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39 results of 9 texts with exact phrase : 'posterior circulation'.

1. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 1, 2005, No. 2 , , ,

Proximal Extracranial Vertebral Artery Disease in the New England Medical Center Posterior Circulation Registry.
Wityk R, Chang H, Rosengart A, Han W, DeWitt L, Pessin M, Caplan L. Proximal Extracranial Vertebral Artery Disease in the New England Medical Center Posterior Circulation Registry.
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2. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 4, 2008, No. 1 , , ,

These findings are systolic spikes or oscillating flow in any cerebral artery which can be recorded by bilateral transcranial insonation for anterior circulation, or any intracranial vertebral or basilar artery which can be recorded by suboccipital insonation for the posterior circulation.
Certain prerequisites must be fulfilled before using Doppler sonography to confirm cerebral circulatory arrest [5, 6, 7]. The cause of coma must be established and must be sufficient to account for a permanent loss of brain function. Other conditions such as intoxication, hypothermia, severe arterial hypotension, metabolic disorders and others have been excluded. Clinical evaluation by two experienced examiners must show no evidence of cerebral or brainstem functions. Cerebral circulatory arrest can be confirmed if certain extraand intracranial Doppler sonographic findings have been recorded and documented bilaterally on two examinations at an interval of at least 30 min. These findings are systolic spikes or oscillating flow in any cerebral artery which can be recorded by bilateral transcranial insonation for anterior circulation, or any intracranial vertebral or basilar artery which can be recorded by suboccipital insonation for the posterior circulation. The diagnosis established by the intracranial examination must be confirmed by the extracranial bilateral recording of the common carotid arteries, internal carotid arteries and vertebral arteries. Ventricular drains or large openings of the skull like in decompressive craniectomy possibly interfering with the development of the intracranial pressure should not be present. During the examination blood pressure should be monitored, documented, and hypotension should be avoided.
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3. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 5, 2009, No. 1 , , ,

In contrast-enhanced examination of the posterior circulation, more detailed information about the anatomical course of the basal cerebral arteries can be obtained.
With the aid of an echo contrast agent, examination with transcranial Doppler sonography as well as color-coded duplex ultrasonography is possible even in patients with an unfavorable acoustic bone window [1, 8]. Following intravenous injection of a first generation contrast agent Levovist, the backscattered signal can be enhanced up to 25 dB because of a transient increase in echogenicity of the blood [9]. In contrast-enhanced examination of the posterior circulation, more detailed information about the anatomical course of the basal cerebral arteries can be obtained. After application of SonoVue, a longer stretch of the basilar artery is visible. Furthermore, the posterior inferior cerebellar artery (PICA), the anterior inferior cerebellar artery (AICA), and the superior cerebellar artery can be displayed. An easier visualization of the intracranial arteries facilitates the diagnostic assessment of pathological conditions.
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In a posterior circulation,
Especially in those patients whose baseline scans are not of good quality, contrast enhancement is of great value to improve the diagnostic results (Fig. 1). For further diagnostic steps and for therapy in cases of an occlusion in a middle cerebral artery, it is important to know whether failure to visualize a cerebral vessel is due to methodological problems or to a pathological condition. The absence of a color-coded signal for the middle cerebral artery is indicative of an occlusion, if a good contrast-enhanced signal for the ipsilateral posterior cerebral artery can be displayed (Fig. 1b). In a posterior circulation,
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4. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 10, 2014, No. 2 , , ,

The VMR assessment shows greater absolute measures in the anterior than the posterior circulation [26].
and this reduction is associated with impairment of the cerebral autoregulation, increased vascular stiffness [6], slow gait speed and frequent falls [27]. Also sex dependence with significantly higher VMR in women than men was found. The VMR assessment shows greater absolute measures in the anterior than the posterior circulation [26]. In orthostatic stress attenuated VMR could be observed and in this case it reflects the reduces cerebral vascular reserve to compensate the instability of the systemic circulation [13].
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5. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 11, 2015, No. 2 , , ,

