Circulatory response in Aschner and Czermak-Hering tests, with special reference to cerebral circulation.

The Aschner and Czermak-Hering tests were carried out in 7 normal young males and 15 elderly patients with cerebral arteriosclerosis. Alterations in the heart rate, blood pressure and blood flow in the internal carotid artery and brachial artery were studied by means of the on-line Doppler ultrasonic apparatus before, during and after the maneuvers, simultaneously and continuously. Aschner Test. Bradycardia, biphasic alteration of blood pressure, increase of blood flow in the internal carotid artery and decrease of blood flow in the brachial artery were observed in the maneuver. The changing rate of the findings was diversified individually. However, no significant difference was observed between the normal young males and the elderly patients. Side effects consisted of slight and transient nausea and dizziness in 6 subjects. Czermak-Hering Test. Bradycardia, hypotension, and decrease of blood flow in the brachial artery were observed in the maneuver. The changing rate of the findings is more conspicuous in the elderly patients than in the normal young males. Alterations in the blood flow in the internal carotid artery were observed. There was a conspicuous increase of the blood flow in the internal carotid artery on the noncompressed side during the maneuver in all the normal young males and in half of the elderly patients. The remainder of the elderly patients showed either no alteration or decrease of the blood flow in the internal carotid artery on the noncompressed side. Slight nausea in 2 subjects, slight dizziness in 5 subjects, and moderate disturbance of consciousness in 1 subject were observed as side effects. The results indicate that the Czermak-Hering test will be more advantageous in investigating the autonomic nervous function (vasovagal reflex) and autoregulation of cerebral circulation in elderly subjects.