Abstract
To disclose the association of tonic asymmetry with vestibulospinal disturbance "Arm-Tonns Reaktion" (A. T. R) was observed in normal 30 cases and 100 patients. Results obtained were as follows:
1) all of normal cases showed "negative" in A. T. R.
2) Thirty-three percent of cases with vertigo showed "positive" in A. T. R. But this per centage was by far small as compared with the rate of abnormality in Nystagmus.
3) To elevate the positive rate of A. T. R, the tonic asymmetry induced by vestibular stimulation was observed. The method to stimulate vestibular apparatus was same as "Nystagmus Cupulometry", the auther called this method "Tonic Cupulometry" By Tonic cupulometry the positive rate of A. T. R coulde be elevated about 20%.
4) Most of the positive reactors showed descendence of the arm on the affccted side.
5) To disclose the nature of tonic asymmetry induced by vestibular disturbance, E. M. G of m. biceps brachi. and m. triceps brachi in meniere's disease were studied. "K-T curve" of both m. biceps brachi and m. triceps brachi of on healthy side were normal, but only m. t. b. on affected side was abnormal. From this result, the nature of Vestrbular tonic asymmetry was considered to be due to hypotomns of extensor muscle on the affected side.
