Measurement of cerebral blood flow by ultasonic Doppler technique. Hemodynamic correlation of internal carotid artery and vertebral artery

Traditional Chinese Medicine's liver yang ascendant hyperactivity pattern of essential hypertension and its treatment approaches: A narrative review

"Liver yang ascendant hyperactivity" (SF52), as termed by WHO, is a commonly observed pattern of essential hypertension (EH), herein referred to as EH-SF52. This paper summarizes the Traditional Chinese Medicine (TCM) perspectives, biomedical findings, and TCM managements for EH-SF52 in modern times. EH-SF52 is generally identified as an EH individual presenting with headache, dizziness, poor sleep quality, tinnitus, facial flushing, fatigue, signs of mild dehydration, and whom are highly irritable individuals with a tendency to overthink, be competitive, or be aggressive. The proposed EH-SF52 model features a state of autonomic imbalance and vascular changes that accounts for the above symptoms. TCM managements for EH-SF52 includes Chinese herbal medication, acupuncture, qigong, taichi, massage, food therapy, as well as lifestyle changes, which targets symptomatic alleviation and blood pressure reduction in a multi-mechanistic manner. An increasing shift towards integrated practice of TCM and western medicine in EH-SF52 requires effective communication between both disciplines.

The effect of a cerebral vasodilator, vinpocetine, on cerebral vascular resistance evaluated by the Doppler ultrasonic technique in patients with cerebrovascular diseases

Changes in cerebral vascular resistance were examined in patients with cerebral circulatory diseases by the Doppler ultrasonic technique after administration of a cerebral vasodilator, vinpocetine, for two months. Continuous index (CI) and pulsatility index (PI) of the blood flow pattern in the internal carotid artery were used as objective parameters for changes in cerebral vascular resistance. 1. The CI and PI changed significantly after administration of the drug; ie, the CI increased while the PI decreased. 2. An inverse correlation was noted between the rate of change of the CI (delta CI) and that of the PI (delta PI). 3. The results suggest that measurement of the CI and PI by the Doppler ultrasonic technique is useful in investigating the effect of drugs on the cerebral circulation.

Diagnostic reliability of the percutaneous ultrasonic Doppler technique for vertebral arterial occlusive diseases

There is little data on the diagnostic reliability of the ultrasonic Doppler technique for vertebral arterial occlusive lesions. Percutaneous vertebral Doppler examination and the vertebral angiograms were compared to determine the diagnostic reliability of this technique in 64 vertebral arteries of 53 patients with cerebrovascular disease. The percutaneous vertebral Doppler findings were quantitatively analyzed using a sound spectrograph and were classified into three types: no flow signal type, poor flow type and normal flow type. In nine patients with the no flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in six, giving a diagnostic reliability of 67%. In 17 patients with poor flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in five, terminal narrowing of the artery in nine, and hypoplasia in two giving a diagnostic reliability of 94%. For all vertebral arteries examined with this technique, including normal ones, the diagnostic reliability was 92% (59/64). Percutaneous vertebral Doppler examination has clinical usefulness as a screening test for occlusive vertebral arterial diseases.

Noninvasive angiography for the diagnosis of vertebral artery disease using Doppler ultrasound (vertebral artery Doppler)

A transoral noninvasive procedure in the oropharynx using local anesthesia was applied to detect flow in the vertebral arteries with a bidirectional continuous-wave Doppler ultrasound system. Common carotid artery compression was used to identify the vertebral artery. Flow direction, amplitude of flow signals, diastolic flow, and reaction of flow on common carotid artery compression served as diagnostic parameters. The procedure was applied in 90 patients of whom 42 underwent angiography. The method has proved to be 82% accurate. It was most reliable in the diagnosis of occlusion or aplasia, subclavian steal and normalcy, and was less reliable in the detection of stenosis or hypoplasia of a vertebral artery. Eleven patients with subclavin steal, five patients with a missing vertebral artery three patients with hypoplasia or stenosis, and 15 patients with normal angiorgraphical findings were correctly diagnosed by Doppler; normal Doppler findings were present in three patients with a mission or stenosed vertebral artery. Those patients (five) with Doppler indications of subclavian steal (one patient), missing vertebral artery (two patients), or stenosis (two patients) had normal angiograms. Application of the Doppler procedure, after 11 subclavin endarterectomies, informed the surgeon immediately about the hemodynamic effect of surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Newer techniques of cerebral blood flow measurement

A variety of methods for measuring cerebral blood flow have been developed in the past 25 years since Kety and Schmidt developed their method based on the Fick principle. None of the currently used methods approaches the clinical ideal, since none of the techniques are accurate, reproducible and noninvasive. Most accurate techniques involve catheterization of internal carotid artery and/or jugular vein with those attendant risks. There has been considerable enhancement of our understanding of the pathophysiology of cerebral circulation, particularly in the areas of brain injury and disordered systemic metabolism, but the clinical usefulness of the test at the present time is limited.