[Equilibrium disorders, vertigo and nystagmus induced by maximal deviation of gaze. Role of extra-ocular proprioception].

The behavior of 64 normal subjects was studied after they had been submitted to excentric lateral ocular fixation of gaze of more than 40 degrees for periods of one the three minutes. A significant proportion developed vertigo, slow segmental deviations and nystagmus. Nystagmus appearing during gaze fixation (physiological nystagmus of extreme lateral gaze) was distinguished from nystagmus in the opposite direction which appeared after cessation of fixation and was named "post-fixation nystagmus". The possible role of proprioceptive receptors in the extra-ocular muscles is discussed and a hypothesis proposed of an oculo-oculogyric reflex possibly through the vestibular nuclei and influencing the control mechanisms of posture and balance.