Losing Vestibular Function

  • Damage from drugs, diseases, etc. can cause loss of function in the vestibular apparatus (balance organ) in one or both ears.
  • Without a functioning vestibular system, the world would feel unsteady during head movements.

Cerebellar Adaptation

  • The cerebellum can surprisingly adapt to vestibular loss.
  • If one vestibular apparatus is lost, the cerebellum recalibrates the VOR to rely solely on the healthy ear.
  • With complete vestibular loss, the cerebellum uses other sensory inputs:
    • Visual input (becomes most important)
    • Somatosensory input (mainly from the neck)

The Recovery Process

  • Losing vestibular function requires the cerebellum to relearn how to stabilize gaze.
  • This process takes about a week.
  • Vision plays a crucial role in regaining stability after vestibular loss.
  • Even with vision loss, the somatosensory system can provide some limited ability to compensate, although it’s less effective and slower.

Key Takeaway

  • The cerebellum’s ability to adjust the VOR gain allows us to recover from significant damage to the vestibular system, even complete loss.