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Jain C, Kumar A, Vyas S, Kumar A, Singh P, Bhatia V, Ahuja C, Sahu JK, Gupta SK, Khandelwal N. Asymmetry in cerebral perfusion from circle of Willis arterial variations in normal population. Neuroradiol J 2023; 36:31-37. [PMID: 35509231 PMCID: PMC9893155 DOI: 10.1177/19714009221098366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Angiographic and cadaveric studies have evidenced variations in the circle of Willis (CoW). Age-related changes in cerebral hemodynamics may be attributable to vascular variations. OBJECTIVES The objective is to assess interdependence of completeness of CoW with age using non-invasive MRA and cerebral perfusion using arterial spin labeling (ASL). METHODS This single-center, prospective study segregated 189 subjects into three groups: ≤5, 5 to 18, and >18 years. Angiographic (complete CoW and vascular asymmetry index) using TOF and contrast-enhanced- (CE-) MRA, and perfusion (perfusion asymmetry index) data using ASL were obtained. RESULTS One hundred and six (56.08%) subjects showed complete CoW on TOF and 100 (52.91%) on CE-MRA. Anterior and posterior collateral pathways were more prevalent in the younger population. Completeness of CoW decreased with increasing age, group 1 (54/60, 90% TOF; 51/60, 85% CE), group 2 (39/64, 60% TOF; 37/64, 56.92% CE), and group 3 (13/65, 20.31% TOF; 12/65, 18.75% CE); p-value < .0001. A statistically significant decrease in cerebral and cerebellar perfusion with increasing age was seen. Cerebellar to frontal perfusion change was higher in group 1. Fetal posterior cerebral artery (PCA) led to ipsilateral low and contralateral hyperperfusion flow asymmetries between occipital lobes. CONCLUSIONS This study shows that a complete CoW is commoner in pediatrics than adults and with increasing age, the completeness of CoW decreases paralleled by decrease in cerebral and cerebellar perfusion. There is age-related shift of perfusion from hindbrain to forebrain and the regression of PCoA occurs with increasing age leading to alterations in cerebral perfusion and hemodynamics.
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Affiliation(s)
- Chirag Jain
- Department of Radiodiagnosis and
Imaging, Safdarjung Hospital, New Delhi, India
| | - Ajay Kumar
- Department of Radiodiagnosis and
Imaging, PGIMER, Chandigarh, India
| | - Sameer Vyas
- Department of Radiodiagnosis and
Imaging, PGIMER, Chandigarh, India
| | - Ashok Kumar
- National Institute of Nursing
Education, PGIMER, Chandigarh, India
| | - Paramjeet Singh
- Department of Radiodiagnosis and
Imaging, PGIMER, Chandigarh, India
| | - Vikas Bhatia
- Department of Radiodiagnosis and
Imaging, PGIMER, Chandigarh, India
| | - Chirag Ahuja
- Department of Radiodiagnosis and
Imaging, PGIMER, Chandigarh, India
| | - Jitendra K Sahu
- Department of Paediatric Neurology, PGIMER, Chandigarh, India
| | - Sunil K Gupta
- Department of Neurosurgery, PGIMER, Chandigarh, India
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Ferrucci M, Biagioni F, Ryskalin L, Limanaqi F, Gambardella S, Frati A, Fornai F. Ambiguous Effects of Autophagy Activation Following Hypoperfusion/Ischemia. Int J Mol Sci 2018; 19:ijms19092756. [PMID: 30217100 PMCID: PMC6163197 DOI: 10.3390/ijms19092756] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/10/2018] [Accepted: 09/11/2018] [Indexed: 01/07/2023] Open
Abstract
Autophagy primarily works to counteract nutrient deprivation that is strongly engaged during starvation and hypoxia, which happens in hypoperfusion. Nonetheless, autophagy is slightly active even in baseline conditions, when it is useful to remove aged proteins and organelles. This is critical when the mitochondria and/or proteins are damaged by toxic stimuli. In the present review, we discuss to that extent the recruitment of autophagy is beneficial in counteracting brain hypoperfusion or, vice-versa, its overactivity may per se be detrimental for cell survival. While analyzing these opposite effects, it turns out that the autophagy activity is likely not to be simply good or bad for cell survival, but its role varies depending on the timing and amount of autophagy activation. This calls for the need for an appropriate autophagy tuning to guarantee a beneficial effect on cell survival. Therefore, the present article draws a theoretical pattern of autophagy activation, which is hypothesized to define the appropriate timing and intensity, which should mirrors the duration and severity of brain hypoperfusion. The need for a fine tuning of the autophagy activation may explain why confounding outcomes occur when autophagy is studied using a rather simplistic approach.
