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Hamdule S, Kirkham FJ. Brain Volumes and Cognition in Patients with Sickle Cell Anaemia: A Systematic Review and Meta-Analysis. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1360. [PMID: 37628359 PMCID: PMC10453222 DOI: 10.3390/children10081360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023]
Abstract
Cognitive decline is a major problem in paediatric and adult patients with sickle cell anaemia (SCA) and affects the quality of life. Multiple studies investigating the association between quantitative and qualitative neuroimaging findings and cognition have had mixed results. Hence, the aetiology of cognitive decline in this population is not clearly understood. Several studies have established cerebral atrophy in SCA children as well as adults, but the relationship between cognition and brain volumes remains unclear. The purpose of this systematic review was therefore to evaluate the literature on regional brain volumes and their association with cognitive outcomes. We also meta-analysed studies which compared regional brain volumes between patients and controls. Studies report that patients with SCA tend to have lower grey matter volumes, including total subcortical volumes in childhood as compared to controls, which stabilise in young adulthood and may be subjected to decline with age in older adulthood. White matter volumes remain stable in children but are subjected to reduced volumes in young adulthood. Age and haemoglobin are better predictors of cognitive outcomes as compared to regional brain volumes.
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Affiliation(s)
- Shifa Hamdule
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK;
| | - Fenella J. Kirkham
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK;
- Clinical and Experimental Sciences, University of Southampton, Southampton SO16 6YD, UK
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2
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Abdi SS, De Haan M, Kirkham FJ. Neuroimaging and Cognitive Function in Sickle Cell Disease: A Systematic Review. CHILDREN 2023; 10:children10030532. [PMID: 36980090 PMCID: PMC10047189 DOI: 10.3390/children10030532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 03/12/2023]
Abstract
Sickle cell disease (SCD) is the most common inherited single-gene disease. Complications include chronic anaemia, reduced oxygen-carrying capability, and cerebral vasculopathy, resulting in silent cerebral infarction, stroke, and cognitive dysfunction with impairments in measures of executive function, attention, reasoning, language, memory, and IQ. This systematic review aims to investigate the association between neuroimaging findings and cognition in children with SCD. Searches of PubMed and Embase were conducted in March 2022. Studies were included if participants were <18 years, if original data were published in English between 1960 and 2022, if any genotype of SCD was included, and if the relationship between cognition and neuroimaging was examined. Exclusion criteria included case studies, editorials, and reviews. Quality was assessed using the Critical Appraisal Skills Programme Case Control Checklist. A total of 303 articles were retrieved; 33 met the eligibility criteria. The presence of overt or silent strokes, elevated blood flow velocities, abnormal functional connectivity, and decreased fMRI activation were associated with neuropsychological deficits in children with SCD when compared to controls. There is a critical need to address the disease manifestations of SCD early, as damage appears to begin at a young age. Most studies were cross-sectional, restricting the interpretation of the directionality of relationships. Future research employing longitudinal neuroimaging and neuropsychological assessments could improve our understanding of the cumulative consequences of SCD on the developing brain.
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Affiliation(s)
- Suad S. Abdi
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Michelle De Haan
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
| | - Fenella J. Kirkham
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London WC1N 1EH, UK
- Clinical and Experimental Sciences, University of Southampton, Southampton SO16 6YD, UK
- Child Health, University Hospital Southampton, Southampton SO16 6YD, UK
- Correspondence:
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3
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Mayer SL, Fields ME, Hulbert ML. Neurologic and Cognitive Outcomes in Sickle Cell Disease from Infancy through Adolescence. Neoreviews 2021; 22:e531-e539. [PMID: 34341160 DOI: 10.1542/neo.22-8-e531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Children with sickle cell disease (SCD) are at risk for neurologic and cognitive complications beginning in early childhood. Current treatment for SCD focuses on primary prevention of complications, such as hydroxyurea for prevention of pain and acute chest syndrome, and chronic transfusion therapy for children who are at high risk for strokes. In this article, the prevalence, pathophysiology, and available interventions to prevent and treat neurologic and cognitive complications of SCD will be reviewed.
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Affiliation(s)
- Sarah L Mayer
- Children's Hospital of Philadelphia, Philadelphia, PA
| | - Melanie E Fields
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Washington University in St Louis, St Louis, MO
| | - Monica L Hulbert
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Washington University in St Louis, St Louis, MO
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4
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Lance EI, Cannon AD, Shapiro BK, Lee LC, Johnston MV, Casella JF. Co-Occurrence of Neurodevelopmental Disorders in Pediatric Sickle Cell Disease. J Dev Behav Pediatr 2021; 42:463-471. [PMID: 34397573 PMCID: PMC8369039 DOI: 10.1097/dbp.0000000000000914] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/01/2020] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The objective of this study is to retrospectively determine the co-occurrence, associated characteristics, and risk factors for neurodevelopmental disorders (NDD) in a pediatric sickle cell disease (SCD) clinic population. METHOD We investigated the co-occurrence and features of NDD in pediatric SCD through a retrospective cohort study conducted between July 2017 and January 2019. The participants were patients with SCD younger than 18 years of age identified from our institutions' clinic rosters and medical records databases. RESULTS A total of 276 participants were eligible for study inclusion, and 65 participants were found to have various NDD. Children with SCD and NDD were more likely to have a history of multiple SCD-related complications in comparison to children with SCD without NDD. Children with SCD and NDD were more likely to use disease-modifying therapies in comparison to children with SCD without NDD (χ2 27.2, p < 0.001). CONCLUSION Children with SCD and NDD have higher odds of having certain disease-related complications and higher use of disease-modifying treatments than children with SCD who do not have NDD. Screening and diagnoses of NDD may be relevant to clinical management of pediatric SCD.
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Affiliation(s)
- Eboni I. Lance
- Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Bruce K. Shapiro
- Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD
- Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Li-Ching Lee
- Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Michael V. Johnston
- Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - James F. Casella
- Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
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5
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Jiao Y, Wang XH, Chen R, Tang TY, Zhu XQ, Teng GJ. Predictive models of minimal hepatic encephalopathy for cirrhotic patients based on large-scale brain intrinsic connectivity networks. Sci Rep 2017; 7:11512. [PMID: 28912425 PMCID: PMC5599725 DOI: 10.1038/s41598-017-11196-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 08/18/2017] [Indexed: 01/09/2023] Open
Abstract
We aimed to find the most representative connectivity patterns for minimal hepatic encephalopathy (MHE) using large-scale intrinsic connectivity networks (ICNs) and machine learning methods. Resting-state fMRI was administered to 33 cirrhotic patients with MHE and 43 cirrhotic patients without MHE (NMHE). The connectivity maps of 20 ICNs for each participant were obtained by dual regression. A Bayesian machine learning technique, called Graphical Model-based Multivariate Analysis, was applied to determine ICN regions that characterized group differences. The most representative ICNs were evaluated by the performance of three machine learning methods (support vector machines (SVMs), multilayer perceptrons (MLP), and C4.5). The clinical significance of these potential biomarkers was further tested. The temporal lobe network (TLN), and subcortical network (SCN), and sensorimotor network (SMN) were selected as representative ICNs. The distinct functional integration patterns of the representative ICNs were significantly correlated with behavior criteria and Child-Pugh scores. Our findings suggest the representative ICNs based on GAMMA can distinguish MHE from NMHE and provide supplementary information to current MHE diagnostic criteria.
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Affiliation(s)
- Yun Jiao
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, 210009, China
| | - Xun-Heng Wang
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Rong Chen
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, School of Medicine, Baltimore, MD, 21201, USA
| | - Tian-Yu Tang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, 210009, China
| | - Xi-Qi Zhu
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, 210009, China.,Department of Radiology, The Second Hospital of Nanjing, Medical School of Southeast University, Nanjing, 210003, China
| | - Gao-Jun Teng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, 210009, China.
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6
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Chen R, Krejza J, Arkuszewski M, Zimmerman RA, Herskovits EH, Melhem ER. Brain morphometric analysis predicts decline of intelligence quotient in children with sickle cell disease: A preliminary study. Adv Med Sci 2017; 62:151-157. [PMID: 28279885 DOI: 10.1016/j.advms.2016.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 09/06/2016] [Accepted: 09/14/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE For children with sickle cell disease (SCD) and at low risk category of stroke, we aim to build a predictive model to differentiate those with decline of intelligence-quotient (IQ) from counterparts without decline, based on structural magnetic-resonance (MR) imaging volumetric analysis. MATERIALS AND METHODS This preliminary prospective cohort study included 25 children with SCD, homozygous for hemoglobin S, with no history of stroke and transcranial Doppler mean velocities below 170cm/s at baseline. We administered the Kaufman Brief Intelligence Test (K-BIT) to each child at yearly intervals for 2-4 years. Each child underwent MR examination within 30 days of the baseline K-BIT evaluation date. We calculated K-BIT change rates, and used rate of change in K-BIT to classify children into two groups: a decline group and a non-decline group. We then generated predictive models to predict K-BIT decline/non-decline based on regional gray-matter (GM) volumes computed from structural MR images. RESULTS We identified six structures (the left median cingulate gyrus, the right middle occipital gyrus, the left inferior occipital gyrus, the right fusiform gyrus, the right middle temporal gyrus, the right inferior temporal gyrus) that, when assessed for volume at baseline, are jointly predictive of whether a child would suffer subsequent K-BIT decline. Based on these six regional GM volumes and the baseline K-BIT, we built a prognostic model using the K* algorithm. The accuracy, sensitivity and specificity were 0.84, 0.78 and 0.86, respectively. CONCLUSIONS GM volumetric analysis predicts subsequent IQ decline for children with SCD.
