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Venkatakrishna SSB, Sharma P, Tierradentro-Garcia LO, Elsingergy M, Worede F, Curic J, Alves CAP, Andronikou S. Frequency of Cerebellar Abnormalities Associated With the Differing Magnetic Resonance Imaging Patterns of Term Hypoxic-Ischemic Injury in Children. Pediatr Neurol 2024; 152:73-78. [PMID: 38232653 DOI: 10.1016/j.pediatrneurol.2023.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 11/30/2023] [Accepted: 12/25/2023] [Indexed: 01/19/2024]
Abstract
BACKGROUND We aimed to determine the frequency of cerebellar injury using delayed magnetic resonance imaging (MRI) in children with cerebral palsy, diagnosed with term hypoxic-ischemic injury (HII), and to characterize this for the different MRI patterns of HII. METHODS We retrospectively reviewed delayed MRI scans in children with cerebral palsy, of whom 1175 had term HII. The pattern of HII was classified into basal ganglia-thalamus (BGT) pattern, watershed (WS) pattern, combined BGT/WS, and multicystic HII. Cerebellar location (hemisphere versus vermis) and the MRI characteristics were documented overall and for each of the different patterns of HII, as well as the association with thalamic injury. RESULTS Cerebellar injury was found in 252 of 1175 (21.4%) (median age 6 years [interquartile range: 3 to 9 years]). Of these, 49% (124 of 252) were associated with a BGT pattern, 13% (32 of 252) with a WS pattern, 28% (72 of 252) with a combined BGT/WS pattern, and 10% (24 of 252) with a multicystic pattern. The vermis was abnormal in 83% (209 of 252), and the hemispheres were abnormal in 34% (86 of 252) (with 17% [43 of 252] showing both vermis and hemispheric abnormality). CONCLUSIONS Over a fifth of patients with cerebral palsy due to HII had a cerebellar abnormality on delayed MRI, most commonly involving the vermis (83%), and as part of a BGT pattern of injury in just under half of these likely reflecting the association of cerebellar vermis injury with profound insults.
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Affiliation(s)
| | - Parth Sharma
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Mohamed Elsingergy
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Fikadu Worede
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Jelena Curic
- Graduate MBA Program, Faculty of Health, Education, Medicine and Social Care, Anglia Ruskin University, Cambridge, UK
| | - Cesar Augusto P Alves
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Savvas Andronikou
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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Kanal HD, Levison SW. Neuroprotective Effects of Delayed TGF-β1 Receptor Antagonist Administration on Perinatal Hypoxic-Ischemic Brain Injury. Dev Neurosci 2023; 46:188-200. [PMID: 37348472 DOI: 10.1159/000531650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 06/19/2023] [Indexed: 06/24/2023] Open
Abstract
Hypoxic-ischemic (HI) brain injury in neonatal encephalopathy triggers a wave of neuroinflammatory events attributed to causing the progressive degeneration and functional deficits seen weeks after the primary damage. The cellular processes mediating this prolonged neurodegeneration in HI injury are not sufficiently understood. Consequently, current therapies are not fully protective. In a recent study, we found significant improvements in neurologic outcomes when a small molecule antagonist for activin-like kinase 5 (ALK5), a transforming growth factor beta (TGF-β) receptor was used as a therapeutic in a rat model of moderate term HI. Here, we have extended those studies to a mouse preterm pup model of HI. For these studies, postnatal day 7 CD1 mice of both sexes were exposed to 35-40 min of HI. Beginning 3 days later, SB505124, the ALK5 receptor antagonist, was administered systemically through intraperitoneal injections performed every 12 h for 5 days. When evaluated 23 days later, SB505124-treated mice had ∼2.5-fold more hippocampal area and ∼2-fold more thalamic tissue. Approximately 90% of the ipsilateral hemisphere (ILH) was preserved in the SB505124-treated HI mice compared to the vehicle-treated HI mice, where the ILH was ∼60% of its normal size. SB505124 also preserved the subcortical white matter. SB505124 treatment preserved levels of aquaporin-4 and n-cadherin, key proteins associated with blood-brain barrier function. Importantly, SB505124 administration improved sensorimotor function as assessed by a battery of behavioral tests. Altogether, these data lend additional support to the conclusion that SB505124 is a candidate neuroprotective molecule that could be an effective treatment for HI-related encephalopathy in moderately injured preterm infants.