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Affiliation(s)
- Michela Ferrucci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
| | | | - Larisa Ryskalin
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
| | - Fiona Limanaqi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
| | | | | | - Francesco Fornai
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
- IRCCS Neuromed, Via Atinense 18, 86077 Pozzilli (IS), Italy.
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3
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Abstract
PURPOSE OF REVIEW Non-invasive neuroimaging methods have been developed as powerful tools for identifying in vivo brain functions for studies in humans and animals. Here we review the imaging biomarkers that are being used to determine the changes within brain metabolic and vascular functions induced by caloric restriction (CR), and their potential usefulness for future studies with dietary interventions in humans. RECENT FINDINGS CR causes an early shift in brain metabolism of glucose to ketone bodies, and enhances ATP production, neuronal activity and cerebral blood flow (CBF). With age, CR preserves mitochondrial activity, neurotransmission, CBF, and spatial memory. CR also reduces anxiety in aging mice. Neuroimaging studies in humans show that CR restores abnormal brain activity in the amygdala of women with obesity and enhances brain connectivity in old adults. SUMMARY Neuroimaging methods have excellent translational values and can be widely applied in future studies to identify dietary effects on brain functions in humans.
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Nagata K, Yamazaki T, Takano D, Maeda T, Fujimaki Y, Nakase T, Sato Y. Cerebral circulation in aging. Ageing Res Rev 2016; 30:49-60. [PMID: 27484894 DOI: 10.1016/j.arr.2016.06.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/20/2022]
Abstract
Cerebral circulation is known to be protected by the regulatory function against the hypoperfusion that will affect the cognitive function as a result of brain ischemia and energy failure. The regulatory function includes cerebrovascular autoregulation, chemical control, metabolic control, and neurogenic control, and those compensatory mechanisms can be influenced by hypertension, atherosclerosis, cardiac diseases, cerebrovascular diseases and aging. On the other hand, large and/or small infarction, intracranial hemorrhage, subarachnoid hemorrhage, atherosclerosis, amylod angiopathy are also more directly associated with cognitive decline not only in those with vascular cognitive impairment or vascular dementia but also those with Alzheimer's disease.
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Affiliation(s)
- Ken Nagata
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan.
| | - Takashi Yamazaki
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan
| | - Daiki Takano
- Department of Neurology, Clinical Research Institute, Yokohama General Hospital, Yokohama, Japan
| | - Tetsuya Maeda
- Department of Neurology and Gerontology, Iwate Medical University, Morioka, Japan
| | - Yumi Fujimaki
- Department of Neurology, Research Institute for Brain and Blood Vessels, Akita, Japan
| | - Taizen Nakase
- Department of Neurology, Research Institute for Brain and Blood Vessels, Akita, Japan
| | - Yuichi Sato
- Department of Neurology, Noshiro Yamamoto Medical Association Hospital, Noshiro, Japan
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5
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Ng K, Higurashi M, Uemiya N, Qian Y. Secondary histomorphological changes in cerebral arteries of normotensive and hypertensive rats following a carotid-jugular fistula induction. PLoS One 2014; 9:e92433. [PMID: 24647348 PMCID: PMC3960250 DOI: 10.1371/journal.pone.0092433] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 02/21/2014] [Indexed: 12/04/2022] Open
Abstract
Haemodynamic changes in cerebral circulation are associated with the natural ageing process and associated pathology, leading to the development of incapacitating neurological and neurovascular diseases. Due to inherent biological limitations, current literatures mostly aimed at studying the correlation descriptively or quantifying the relationship in vitro or using computational models. In this paper, a model of a carotid-jugular fistula in the rat was used to create a haemodynamic insult to the intracranial arterial circulation and subsequent venous drainage. An arterial-venous (AV) fistula was created in 12 rats, 6 of which are normotensive Wistar-Kyoto strain (WKY) and the rest spontaneously hypertensive strain (SHR) with an additional 6 in each strains designed as controls without previous surgery. After 4 weeks of convalescence, all 24 rats were euthanised and their cerebral circulation was examined histomorphologically. We confirmed an intrinsic morphological difference between normotensive WKY and hypertensive SHR and found a modest but significant arterial shrinkage in both strains induced with AV fistula. We also reported that alterations in blood flow are also associated with marked extracellular matrix changes. We concluded that the model was suitable for studying the relative contributions of altering haemodynamic patterns and venous drainage on cerebrovascular changes. We also found that hypertension modulated cerebral vascular changes in addition to disrupted blood flow.
