Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transcranial Doppler sonography examination was performed on 44 patients with migraine with aura and 88 controls. All patients were investigated in headache-free periods and 10 of them also during a migraine attack. During the headache-free period a not significant increase of mean flow velocity in patients compared to controls was obtained. The pulsatility index (PI) mean values were also higher in patients than in controls and the differences were significant in the MCA (p < 0.05). No difference between right and left side was observed. During the attack the mean flow velocity (MFV) decreased in all arteries but the decrease was significant only in MCA and ACA (p < 0.05). The mean PI increased in all arteries but not significantly. These variations were observed both on the headache and contralateral side. Nevertheless, the MFV decrease in all arteries was observed in four patients only. In four patients the MFV decrease was found in the anterior arteries and the MFV increase in the posterior arteries, while in two patients the MFV increase was observed both in the anterior and posterior arteries. The correlation between the variations of MFV values during the attacks and the time interval from the onset of attacks showed that the PCA and BA flow velocities were increased in patients examined between 0.5 and 3 hours, while an increase in MCA and ACA flow velocities were observed only in patients examined after 1.5 hours.
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PMID:Cerebral blood flow in migraine with aura: a transcranial Doppler sonography study. 144 88

A case of fibromuscular dysplasia (FMD) with intra- and extracranial multiple aneurysms is reported. A 42-year-old woman was admitted to Kagawa Central Hospital with severe headache and stiffness of the neck. CT scan showed subarachnoid hemorrhage predominantly in the left side of the basal cisterns and hydrocephalus. Angiography at admission revealed marked stenosis and dilatation of the extracranial major arteries and multiple aneurysms in the lt. PCA, lt. ICA, bil. VA, and the lt. renal artery. String-of-beads appearance was also seen in the branches of the lt. external carotid artery. During the operation, the PCA aneurysm which has been diagnosed as the ruptured one, was found to arise from the posterior communicating artery itself. It was thus a so-called true posterior communicating aneurysm. The aneurysm was trapped by clipping the artery on both the ICA and the PCA sides. The giant aneurysm of the lt. ICA was successfully treated by lt. STA-MCA anastomosis and ligation of the lt. ICA. Postoperative angiography demonstrated no visualization of the aneurysm and total occlusion at the origin of the lt. VA that had been patent preoperatively. On histological examination, intimal and medial hyperplasia was seen in the aneurysmal wall and occipital artery biopsied at operation. There has been no report of FMD associated with multiple and very rare posterior communicating aneurysms. Wide involvement of vascular change and advance of arterial occlusion noted by serial angiography indicates that FMD is a disease in which pathology would be progressive in some cases.
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PMID:[A case of fibromuscular dysplasia associated with intra- and extracranial multiple aneurysms]. 159 38

A 49-year-old male patient was admitted to Ryukyu University Hospital complaining chiefly of progressive loss of mental activity for one year. He had a history of head trauma at the right retromastoid region when he was 24. Generalized convulsions developed three years later, and left exophthalmos, facial varix and impairment of visual acuity developed seven years later. Dural arteriovenous fistula of the posterior fossa was diagnosed at the age of 32, and feeding EC and tentorial arteries were successively ligated on the right several times without any effect. Angiography during this admission revealed tremendous collateral flows; a marked dilated tortuous occipital artery fed from the right vertebral artery, meningeal branches of VA and PICA, the marginal tentorial artery, and the posterior temporal artery from MCA, PCA were drained into the right transverse sinus. But transverse sinuses were occluded bilaterally, and venous outflows were directed to the superior sagittal sinus retrograde via the ascending cortical vein, Trolard veins, and sphenoparietal and cavernous sinuses. The final drainer was the superior ophthalmic vein on the left. Normal deep veins were not visible. In park bench position, the nidus was totally resected with a part of the transverse and thrombosed sigmoid sinus. Postoperative course was uneventful, and an angiogram showed complete disappearance of the AVF. Dural AVG in the posterior fossa with characteristics such as high flow, and which is rich in collaterals following palliative treatment indicates that total surgical resection should be undertaken.
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PMID:[A case of successfully removed posttraumatic high flow dural arteriovenous fistula in the posterior fossa]. 188 27

Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alexia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blindness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exhibited cerebral color blindness and prosopagnosia.
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PMID:Occipital lobe infarction and positron emission tomography. 208 96

In 100 normal subjects mean flow velocity in the middle (MCA), anterior (ACA), and posterior (PCA) cerebral arteries and mean pulsatility index were examined by transcranial Doppler ultrasound. Age-dependent normal reference values were assessed. The measured parameters showed a large variation increasing with age. The highest flow velocities were found in the MCA, the lowest in the PCA. The highest mean side difference in flow velocity was observed in the ACA. An increase of pulsatility index and a decrease of flow velocities in all examined vessels were found with increasing age. The influence of ventilation and heart function on flow velocity and pulsatility index was demonstrated by the investigation of 10 normal subjects in different phases of ventilation and 1 patient with aortic valve insufficiency.
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PMID:[Transcranial Doppler sonography. Normal values and physiologic changes]. 215 57

Cerebral artery blood velocity and regional blood flow (rCBF) were investigated in 17 normal subjects. Blood velocity was measured with 2 MHz pulsed Doppler ultrasound in the proximal segments of the middle, anterior and posterior cerebral artery (MCA, ACA, and PCA) and in the distal extracranial internal carotid artery (ICA). The rCBF in the regions of interest tentatively corresponding to the perfusion territories of these vessels was estimated using 133Xe inhalation and a rapidly rotating single photon emission computer tomograph. Concomitant capnograph recordings showed that the end-expiratory pCO2 was higher during the rCBF than during the blood velocity examinations. This differences was highly significant. While there was no significant correlation between blood velocity and rCBF when these clear differences in pCO2 were disregarded, we did find significant positive correlations when the data were normalized to a standard pCO2 (5.3 kPa) using accepted formulas. The best correlation was found for the MCA (r = 0.630, p less than 0.001) and the PCA (r = 0.73, p less than 0.001), with a lower correlation in the ACA (r = 0.49, p less than 0.01) and the ICA (r = 0.41, p less than 0.05). The estimated blood velocity (V) given rCBF = 0 was not significantly different from 0. The results support the validity of expressing the relationship between blood velocity (V) and rCBF in defined cerebral artery systems as: V = 1/60 (rCBF) T (A)-1, where A represents the area of the lumen of the vessel segment where the velocity is being measured, and T denotes the size of the brain region being perfused from this artery.
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PMID:Blood velocity and regional blood flow in defined cerebral artery systems. 278 44

The effect of intravenous acetazolamide 1 g on cerebral artery blood velocity and regional blood flow (rCBF) was investigated in eight normal subjects. Blood velocity was measured with 2 MHz pulsed Doppler in the proximal segments of the middle, anterior and posterior cerebral artery (MCA, ACA, and PCA) and in the distal extracranial internal carotid artery (ICA). The rCBF in the regions of interest tentatively corresponding to the perfusion territories of these vessels was estimated using 133Xe inhalation and a rapidly rotating single photon emission computer tomograph. Both blood velocity and rCBF increased after acetazolamide. There was no significant difference between the percentage ICA blood velocity increase (22 +/- 12%) and the percentage rCBF increase in the ICA region of interest (25 +/- 9%). In the MCA, ACA, and PCA, however, blood velocity increased more (mean increase 36-42%) than the rCBF in the corresponding regions of interest (mean increase 24-26%). These differences were highly significant suggesting a direct and site specific effect of acetazolamide in narrowing the lumen of the proximal MCA, ACA, and PCA, but not of the extracranial ICA. We also propose that the effect of acetazolamide induces reciprocal changes in the extent of adjacent perfusion territories in individual brain hemispheres. Data compiled from all subjects investigated at two very different perfusion levels (before and after acetazolamide) revealed a significant positive correlation between blood velocity and rCBF.
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PMID:Effect of acetazolamide on cerebral artery blood velocity and regional cerebral blood flow in normal subjects. 278 46

Doppler analysis of flow in intracranial arteries is now possible using a 2 MHz probe, allowing sufficient penetration of bone to obtain signals noninvasively and to measure rate of flow in middle (MCA), anterior (ACA) and posterior (PCA) cerebral arteries and in basilar trunk. Practical applications of this new method are numerous in cerebrovascular disease and, despite certain limitations due to anatomic factors, transcranial Doppler may identify stenosis of the intracranial arteries and study the value of collateral flow across the anterior circle of Willis in patients with extracranial carotid artery stenosis.
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PMID:[Transcranial pulsed Doppler in the diagnosis of cerebrovascular pathology: methodology, indications and limitations]. 297 76

Measurements of flow velocity in the basal cerebral arteries can be obtained non-invasively through the intact skull using 2 MHz pulsed Doppler ultrasound. We investigated 47 patients with subarachnoid hemorrhage and compared flow velocity with angiography. Flow velocity in the middle and posterior cerebral arteries (MCA and PCA) was inversely related to the lumen diameter. Further clues to diagnose MCA spasm were obtained from the ratio of MCA flow velocity divided by the velocity in the distal extracranial internal carotid artery. In the individual patient, the two anterior cerebral arteries should be considered together, since this communicating system often has unique possibilities for collateral flow. Recordings from large MCA aneurysms were obtained before angiography in 4 patients.
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PMID:A non-invasive Doppler ultrasound method for the evaluation of patients with subarachnoid hemorrhage. 298 Jun 23

Measurements of flow velocity in defined segments of the basal cerebral arteries can be obtained through the intact adult skull using 2 MHz pulsed Doppler ultrasound. We compared flow velocity in these vessels with findings from 56 cerebral angiographies obtained in 51 patients at from day 1 to day 21 after subarachnoid haemorrhage (SAH). The diameter of the proximal segment of the middle cerebral, anterior cerebral, and posterior cerebral arteries (MCA, ACA, and PCA, respectively) were measured from anteroposterior films produced in one angiographic laboratory. In patients investigated on day 1-2, the median MCA diameter was 2.8 mm with range 2.3-3.4 mm. The median flow velocity was 56 cm/s, range 36-88 cm/s (within normal limits). There was a clear inverse relationship between the MCA diameter and MCA flow velocity. Eleven of the 13 MCA's having diameter 1.5 mm or less showed flow velocity in excess of 140 cm/s. This seems a useful limit to diagnose pronounced MCA spasm (50% diameter reduction) with this method. Further clues to the severity of MCA spasm were obtained from the ratio calculated dividing the MCA flow velocity by the flow velocity in the ipsilateral, extracranial internal carotid artery (ICA), since spasm probably does not involve the neck vessels. This ratio was from 1.1 to 2.3, median 1.7 at day 1-2, but rose to over 10 in patients with the most severe MCA lumen narrowing. The PCA flow velocity was inversely related to the PCA diameter. Assessment of ACA spasm requires considering findings from both hemispheres combined, since the two proximal ACA's usually anastomose through the anterior communicating artery.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cerebral vasospasm after subarachnoid haemorrhage investigated by means of transcranial Doppler ultrasound. 305 38


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