We performed the Schellong test and measured the RR intervals on the ECGs of patients with equilibrium disorders to determine whether or not the autonomic nervous system was effected. The RR intervals were analyzed by a microcomputer to obtain two parameters,"CV%"(the static function of the autonomic nervous system while standing)and"A-B"(the dynamic function of the autonomic nervous system when changing from the supine to the standing position). The blood pressure was measured with an

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... sphygmomanometer. Both parameters(CV% and A-B)were outside the normal range more definitly in patients with central nervous system disorders than in those with peripheral vestibular disorders. This tendency was more marked for A-B. Furthermore, as the age of the patients increased, the incidence of abnormal A-B also increased in patients with peripheral vestibular disorders and in those with CNS disorders, especially the latter. The results of the Schellong test corresponded fairly well with the A-B findings. Therefore, it appears that disorders of the dynamic function of the autonomic nervous system cause an impairment of autoregulation originating in CNS disorders in elderly patients.