Correlation between vestibular habituation and postural recovery in cerebellar patients

Vestibular habituation was studied in normal subjects and in patients with cerebellar disease using a stimulation paradigm proposed in this paper. Six caloric stimuli were repeated daily in the same ear during six days and electronystagmographic responses at the beginning and the end of that period were compared. The normal behaviour was a clear reduction of the response across time. Two groups of cerebellar patients were identified by their ability to recover from positional imbalance after treatment. Compensated patients responded to repeated caloric stimulation in the same way as normal subjects. Conversely, uncompensated patients increased their response after the stimulation paradigm. The role played by the cerebellum in vestibular plasticity is discussed together with the observed correlation between vestibular habituation and the ability for postural recovery to occur.