Evaluation of imbalance of the vestibulo-spinal reflex by "the circular walking test".

A sensitive method of demonstrating latent imbalance of labyrinthine function was devised. The subject was asked to walk at his or her usual speed with eyes closed in a circle 2 m in diameter. This test was done by 22 patients whose vestibular function as tested by the Romberg, Mann, Fukuda and Babinski-Weil's methods had become normal after an attack of vertigo due to unilateral vestibular disorder. Eighteen patients complained of difficulty in walking while turning toward the affected side, and 11 tended to fall to the inside of the circle. Turning in the opposite direction, however, was performed without any difficulty. It was thought that disorders of the cristospinal reflex became manifest during circular walking toward the affected side. The body is inclined to the inner side of circular walking. Endolymph flows toward the ampulla of the lateral semicircular canal on the same side as turning. This would exert a facilitatory action on extensor neurons and give the ipsilateral leg assistance for supporting the body's weight which shifts to the centre of the circle. Disorders of the cristospinal reflex would cause difficulty in circular walking toward the affected side.