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7
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Chai Y, Lao Y, Li Y, Ji C, O'Neil S, Wang Y, Lepore N, Wood J. Multivariate surface-based analysis of corpus callosum in patients with sickle cell disease. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016; 10160:101600A. [PMID: 31178616 PMCID: PMC6554202 DOI: 10.1117/12.2257399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sickle cell disease (SCD) is a genetic hematological disease in which the hemoglobin molecule in red blood cells is abnormal. It is closely associated with many symptoms, including pain, anemia, chest syndrome and neurocognitive impairment. One of the most debilitating symptoms is elevated risk for cerebro-vascular accidents. The corpus callosum (CC), as the largest and most prominent white matter (WM) structure in the brain, can reflect the chronic cerebrovascular damage resulting from silent strokes or infarctions in asymptomatic SCD patients. While a lot of studies have reported WM alterations in this cohort, little is known about the shape deformation of the CC. Here we perform the first surface morphometry analysis of the CC in SCD patients using four different shape metrics on T1-weighted magnetic resonance images. We detect regional surface morphological differences in the CC between 11 patients and 10 healthy control subjects. Differences are located in the genu, posterior midbody and splenium, potentially casting light on the anatomical substrates underlying neuropsychological test differences between the SCD and control groups.
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Affiliation(s)
- Yaqiong Chai
- CIBORG laboratory, Department of Radiology, Children's Hospital Los Angeles, CA, USA
- Department of Radiology, University of Southern California, CA, USA
- Department of Biomedical Engineering, University of Southern California, CA, USA
| | - Yi Lao
- CIBORG laboratory, Department of Radiology, Children's Hospital Los Angeles, CA, USA
- Department of Radiology, University of Southern California, CA, USA
- Department of Biomedical Engineering, University of Southern California, CA, USA
| | - Yicen Li
- Department of Electrical Engineering, University of Southern California, CA, USA
| | - Chaoran Ji
- Department of Electrical Engineering, University of Southern California, CA, USA
| | - Sharon O'Neil
- CIBORG laboratory, Department of Radiology, Children's Hospital Los Angeles, CA, USA
- Department of Radiology, University of Southern California, CA, USA
- Department of Biomedical Engineering, University of Southern California, CA, USA
- Department of Electrical Engineering, University of Southern California, CA, USA
- School of Computing, Informatics and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
- Division of Cardiology, Children's Hospital Los Angeles, CA, USA
| | - Yalin Wang
- School of Computing, Informatics and Decision Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Natasha Lepore
- CIBORG laboratory, Department of Radiology, Children's Hospital Los Angeles, CA, USA
- Department of Radiology, University of Southern California, CA, USA
- Department of Biomedical Engineering, University of Southern California, CA, USA
| | - John Wood
- Division of Cardiology, Children's Hospital Los Angeles, CA, USA
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8
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Steven A, Raghavan P, Rath TJ, Gandhi D. Neurologic and Head and Neck Manifestations of Sickle Cell Disease. Hematol Oncol Clin North Am 2016; 30:779-98. [PMID: 27443997 DOI: 10.1016/j.hoc.2016.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sickle cell disease is a common, inherited disordered characterized by chronic hemolytic anemia with repetitive episodes of vasoocclusion resulting from deformed red blood cells. This article reviews the most significant neurologic and head and neck manifestations of this disease.
