ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Pulsatile blood flow within the normal carotid sinus involves at least two distinct components. That near the flow divider is laminar and antegrade, whereas a boundary layer separation zone in the posterolateral aspect exhibits transient blood flow reversal. It is now possible to document these flow velocity components using pulsed Doppler ultrasound methods. When atherosclerosis develops, it preferentially involves the posterolateral bulb region, obliterating the normal configuration of the sinus with consequent loss of the flow separation zone. It was therefore hypothesized that if flow separation could be detected, it should be predictive of a normal angiogram. To assess this, we evaluated 20 symptomatic patients and two with only bruits found by duplex scanning to have flow separation in either one or both carotid bulbs and who also underwent cerebral angiography. Initial diagnoses were stroke in seven, reversible ischemic neurologic deficit in one, transient ischemic attack in 12, and bruit in two. Flow separation was bilateral in 13 patients (59%). There were 15 patients with symptoms in the territory of a carotid bulb exhibiting flow separation. By angiography, of the 35 bulbs with boundary layer separation, 27 (77%) were normal, with the remainder snowing lesions that reduced the diameter of the vessel by 20% or less. Final diagnoses of the 15 patients with symptoms ipsilateral to a carotid sinus exhibiting flow separation were fibromuscular disease in two, lacunar stroke in three, dissection in two, subclavian steal in one, cardiogenic embolus in three, migraine in one, hyperventilation syndrome in one, kink of the mid‐internal carotid artery in one, and no diagnosis in one. A normal ultrasound image coupled with flow separation in the carotid bulb in patients presenting with presumptive extracramal carotid disease is therefore shown to be associated with minimal or no carotid atherosclerotic disease on angiography and to reliably predict etiology other than carotid artery disease for the symptoms. (Stroke1989;20:175–182)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Single‐photon emission computed tomography with iV‐isopropyl[mI]‐p‐iodoamphetamine (IMPSPECT) was performed in 14 normal volunteers (seven men and seven women aged 25.1±5.3 years) and 29 patients with cerebrovascular disease (18 men and 11 women aged 54.1±13.7 years). The fluid microsphere model was used to estimate cerebral blood flow (CBF). Normal subjects were scanned twice, 1 week apart, to determine the reproducibility of the CBF estimates. Hemispheric blood flow (hCBF) was calculated as the mean of regional cerebral blood flow (rCBF) values in 16 gray matter regions per hemisphere. In normal subjects mean hCBF was 68 ml/100 g/min. The highest rCBF was found in the occipital cortex, followed by the frontal, temporal, and parietal cortexes. CBF values were reproducible (p< 0.001 except the right thalamic region, wherep< 0.01). Intraindividual variation ranged between 0.3% and 15%. Women exhibited significantly higher (16%,p< 0.02) CBF than men. Patients were subdivided into groups with reversible (n= 19) and persistent (n= 10) symptoms. Significant hCBF differences between the affected and the contralateral hemispheres were recorded only in the group with reversible symptoms (/? < 0.005), whereas the group with persistent symptoms showed a significant bilateral decrease of hCBF compared with normal subjects and patients with reversible symptoms. Focal CBF was significantly lower in patients with completed stroke than in patients with transient symptoms (p< 0.001). Our results indicate that IMP‐SPECT can be used for the routine estimation of CBF in normal and pathologic states. (Stroke1989; 20:183–191)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We measured regional cerebral blood flow and [123I]iodoamphetamine (IMP) uptake in 16 patients with unilateral brain infarcts during the subacute period (Day 3 to Day 50) and again after 3 months. Our results show that the central and peripheral areas described earlier in the chronic period were already differentiated in the subacute period. The central area presented a short phase of luxury perfusion and a longer phase of IMP hyperfixation. The peripheral area showed both a slight regional cerebral blood flow decrease and an early IMP uptake decrease similar to those previously found in the chronic period. Contralateral regional cerebral blood flow during the subacute period, considered normal, was significantly lower than that during the chronic period. (Stroke1989;20:192–204)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