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Affiliation(s)
- Hur Dolunay Kanal
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Steven W Levison
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
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Kim BH, Jeziorek M, Kanal HD, Contu VR, Dobrowolski R, Levison SW. Moderately Inducing Autophagy Reduces Tertiary Brain Injury after Perinatal Hypoxia-Ischemia. Cells 2021; 10:898. [PMID: 33919804 PMCID: PMC8070811 DOI: 10.3390/cells10040898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 01/13/2023] Open
Abstract
Recent studies of cerebral hypoxia-ischemia (HI) have highlighted slowly progressive neurodegeneration whose mechanisms remain elusive, but if blocked, could considerably improve long-term neurological function. We previously established that the cytokine transforming growth factor (TGF)β1 is highly elevated following HI and that delivering an antagonist for TGFβ receptor activin-like kinase 5 (ALK5)-SB505124-three days after injury in a rat model of moderate pre-term HI significantly preserved the structural integrity of the thalamus and hippocampus as well as neurological functions associated with those brain structures. To elucidate the mechanism whereby ALK5 inhibition reduces cell death, we assessed levels of autophagy markers in neurons and found that SB505124 increased numbers of autophagosomes and levels of lipidated light chain 3 (LC3), a key protein known to mediate autophagy. However, those studies did not determine whether (1) SB was acting directly on the CNS and (2) whether directly inducing autophagy could decrease cell death and improve outcome. Here we show that administering an ALK5 antagonist three days after HI reduced actively apoptotic cells by ~90% when assessed one week after injury. Ex vivo studies using the lysosomal inhibitor chloroquine confirmed that SB505124 enhanced autophagy flux in the injured hemisphere, with a significant accumulation of the autophagic proteins LC3 and p62 in SB505124 + chloroquine treated brain slices. We independently activated autophagy using the stimulatory peptide Tat-Beclin1 to determine if enhanced autophagy is directly responsible for improved outcomes. Administering Tat-Beclin1 starting three days after injury preserved the structural integrity of the hippocampus and thalamus with improved sensorimotor function. These data support the conclusion that intervening at this phase of injury represents a window of opportunity where stimulating autophagy is beneficial.
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Affiliation(s)
- Brian H. Kim
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, USA; (B.H.K.); (H.D.K.)
| | - Maciej Jeziorek
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Rutgers University, Newark, NJ 07102, USA; (M.J.); (V.R.C.); (R.D.)
| | - Hur Dolunay Kanal
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, USA; (B.H.K.); (H.D.K.)
| | - Viorica Raluca Contu
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Rutgers University, Newark, NJ 07102, USA; (M.J.); (V.R.C.); (R.D.)
| | - Radek Dobrowolski
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Rutgers University, Newark, NJ 07102, USA; (M.J.); (V.R.C.); (R.D.)
- Glenn Biggs Institute for Alzheimer’s & Neurodegenerative Diseases, University of Texas Health Sciences Center, San Antonio, TX 78229, USA
| | - Steven W. Levison
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, USA; (B.H.K.); (H.D.K.)
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4
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Murden S, Borbélyová V, Laštůvka Z, Mysliveček J, Otáhal J, Riljak V. Gender differences involved in the pathophysiology of the perinatal hypoxic-ischemic damage. Physiol Res 2020; 68:S207-S217. [PMID: 31928039 DOI: 10.33549/physiolres.934356] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is a neonatal condition that occurs as a consequence of perinatal asphyxia, which is caused by a number of factors, commonly via compression of the umbilical cord, placental abruption, severe meconium aspiration, congenital cardiac or pulmonary anomalies and birth trauma. Experimental studies have confirmed that male rat pups show a higher resistance to HIE treatment. Moreover, the long-term consequences of hypoxia in male are more severe in comparison to female rat pups. These sex differences can be attributed to the pathophysiology of hypoxia-ischemia, whereby studies are beginning to establish such gender-specific distinctions. The current and sole treatment for HIE is hypothermia, in which a reduction in temperature prevents long-term effects, such as cerebral palsy or seizures. However, in most cases hypothermia is not a sufficient treatment as indicated by a high mortality rate. In the present review, we discuss the gender differences within the pathophysiology of hypoxia-ischemia and delve into the role of gender in the incidence, progression and severity of the disease. Furthermore, this may result in the development of potential novel treatment approaches for targeting and preventing the long-term consequences of HIE.