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Affiliation(s)
- Andrew Steven
- Department of Diagnostic Radiology, University of Maryland Medical System, 22 S Greene St., Baltimore, MD 21201, USA.
| | - Prashant Raghavan
- Department of Diagnostic Radiology, University of Maryland Medical System, 22 S Greene St., Baltimore, MD 21201, USA
| | - Tanya J Rath
- Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite 200 East Wing, Pittsburgh, PA 15213, USA
| | - Dheeraj Gandhi
- Department of Diagnostic Radiology, University of Maryland Medical System, 22 S Greene St., Baltimore, MD 21201, USA
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9
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Kawadler JM, Kirkham FJ, Clayden JD, Hollocks MJ, Seymour EL, Edey R, Telfer P, Robins A, Wilkey O, Barker S, Cox TC, Clark CA. White Matter Damage Relates to Oxygen Saturation in Children With Sickle Cell Anemia Without Silent Cerebral Infarcts. Stroke 2015; 46:1793-9. [DOI: 10.1161/strokeaha.115.008721] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/14/2015] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Sickle cell anemia is associated with compromised oxygen-carrying capability of hemoglobin and a high incidence of overt and silent stroke. However, in children with no evidence of cerebral infarction, there are changes in brain morphometry relative to healthy controls, which may be related to chronic anemia and oxygen desaturation.
Methods—
A whole-brain tract-based spatial statistics analysis was carried out in 25 children with sickle cell anemia with no evidence of abnormality on T2-weighted magnetic resonance imaging (13 male, age range: 8–18 years) and 14 age- and race-matched controls (7 male, age range: 10–19 years) to determine the extent of white matter injury. The hypotheses that white matter damage is related to daytime peripheral oxygen saturation and steady-state hemoglobin were tested.
Results—
Fractional anisotropy was found to be significantly lower in patients in the subcortical white matter (corticospinal tract and cerebellum), whereas mean diffusivity and radial diffusivity were higher in patients in widespread areas. There was a significant negative relationship between radial diffusivity and oxygen saturation (
P
<0.05) in the anterior corpus callosum and a trend-level negative relationship between radial diffusivity and hemoglobin (
P
<0.1) in the midbody of the corpus callosum.
Conclusions—
These data show widespread white matter abnormalities in a sample of asymptomatic children with sickle cell anemia, and provides for the first time direct evidence of a relationship between brain microstructure and markers of disease severity (eg, peripheral oxygen saturation and steady-state hemoglobin). This study suggests that diffusion tensor imaging metrics may serve as a biomarker for future trials of reducing hypoxic exposure.
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Affiliation(s)
- Jamie M. Kawadler
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Fenella J. Kirkham
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Jonathan D. Clayden
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Matthew J. Hollocks
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Emma L. Seymour
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Rosanna Edey
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Paul Telfer
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Andrew Robins
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Olu Wilkey
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Simon Barker
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Tim C.S. Cox
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
| | - Chris A. Clark
- From the Developmental Imaging and Biophysics Section (J.M.K., J.D.C., C.A.C.), Clinical Neurosciences Section (F.J.K.), and Cognitive Neuroscience and Neuropsychiatry Section (E.L.S., R.E.), UCL Institute of Child Health, London, United Kingdom; Department of Clinical Neuroscience, University of Cambridge, Cambridge, United Kingdom (M.J.H.); Department of Paediatric Haematology, Barts and The London Hospital NHS Trust, London, United Kingdom (P.T.); Department of Paediatrics, Whittington Hospital
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10
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Chen HJ, Chen R, Yang M, Teng GJ, Herskovits EH. Identification of minimal hepatic encephalopathy in patients with cirrhosis based on white matter imaging and Bayesian data mining. AJNR Am J Neuroradiol 2014; 36:481-7. [PMID: 25500314 DOI: 10.3174/ajnr.a4146] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE White matter abnormalities have been demonstrated to play an important role in minimal hepatic encephalopathy. In this study, we aimed to evaluate whether WM diffusion tensor imaging can be used to identify minimal hepatic encephalopathy among patients with cirrhosis. MATERIALS AND METHODS Our study included 65 patients with cirrhosis with covert hepatic encephalopathy (29 with minimal hepatic encephalopathy and 36 without hepatic encephalopathy). Participants underwent DTI, from which we generated mean diffusivity and fractional anisotropy maps. We used a Bayesian machine-learning technique, called Graphical-Model-based Multivariate Analysis, to determine WM regions that characterize group differences. To further test the clinical significance of these potential biomarkers, we performed Cox regression analysis to assess the potential of these WM regions in predicting survival. RESULTS In mean diffusivity or fractional anisotropy maps, 2 spatially distributed WM regions (predominantly located in the bilateral frontal lobes, corpus callosum, and parietal lobes) were consistently identified as differentiating minimal hepatic encephalopathy from no hepatic encephalopathy and yielded 75.4%-81.5% and 83.1%-92.3% classification accuracy, respectively. We were able to follow 55 of 65 patients (median = 18 months), and 15 of these patients eventually died of liver-related causes. Survival analysis indicated that mean diffusivity and fractional anisotropy values in WM regions were predictive of survival, in addition to the Child-Pugh score. CONCLUSIONS Our findings indicate that WM DTI can provide useful biomarkers differentiating minimal hepatic encephalopathy from no hepatic encephalopathy, which would be helpful for minimal hepatic encephalopathy detection and subsequent treatment.