I provide the theoretical basis for an error calculus for measurements of cerebral blood flow using a freely diffusible tracer substance such as xenon‐133. The use of the error calculus is exemplified by a study of the effect on the error margins in measurements of gray matter blood flow from flow level, relative weight of the gray matter compartment, and use of the earliest parts of the clearance curves. The clinical value of the error calculus is illustrated by its ability to separate different sources of measurement error. As a consequence, it is possible to optimize the method for blood flow calculation from the clearance curves, depending on the type of cerebral blood flow measurement. I show that if a true picture of the regional gray matter blood flow distribution is sought, the earliest part of the clearance curves should be used. This does, however, increase the error in the estimate of the average cerebral blood flow value. (Stroke1989;20:205–210)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The two‐dimensional xenon‐133 inhalation method was used to measure cortical blood flow in 16 patients with small subcortical ischemk infarcts and in 10 patients with larger cortical infarcts in the chronic phase of stroke. An abnormal hemispheric asymmetry of blood flow was seen, not only in patients with cortical infarcts, but also in those with subcortical infarcts. In the patients with subcortical infarcts, focal areas of reduced cortical blood flow were seen in the symptomatic hemisphere remote from the tissue destruction, usually including part of the noninfarcted frontoparietal cortex. The cortical dysfunction may have contributed to the clinical manifestations including aphasia, which was present in 14 of the 16 patients with subcortical lesions. (Stroke1989;20:211–216)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Five consecutively admitted patients with aneurysmal subarachnoid hemorrhage were treated with an indwelling lumbar spinal catheter. Daily samples of cerebrospinal fluid were analyzed for erythrocyte, protein, glucose, dopamine, epinephrine, serotonin, 5‐hydroxyindoleacetic acid, tryptophan, histamine, thromboxane, 6‐ketoprostaglandin F, a, prostaglandin E, and prostaglandin F2αconcentrations. The patients' neurologic grade on admission, hospital course, presence of vasospasm, level of consciousness, computed tomographic and angiographic findings, and outcome were compared with the concentrations of the above substances in the cerebrospinal fluid. All patients had elevated concentrations of serotonin, with the highest levels found early in the hospital course of the patients who developed vasospasm. Tryptophan content increased markedly in association with clinical and angiographic vasospasm. Concentrations of prostaglandin F2αcorrelated highly with development of and fluctuations in clinical vasospasm, with angiographic findings, with neurologic grade on admission, and with outcome. Our results suggest that prostaglandin F2αmay be involved in delayed clinical vasospasm in patients with subarachnoid hemorrhage. (Stroke1989;20:217–224)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We studied 23 patients suffering cerebral ischemia who also had laboratory evidence of either a lupus anticoagulant (LA) or an abnormal anticardiolipin antibody (ACA). Four patients had lupus or a lupus‐like illness, three had drug‐induced lupus, and 16 had no overt evidence of collagen‐vascular disease. Cerebral ischemic events were multiple in 71% of the patients; two patients presented with multi‐infarct dementia. Recognized cerebrovascular disease risk factors were present in 57% of the patients. The partial thromboplastin time was prolonged in only 35% of the patients. An LA was identified in 15 of 21 patients tested, and an elevated AC A Uter was identified in 10 of 12 patients tested. Simultaneous assays for LA and ACA were discordant in eight of 10 patients tested. LA‐ and ACA‐associated brain ischemia is often recurrent, but other risk factors for cerebrovascular disease are often present. The laboratory findings in such patients may display considerable heterogeneity. (Stroke1989;20:225–229)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

To determine the importance of syphilis testing in cerebrovascular disease, we prospectively assessed 218 consecutive patients with either transient ischemic attack or completed stroke. The results from this study group were compared with those from a control group of 150 neurological patients without cerebrovascular disease. Of 275 patients from both groups specifically tested by the fluorescent treponemal antibody‐absorption test, 34% of the study group were seropositive compared with 18% of the controls (X2⩾7.7,p< 0.01). Fifty‐four percent of the patients with a positive fluorescent treponemal antibody‐absorption test underwent a cerebrospinal fluid examination; meningovascular syphilis was detected in one (0.4%) of these. This patient was a homosexual male with antibodies to the human immunodeficiency virus; a second patient, with possible meningovascular syphilis, also had antibodies to this virus. Despite the relatively high rate of syphilis seropositivity noted in our study group, syphilis was not found to be a common cause of cerebrovascular disease; therefore, routine screening is seen to be of low diagnostic yield. Attention to patients who are at higher risk for syphilitic infection, patients with clinical features suggestive of meningovascular syphilis, and the proper choice of serologic studies can help make the assessment of syphilis seropositivity more clinically appropriate and cost effective. (Stroke1989;20:230–234)

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID