ADAPTATION TO VESTIBOLOPATHIES 

Otorinolaringologia 2005 September;55(3):169-73

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: Italian

Vestibular compensation after surgical ablation

Modugno G. C.

Dipartimento di Scienze Chirurgiche ed Anestesiologiche Università degli Studi di Bologna, Bologna

A suddenly monolateral loss of vestibular function causes a symptomatic and semeiologic pattern named “vestibular decompensation”. The physiological basis of vestibular decompensation consists in a loss of functional equilibrium of tonic activity present through both sides brainstem nuclear complexes.
Already in the initial phases of vestibular decompensation, the central nervous system activates a complex neurobiological mechanism named “vestibular compensation” (CV) that in a period of 6-18 months, attenuates significantly the subjective symptomatology and semeiology until a substantial stable condition. Clinically CV distinguishes itself in “static” and “dynamic”. In the first case there is an attenuation of symptom and vestibular decompensation signs, while in dynamic compensation there is a restoration, nearly complete, of complex motor acts thanks to new dynamic-postural strategies. The achievement of this phase of CV depends on the interaction between CNS and other sensorial inputs (ocular, proprioceptive, esteroceptive, etc). A sudden loss of vestibular hemi-system input driven by a surgical act will produce many clinical-semeiological events superimposable to whom it occurs in the subsequent phases of vestibular decompensation. A different clinical expression that we will observe depends on two factors: A) vestibular function before event B) ablative treatment. Today it remains the problem of qualitative characterization of CV after surgical deafferentation. In fact we can assist a trend to entrust to self-evaluation methods the quantification of CV degree reached after ablative intervention instead of an appropriate and detailed analysis of different reflex functionality of vestibular origins or a modern bedside examination (Halmagyi test, Head shaking test, etc.).