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Affiliation(s)
- H-J Chen
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China Department of Radiology (H.-J.C.), The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - R Chen
- Department of Diagnostic Radiology and Nuclear Medicine (R.C., E.H.H.), University of Maryland School of Medicine, Baltimore, Maryland
| | - M Yang
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - G-J Teng
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - E H Herskovits
- Department of Diagnostic Radiology and Nuclear Medicine (R.C., E.H.H.), University of Maryland School of Medicine, Baltimore, Maryland
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11
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Chen R, Arkuszewski M, Krejza J, Zimmerman RA, Herskovits EH, Melhem ER. A prospective longitudinal brain morphometry study of children with sickle cell disease. AJNR Am J Neuroradiol 2014; 36:403-10. [PMID: 25234033 DOI: 10.3174/ajnr.a4101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Age-related changes in brain morphology are crucial to understanding the neurobiology of sickle cell disease. We hypothesized that the growth trajectories for total GM volume, total WM volume, and regional GM volumes are altered in children with sickle cell disease compared with controls. MATERIALS AND METHODS We analyzed T1-weighted images of the brains of 28 children with sickle cell disease (mean baseline age, 98 months; female/male ratio, 15:13) and 28 healthy age- and sex-matched controls (mean baseline age, 99 months; female/male ratio, 16:12). The total number of MR imaging examinations was 141 (2-4 for each subject with sickle cell disease, 2-3 for each control subject). Total GM volume, total WM volume, and regional GM volumes were measured by using an automated method. We used the multilevel-model-for-change approach to model growth trajectories. RESULTS Total GM volume in subjects with sickle cell disease decreased linearly at a rate of 411 mm(3) per month. For controls, the trajectory of total GM volume was quadratic; we did not observe a significant linear decline. For subjects with sickle cell disease, we found 35 brain structures that demonstrated age-related GM volume reduction. Total WM volume in subjects with sickle cell disease increased at a rate of 452 mm(3) per month, while the trajectory of controls was quadratic. CONCLUSIONS There was a significant age-related decrease in total GM volume in children with sickle cell disease. The GM volume reduction was spatially distributed widely across the brain, primarily in the frontal, parietal, and occipital lobes. Total WM volume in subjects with sickle cell disease increased at a lower rate than for controls.
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Affiliation(s)
- R Chen
- From the Department of Diagnostic Radiology and Nuclear Medicine (R.C., J.K., E.H.H., E.R.M.), University of Maryland, Baltimore, Maryland Department of Radiology (R.C., R.A.Z.), Raymond and Ruth Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - M Arkuszewski
- Department of Neurology (M.A.), Medical University of Silesia, Katowice, Poland
| | - J Krejza
- From the Department of Diagnostic Radiology and Nuclear Medicine (R.C., J.K., E.H.H., E.R.M.), University of Maryland, Baltimore, Maryland
| | - R A Zimmerman
- Department of Radiology (R.A.Z.), Children's Hospital of Philadelphia, Philadelphia, Pennsylvania Department of Radiology (R.C., R.A.Z.), Raymond and Ruth Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - E H Herskovits
- From the Department of Diagnostic Radiology and Nuclear Medicine (R.C., J.K., E.H.H., E.R.M.), University of Maryland, Baltimore, Maryland
| | - E R Melhem
- From the Department of Diagnostic Radiology and Nuclear Medicine (R.C., J.K., E.H.H., E.R.M.), University of Maryland, Baltimore, Maryland
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Tract-based Bayesian multivariate analysis of mild traumatic brain injury. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:120182. [PMID: 24711857 PMCID: PMC3966337 DOI: 10.1155/2014/120182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 01/20/2014] [Indexed: 11/21/2022]
Abstract
Purpose. Detecting brain regions characterizing mild traumatic brain injury (mTBI) by combining Tract-Based Spatial Statistics (TBSS) and Graphical-model-based Multivariate Analysis (GAMMA). Materials and Methods. This study included 39 mTBI patients and 28 normal controls. Local research ethics committee approved this prospective study. Diffusion-tensor imaging was performed in mTBI patients within 7 days of injury. Skeletonized fractional anisotropy (FA) maps were generated by using TBSS. Brain regions characterizing mTBI were detected by GAMMA. Results. Two clusters of lower frontal white matter FA were present in mTBI patients. We constructed classifiers based on FA values in these two clusters to differentiate mTBI and controls. The mean accuracy, sensitivity, and specificity, across five different classifiers, were 0.80, 0.94, and 0.61, respectively. Conclusions. Combining TBSS and GAMMA can detect neuroimaging biomarkers characterizing mTBI.