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Affiliation(s)
- S Murden
- Department of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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Millar LJ, Shi L, Hoerder-Suabedissen A, Molnár Z. Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges. Front Cell Neurosci 2017; 11:78. [PMID: 28533743 PMCID: PMC5420571 DOI: 10.3389/fncel.2017.00078] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.
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Affiliation(s)
- Lancelot J. Millar
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
| | - Lei Shi
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan UniversityGuangzhou, China
| | | | - Zoltán Molnár
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
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Lemmon ME, Wagner MW, Bosemani T, Carson KA, Northington FJ, Huisman TAGM, Poretti A. Diffusion Tensor Imaging Detects Occult Cerebellar Injury in Severe Neonatal Hypoxic-Ischemic Encephalopathy. Dev Neurosci 2017; 39:207-214. [PMID: 28095379 DOI: 10.1159/000454856] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 11/30/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite the benefits of whole-body hypothermia therapy, many infants with hypoxic-ischemic encephalopathy (HIE) die or have significant long-term neurodevelopmental impairment. Prospectively identifying neonates at risk of poor outcome is essential but not straightforward. The cerebellum is not classically considered to be a brain region vulnerable to hypoxic-ischemic insults; recent literature suggests, however, that the cerebellum may be involved in neonatal HIE. In this study, we aimed to assess the microstructural integrity of cerebellar and linked supratentorial structures in neonates with HIE compared to neurologically healthy neonatal controls. METHODS In this prospective cohort study, we performed a quantitative diffusion tensor imaging (DTI) analysis of the structural pathways of connectivity, which may be affected in neonatal cerebellar injury by measuring fractional anisotropy (FA) and mean diffusivity (MD) within the superior, middle, and inferior cerebellar peduncles, dentate nuclei, and thalami. All magnetic resonance imaging (MRI) studies were grouped into 4 categories of severity based on a qualitative evaluation of conventional and advanced MRI sequences. Multivariable linear regression analysis of cerebellar scalars of patients and controls was performed, controlling for gestational age, age at the time of MRI, and HIE severity. Spearman rank correlation was performed to correlate DTI scalars of the cerebellum and thalami. RESULTS Fifty-seven (23 females, 40%) neonates with HIE and 12 (6 females, 50%) neonatal controls were included. There were 8 patients (14%) in HIE severity groups 3 and 4 (injury of the basal ganglia/thalamus and/or cortex). Based on a qualitative analysis of conventional and DTI images, no patients had evidence of cerebellar injury. No significant differences between patients and controls were found in the FA and MD scalars. However, FA values of the middle cerebellar peduncles (0.294 vs. 0.380, p < 0.001) and MD values of the superior cerebellar peduncles (0.920 vs. 1.007 × 10-3 mm/s2, p = 0.001) were significantly lower in patients with evidence of moderate or severe injury on MRI (categories 3 and 4) than in controls. In patients, cerebellar DTI scalars correlated positively with DTI scalars within the thalami. CONCLUSION Our results suggest that infants with moderate-to-severe HIE may have occult injury of cerebellar white-matter tracts, which is not detectable by the qualitative analysis of neuroimaging data alone. Cerebellar DTI scalars correlate with thalamic measures, highlighting that cerebellar injury is unlikely to occur in isolation and may reflect the severity of HIE. The impact of concomitant cerebellar injury in HIE on long-term neurodevelopmental outcome warrants further study.
