Evolution of BV and stabilization process

Balance disorders and oscillopsia are better tolerated over time thanks to self-care, health professionals and close friends who all support the patient in his or her development. Different processes are brought into play by the body over time to respond to the loss of vestibular function and the two reflexes related to it.

  • Vicariance

In particular, the patient will develop his cervico-ocular reflex (OCR), which involves proprioception. Tests have shown that this function quickly becomes ten times more developed in an areflexic patient than in a healthy subject. This rise in power of hitherto untapped resources is what is known as vicariance. Etymologically, "the vicar tries to become a parish priest".
The cervico-ocular reflex attempts, with very little effectiveness, to replace the deficit vestibulo-ocular reflex. The efficiency of the cervico-ocular reflex in patients with bilateral arereflexia is only 40%, which is therefore not very useful even if this efficiency is much higher than the zero efficiency in healthy subjects..

  • Adaptation

In addition to seeing a reflex try to compensate for the absence of the other two, the brain, and in particular the cerebellum, will learn, on the one hand, to better process the information provided to them and, on the other hand, to find, through other circuits, those that they lack. The brain and cerebellum are neuro-plastic organs, "plastic" here meaning "flexible and adaptable". Neuroplasticity contributes to our ability to learn and adapt to new situations throughout our lives. It is thanks to this ability that spatial orientation gradually improves. In practice, this adaptation requires an immense effort of willpower and daily exercises, repeated; It is repetition that allows the brain to adapt and retain new information.

  • Habituation

Time doing its work, patients "forget" what life is like with stable vision and uncontrolled walking. This habituation can be considered as a resource, even if it is obviously difficult to conceive of its benefit when the diagnosis is announced. It is important to understand that habit contributes to the acceptance of illness and disability. However, it does not prevent fatigue, daily difficulties and the risk of falling. It is essential that those around the patient are aware of this.

  • From substitute to dependency

As we have seen, in the absence of vestibules, the predominant sources of information are sight and proprioception. The use of these substitutes requires a learning time. This learning time and the effectiveness of the substitutes used will be directly determined by the intensity of the reeducation, or rather the spontaneous self-reeducation, offered by going back to daily life. However, the substitute often generates dependency, especially on sight. By dependency, we mean that the substitute goes beyond its purpose. Vision helps, but it can get in the way. So when the image moves, the patient does not know if it is oscillopsia, if it is his own body that is moving, or if it is what he is seeing; And that can make him stagger. This is what makes it so difficult for him or her to experience the crowd, and makes one patient say: "On public transport, what bothers me the most is the fast-moving crowd passing by me." The patient must therefore learn not to be deceived by an excess of visual information that comes as a substitute.


Last edited: 04/05/2024