A4. Examination of the trigeminal nerve

• Examination of somatosensory function
  • Lightly touch the area of each branch of the trigeminal nerve symmetrically with your thumb and index finger
    • Ophthalmic nerve – eyes and above
    • Maxillary nerve – between eyes and lips
    • Mandibular nerve – lips and below
  • Examine the pain sensation using something sharp in the same way, comparing both sides
• Examination of motor function
  • Ask: Do you get tired when chewing?
  • Palpate the temporal and masseter muscles while patient opens and closes their mouth
    • They should contract and have normal trophy (size)
• Examination of corneal reflex
  • Not routinely checked
    • Important in comatose patients, Bell’s palsy, patients with sensory loss on face
  • Touch the patient’s eye with a cotton tip
  • Normally, the patient will blink with both eyes in response
• Examination of masseter reflex
  • Ask patient to slightly, not completely, open their mouth
  • Place your finger on the patient’s chin and tap your finger with a reflex hammer
  • Normally, the jaw closes slightly in response