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Mackin RS, Insel P, Truran D, Vichinsky EP, Neumayr LD, Armstrong FD, Gold JI, Kesler K, Brewer J, Weiner MW. Neuroimaging abnormalities in adults with sickle cell anemia: associations with cognition. Neurology 2014; 82:835-41. [PMID: 24523480 DOI: 10.1212/wnl.0000000000000188] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE This study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA). METHODS Participants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition). RESULTS After adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p < 0.001). Reduced volume of the basal ganglia and thalamus was significantly associated with lower Performance IQ (model estimate = 3.75, p = 0.004) as well as lower Perceptual Organization (model estimate = 1.44, p = 0.007) and Working Memory scores (model estimate = 1.37, p = 0.015). Frontal lobe cortex thickness was not significantly associated with any cognitive measures. CONCLUSIONS Our findings suggest that basal ganglia and thalamus abnormalities may represent a particularly salient contributor to cognitive dysfunction in adults with SCA.
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Affiliation(s)
- R Scott Mackin
- From the Department of Psychiatry (R.S.M.), University of California, San Francisco; Center for Imaging of Neurodegenerative Diseases (R.S.M., P.I., D.T., J.B., M.W.W.), San Francisco Veterans Administration Medical Center, San Francisco; Hematology/Oncology Department (E.P.V., L.D.N.), Children's Hospital & Research Center Oakland; Keck School of Medicine (J.I.G.), University of Southern California; Departments of Anesthesiology and Pediatrics (J.I.G.), Children's Hospital Los Angeles, CA; Rho, Inc. (K.K.), Research Triangle Park, NC; Department of Pediatrics (F.D.A.), University of Miami Miller School of Medicine and Holtz Children's Hospital, Miami, FL; and Veterans Administration Medical Center (M.W.W.), and Departments of Radiology, Medicine, Psychiatry, and Neurology, University of California, San Francisco
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Kawadler JM, Clayden JD, Kirkham FJ, Cox TC, Saunders DE, Clark CA. Subcortical and cerebellar volumetric deficits in paediatric sickle cell anaemia. Br J Haematol 2013; 163:373-6. [PMID: 23889205 DOI: 10.1111/bjh.12496] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/26/2013] [Indexed: 11/29/2022]
Abstract
Sickle cell anaemia (SCA) is associated with silent cerebral infarction (SCI), affecting white and cortical grey matter, but there are few data on subcortical volumes. We analysed retrospective magnetic resonance imaging (MRI) data in 26 SCA patients and 20 controls, comparing mean subcortical volumes between three groups: controls, SCA with SCI (n = 13) and SCA without visible abnormality (n = 13). Specific volumetric differences were found in the hippocampus, amygdala, pallidum, caudate, putamen, thalamus, and cerebellum. This is the first study to demonstrate subcortical volume change in SCA, with the most severe volumetric deficits occurring in children with SCI seen on MRI.
