[Balance disorders].

Balance disorders may result from an impairment of one of the sensorial modalities involved in the perception of the self-location in space: vestibular, proprioception and vision, a deficit of the neuronal multisensorial integration, a less effective motor or loco-motor system, the medication side effects or psychological interferences. The basic examination of a dizzy patient implies the assessment of these different aspects. The balance is not restricted to à set of reflexes. It is a distinctive expression of the sixth sense : the sense of orientation. For every moving being, to go around in circles is ineffective to find new sources of food or avoid a predator. So, the ability of self-orientation in space is a primitive, unconscious function, critical to stay alive and closely related to the limbic system. The experience of the mobility, that required the spatial memory, which evolved towards the episodic memory, could be considered as the foundation of our thought.