Neuroform stent deployment for treatment of a basilar tip aneurysm via a posterior communicating artery route.
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Coiling of a wide-necked basilar tip aneurysm can be accomplished in selected cases by placing a single Neuroform stent horizontally across the aneurysm neck via a posterior communicating artery approach rather than by placing 2 stents in a Y configuration via a basilar artery approach. (+info)
Intravenous glycoprotein IIb/IIIa inhibitor (tirofiban) followed by intra-arterial urokinase and mechanical thrombolysis in stroke.
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BACKGROUND AND PURPOSE: The purpose of this study was to evaluate preliminarily the efficacy and safety of intravenous tirofiban combined with intra-arterial pharmacologic and mechanical thrombolysis in patients with stroke. METHODS: Twenty-one consecutive patients with an acute ischemic stroke due to major cerebral arteries occlusion and a National Institutes of Health Stroke Scale [NIHSS] score > or = 18 were treated with an intravenous bolus of tirofiban and heparin followed by intra-arterial administration of urokinase coupled with mechanical thrombolysis. RESULTS: Thirteen patients had an anterior circulation stroke (T-siphon internal carotid artery [ICA] = 7; middle cerebral artery [MCA] = 6), 6 patients a posterior circulation stroke, and 2 patients an anterior plus posterior circulation stroke (left ICA or M1 tract of MCA plus basilar artery occlusions). Mean NIHSS score on admission was 21 (range, 18-27). Immediate recanalization was successful (thrombolysis in myocardial infarction [TIMI] 2-3) in 17 of 21 patients. The following day, 14 of 19 patients improved substantially and complete vessel patency (TIMI 3-4) was confirmed by digital subtraction angiography. Intracranial bleeding occurred in 5 of 21 patients (3 symptomatic cerebral hemorrhages and 2 subarachnoid hemorrhages) and was fatal in the case of 3 patients. At discharge, the mean NIHSS was 5.4 (range, 0-25). Overall, at 3-month follow-up the functional outcome was favorable (modified Rankin Scale score = 0-2) in 13 of 21 (62%) patients. Death (including all causes) at 90 days occurred in 6 of 21 (28%) cases. CONCLUSIONS: The combination of intravenous tirofiban with intra-arterial urokinase and mechanical thrombolysis may be successful in reestablishing vessel patency and result in a good functional outcome in patients with major cerebral arteries occlusions. (+info)
The hyperdense posterior cerebral artery sign: a computed tomography marker of acute ischemia in the posterior cerebral artery territory.
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BACKGROUND AND PURPOSE: In the anterior circulation, the hyperdense middle cerebral artery (MCA) sign is a well-established marker for early ischemia. Similarly, the hyperdense basilar artery sign or the MCA "dot" sign may be a diagnostic clue for basilar artery or distal MCA branch thrombosis. The purpose of this study was to define the hyperdense posterior cerebral artery (PCA) sign and determine its incidence, diagnostic value, and reliability as a marker for ischemia in the territory of the PCA. METHODS: Cranial computed tomographies (CCTs) of 48 patients with proven acute ischemia (<12 hours) in the PCA territory were compared by 3 independent and blinded readers to the CCTs of 86 age-matched patients without PCA infarction. Using follow-up imaging, the correlation of the hyperdense PCA (HPCA) with infarct size, thalamic infarction, and bleeding were investigated. RESULTS: An HPCA was found in 35.4% of all patients with PCA infarction, typically within the ambient cistern, with a specificity of 95.4%. The thalamus was affected significantly more often (P=0.009) and the size of the infarct was significantly more often large than medium (P=0.018) or small (P<0.001) when an HPCA was present. Hemorrhagic transformation tended to occur more often when the HPCA was present. CONCLUSIONS: An HPCA was detected in more than one third of all patients with PCA ischemia, suiting the incidence of the hyperdense MCA. Based on our results, this sign may not only be helpful in the early diagnosis of PCA infarction but might also act as a prognostic marker in acute PCA territory ischemic stroke. (+info)
Selective posterior cerebral artery amobarbital test in patients with temporal lobe epilepsy for surgical treatment.
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PURPOSE: To evaluate whether the selective posterior cerebral artery amobarbital test (PCAAT) can predict postoperative memory function in patients with temporal lobe epilepsy (TLE) for surgical treatment and its clinical safety. METHODS: The database included adult patients with intractable TLE undergoing presurgical evaluation at Taipei Veterans General Hospital between 1995 and 2002. The PCAAT was carried out on patients who had failed conventional intracarotid amobarbital test (IAT) or had IAT results that evoked a concern of postoperative memory function decline. A battery of learning and memory testing was performed immediately before and after injection of amobarbital into the peduncular segment of the posterior cerebral artery (PCA) on the presumed hemisphere of epileptogenicity. Neuropsychological assessments were followed in surgically treated patients. RESULTS: A total of 16 patients completed PCAAT successfully and underwent anterior temporal lobectomy (ATL). Four patients failed PCAAT angiographic procedures due to technical difficulty in one patient, transient signs of vasospasm in two patients, and subarachnoid hemorrhage in one patient. Of the 12 patients who performed well in PCAAT learning and memory testing items by free recall or recognition, only 1 patient demonstrated postoperative memory decline in follow-up neuropsychological assessments. In contrast, two of the four patients with a deficit in PCAAT memory testing showed postoperative memory decline. Regarding subjective memory function (not necessarily associated with objective memory decline), patients not seizure-free after ATL were more likely to have memory complaints (in 3 out of 6 patients) than patients with seizure-free outcomes (in 1 out of 10 patients). CONCLUSIONS: The PCAAT memory test reliably predicts postoperative memory function in patients with TLE for surgical treatment. However, the inherent risks of PCAAT must be considered and it should be used judiciously. (+info)
Peroxynitrite diminishes myogenic activity and is associated with decreased vascular smooth muscle F-actin in rat posterior cerebral arteries.
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BACKGROUND AND PURPOSE: This study investigated the effect of peroxynitrite (ONOO-) on pressure-induced myogenic activity and vascular smooth muscle (VSM) actin of isolated posterior cerebral arteries (PCAs). METHODS: Histochemical staining of nitrotyrosine (NT) was used to demonstrate the presence of ONOO- in the cerebrovasculature after 1 hour of middle cerebral artery occlusion with 30 minutes of reperfusion. To determine the effect of ONOO- on pressure-induced myogenic activity, third-order PCAs from nonischemic animals were isolated and mounted in an arteriograph chamber. Diameter in response to changes in pressure was determined in the absence and presence of ONOO- (10(-8) to 10(-4) mol/L). Filamentous actin (F-actin) and globular actin (G-actin) were quantified using confocal microscopy in PCAs with and without exposure to ONOO-. RESULTS: NT staining of vascular cells was greater in ischemic brain versus sham animals (56+/-3% versus 35+/-3%; P<0.01). Addition of low concentrations of ONOO- (< or =10(-6) mol/L) to isolated PCAs caused constriction from 129+/-16 microm to 115+/-15 microm (P<0.01), whereas concentrations >10(-6) mol/L caused dilation of spontaneous tone and loss of myogenic activity in the physiological range of 50 to 125 mm Hg, increasing diameter from 130+/-6 to 201+/-5 microm at 75 mm Hg (P<0.01). In addition, the diminished myogenic activity was associated with a 4.5-fold decrease in F-actin content of VSM and a 27% increase in G-actin content (P<0.01). CONCLUSIONS: This study demonstrates that ONOO- affects the myogenic activity of cerebral arteries and causes F-actin depolymerization in VSM, a consequence that could promote vascular damage during reperfusion injury and further brain injury. (+info)
Differential diagnosis of the infundibular dilation and aneurysm of internal carotid artery: assessment with fusion imaging of 3D MR cisternography/angiography.
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Fusion imaging of 3D MR cisternography/angiography was used for the assessment of the vascular bulging finding detected by MR angiography from the viewpoint of the outer wall configuration of the corresponding internal carotid artery depicted by MR cisternography. With a fusion image, useful information was obtained to distinguish an infundibular dilation and enlarged origin of the normal posterior communicating artery from an aneurysm. This imaging technique can be a feasible addition to a noninvasive screening of cerebrovascular lesions with MR angiography alone. (+info)
Cerebral hemodynamics in Moyamoya disease: correlation between perfusion-weighted MR imaging and cerebral angiography.
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BACKGROUND AND PURPOSE: In Moyamoya disease, the relationship between cerebral hemodynamics and angiographic findings has not been fully evaluated. The purpose of this study is to evaluate hemodynamics in Moyamoya disease with perfusion-weighted MR imaging (PWI) and cerebral angiography. METHODS: Twenty patients with Moyamoya disease were the subjects. Mean transit time (MTT) derived from PWI was calculated in the medial frontal lobes, the posterior frontal lobes, the occipital lobes, and the basal ganglia. From the angiographies, we classified the degrees of internal carotid artery (ICA) and posterior cerebral artery (PCA) stenoses as well as the degrees of Moyamoya vessels and leptomeningeal anastomosis (LMA). MTT in each region was compared with the angiographic findings. RESULTS: MTT positively correlated with the degree of ICA stenosis in the medial frontal (P < .01), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001). MTT correlated with the degree of PCA stenosis in the medial frontal (P < .001), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001). MTT correlated with the degree of Moyamoya vessels in the medial frontal (P < .05) and posterior frontal (P < .01) lobes. A multivariate analysis revealed that ICA and PCA stenoses and Moyamoya vessels were independent factors that prolonged MTT. CONCLUSION: Both ICA and PCA stenoses may influence overall cerebral perfusion in Moyamoya disease. The development of Moyamoya vessels may indicate hemodynamic impairment. (+info)
Visual neglect after right posterior cerebral artery infarction.
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OBJECTIVES: To investigate the characteristics and neuroanatomical correlates of visual neglect after right-sided posterior cerebral artery (PCA) infarction. METHODS: 15 patients with acute PCA strokes were screened for the presence of neglect on a comprehensive battery of cognitive tests. Extra tests of visual perception were also carried out on six patients. To establish which areas were critically associated with neglect, the lesions of patients with and without neglect were compared. RESULTS: Neglect of varying severity was documented in 8 patients. In addition, higher-order visual perception was impaired in 5 of the 6 patients. Neglect was critically associated with damage to an area of white matter in the occipital lobe corresponding to a white matter tract connecting the parahippocampal gyrus with the angular gyrus of the parietal lobe. Lesions of the thalamus or splenium of the corpus callosum did not appear necessary or sufficient to cause neglect, but may mediate its severity in these patients. CONCLUSIONS: PCA stroke can result in visual neglect. Interruption of the white matter fibres connecting the parahippocampal gyrus to the angular gyrus may be important in determining whether a patient will manifest neglect. (+info)