Application of TCCS/TCD in Posterior Circulation Disorders.
Application of TCCS/TCD in Posterior Circulation Disorders.
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However prospective data for the posterior circulation are not yet available.
These results refer to the anterior circulation. In Basilar Artery Occlusion TE is feasible and reduces mortality to around 35%, as shown in recent registry data. However prospective data for the posterior circulation are not yet available.
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APPLICATION OF TCCS/TCD IN POSTERIOR CIRCULATION DISORDERS
APPLICATION OF TCCS/TCD IN POSTERIOR CIRCULATION DISORDERS
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Posterior circulation disorders (PCD) refer to the symptoms elicited due to the decreased blood flow in the posterior circulation (PC) of the brain.
Posterior circulation disorders (PCD) refer to the symptoms elicited due to the decreased blood flow in the posterior circulation (PC) of the brain. PCD have the following clinical manifestations: vertebrobasilar insufficiency, transitory ischemic attacks and stroke (brainstem infarction). Main causes for PCD are: stenosis or occlusion of PC vessels. Risk factors include VA hypoplasia, dissection, course anomalies, arterio-arterial embolism etc. The PCD may be caused by occlusive compression during head positional changes also.
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6. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 12, 2016, No. 1 , , ,

Areas involved by pathological changes on the scale ASPECTS: A front-circulation; P-posterior circulation; C-n.
Areas involved by pathological changes on the scale ASPECTS: A front-circulation; P-posterior circulation; C-n. caudatus; L-n. lentiformis; IC-internal capsula; I-insular ribbon; MCA-middle cerebral artery; M1 front SMA crust; M2-SMA lateral cortex of the insular ribbon; M3 rear of SMA crust; M4 M5iM6 are front, side and rear part of the territory of SMA just above the M1, M2 and M3; rostral of the basal ganglia. Subcortical structures are divided into 3 points (C, I, IC). The bark of MSA contains 7 points (insular cortex, M1, M2, M3, M4, M5 and M6).
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It is important to note that development of symptoms and the severity of stenosis are not necessarily directly related, due to collateral circulation from the contralateral carotid artery and the posterior circulation.
Clinical presentation includes transient ischemic attacks (TIA) or retinal ischemia so that typical manifestations of extracranial carotid stenosis include amaurosis fugax (transient blindness in one eye), unilateral paresis, unilateral sensory disturbances, aphasia, and dysarthria. It is important to note that development of symptoms and the severity of stenosis are not necessarily directly related, due to collateral circulation from the contralateral carotid artery and the posterior circulation.
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7. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 12, 2016, No. 2 , , ,