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Affiliation(s)
- Keith Ng
- Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia
| | - Masakazu Higurashi
- Department of Neurosurgery, Yokohama Minami Kyousai Hospital, Yokohama, Japan
| | - Nahoko Uemiya
- Department of Endovascular Neurosurgery, Saitama Medical University, Saitama, Japan
| | - Yi Qian
- Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia
- * E-mail:
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6
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Shao WH, Li C, Chen L, Qiu X, Zhang W, Huang CX, Xia L, Kong JM, Tang Y. Stereological Investigation of Age-Related Changes of the Capillaries in White Matter. Anat Rec (Hoboken) 2010; 293:1400-7. [DOI: 10.1002/ar.21184] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Patton N, Aslam T, Macgillivray T, Pattie A, Deary IJ, Dhillon B. Retinal vascular image analysis as a potential screening tool for cerebrovascular disease: a rationale based on homology between cerebral and retinal microvasculatures. J Anat 2005; 206:319-48. [PMID: 15817102 PMCID: PMC1571489 DOI: 10.1111/j.1469-7580.2005.00395.x] [Citation(s) in RCA: 499] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The retinal and cerebral microvasculatures share many morphological and physiological properties. Assessment of the cerebral microvasculature requires highly specialized and expensive techniques. The potential for using non-invasive clinical assessment of the retinal microvasculature as a marker of the state of the cerebrovasculature offers clear advantages, owing to the ease with which the retinal vasculature can be directly visualized in vivo and photographed due to its essential two-dimensional nature. The use of retinal digital image analysis is becoming increasingly common, and offers new techniques to analyse different aspects of retinal vascular topography, including retinal vascular widths, geometrical attributes at vessel bifurcations and vessel tracking. Being predominantly automated and objective, these techniques offer an exciting opportunity to study the potential to identify retinal microvascular abnormalities as markers of cerebrovascular pathology. In this review, we describe the anatomical and physiological homology between the retinal and cerebral microvasculatures. We review the evidence that retinal microvascular changes occur in cerebrovascular disease and review current retinal image analysis tools that may allow us to use different aspects of the retinal microvasculature as potential markers for the state of the cerebral microvasculature.
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Affiliation(s)
- Niall Patton
- Princess Alexandra Eye Pavilion, Chalmers Street, Edinburgh, UK.
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8
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Abstract
The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide range of histological and pathophysiological changes eventually leading to a compromised cognitive status. Although the diverse triggers of the neurodegenerative processes and their interactions are still the topic of extensive debate, the possible contribution of cerebrovascular deficiencies has been vigorously promoted in recent years. Various forms of cerebrovascular insufficiency such as reduced blood supply to the brain or disrupted microvascular integrity in cortical regions may occupy an initiating or intermediate position in the chain of events ending with cognitive failure. When, for example, vasoconstriction takes over a dominating role in the cerebral vessels, the perfusion rate of the brain can considerably decrease causing directly or through structural vascular damage a drop in cerebral glucose utilization. Consequently, cerebral metabolism can suffer a setback leading to neuronal damage and a concomitant suboptimal cognitive capacity. The present review focuses on the microvascular aspects of neurodegenerative processes in aging and AD with special attention to cerebral blood flow, neural metabolic changes and the abnormalities in microvascular ultrastructure. In this context, a few of the specific triggers leading to the prominent cerebrovascular pathology, as well as the potential neurological outcome of the compromised cerebral microvascular system are also going to be touched upon to a certain extent, without aiming at total comprehensiveness. Finally, a set of animal models are going to be presented that are frequently used to uncover the functional relationship between cerebrovascular factors and the damage to neural networks.
