09 Brainstem

Sections

  • top: midbrain
  • right: pons
  • lower: medulla

Midbrain

  • MLF: medial longitudinal fascicules: lesion causes lateral gaze (internuclear ophthalmoplegia)

  • red nucleus: fine tuning fine movements

  • coordinate upward gaze

Pons

  • vestibular: nausea, vomiting, vertigo, nyastagmus
  • V: pain and sensation in face
  • PPRF, MLF, CN 6 all needed for lateral gaze

Medial Pontine Syndrome

Lateral Pontine Syndrome

Medulla

  • hypothalamospinal: sympathetic nerves

Medial Medullary Syndrome

Lateral Medullary Syndrome

Rule of 4's

  • 4 CN's in medulla, 4 in pons, 4 above pons

  • big cranial nerve, stretches from pons to medulla
  • CN 8: only use hearing loss to localize to pons, not vestibular signs

Cases