Examination of Cranial Nerves III, IV, V, VI, VII, VIII, IX, X, XI and XII

Examination of Cranial Nerves III, IV, V, VI, VII, VIII, IX, X, XI and XII

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III, IV and VI - Oculomotor, Trochlear and Abducens 

  • Observe for Ptosis
  • Test Extraocular Movements
    1. Stand or sit 3 to 6 feet in front of the patient.
    2. Ask the patient to follow your finger with their eyes without moving their head.
    3. Check gaze in the six cardinal directions using a cross or "H" pattern.
    4. Pause during upward and lateral gaze to check for nystagmus.
    5. Check convergence by moving your finger toward the bridge of the patient's nose.
  • Test Pupillary Reactions to Light
    1. Dim the room lights as necessary.
    2. Ask the patient to look into the distance.
    3. Shine a bright light obliquely into each pupil in turn.
    4. Look for both the direct (same eye) and consensual (other eye) reactions.
    5. Record pupil size in mm and any asymmetry or irregularity.
  • Test accommodation by making patient to look into distance, then a hat pin 30cm from nose.
  • If Myasthenia Gravis suspected: Patient gazes upward at Doctor's finger to show worsening ptosis

V - Trigeminal

  • Test Temporal and Masseter Muscle Strength
    1. Ask patient to both open their mouth and clench their teeth.
    2. Palpate the temporal and massetter muscles as they do this.
  •  Test the 3 Divisions for Pain Sensation
    1. Explain what you intend to do.
    2. Use a suitable sharp object to test the forehead, cheeks, and jaw on both sides.
    3. Substitute a blunt object occasionally and ask the patient to report "sharp" or "dull."
  • If you find and abnormality then:
    1. Test the three divisions for temperature sensation with a tuning fork heated or cooled by water. 
    2. Test the three divisions for sensation to light touch using a wisp of cotton. 
  • Test the Corneal Reflex
    1. Ask the patient to look up and away.
    2. From the other side, touch the cornea lightly with a fine wisp of cotton.
    3. Look for the normal blink reaction of both eyes.
    4. Repeat on the other side.
    5. Use of contact lens may decrease this response.

VII - Facial

  • Observe for Any Facial Droop or Asymmetry
  • Ask Patient to do the following, note any lag, weakness, or assymetry:
    1. Raise eyebrows
    2. Close both eyes to resistance
    3. Smile
    4. Frown
    5. Show teeth
    6. Puff out cheeks
  • Test the Corneal Reflex

VIII - Acoustic

  • Screen Hearing
    1. Face the patient and hold out your arms with your fingers near each ear.
    2. Rub your fingers together on one side while moving the fingers noiselessly on the other.
    3. Ask the patient to tell you when and on which side they hear the rubbing.
    4. Increase intensity as needed and note any assymetry.
    5. If abnormal, proceed with the Weber and Rinne tests.
  • Test for Lateralization (Weber)
    1. Use a 512 Hz or 1024 Hz tuning fork.
    2. Start the fork vibrating by tapping it on your opposite hand.
    3. Place the base of the tuning fork firmly on top of the patient's head.
    4. Ask the patient where the sound appears to be coming from (normally in the midline).
  • Compare Air and Bone Conduction (Rinne)
    1. Use a 512 Hz or 1024 Hz tuning fork.
    2. Start the fork vibrating by tapping it on your opposite hand.
    3. Place the base of the tuning fork against the mastoid bone behind the ear.
    4. When the patient no longer hears the sound, hold the end of the fork near the patient's ear (air conduction is normally greater than bone conduction).
  • Vestibular Function is Not Normally Tested

IX and X- Glossopharyngeal and Vagus

  • Listen to the patient's voice, is it hoarse or nasal?
  • Ask Patient to Swallow (bovine cough: recurrent laryngeal)
  • Examine palate for uvular movement (unilateral lesion: uvula drawn to normal side)
  • Ask Patient to Say "Ah"
    • Watch the movements of the soft palate and the pharynx.
  • Test Gag Reflex (Unconscious/Uncooperative Patient)
    1. Stimulate the back of the throat on each side.
    2. It is normal to gag after each stimulus.

XI - Accessory

  • From behind, look for atrophy or asymmetry of the trapezius muscles.
  • Ask patient to shrug shoulders against resistance.
  • Ask patient to turn their head against resistance. Watch and palpate the sternomastoid muscle on the opposite side.

XII - Hypoglossal

  • Listen to the articulation of the patient's words.
  • Observe the tongue as it lies in the mouth
  • Ask patient to:
    1. Protrude tongue (unilateral lesion deviates to affected side)
    2. Move tongue from side to side

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