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Affiliation(s)
- E Farkas
- Department of Animal Physiology, Graduate School of Behavioral and Cognitive Neurosciences, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands.
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9
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Dror IE, Kosslyn SM. Age degradation in top-down processing: identifying objects from canonical and noncanonical viewpoints. Exp Aging Res 1998; 24:203-16. [PMID: 9642549 DOI: 10.1080/036107398244210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Twenty-four young (mean age 21.8 years) and 24 old (mean age 65.2 years) participants were asked to determine whether spoken words correctly named pictures of objects. Half of the objects were portrayed from noncanonical (unusual) viewpoints, and half were portrayed from canonical viewpoints. The older participants required more time and made more errors when they evaluated the noncanonical pictures (relative to the canonical pictures) than the younger participants. This finding is consistent with previous evidence that frontal lobe function degrades with aging and with results from a positron emission tomography study (S. M. Kosslyn et al., 1994) that showed that the frontal lobes (among other areas) are activated more in the noncanonical condition than in the canonical condition.
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Affiliation(s)
- I E Dror
- Southampton University, England.
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10
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Abstract
We examined sclerotic changes of the medullary arteries in 110 nonneuropsychiatric patients ranging in age from the second to the ninth decades, in 20 patients with subcortical arteriosclerotic encephalopathy (Binswanger's disease), and in 20 patients with dementia of the Alzheimer type. The principal sclerotic change was fibrohyaline thickening of the wall, which began to appear during the late fourth decade, increased in incidence gradually with age, and was most severe in patients with subcortical arteriosclerotic encephalopathy. Morphometry showed that the sclerotic changes of the medullary arteries were most prominent in the frontal lobe, followed by the parietal, occipital, and temporal lobes, in both the nonneuropsychiatric and demented groups. The sclerotic rate in the frontal lobe of patients with dementia of the Alzheimer type was slightly higher than that in the nonneuropsychiatric patients (p less than 0.05) but far less than that in the patients with subcortical arteriosclerotic encephalopathy (p less than 0.001). The sclerotic rate correlated well with the degree of ischemic white matter changes as well as with blood pressure.
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Affiliation(s)
- A Furuta
- Department of Pathology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu-shi, Japan
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11
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Ashwal S, Stringer W, Tomasi L, Schneider S, Thompson J, Perkin R. Cerebral blood flow and carbon dioxide reactivity in children with bacterial meningitis. J Pediatr 1990; 117:523-30. [PMID: 2120412 DOI: 10.1016/s0022-3476(05)80683-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We examined total and regional cerebral blood flow (CBF) by stable xenon computed tomography in 20 seriously ill children with acute bacterial meningitis to determine whether CBF was reduced and to examine the changes in CBF during hyperventilation. In 13 children, total CBF was normal (62 +/- 20 ml/min/100 gm) but marked local variability of flow was seen. In five other children, total CBF was significantly reduced (26 +/- 10 ml/min/100 gm; p less than 0.05), with flow reduced more in white matter (8 +/- 5 ml/min/100 gm) than in gray matter (30 +/- 15 ml/min/100 gm). Autoregulation of CBF appeared to be present in these 18 children within a range of mean arterial blood pressure from 56 to 102 mm Hg. In the remaining two infants, brain dead within the first 24 hours, total flow was uniformly absent, averaging 3 +/- 3 ml/min/100 gm. In seven children, CBF was determined at two carbon dioxide tension (PCO2) levels: 40 (+/- 3) mm Hg and 29 (+/- 3) mm Hg. In six children, total CBF decreased 33%, from 52 (+/- 25) to 35 (+/- 15) ml/min/100 gm; the mean percentage of change in CBF per millimeter of mercury of PCO2 was 3.0%. Regional variability of perfusion to changes in PCO2 was marked in all six children. The percentage of change in CBF per millimeter of mercury of PCO2 was similar in frontal gray matter (3.1%) but higher in white matter (4.5%). In the seventh patient a paradoxical response was observed; total and regional CBF increased 25% after hyperventilation. Our findings demonstrate that (1) CBF in children with bacterial meningitis may be substantially decreased globally, with even more variability noted regionally, (2) autoregulation of CBF is preserved, (3) CBF/CO2 responsitivity varies among patients and in different regions of the brain in the same patient, and (4) hyperventilation can reduce CBF below ischemic thresholds.
