Glasgow Coma Scale and Cranial Nerve Assessment

Oct 17, 2024

Neurological Assessment Part 2: Glasgow Coma Scale and Cranial Nerves

Glasgow Coma Scale (GCS)

  • Purpose: Measures consciousness impairment in patients
  • History: Developed in 1974, used widely in hospitals
  • Components:
    • Eye Opening
      • Spontaneous - 4 points
      • To voice - 3 points
      • To pain - 2 points
      • No response - 1 point
      • Closed due to trauma - C
    • Best Verbal Response
      • Oriented - 5 points
      • Confused - 4 points
      • Inappropriate words - 3 points
      • Incomprehensible sounds - 2 points
      • No response - 1 point
      • Trach/tube - T
    • Best Motor Response
      • Obeys commands - 6 points
      • Localizes pain - 5 points
      • Withdraws from pain - 4 points
      • Abnormal flexion (decorticate) - 3 points
      • Abnormal extension (decerebrate) - 2 points
      • No response - 1 point

Scoring

  • Total range: 3 (least responsive) to 15 (most responsive)
  • Score 14-15: No neurological impairment
  • Score < 8: Comatose
  • Score < 10: Should be reported
  • Injury Severity:
    • Mild: 14-15
    • Moderate: 9-12
    • Severe: <8

Cranial Nerve Assessment

  • Memorization: Key for identifying and assessing cranial nerves
  • Mnemonics: For remembering cranial nerves order and function

Cranial Nerves Overview

  1. Olfactory Nerve (I)
    • Function: Smell
    • Type: Sensory
    • Assessment: Identify common odors
  2. Optic Nerve (II)
    • Function: Vision
    • Type: Sensory
    • Assessment: Visual acuity (Snellen chart), visual fields, color vision
  3. Oculomotor Nerve (III)
    • Function: Eye movement, lid elevation, pupil constriction
    • Type: Motor
    • Assessment: Eyelid drooping, PERLA, extraocular movements
  4. Trochlear Nerve (IV)
    • Function: Down and in eye movement
    • Type: Motor
  5. Trigeminal Nerve (V)
    • Function: Sensation in face, chewing
    • Type: Both
    • Assessment: Sensory to dull/sharp touch, motor by jaw strength
  6. Abducens Nerve (VI)
    • Function: Outward eye movement
    • Type: Motor

Combined Assessment for Cranial Nerves III, IV, and VI

  • Procedures:
    • Check for ptosis
    • PERLA and accommodation
    • EOM (Extraocular Movements)
    • Six cardinal fields of gaze

Additional Notes

  • Mnemonic for Cranial Nerves: On Old Olympus' Towering Top A Finn And German Viewed Some Hops
  • Mnemonic for Sensory/Motor/Both: Some Say Marry Money But My Brother Says Big Brains Matter More
  • Next Video: Will cover Cranial Nerve VII and beyond.