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Affiliation(s)
- Monica E Lemmon
- Division of Pediatric Neurology, Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
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7
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Smith AL, Hill CA, Alexander M, Szalkowski CE, Chrobak JJ, Rosenkrantz TS, Fitch RH. Spatial working memory deficits in male rats following neonatal hypoxic ischemic brain injury can be attenuated by task modifications. Brain Sci 2014; 4:240-72. [PMID: 24961760 PMCID: PMC4101476 DOI: 10.3390/brainsci4020240] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 01/22/2014] [Accepted: 03/18/2014] [Indexed: 12/19/2022] Open
Abstract
Hypoxia-ischemia (HI; reduction in blood/oxygen supply) is common in infants with serious birth complications, such as prolonged labor and cord prolapse, as well as in infants born prematurely (<37 weeks gestational age; GA). Most often, HI can lead to brain injury in the form of cortical and subcortical damage, as well as later cognitive/behavioral deficits. A common domain of impairment is working memory, which can be associated with heightened incidence of developmental disorders. To further characterize these clinical issues, the current investigation describes data from a rodent model of HI induced on postnatal (P)7, an age comparable to a term (GA 36–38) human. Specifically, we sought to assess working memory using an eight-arm radial water maze paradigm. Study 1 used a modified version of the paradigm, which requires a step-wise change in spatial memory via progressively more difficult tasks, as well as multiple daily trials for extra learning opportunity. Results were surprising and revealed a small HI deficit only for the final and most difficult condition, when a delay before test trial was introduced. Study 2 again used the modified radial arm maze, but presented the most difficult condition from the start, and only one daily test trial. Here, results were expected and revealed a robust and consistent HI deficit across all weeks. Combined results indicate that male HI rats can learn a difficult spatial working memory task if it is presented in a graded multi-trial format, but performance is poor and does not appear to remediate if the task is presented with high initial memory demand. Male HI rats in both studies displayed impulsive characteristics throughout testing evidenced as reduced choice latencies despite more errors. This aspect of behavioral results is consistent with impulsiveness as a core symptom of ADHD—a diagnosis common in children with HI insult. Overall findings suggest that task specific behavioral modifications are crucial to accommodating memory deficits in children suffering from cognitive impairments following neonatal HI.
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Affiliation(s)
- Amanda L Smith
- Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
| | - Courtney A Hill
- Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
| | - Michelle Alexander
- Division of Neonatology, Department of Pediatrics, University of Minnesota, 516 Delaware Street S.E. Minneapolis, MN 55454, USA.
| | - Caitlin E Szalkowski
- Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
| | - James J Chrobak
- Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
| | - Ted S Rosenkrantz
- Department of Pediatrics, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA.
| | - R Holly Fitch
- Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT 06269, USA.
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8
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Abstract
Hypoxia-ischemia is a leading cause of morbidity and mortality in the perinatal period with an incidence of 1/4000 live births. Biochemical events such as energy failure, membrane depolarization, brain edema, an increase of neurotransmitter release and inhibition of uptake, an increase of intracellular Ca(2+), production of oxygen-free radicals, lipid peroxidation, and a decrease of blood flow are triggered by hypoxia-ischemia and may lead to brain dysfunction and neuronal death. These abnormalities can result in mental impairments, seizures, and permanent motor deficits, such as cerebral palsy. The physical and emotional strain that is placed on the children affected and their families is enormous. The care that these individuals need is not only confined to childhood, but rather extends throughout their entire life span, so it is very important to understand the pathophysiology that follows a hypoxic-ischemic insult. This review will highlight many of the mechanisms that lead to neuronal death and include the emerging area of white matter injury as well as the role of inflammation and will provide a summary of therapeutic strategies. Hypothermia and oxygen will also be discussed as treatments that currently lack a specific target in the hypoxic/ischemic cascade.
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Affiliation(s)
- John W Calvert
- Departments of Neurosurgery and Molecular and Cellular Physiology, Loma Linda University Medical Center, 11234 Anderson Street, Loma Linda, CA 92354, USA
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9
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Pienaar R, Paldino MJ, Madan N, Krishnamoorthy KS, Alsop DC, Dehaes M, Grant PE. A quantitative method for correlating observations of decreased apparent diffusion coefficient with elevated cerebral blood perfusion in newborns presenting cerebral ischemic insults. Neuroimage 2012; 63:1510-8. [PMID: 22892333 DOI: 10.1016/j.neuroimage.2012.07.062] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/25/2012] [Accepted: 07/31/2012] [Indexed: 11/27/2022] Open
Abstract
In patients presenting with cerebral ischemic injury, the outcome of injured brain tissue quantified as decreased apparent diffusion coefficient (ADC) may depend on associated alterations in cerebral blood perfusion (CBP). This study proposes a non-biased method to quantify associations between ADC and CBP in newborns with global or focal cerebral ischemia. The study population consisted of nine neonates (age: 0 to 3 days) presenting with clinical and imaging evidence of ischemia (seven with global hypoxic ischemia, and two with focal arterial ischemic stroke) with decreased ADC. Six newborns without diffusion abnormalities on magnetic resonance (MR) imaging served as a comparative cohort (age: 0 days to 4 weeks). All patients underwent MR imaging including diffusion weighted imaging (DWI) to determine ADC and axial arterial spin labeling (ASL) to determine CBP. An algorithm was developed that uses the B0 volume from the DWI raw data as a reference, co-registers the ADC and ASL-CBP data to the B0, generates mask filters, and finally performs a statistical analysis to automatically select regions of interest (ROIs) with ADC or ASL-CBP values that deviate significantly from the rest of the brain. If ROIs are identified in this analysis, the algorithm then evaluates correlation based on ROI location and volume. A significant correlation was found between decreased ADC and elevated ASL-CBP with regions of elevated ASL-CBP typically larger than the corresponding ADC abnormality. The association between decreased diffusivity and increased ASL-CBP suggests that, for this cohort, cerebral ischemia is associated with hyperperfusion.