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Affiliation(s)
- S Ashwal
- Department of Pediatrics, Loma Linda University School of Medicine, California 92350
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12
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Bednarczyk EM, Rutherford WF, Leisure GP, Munger MA, Panacek EA, Miraldi FD, Green JA. Hyperventilation-induced reduction in cerebral blood flow: assessment by positron emission tomography. DICP : THE ANNALS OF PHARMACOTHERAPY 1990; 24:456-60. [PMID: 2343589 DOI: 10.1177/106002809002400501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The use of positron emission tomography (PET) has been well documented as a relatively noninvasive method of measuring cerebral blood flow (CBF), both globally and regionally. The utility of readily detecting alterations in CBF is apparent, particularly when applied to the evaluation of therapeutic interventions thought to influence CBF. We report the effects of hypocapnia, an experimental condition of known cerebral vasoconstriction, in ten normal volunteers. Subjects had brain blood flow evaluated utilizing H215O as the positron emitter before and after approximately five minutes of hyperventilation. Baseline CBF was measured as a mean +/- SD of 61.2 +/- 16.3 mL/min/100 g of tissue. Mean baseline arterial blood gas values were PaO2 107.4 +/- 14 mm Hg, PaCO2 37.7 +/- 0.89 mm Hg, and pH 7.39 (calculated from mean [H+]). Post hyperventilation, global CBF was measured as 31.1 +/- 10.8 mL/min/100 g. Mean arterial blood gas values were PaO2 141.7 +/- 21 mm Hg, PaCO2 19.7 +/- 5 mm Hg, and pH 7.63 (calculated from mean [H+]). CBF decreased by a mean of 49.5 +/- 11 percent. Data analysis using the Student's t-test showed a significant change over baseline in PaCO2 (p less than 0.001) and CBF (p less than 0.001), in the hyperventilated state. Correlations were noted between the decrease in CBF and change in PaCO2 (r = 0.81) as well as between hyperventilation PaCO2 and the change in CBF (r = 0.97). We conclude that, as measured by PET, CBF decreases significantly during a state of artificial hyperventilation to a degree consistent with results seen using other methods. PET appears to be a valuable tool in the assessment of interventions that could influence CBF.
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Affiliation(s)
- E M Bednarczyk
- Case Western Reserve University School of Medicine, Division of Cardiology, University Hospitals of Cleveland, OH 44106
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13
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Numaguchi Y, Haller JS, Humbert JR, Robinson AE, Lindstrom WW, Gruenauer LM, Carey JE. Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease. Neuroradiology 1990; 32:289-95. [PMID: 2234387 DOI: 10.1007/bf00593047] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a Xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the Xenon-CT flow studies. CBF defects on Xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images.
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Affiliation(s)
- Y Numaguchi
- Department of Radiology, Tulane University Medical Center, New Orleans, Louisiana
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14
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Ashwal S, Schneider S, Thompson J. Xenon computed tomography measuring cerebral blood flow in the determination of brain death in children. Ann Neurol 1989; 25:539-46. [PMID: 2742357 DOI: 10.1002/ana.410250603] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Local cerebral blood flow was measured using stable xenon computed tomography in 21 children, 10 of whom were clinically brain dead and had electrocerebral silence as determined by electroencephalography. Radioisotopic brain scanning in 9 patients showed no visible cerebral activity in all patients and minimal residual sagittal sinus activity in 4. In this population, mean cerebral blood flow as measured by xenon computed tomography was 1.3 +/- 1.6 ml/min/100 gm. Respiratory support was discontinued in 8 patients, and 2 patients had cardiac arrest. Eleven profoundly comatose children who did not meet all clinical criteria for brain death and who had markedly suppressed but not isoelectric electroencephalograms had an average cerebral blood flow of 33.5 +/- 16.3 ml/min/100 gm. There was no difference in cerebral blood flow in those children who survived (30.4 +/- 16.3 ml/min/100 gm; n = 7) compared with those who died acutely (38.3 +/- 14.3 ml/min/100 gm; n = 4). Two patients who survived had average total flows of only 11.8 and 12.1 ml/min/100 gm. Our findings suggest that in infants and children older than 1 month, (1) cerebral blood flow below approximately 10 ml/min/100 gm is consistent with clinical brain death, (2) cerebral blood flow of less than 5 ml/min/100 gm is consistent with no flow as demonstrated by radionuclide techniques, and (3) flow of more than 10 to 15 ml/min/100 gm is associated with the potential for survival.
