Nervous System

1. Nervous System Temple College EMS Professions

2. Nervous System Components • Central Nervous System • Brain • Spinal Cord • Peripheral Nervous System • Motor nerves • Sensory nerves

3. Brain • Body’s controlling organ • Responsible for organizing functions of other body organ systems

4. Brain • Functions localized to specific areas • Cerebrum • Cerebellum • Brainstem

5. Frontal lobe Foresight, planning, judgment Movement Parietal lobe Sensation from body surface Temporal lobe Hearing Speech Occipital lobe Vision Cerebrum Center for conscious perception and response

6. Cerebrum Left side of cerebrum Right side of cerebrum Sensory, motor functions of body’s right side Sensory, motor functions of body’s left side

7. Cerebellum • Posture • Balance • Equilibrium • Fine motor skills

8. Brain Stem • Automatic functions below level of consciousness • Heart rate • Respirations • Blood pressure • Body temperature

9. Spinal Cord • Connects brain with body • Serves as center for reflex action • Surrounded, protected by spinal column • Damage cuts brain off from body structures distal to injury site

10. Peripheral Nerves Brain Spinal Cord Motor Nerves Sensory Nerves

11. Nervous System Autonomic Nervous System Voluntary Nervous System Unconscious (Visceral) Functions Conscious Functions

12. Brain/Spinal Cord • Enclosed in protective box • Skin • Muscle • Bone • Meninges

13. Meninges • Three layers of tissue enclosing brain, spinal cord • Dura mater • Arachnoid • Pia mater

14. Cerebrospinal Fluid (CSF) • Surrounds brain, spinal cord in space between arachnoid and pia mater (subarachnoid space) • Acts as a shock absorber • Protects brain from jolts, shocks

15. Injuries to Scalp and Skull • Scalp Lacerations • Skull Fracture

16. Scalp Lacerations • VERY vascular area • Can distract EMT from possible underlying injuries • Care for laceration, but ask, “WHAT HAPPENED TO BRAIN ANDNECK?”

17. Scalp Lacerations • Bleeding usually NOT severe enough to produce hypovolemic shock • If shock present, think about other injuries • Exceptions • Laceration that involves a large artery • Scalp injuries in children. Why?

18. Skull Fractures • Injury to rigid box around brain • Indicates significant force • What happened to brain and neck?

19. Linear Most common Crack in skull Detected only on x-ray Comminuted Multiple cracks radiate from impact point Types of Skull Fracture

20. Depressed Bone fragments pressed inward Places pressure on brain Brain tissue may be exposed through injury Basilar Fractures in floor of skull Diagnosis made clinically Signs and symptoms Periorbial ecchymosis (Raccoon eyes) Battle’s sign CSF drainage from nose, ears Types of Skull Fracture

21. Skull Fractures DO NOT TRY TO STOP FLOW OF BLOOD, FLUID FROM NOSE OR EARS MAY CAUSE INCREASED INTRACRANIAL PRESSURE AND BRAIN INFECTION

22. Injuries to Brain

23. Concussion • Temporary disturbance in brain function • Probably due to brain being “rattled” inside the skull by a blow to the head • Usually confused or unconscious • Retrograde amnesia--“What happened?” • Effects clear without residual effects

24. Cerebral Contusion • Bruising, swelling • Results from brain hitting skull’s inside • Coup-contracoup pattern • Since brain is in closed box, pressure increases as brain swells, blood flow to brain decreases

25. Cerebral Contusion • Signs and Symptoms • Personality changes • Loss of consciousness • Paralysis (one-sided or total) • Unequal pupils • Vomiting

26. Epidural Hematoma • Usually associated with skull fracture in temporal area • Fracture damages artery on skull’s inside • Blood collects in epidural space between skull and dura mater • Since skull is closed box, intracranial pressure rises

27. Epidural Hematoma • Signs and Symptoms • Loss of consciousness followed by return of consciousness (lucid interval) • Headache • Deterioration of consciousness • Dilated pupil on side of injury • Weakness, paralysis on side of body opposite injury • Seizures