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Affiliation(s)
- Rudolph Pienaar
- Harvard Medical School, 25 Shattuck St., Boston, MA 02115, USA.
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Hassel B. Hans (Hansemann) Tønnesen, en diagnostisk gåte fra Amalie Skram. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2012; 132:2632-5. [DOI: 10.4045/tidsskr.12.0912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Abstract
Diffusion-weighted imaging (DWI) has become an important tool in pediatric neuroradiology, helping in the evaluation of the encephalopathic and seizing neonate, and adding conspicuity, specificity, and prognostic value to the conventional magnetic resonance (MR) imaging data. DWI also facilitates understanding the pathophysiology and natural time course of ischemic and nonischemic disorders. When interpreted concurrently with the conventional MR imaging and other advanced MR imaging techniques, such as spectroscopy and arterial spin labeling, DWI can give clues leading to an accurate diagnosis and provide important information about pathophysiology and prognosis of the diseases, as well as guide adequate therapeutic modalities.
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Affiliation(s)
- Katyucia Rodrigues
- Multi-Imagem/CDPI Clinics, R. Alm. Saddock de Sá, 266-Ipanema, Rio de Janeiro 22411-040, Brazil.
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12
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Utsunomiya H. Diffusion MRI abnormalities in pediatric neurological disorders. Brain Dev 2011; 33:235-42. [PMID: 20880644 DOI: 10.1016/j.braindev.2010.08.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 08/22/2010] [Accepted: 08/31/2010] [Indexed: 12/22/2022]
Abstract
Diffusion-weighted imaging (DWI) makes it possible to measure early changes in cellular function in the central nervous system. The purpose of this article is to discuss the diagnostic value of diffusion-weighted and diffusion tensor imaging (DTI) in different pediatric cerebral disorders. First, the principles of DWI and DTI are briefly reviewed. The clinical usefulness of these imaging techniques is then discussed using cases with pediatric neurological disorders, such as hypoxic-ischemic encephalopathy in neonates, trauma (shaken baby syndrome), encephalopathy or encephalitis in infants, posterior reversible encephalopathy syndrome and congenital brain anomaly (callosal dysgenesis). In addition, using DTI, we evaluate normal brain development, particularly in the corpus callosum and cortico-spinal tract, and discuss the application of DTI to the study of white matter in the developing brain.
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Affiliation(s)
- Hidetsuna Utsunomiya
- Department of Radiological Sciences, International University of Health and Welfare, Graduate School, Japan.
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13
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Azzopardi D, Edwards AD. Magnetic resonance biomarkers of neuroprotective effects in infants with hypoxic ischemic encephalopathy. Semin Fetal Neonatal Med 2010; 15:261-9. [PMID: 20359970 DOI: 10.1016/j.siny.2010.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Evaluation of infants with hypoxic ischemic encephalopathy by magnetic resonance spectroscopy and imaging is useful to direct clinical care, and may assist the evaluation of candidate neuroprotective therapies. Cerebral metabolites measured by magnetic resonance spectroscopy, and visual analysis of magnetic resonance images during the first 30 days after birth accurately predict later neurological outcome and are valid biomarkers of the key physiological processes underlying brain injury in neonatal hypoxic ischemic encephalopathy. Visual assessment of magnetic resonance images may also be a suitable surrogate outcome in studies of neuroprotective therapies but current magnetic resonance methods are relatively inefficient for use in early phase, first in human infant studies of novel neuroprotective therapies. However, diffusion tensor imaging and analysis of fractional anisotropy with tract-based spatial statistics promises to be a highly efficient biomarker and surrogate outcome for rapid preliminary evaluation of promising therapies for neonatal hypoxic ischemic injury. Standardisation of scanning protocols and data analysis between different scanners is essential.
