A Study on Labyrinthine Ataxia with Special Reference to Proprioceptive Reflexes

Abstract

Since Ewald, the changes in the posture of animals with unilaterally or bilaterally destroyed labyrinths have been explained by a reduced muscular tonus due to a loss of “Labyrinthtonus”. However, by observing the posture of crabs with removed otocysts and rabbits with destroyed labyrinths, and the recovery curve of the H-waves in evoked EMGs recorded from the gastrocnemius m. in clinical cases with bilateral loss of excitability of the labyrinths as well as body sway in the upright position and the correlograms of the sway curve, we have demonstrated that increased antigravity muscular tonus due to increased proprioceptive reflexes is responsible for the change in posture of animals with destroyed labyrinths and for some of the features of body sway in clinical cases of loss of labyrinthine response.