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Circulatory response in Aschner and Czermak-Hering tests, with special reference to cerebral circulation
Insights
The Czermak-Hering test revealed more pronounced autonomic responses in elderly patients compared to young males, suggesting its utility in assessing cerebral circulation and vasovagal reflexes in older adults.
Area of Science:
- Neuroscience
- Cardiovascular Physiology
- Gerontology
Background:
- Autonomic nervous system function and cerebral circulation autoregulation can decline with age.
- Cerebral arteriosclerosis may impact cardiovascular responses to autonomic challenges.
- Understanding these changes is crucial for geriatric health assessment.
Purpose of the Study:
- To compare the cardiovascular and cerebral blood flow responses to Aschner and Czermak-Hering tests in young males and elderly patients with cerebral arteriosclerosis.
- To evaluate the utility of these tests in assessing autonomic nervous function and cerebral autoregulation in the elderly.
Main Methods:
- Seven young males and 15 elderly patients underwent Aschner and Czermak-Hering tests.
- On-line Doppler ultrasonography continuously monitored heart rate, blood pressure, and blood flow in the internal carotid and brachial arteries.
- Measurements were taken before, during, and after the maneuvers.
Main Results:
- Aschner Test: Both groups showed similar bradycardia, biphasic blood pressure changes, increased internal carotid artery flow, and decreased brachial artery flow.
- Czermak-Hering Test: Elderly patients exhibited more conspicuous changes in heart rate, blood pressure, and brachial artery flow compared to young males.
- Czermak-Hering Test: Internal carotid artery flow responses varied in the elderly, with some showing decreased flow on the noncompressed side, unlike young males.
Conclusions:
- The Czermak-Hering test appears more sensitive in detecting autonomic nervous system (vasovagal reflex) and cerebral circulation autoregulation differences in elderly individuals.
- The Aschner test showed no significant differences between young and elderly groups in this study.
- The Czermak-Hering test is recommended for investigating autonomic function and cerebral autoregulation in the elderly, particularly those with cerebral arteriosclerosis.
Abstract:
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.