Further observations of the digital plethysmography with auditory stimuli and its clinical applications were performed in patients with vibration disease and heart diseases. The responsive pattern to the auditory stimuli in the digital plethysmogram could be faithfully reproducible if it elapses more than 5 minutes apart between the first stimulus and the second one. The responsive patterns were divided into four types: normal (N), hyperreactive (I and D) types and hyporeactive (P) type. The values of urinary catecholamine increased in parallel to the activity level of the autonomic nerve. The hyperreactive type (D) had the highest value of urinary catecholamine, and vice versa. With regard to the age, the elderly was prone to show hyporeactive (P) type, and the young tended to be hyperreactive (D) type. Psychologic factors were examined by Cornell medical index. Neurosis was not necessarily related to the hyperreactive type. In clinical applications, it was observed by this method that the autonomic imbalance in patients with vibration disease, angina pectoris, or hypertension was recovered by the treatment, and the abnormal types of the response recovered to N type. In conclusion, the digital plethysmography with auditory stimuli as one of the autonomic nerve function tests would be much useful and non-invasive method for observation of clinical course and decision of the severity.