28. Subdural Hematoma • Usually results from tearing of large veins between dura mater and arachnoid • Blood accumulates more slowly than in epidural hematoma • Signs and symptoms may not develop for days to weeks

29. Subdural Hematoma • Signs and Symptoms • Deterioration of consciousness • Dilated pupil on side of injury • Weakness, paralysis on side of body opposite injury • Seizures Because of slow or delayed onset, may be mistaken for stroke

30. Cerebral Laceration • Tearing of brain tissue • Can result from penetrating or blunt injury • Can cause: • Massive destruction of brain tissue • Bleeding into cranial cavity with increased intracranial pressure

31. Assessment of Head Injury • Early detection of increasedintracranialpressure is critical • If pressure inside skull exceeds average blood pressure, blood flow to brain stops • Increasing intracranial pressure can force brain downward into spinal canal, crushing it

32. Assessment of Head Injury • Level of consciousness is BEST indicator of patient’s condition • AVPU system • Glasgow scale

33. AVPU System • Alert • Responds to Verbal Stimulus • Responds to Painful Stimulus • Unresponsive

34. Eye Opening Spontaneous = 4 To Voice = 3 To Pain = 2 None = 1 Glasgow Scale • Verbal Response • Oriented = 5 • Confused = 4 • Inappropriate Words = 3 • Incomprehensible Sounds = 1 • None = 1 • Motor Response • Follows Commands = 6 • Localizes Pain = 5 • Withdraws = 4 • Flexion = 3 • Extension = 2 • None = 1 Score each response then total scores Maximum Score = 15 Minimum Score = 3

35. Assessment of Head Injury • Vital Signs • Body responds to increasing intracranial pressure by raising BP • Increased BP moves blood into brain against rising ICP • Heart rate falls in response to rising BP

36. Increased BP Altered Breathing Slow Pulse Cushing’s Triad

37. Vital Signs Isolated head injury does not cause hypotension or tachycardia! Signs of shock in head injured patient indicate other injuries are present!

38. Pupils • Diffuse cerebral edema • Dilated • Equal • Sluggish or absent response

39. Pupils • Focal lesion (contusion, hematoma) • Unequal • Dilated pupil sluggish or fixed Dilated pupil is on SAME side as injury

40. Assessment of Head Injury • Other Indicators of Increased ICP • Headache • Nausea • Vomiting (often projectile) • Seizures

41. Management of Head Injury • ABCs with C-spine control • C-collar, long board, CID Any patient with significant head injury has neck injury until proven otherwise • Ensure adequate oxygenation • If signs of increased ICP present, controlled hyperventilation with BVM at 20-24 breaths/minute

42. Management of Head Injury • Controlled hyperventilation • Lowers blood carbon dioxide levels • Causes constriction of blood vessels in brain • As vessels constrict brain shrinks • As brain shrinks intracranial pressure drops

43. Management of Head Injury • Do NOT apply pressure to open or depressed skull fractures • Do NOT attempt to stop flow of blood or CSF from nose, ears • Do NOT remove penetrating objects

44. Spinal Injuries

45. Significance • Spinal injury can lead to spinal cord injury • Spinal cord injury can lead to: • Paraplegia • Quadraplegia

46. Most important spinal injury indicator… MECHANISM

47. Compression Flexion Extension Rotation Lateral bending Distraction Penetration Common Mechanisms

48. Suspect spinal injury with... • Sudden decelerations (MVCs, falls) • Compression injuries (diving, falls onto feet/buttocks) • Significant blunt trauma above clavicles • Very violent mechanisms (explosions, cave-ins, lightning strike)

49. Significant Head Injury = Neck Injury Until Proven Otherwise

50. Other indications • Decreased LOC in trauma patient • Pain in spine or paraspinal area • Pain in back of head, shoulders, arms, legs • Absent, altered sensation (numbness, paresthesias, loss of temperature, position, touch sense) • Absent, altered motor function (weakness, paralysis)