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Affiliation(s)
- Denis Azzopardi
- Institute of Clinical Sciences, Imperial College London and MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK.
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14
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Abstract
Hypoxia-ischemia in the perinatal period is an important cause of cerebral palsy and associated disabilities in children. There has been significant research progress in hypoxic-ischemic encephalopathy over the last 2 decades, and many new molecular mechanisms have been identified. Despite all these advances, therapeutic interventions are still limited. In this article the authors discuss several molecular pathways involved in hypoxia-ischemia, and potential therapeutic targets.
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Affiliation(s)
- Ali Fatemi
- Assistant Professor of Neurology and Pediatrics, Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, MD
| | - Mary Ann Wilson
- Associate Professor of Neurology and Neuroscience, Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, MD
| | - Michael V. Johnston
- Blum-Moser Chair for Pediatric Neurology at the Kennedy Krieger Institute, Professor of Neurology, Pediatrics, Physical Medicine and Rehabilitation, Johns Hopkins Medical Institutions, Baltimore, MD
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15
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Kumakura A, Asada J, Okumura R, Fujisawa I, Hata D. Diffusion-weighted imaging in preclinical Leigh syndrome. Pediatr Neurol 2009; 41:309-11. [PMID: 19748055 DOI: 10.1016/j.pediatrneurol.2009.04.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 04/20/2009] [Indexed: 11/30/2022]
Abstract
We report on a preterm Japanese male baby with Leigh syndrome, i.e., intrauterine growth restriction, central apnea, and feeding difficulty. These signs improved at 41 weeks of corrected age. At that time, brain magnetic resonance imaging revealed increased signal in diffusion-weighted imaging in the parietal white matter, bilaterally and symmetrically not respecting vascular territory or boundaries. However, clinical improvement deterred us from further investigation. About 3 months later, he manifested frequent ictal apnea with myoclonic seizures and deterioration of consciousness to semicoma. Subsequent diffusion-weighted imaging revealed increased signal in the bilateral symmetric thalamus, internal segments of the globus pallidus, substantia nigra, and pontine tegmentum. Laboratory investigation indicated remarkable elevation of lactate levels in cerebrospinal fluid. The diagnosis was of Leigh syndrome. We think this is the first reported case of Leigh encephalopathy with transient abnormality of diffusion-weighted imaging of the white matter before apparent clinical onset. Leigh syndrome should be included in the differential diagnosis of abnormality of diffusion-weighted imaging in white matter without apparent clinical signs.
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Affiliation(s)
- Akira Kumakura
- Department of Pediatrics, Kitano Hospital, Tazuke Kofukai Medical Institute, Kita-Ku, Osaka 530-8480, Japan.
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Eichler F, Krishnamoorthy K, Grant PE. Magnetic resonance imaging evaluation of possible neonatal sinovenous thrombosis. Pediatr Neurol 2007; 37:317-23. [PMID: 17950416 DOI: 10.1016/j.pediatrneurol.2007.06.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 04/25/2007] [Accepted: 06/21/2007] [Indexed: 11/17/2022]
Abstract
There are few data on magnetic resonance imaging findings in newborns for whom there is a concern for cerebral sinovenous thrombosis. The study objective was to document findings on magnetic resonance imaging or magnetic resonance venography in cases of suspected neonatal sinovenous thrombosis. A retrospective search of the institutional database was performed to find neonates whose cranial computed tomography raised the suspicion for thrombus. Documented abnormalities were detected on magnetic resonance venography, diffusion-weighted imaging, and T(2)-weighted imaging. Of 15 neonates with suspicious computed tomography studies, 2 had a definite intraluminal clot in the deep venous system; the remainder showed decreased flow-related enhancement within the dural venous sinuses. In all these cases, the sinus was compressed by adjacent subdural hematoma or sutural diastasis. Of the 15 patients, 5 had parenchymal abnormalities (2 of these had definite intraluminal clot). Parenchymal abnormalities were classified as hemorrhage (3/5), cytotoxic edema (3/5), or vasogenic edema (1/5). Intraluminal clot in the newborn is more often identified in the deep than in the superficial venous system. With evidence of venous injury in the absence of identified thrombus, it is possible that either clots dissolve quickly, escaping detection, or that the superficial venous system is vulnerable to mechanical forces during delivery.