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Affiliation(s)
- S Ashwal
- Department of Pediatrics, Loma Linda University School of Medicine, CA 92350
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15
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Meyer JS, Shinohara T, Imai A, Kobari M, Sakai F, Hata T, Oravez WT, Timpe GM, Deville T, Solomon E. Imaging local cerebral blood flow by Xenon-enhanced computed tomography--technical optimization procedures. Neuroradiology 1988; 30:283-92. [PMID: 3173669 DOI: 10.1007/bf00328177] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% Xenon gas in order to measure local cerebral blood flow (LCBF). Optimized Xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of Xenon gas via a face mask. Values for local brain-blood partition coefficients (L lambda) measured in vivo were utilized to calculate LCBF values. Previous methods assumed L lambda values to be normal, introducing the risk of systematic errors, because L lambda values differ throughout normal brain and may be altered by disease. Color-coded maps of L lambda and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 +/- 7.7, for subcortical gray matter was 50.3 +/- 13.2 and for white matter was 18.8 +/- 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid Xenon saturation of the blood provides correlations of L lambda and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner.
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Affiliation(s)
- J S Meyer
- Cerebral Blood Flow Laboratory, Veterans Administration Medical Center, Houston, Texas
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Sullivan HG, Kingsbury TB, Morgan ME, Jeffcoat RD, Allison JD, Goode JJ, McDonnell DE. The rCBF response to Diamox in normal subjects and cerebrovascular disease patients. J Neurosurg 1987; 67:525-34. [PMID: 3655890 DOI: 10.3171/jns.1987.67.4.0525] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Age-related norms for the regional cerebral blood flow (rCBF) response to Diamox (acetazolamide) were based on studies of 55 normal subjects at rest and on studies of 33 of these 55 normal subjects following an intravenous injection of Diamox (22 mg/kg). After the Diamox injection, rCBF increased at all locations measured in all subjects. On average, rCBF increased 1.7 times. The following were found for rCBF in both resting and Diamox-treated subjects: 1) rCBF decreased significantly with increasing age; 2) slope and intercept for the regression of rCBF on age were largest for frontal detectors, intermediate for parietal detectors, and smallest for occipital detectors; 3) rCBF hyperfrontality was most noticeable in younger subjects; 4) in subjects of any age, 95% confidence intervals for rCBF were relatively large (expected value +/- 30%) and lower 95% confidence intervals for Diamox rCBF tended to overlap the upper 95% confidence intervals for resting rCBF; and 5) side-to-side percentage difference in rCBF did not have a significant regression on age and tended to be less than 10% to 20%. Diamox did not have an important effect on blood pressure, pulse rate, or respiratory rate. The normative data for the rCBF response to Diamox was used in evaluating 20 patients with cerebrovascular disease. Forty percent of these patients, all of whom exhibited angiographic evidence of potentially hemodynamically significant lesions, had normal rCBF at rest and after Diamox injection. Twenty percent had normal resting flows with abnormal Diamox-activated flows. Asymmetry in rCBF was the most sensitive indicator of a potential abnormality in cerebral perfusion. Thirty percent of the abnormal studies showed only significant asymmetry. It is suggested that rCBF studies at rest and after Diamox treatment, with age-related norms, may be useful in the management of patients with cerebrovascular disease.
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Affiliation(s)
- H G Sullivan
- Section of Neurosurgery, Medical College of Georgia, Augusta
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