The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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Nowadays, more and more conditions are associated with posterior circulation.
able symptoms such as vertigo [23, 28]. The introduction of noninvasive ultrasound methods for study of blood vessels led to a greater interest in vertebral arteries [4, 5, 14]. Nowadays, more and more conditions are associated with posterior circulation. Vertebral artery hypoplasia is more and more recognized [12, 22], not only as an entity, but also as a condition that may cause certain disorders, e.g. migraine [19, 27].
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Association between vertebral artery hypoplasia and posterior circulation stroke.
Gaigalaite V, Vilimas A, Ozeraitiene V, Dementaviciene J, Janilionis R, Kalibatiene D, Rocka S. Association between vertebral artery hypoplasia and posterior circulation stroke.
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Relationship between Vertebral Artery Hypoplasia and Posterior Circulation Ischemia.
Mitsumura H, Miyagawa S, Komatsu T, et al. Relationship between Vertebral Artery Hypoplasia and Posterior Circulation Ischemia.
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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EDS, posterior circulation, rotational functional tests, TCCD, vertebrobasilar insufficiency
EDS, posterior circulation, rotational functional tests, TCCD, vertebrobasilar insufficiency
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Posterior circulation disorders (PCD) include a) vertebrobasilar insufficiency (VВI) with different clinical manifestations: vestibulocerebellar syndrome, cephalgia, cochlear syndrome, vegetovascular dystonia, visual disturbances, “syndrome of vertebral artery compression", etc.; b) vertebrobasilar TIA; and c) stroke.
Posterior circulation disorders (PCD) include a) vertebrobasilar insufficiency (VВI) with different clinical manifestations: vestibulocerebellar syndrome, cephalgia, cochlear syndrome, vegetovascular dystonia, visual disturbances, “syndrome of vertebral artery compression", etc.; b) vertebrobasilar TIA; and c) stroke. All of them are caused by blood flow disturbances in vertebral (VA), basilar (ВA) and posterior cerebral arteries (PCA).
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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Approximately 25% of ischemic strokes involve the posterior circulation.
Approximately 25% of ischemic strokes involve the posterior circulation. Vertebral artery stenosis may account for up to 20% of vertebrobasilar ischemic strokes. ln an angiographic study of 4748 patients with ischemic stroke, some degree of proximal extracranial VA stenosis was seen in 18% of the vessels on the right side of the brain and in 22% of the vessels on the left side [5]. Because of the brainstem and cerebellum involvement, vertebrobasilar stroke carries a mortality rate of more than 85%. Most survivors of basilar artery occlusion have severe, persisting disability [6].
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Symptoms are clearly of vascular origin and referable to the posterior circulation.
Brainstem softening was recognized in the 19th century, but the underlying pathology was not understood until the classic report of Kubik and Adams in 1946. lt was described as basilar artery stenosis or occlusion, vertebral artery disease in the neck (severe stenosis, hypoplasia, or occlusion), intracranial vertebral artery stenosis or occlusion, bilateral vertebral occlusive disease, arterio-arterial embolism, etc. Symptoms are clearly of vascular origin and referable to the posterior circulation. Functional vascular spasm or hemodynamic disturbances related to neck and head posture have been suggested, but mechanisms still remain unproven [7, 8].
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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ln patients with posterior circulation TlA and stroke, the presence of VB stenosis is associated with a greatly increased risk of recurrent stroke.
questions about the benefits of endovascular treatment of VA stenosis compared to medical therapy. Larger randomized trials are needed to answer this question. ln clinical practice vascular reconstruction by surgical or endovascular means is logically a reasonable option to improve the VB blood supply [16]. ln patients with posterior circulation TlA and stroke, the presence of VB stenosis is associated with a greatly increased risk of recurrent stroke. lt identifies a group of patients who have a risk as high as 33% in the first month after their initial event. Traditionally, posterior circulation stroke and TlA have been thought to have a lower recurrent stroke risk than other types of stroke. ln contrast, studies demonstrate that it is associated with a high early stroke risk; a metaanalysis suggests that the risk is higher than that seen in anterior circulation stroke [17]. Seizures and syncope are common causes for temporary loss of consciousness in РCD. The reticular activating system, which promotes wakefulness, is located in paramedian tegmentum of the upper brainstem.
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Traditionally, posterior circulation stroke and TlA have been thought to have a lower recurrent stroke risk than other types of stroke.
questions about the benefits of endovascular treatment of VA stenosis compared to medical therapy. Larger randomized trials are needed to answer this question. ln clinical practice vascular reconstruction by surgical or endovascular means is logically a reasonable option to improve the VB blood supply [16]. ln patients with posterior circulation TlA and stroke, the presence of VB stenosis is associated with a greatly increased risk of recurrent stroke. lt identifies a group of patients who have a risk as high as 33% in the first month after their initial event. Traditionally, posterior circulation stroke and TlA have been thought to have a lower recurrent stroke risk than other types of stroke. ln contrast, studies demonstrate that it is associated with a high early stroke risk; a metaanalysis suggests that the risk is higher than that seen in anterior circulation stroke [17]. Seizures and syncope are common causes for temporary loss of consciousness in РCD. The reticular activating system, which promotes wakefulness, is located in paramedian tegmentum of the upper brainstem. Basilar artery stenosis or occlusion can interrupt the function of these fibers and impair consciousness leading to coma. However, basilar occlusive disease always causes other accompanying findings, such as oculomotor and motor signs [18].