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Affiliation(s)
- Florian Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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17
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Winter JD, Lee DS, Hung RM, Levin SD, Rogers JM, Thompson RT, Gelman N. Apparent diffusion coefficient pseudonormalization time in neonatal hypoxic-ischemic encephalopathy. Pediatr Neurol 2007; 37:255-62. [PMID: 17903669 DOI: 10.1016/j.pediatrneurol.2007.06.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 02/15/2007] [Accepted: 06/06/2007] [Indexed: 11/30/2022]
Abstract
The apparent diffusion coefficient changes with time after hypoxic-ischemic brain injury. In this study, we quantitatively examined the relationship between the apparent diffusion coefficient and postnatal age for neonates with hypoxic-ischemic encephalopathy and poor outcome, and determined the postnatal age at which these values cannot be distinguished from those of neonates without hypoxic-ischemic encephalopathy (pseudonormalization time). Diffusion-weighted brain images were obtained from clinical scans of term neonates with hypoxic-ischemic encephalopathy and poor outcome (12 neonates, 23 scans) and from control subjects (30 neonates, 31 scans). The correlation between apparent diffusion coefficient and postnatal age was investigated for several brain regions. Pseudonormalization times were determined (1) from the intersection of the regression lines for the hypoxic-ischemic encephalopathy and control groups, as well as (2) from intrasubject apparent diffusion coefficient changes between two scans within a small subgroup. Pseudonormalization times from the regression ranged from 8.3 +/- 1.9 days to 10.1 +/- 2.1 days. Slightly (approximately 1 day) longer values were obtained from the intrasubject analysis. The results suggest that, although abnormally decreased apparent diffusion coefficient values may be evident from approximately 2 days to almost 1 week of postnatal age, abnormally elevated values may not be apparent until late in the second week of life.
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Affiliation(s)
- Jeff D Winter
- Imaging Division, Lawson Health Research Institute, University of Western Ontario, London, Ontario, Canada
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18
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Benedict SL. Diffusion-weighted imaging in diagnosing neurological disorders in children: a pediatric neurologist's perspective. Pediatr Radiol 2007; 37:734-8. [PMID: 17598101 DOI: 10.1007/s00247-007-0505-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 03/26/2007] [Indexed: 10/23/2022]
Abstract
Diffusion-weighted imaging (DWI) has provided a way to measure early changes in cellular function in the central nervous system. It has permitted rapid, less invasive diagnosis and treatment of neurological disorders that were once thought to be untreatable. DWI has also created new avenues of research and alternative ways to measure study outcomes. Seven clinical cases illustrate how DWI enhances the ability of the pediatric neurologist to rapidly diagnose acute neurological disorders in infants and children.
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Affiliation(s)
- Susan L Benedict
- Division of Pediatric Neurology, The University of Utah, P.O. Box 581289, Salt Lake City, UT 84158, USA.
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19
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Eichler F, Tan WH, Shih VE, Grant PE, Krishnamoorthy K. Proton magnetic resonance spectroscopy and diffusion-weighted imaging in isolated sulfite oxidase deficiency. J Child Neurol 2006; 21:801-5. [PMID: 16970890 DOI: 10.1177/08830738060210090601] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Isolated sulfite oxidase deficiency is a rare autosomal recessive disorder of the newborn that can be mistaken for neonatal asphyxia. Diffusion-weighted imaging of the brain demonstrates widespread diffusion restriction, and proton magnetic resonance spectroscopy shows an elevated lactate level, a decrease in the ratio of N-acetylaspartate to creatine, and a rise in the ratio of choline to creatine. This precedes severe cystic encephalomalacia and suggests that the energy failure associated with neuronal dysfunction and myelin disintegration occurs early in isolated sulfite oxidase deficiency.