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Affiliation(s)
- Jamie M Kawadler
- Imaging & Biophysics Unit, Institute of Child Health, University College London, London, UK
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15
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Arkuszewski M, Krejza J, Chen R, Melhem ER. Sickle cell anemia: reference values of cerebral blood flow determined by continuous arterial spin labeling MRI. Neuroradiol J 2013; 26:191-200. [PMID: 23859242 PMCID: PMC5228728 DOI: 10.1177/197140091302600209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/02/2013] [Indexed: 11/16/2022] Open
Abstract
Sickle cell anemia (SCA) is a chronic illness associated with progressive deterioration in patients' quality of life. The major complications of SCA are cerebrovascular accidents (CVA) such as asymptomatic cerebral infarct or overt stroke. The risk of CVA may be related to chronic disturbances in cerebral blood flow (CBF), but the thresholds of "normal" steady-state CBF are not well established. The reference tolerance limits of CBF can be useful to estimate the risk of CVA in asymptomatic children with SCA, who are negative for hyperemia or evidence of arterial narrowing. Continuous arterial spin labeling (CASL) MR perfusion allows for non-invasive quantification of global and regional CBF. To establish such reference tolerance limits we performed CASL MR examinations on a 3-Tesla MR scanner in a carefully selected cohort of 42 children with SCA (mean age, 8.1±3.3 years; range limits, 2.3-14.4 years; 24 females), who were not on chronic transfusion therapy, had no history of overt stroke or transient ischemic attack, were free of signs and symptoms of focal vascular territory ischemic brain injury, did not have intracranial arterial narrowing on MR angiography and were at low risk for stroke as determined by transcranial Doppler ultrasonography.
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Affiliation(s)
- M Arkuszewski
- Department of Radiology, Division of Neuroradiology, University of Pennsylvania, Philadelphia, PA, USA.
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16
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Quantitative brain diffusion-tensor MRI findings in patients with sickle cell disease. AJR Am J Roentgenol 2012; 198:1167-74. [PMID: 22528909 DOI: 10.2214/ajr.11.7404] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the microstructure of various regions of the brain using diffusion-tensor imaging (DTI) in patients with sickle cell disease (SCD) and in age- and sex-matched healthy control subjects. We also investigated the fiber tractography findings of the corpus callosum (CC) and corticospinal tracts (CSTs). SUBJECTS AND METHODS Sixteen right-handed patients with SCD and 14 age- and sex-matched right-handed healthy control subjects were scanned using conventional MR sequences and DTI. Fractional anisotropy (FA) and apparent diffusion coefficients (ADCs) were calculated and regions of interest were selected in various brain areas (superior and inferior frontal, parietal, occipital, and temporal white matter areas), anterior and posterior periventricular areas, centrum semiovale, basal ganglia (lentiform nucleus, head of caudate nucleus), thalamus, cerebral peduncles, pons, cerebellar white matter areas, and CC. Diffusion-tensor tractography of the CC and CSTs was also performed. RESULTS For the patients with SCD, significantly reduced FA values, increased ADC values, or both were seen clustered in several brain areas, including the CC, frontal white matter, centrum semiovale, periventricular areas, head of the caudate nucleus, thalamus, brainstem, and pons (p < 0.05). Statistically significant reductions in fiber counts in the first and fifth segments of the CC and in CSTs bilaterally were also observed in patients with SCD (p < 0.05). CONCLUSION DTI shows microstructural abnormalities of various brain areas in patients with SCD.
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DeBaun MR, Armstrong FD, McKinstry RC, Ware RE, Vichinsky E, Kirkham FJ. Silent cerebral infarcts: a review on a prevalent and progressive cause of neurologic injury in sickle cell anemia. Blood 2012; 119:4587-96. [PMID: 22354000 PMCID: PMC3367871 DOI: 10.1182/blood-2011-02-272682] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 01/05/2012] [Indexed: 11/20/2022] Open
Abstract
Silent cerebral infarct (SCI) is the most common form of neurologic disease in children with sickle cell anemia (SCA). SCI is defined as abnormal magnetic resonance imaging (MRI) of the brain in the setting of a normal neurologic examination without a history or physical findings associated with an overt stroke. SCI occurs in 27% of this population before their sixth, and 37% by their 14th birthdays. In adults with SCA, the clinical history of SCI is poorly defined, although recent evidence suggests that they too may have ongoing risk of progressive injury. Risk factors for SCI include male sex, lower baseline hemoglobin concentration, higher baseline systolic blood pressure, and previous seizures. Specific morbidity associated with SCI includes a decrement in general intellectual abilities, poor academic achievement, progression to overt stroke, and progressive SCI. In addition, children with previous stroke continue to have both overt strokes and new SCI despite receiving regular blood transfusion therapy for secondary stroke prevention. Studies that only include overt stroke as a measure of CNS injury significantly underestimate the total cerebral injury burden in this population. In this review, we describe the epidemiology, natural history, morbidity, medical management, and potential therapeutic options for SCI in SCA.