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Rotational vertebrobasilar ischemia can be very incapacitating because of the temporary impairment of cerebral blood flow to the brainstem, thalamus, and occipital lobes and possible posterior circulation stroke.
Rotational vertebrobasilar ischemia can be very incapacitating because of the temporary impairment of cerebral blood flow to the brainstem, thalamus, and occipital lobes and possible posterior circulation stroke. An accurate diagnosis depends not only on clinical symptoms, but also on hemodynamic and angiographic studies. The recognition of its peculiar characteristics and the use of TCCD are important for proper selection of patients for surgical treatment [19, 20]. The present study proves that EDS and TCCD are the noninvasive and real-time high sensitive monitoring tools assessing the structural and hemodynamic status of all arteries providing the posterior blood circulation. They can confirm the etiology of hypoperfusion in cerebrovascular insufficiency, TlA or stroke by suggesting a drop in blood flow in the presence of arterial stenosis. These methods give the possibility to evaluate the blood supply in different body positions, to detect the decrease in peak systolic velocity and MFV in BA in patients with positive RFT, estimate the collateral supply, and detect embolic
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The Role of Duplex Sonography in Posterior Circulation Disorders
The Role of Duplex Sonography in Posterior Circulation Disorders
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EDS and TCCD are important tools for estimation of high hemodynamic risk patients with PCD and rotation induced vertebrobasilar ischemia, which predicts a possible posterior circulation TIA or stroke.
EDS and TCCD are important tools for estimation of high hemodynamic risk patients with PCD and rotation induced vertebrobasilar ischemia, which predicts a possible posterior circulation TIA or stroke. These methods help the proper selection of further treatment strategy.
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Posterior circulation ischemia: then, now, and tomorrow.
Caplan LR. Posterior circulation ischemia: then, now, and tomorrow.
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Vertebral artery hypoplasia: a predisposing factor for posterior circulation stroke?
Giannopoulos S, Kosmidou M, Pelidou SH, Kyritsis AP. Vertebral artery hypoplasia: a predisposing factor for posterior circulation stroke?
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Vertebrobasilar stenosis predicts high early recurrent stroke risk in posterior circulation stroke and TIA.
Gulli G, Khan S, Markus HS. Vertebrobasilar stenosis predicts high early recurrent stroke risk in posterior circulation stroke and TIA.
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Is vertebral artery hypoplasia a predisposing factor for posterior circulation cerebral ischemic events?
Katsanos AH, Kosmidou M, Kyritsis AP, Giannopoulos S. Is vertebral artery hypoplasia a predisposing factor for posterior circulation cerebral ischemic events? A comprehensive review.
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Recent advances in acute hearing loss due to posterior circulation ischemic stroke.
Lee H. Recent advances in acute hearing loss due to posterior circulation ischemic stroke.
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Vertebral artery hypoplasia: a predisposing factor for posterior circulation stroke?
Perren F, Poglia D, Landis T, Sztajzel R. Vertebral artery hypoplasia: a predisposing factor for posterior circulation stroke?
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Vertigo, Vertebrobasilar Disease, and Posterior Circulation Ischemic
Schneider JI, Olshaker JS. Vertigo, Vertebrobasilar Disease, and Posterior Circulation Ischemic
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8. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 13, 2017, No. 1 , , ,

Left internal carotid artery occlusion; MR-angiography, gad-fl3d-tof-MIP; absence of flow signal from ICA; compensatory enhancement of signal intensity at the contralateral carotid artery and posterior circulation arteries.
Left internal carotid artery occlusion; MR-angiography, gad-fl3d-tof-MIP; absence of flow signal from ICA; compensatory enhancement of signal intensity at the contralateral carotid artery and posterior circulation arteries.
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In all cases of ICA occlusion dilatation of the contralateral ICA lumen and enhancement of the signal intensity as in the contralateral ICA and in the system of posterior circulation, as a sign of recruitment of posterior circulation flow was observed (Fig. 4).
In all cases of the occlusion of the ICA revealed by CDUS, the diagnosis was confirmed by 3D-TOF MR-angiography (100% confirmation). In all cases of ICA occlusion dilatation of the contralateral ICA lumen and enhancement of the signal intensity as in the contralateral ICA and in the system of posterior circulation, as a sign of recruitment of posterior circulation flow was observed (Fig. 4).
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9. NEUROSONOLOGY AND CEREBRAL HEMODYNAMICS, vol. 13, 2017, No. 2 , , ,

Prospective data are however not yet available for the posterior circulation.
Prospective data are however not yet available for the posterior circulation.
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