12 Vestibular System

  • head turn to left, eyes stay focus on object

  • 3 loops: semicircular canal
  • filled with endolymph fluid

  • otolith stones on top of hair cells move forward/backward with motion

Vestibular Dysfunction

  • vertigo: motion when there's no movement

  • 2 CN 8 pushing eye toward middle of head, keep eye centered.
  • If one nerve is gone, other slowly pushes eye towards one side. When brain detects the error, it quickly jerks the eye in the opposite direction

  • peripheral: vestibular apparatus dysfunction in inner ear
  • central: brain stem lesions, strokes

Central Vs Peripheral

  • BPV common cause of peripheral

  • changing direction: when look left may have upbeat nystagmus, look right downbeat
  • lower pt down will get immediate nystagmus
  • skew deviation: one eye higher than other

  • lie down on table: delayed

Dix-Hallpike

Benign Positional Vertigo

  • debris moves hair cells when they shouldn't be moved

Vestibular Neuronitis

  • usually after cold

Meniere's Disease