The purpose of the study was to investigate the association between Ischemic stroke and the ultrasonographic (US) characterization of carotid plaque on the basis of our original work and of a review of the literature. Carotid plaque is known to be a reliable marker of Ischemic stroke and systemic atherosclerosis. There is much evidence from secondary prevention trials to indicate a direct relationship between the surface and internal US characterization of carotid plaque and stroke. Moreover, in the primary prevention of stroke, the Cardiovascular Health Study showed that the risk of incident stroke was associated with two US features, hypoechoic internal carotid arterial plaque and an estimated internal carotid arterial stenosis of 50%-100%, in asymptomatic adults aged 65 years. However, many studies that have compared the morphologic features of carotid plaque as revealed by both US studies and histology have shown a relatively low rate of detection of important features such as intraplaque hemorrhage. Furthermore, although severe carotid stenosis is associated with a higher risk of stroke events, the power of US to predict such events is limited by low incidence rates and low rate of progression. We conclude that US plaque characterization should be used together with other risk factors in prospective natural history studies that aim to identify a subgroup of patients at high risk of stroke.
Cerebral blood flow changes during and after indirect moxibustion stimulation at the acupuncture point HO-KU (L-14), which is located between the thumb and index finger, were measured by transcranial Doppler ultrasound (TCD) . The mean blood flow velocities (Vm) of the right middle cerebral artery (MCA) in 10 normal subjects were measured continuously during and until 15 minutes after the stimulation. The Vm showed 2 peaks, at 1 minute after and 7 minutes after the stimulation. The extent of change in flow velocity was 23% at the first elevation and 20 - 26% at the second elevation. The second elevation of the flow velocity continued until 15 minutes after the stimulation. The heart rate increased at the first elevation and then returned to its previous level, but did not change at the second elevation. To evaluate vascular reactivity, a hyperventilation test was done before and after the examination ; it showed normal vascular reactivity at both points. The second elevation seemed to be induced by the effect of moxibustion. Vascular reactivity remained normal and no significant vascular diameter changes seemed to occur. From our results, a significant increase of cerebral blood flow is induced by indirect moxibustion stimulation.
The aim of this study is to clarify whether it is possible to diagnose occlusion of the internal carotid artery (ICA) by observing the existence of anterograde diastolic flow at the cervical ICA by duplex carotid Sonography (DCS) . 77 patients (cardioembolic brain infarction, 12 cases ; atherothrombotic brain infarction, 22 cases ; lacunar brain infarction, 12 cases ; other brain infarction or miscellaneous brain infarction, 9 cases ; TIA, 8 cases ; other disease, 14 cases) who had undergone both cerebral angiography and DCS were included. For all cases we established whether or not anterograde diastolic flow at the cervical ICA could be detected by DCS, and these findings were compared with those of cerebral angiography. All the 8 cases without anterograde diastolic flow in the internal carotid artery were diagnosed by cerebral angiography as having occluded internal carotid artery. Sixty - eight of the 69 patients with anterograde diastolic flow were diagnosed as having patent internal carotid artery. We conclude that diagnosis of internal carotid artery occlusion can be made by observing the presence of anterograde diastolic flow at the cervical ICA by DCS.
To evaluate the usefulness of ophthalmic artery (OA) color Doppler flow imaging (CDFI) in the occlusive internal carotid artery (ICA) diseases, the authors examined OA CDFI findings. Materials and Methods : OA CDFI was performed in 140 patients to determine OA flow direction, waveform and peak systolic flow velocity (PSV) . Revascularization surgery was performed in 41 patients. Results : 1) Twenty-four patients showed a reversed waveform pattern. Among these, 18 patients (74%) had ICA occlusion and the other 6 patients (27%) had more than 70% ICA stenosis. 2) Thirty-four patients demonstrated the arch stenotic waveform. More than 50% ICA stenosis was seen in 16 patients (48%), and ICA occlusion was seen in 26% of cases. 3) We observed a sclerotic waveform in 19 patients. Four patients showed another type of abnormal waveform, and 59 patients showed the normal waveform. Among the 59 patients showing the normal waveform, 16 patients (27%) had more than 50% ICA stenosis. 4) In 15 patients who received superficial temporal artery to middle cerebral artery bypass, the patients with preoperative reversed waveform showed a significant (p<0.05) improvement of the flow direction and PSV during the postoperative stage. In 26 patients who received carotid endarterectomy, the OA CDFI findings significantly improved immediately after surgery (p<0.05) . Conclusion : OA CDFI shows good correlation with occlusive ICA diseases and reflects the effects of revascularization surgery.
There are multiple factors and disorders causing vertigo and dizziness. Furthermore, it is improved soon under the usual therapies, so enough study of its pathogenecity has not been done and not been able to be done. But some cases (especially so-called cervical vertigo, benign positional vertigo, vertebrobasilar insufficiency etc. ) seem to be related to a low blood flow state of vertebro-basilar arterial circulation. There is objectively almost no adequate method to detect the phenomena at present. At this time we have studied 43 patients without otological diseases who complained of vertigo or have had it before. First we used ultrasonography and examined the blood flow and the form of the first segment of the vertebral artery (VAlst) by Color Doppler flow image (CDFI) and 3 dimensional color power angio (3D-CPA) with the power doppler method. By using these modalities, we have been able to see the vascular specifics and deviations of VAl St that were accompanied by the process of neck rotations from right to left. Pulsatility index (PI) and Resistive index (RI) show vascular perculiarity and vascular blood flow changes. According to statistics in RI, there were differences between the neck position of rotating to the right side (R-rVA) and the neutral position of the right VAlst (N-rVA) (p=0.0105), the neck position of rotating to the right side (R-1VA) and the neck position of rotating to the left of the left VAlst (L-1VA) (p=0.0054) . Furthermore, in the PI, there were differences between R-rVA and N-rVA (p=0.0276), L-rVA and N-rVA (p=0.0130) of the right VAlst, R-1VA and L-1VA (p=0.0130) . So neck rotations have to be exercised greatly as influences on the blood flow mechanism at VAlst. Furthermore, there is a sufficiently similar correlation between CPA and cervical magnetic resonance angiography.
We report a case with AVM who was studied by TCD and SPECT to evaluate the hemodynamic changes before and after treatment (feeder embolizations followed by surgical resection) . A 23 - year - old man was admitted to our hospital with convulsive seizures. Preoperative cerebral angiogram showed left parieto-occipital AVM fed from the MCA and PCA branches. A preoperative SPECT study showed decreased blood flow in the area surrounding the AVM. SPECT with acetazolamide challenge showed a decrease of cerebrovascular response at the left parieto - occipital lobe. A TCD study showed an increase of the left middle cerebral artery mean flow velocity (MCAmFV) and a decrease of the pulsatility index (PI) . TCD after hyperventilation (5 min) showed a decrease of the right MCAmFV and an increase of PI. Conversely, left MCAmFV and PI were not changed. These findings indicated a potential risk of post - operative hyperemic complications from a single - stage resection of the AVM. We performed feeder embolization (TAE) as the first step. SPECT with acetazolamide challenge showed improvement of the cerebrovascular response at the parieto - occipital lobe. A TCD study after embolization also showed a decrease of the left MCAmFV and an increase of PI. The changes in mFV and PI after hyperventilation returned to the normal response. Surgical resection was performed uneventfully one week after embolization and the patient returned to normal life. TCD is a useful monitoring tool to evaluate hemodynamic changes and guide the selection of the optimum surgical treatment of high flow AVM.