. Muhhahad Ali

12. Brain Trauma • Classic cerebral concussion • Consciousness: lost for up to 6 hours, ↑ falls with loss of reflexes • Vital signs: transient ↓(BP, HR, R) • Retrograde and antegrade amnesia with confusion x hours to days • Head pain, nausea, fatigue, mood & affect changes

13. Brain Trauma • Post concussive syndrome • Headache, nervousness/anxiety, irritability, insomnia, depression, inability to concentrate, forgetfulness and fatigability • Reassurance and symptomatic relief with 24° of close observation

14. Brain Trauma • Focal Brain Injury(broken blood vessels) : contusion; 2/3 of deaths, visible • Direct contact (severe blunt trauma) • Epidural hematoma • Subdural hematoma • Intracerebral hematoma(subarachnoid) • Injury related to amount of energy transmitted • Coup or/and contrecoup • ↑ brain edema - ↑ ICP with infarction and necrosis

15. Meninges

17. Brain Trauma: coup-contracoup

18. Brain Trauma- hematomas • Extradural(epidural) – middle meningeal artery (temporal lobe) 85% • 20 to 40 year olds – MVA • Subdural – venous bleeding between dura mater and arachnoid • Fall in the elderly, MVA, Shaken Baby Syndrome • Subacute (2 days – 2 weeks), chronic (elderly, ETOH ) Intracebral(subarachnoid) – frontal and temporal lobes • Penetrating injury and shearing force traumatizes small blood vessels

20. Natasha Richardson: Epidural hematoma

21. Subdural (Acute) Hematomas

22. BretMichaels: subarachnoid hemorrhage etiology ? (type I DM, cocaine, EtOH)

23. Hematomas

26. Spinal Cord Trauma • 12,000 per year: 81% men at 33.4 years (MVA(41%, sports, violence), falls in the elderly (27% injuries) • Vertebral injuries (trauma) → neural tissue damage • Most common C1,2,4-7 and T10 – L2 (most mobile)* • Simple – transverse or spinous process • Compression –wedged • Comminuted – shattered • Dislocation *cervical-lumbar

29. Spinal Cord Trauma

30. Spinal Cord Trauma

31. Spinal Cord Trauma • Gray matter– hemorrhage with necrosis • - loss of perfusion and remains altered • White matter – edema (swelling) • So: ↓ perfusion → ischemic areas (returns 24 hours) • Injury: maximal at the level of injury and 2 cord segments above/below • Cord swelling → ↑ degree of dysfunction • Temporary or permanent • Life threatening • phrenic nerve C3-5 • Vegetative function (medulla)

33. Spinal Cord Trauma • Spinal shock (7 to 20 days) • Normal activity of the spinal cord ceases at and below the level of injury. Sites lack continuous nervous discharge from the brain. • Complete loss of reflex function (skeletal, bladder, bowel, sexual, thermal and autonomic control) below level of lesion.

34. Spinal Cord Trauma • Paraplegia • Injury to thoracic cord • Lower body and both legs • Quadriplegia– injury to cervical cord • All 4 extremities • Autonomic hyperreflexia (dysreflexia) • Massive uncompensated cardiovascular response to stimulation of the sympathetic nervous system • Stimulation of the sensory receptors below the level of the cord lesion

38. Degenerative Disorders of the Spine • Degenerative joint disease (DJD) • Degenerative disk disease (DJD) • Herniated nucleus pulposis • Spondylolysis • Neural arch of the vertebra • Spondylolisthesis • Vertebra slides forward • Spinal stenosis • Trauma or arthritis

39. Degenerative Disorders of the Spine • Herniated intervertebral disk • “protrusion of part of the nucleus pulposus through a tear in the posterior rim of the annulus fibrosus” • Trauma, degenerative disk disease, or both • Most common L 5 – S 1 and L 4-5

40. Vertebral Column

43. New Spinal Disc

44. Stroke

47. Cerebrovascular Disorders • “Most frequent occurring neurological disorder” • Third leading cause of death in the U.S.A. • Abnormalities • Ischemia = infarction (death of brain tissue) • Hemorrhage • Cerebrovascular accident (CVA, stoke) • “sudden non-convulsive focal neurological deficit”

48. Stroke

49. Stroke: Ischemic

50. Cerebrovascular Accidents • Mainly > 65 years old(75%): 28% < 65 years old: men> women: Blacks 2: Whites 1 • HTN & DM 2- 4X increase & 8X mortality • Spectrum: minimal (unnoticed) → severe state (hemiplegia, coma and death) • Classified 2° to pathophysiology • Global hypoperfusion (shock) • Ischemia (thrombotic or embolic) • Hemorrhagic See risk factors page 388