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Affiliation(s)
- Michael R DeBaun
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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Daly B, Kral MC, Tarazi RA. The Role of Neuropsychological Evaluation in Pediatric Sickle Cell Disease. Clin Neuropsychol 2011; 25:903-25. [DOI: 10.1080/13854046.2011.560190] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Arkuszewski M, Krejza J, Chen R, Kwiatkowski JL, Ichord R, Zimmerman R, Ohene-Frempong K, Desiderio L, Melhem ER. Sickle cell disease: reference values and interhemispheric differences of nonimaging transcranial Doppler blood flow parameters. AJNR Am J Neuroradiol 2011; 32:1444-50. [PMID: 21700785 DOI: 10.3174/ajnr.a2529] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE TCD screening is widely used to identify children with SCD at high risk of stroke. Those with high mean flow velocities in major brain arteries have increased risk of stroke. Thus, our aim was to establish reference values of interhemispheric differences and ratios of blood flow Doppler parameters in the tICA, MCA, and ACA as determined by conventional TCD in children with sickle cell anemia. MATERIALS AND METHODS Reference limits of blood flow parameters were established on the basis of a consecutive cohort of 56 children (mean age, 100 ± 40 months; range, 29-180 months; 30 females) free of neurologic deficits and intracranial stenosis detectable by MRA, with blood flow velocities <170 cm/s by conventional TCD. Reference limits were estimated by using tolerance intervals, within which are included with a probability of .90 of all possible data values from 95% of a population. RESULTS Average peak systolic velocities were significantly higher in the right hemisphere in the MCA and ACA (185 ± 28 cm/s versus 179 ± 27 and 152 ± 30 cm/s versus 143 ± 34 cm/s respectively). Reference limits for left-to-right differences in the mean flow velocities were the following: -43 to 33 cm/s for the MCA; -49 to 38 cm/s for the ACA, and -38 to 34 cm/s for the tICA, respectively. Respective reference limits for left-to-right velocity ratios were the following: 0.72 to 1.25 cm/s for the MCA; 0.62 to 1.39 cm/s for the ACA, and 0.69 to 1.27 cm/s for the tICA. Flow velocities in major arteries were inversely related to age and Hct or Hgb. CONCLUSIONS The study provides reference intervals of TCD flow velocities and their interhemispheric differences and ratios that may be helpful in identification of intracranial arterial stenosis in children with SCD undergoing sonographic screening for stroke prevention.
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Affiliation(s)
- M Arkuszewski
- Department of Radiology, Division of Neuroradiology, University of Pennsylvania, Philadelphia, 19104, USA
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Krejza J, Chen R, Romanowicz G, Kwiatkowski JL, Ichord R, Arkuszewski M, Zimmerman R, Ohene-Frempong K, Desiderio L, Melhem ER. Sickle cell disease and transcranial Doppler imaging: inter-hemispheric differences in blood flow Doppler parameters. Stroke 2010; 42:81-6. [PMID: 21088242 DOI: 10.1161/strokeaha.110.591818] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE to establish reference values of interhemispheric differences and ratios of blood flow Doppler parameters in the terminal internal carotid artery, middle cerebral artery, and anterior cerebral artery in children with sickle cell anemia. METHODS fifty-seven out of 74 recruited children (mean age, 7.8 ± 3.4 years; range limits, 3-14 years), who were free of neurological deficits and intracranial narrowing detectable by MRA and had flow velocities <170 cm/s by conventional transcranial Doppler ultrasound, underwent transcranial color-coded duplex ultrasonography. Reference limits of flow parameters corrected and uncorrected for the angle of insonation were estimated using tolerance intervals, with P=0.90 for all possible data values from 95% of a population. RESULTS reference limits for left-to-right differences in cm/s in the mean angle-corrected and uncorrected flow velocities were -56 to 53 and -72 to 75 for middle cerebral artery, -49 to 57 and -81 to 91 for anterior cerebral artery, and -55 to 64 and -73 to 78 for terminal internal carotid artery, respectively. Respective reference limits for left-to-right velocity ratios were 0.31 to 1.84 and 0.38 to 1.75 for middle cerebral artery, 0.48 to 2.99 and 0.46 to 2.89 for anterior cerebral artery, and 0.61 to 2.56 and 0.56 to 2.23 for terminal internal carotid artery. CONCLUSIONS the study provides reference limits of interhemispheric differences and ratios of blood flow Doppler parameters that may be helpful in identification of intracranial arterial narrowing in children with sickle cell disease undergoing ultrasound screening for stroke prevention.
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Affiliation(s)
- Jaroslaw Krejza
- Department of Radiology, Division of Neuroradiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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