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MESH Headings
- Amino Acid Metabolism, Inborn Errors/complications
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/enzymology
- Amino Acid Metabolism, Inborn Errors/genetics
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/genetics
- Diagnosis, Differential
- Diffusion Magnetic Resonance Imaging
- Electroencephalography
- Gene Deletion
- Humans
- Hypoxia-Ischemia, Brain/diagnosis
- Infant
- Infant, Newborn
- Magnetic Resonance Spectroscopy
- Male
- Seizures/enzymology
- Seizures/etiology
- Sulfite Oxidase/deficiency
- Sulfite Oxidase/genetics
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Affiliation(s)
- Florian Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
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20
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Grant PE, Yu D. Acute Injury to the Immature Brain with Hypoxia with or Without Hypoperfusion. Magn Reson Imaging Clin N Am 2006; 14:271-85. [PMID: 16873014 DOI: 10.1016/j.mric.2006.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hypoxia with or without hypoperfusion is a common mechanism of injury in the immature brain and can result in normal or minimally abnormal imaging studies in the first 12 hours. Often, injury progresses over time suggesting a central role for delayed cell death pathways. An awareness of the patterns of injury associated with different mechanisms of injury and the central role of delayed cell death pathways in injury evolution is important for the radiologist to understand the significance and potential outcome of these injuries.
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Affiliation(s)
- P Ellen Grant
- Division of Pediatric Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
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21
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Ward P, Counsell S, Allsop J, Cowan F, Shen Y, Edwards D, Rutherford M. Reduced fractional anisotropy on diffusion tensor magnetic resonance imaging after hypoxic-ischemic encephalopathy. Pediatrics 2006; 117:e619-30. [PMID: 16510613 DOI: 10.1542/peds.2005-0545] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Apparent diffusion coefficients (ADC) that are measured by diffusion-weighted imaging are reduced in severe white matter (WM) and in some severe basal ganglia and thalamic (BGT) injury in infants who present with hypoxic-ischemic encephalopathy (HIE). However, ADC values may pseudonormalize or even be high during this time in some less severe but clinically significant injuries. We hypothesized that fractional anisotropy (FA), a measure of the directional diffusivity of water made using diffusion tensor imaging, may be abnormal in these less severe injuries; therefore, the objective of this study was to use diffusion tensor imaging to measure ADC and FA in infants with moderate and severe hypoxic-ischemic brain injury. METHODS Twenty infants with HIE and 7 normal control infants were studied. All infants were born at >36 weeks' gestational age, and MRI scans were obtained within 3 weeks of delivery. Data were examined for normality, and comparisons were made using analysis of variance or Kruskal-Wallis as appropriate. RESULTS During the first week, FA values were decreased with both severe and moderate WM and BGT injury as assessed by conventional imaging, whereas ADC values were reduced only in severe WM injury and some severe BGT injury. Abnormal ADC values pseudonormalized during the second week, whereas FA values continued to decrease. CONCLUSION FA is reduced in moderate brain injury after HIE. A low FA may reflect a breakdown in WM organization. Moderate BGT injury may result in atrophy but not overt infarction; it is possible that delayed apoptosis is more marked than immediate necrosis, and this may account for normal early ADC values. The accompanying low FA within some severe and all moderate gray matter lesions, which is associated with significant later impairment, may help to confirm clinically significant abnormality in infants with normal ADC values.
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Affiliation(s)
- Phil Ward
- Department of Paediatrics, MRC Clinical Sciences Centre, Imperial College Faculty of Medicine, Hammersmith Hospital, London, England
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22
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Grant PE, Yu D. Acute injury to the immature brain with hypoxia with or without hypoperfusion. Radiol Clin North Am 2006; 44:63-77, viii. [PMID: 16297682 DOI: 10.1016/j.rcl.2005.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This article reviews the imaging features and evolution of immature brain injury caused by hypoxia with or without hypoperfusion in the neonate and young child. Clinical presentations and available literature on mechanisms and clinical outcomes are discussed. In many of these cases, diffusion-weighted imaging does not show the full extent of the injury but detects a pattern of injury that is important in guiding clinical care. Awareness of the delayed cell death mechanisms is essential to understand diffusion-weighted imaging sensitivity and evolution and to provide the most accurate clinical interpretation, especially in cases of hypoxia with or without hypoperfusion.
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Affiliation(s)
- P Ellen Grant
- Division of Pediatric Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
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23
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Rutherford MA, Ward P, Malamateniou C, Malamatentiou C. Advanced MR techniques in the term-born neonate with perinatal brain injury. Semin Fetal Neonatal Med 2005; 10:445-60. [PMID: 15979420 DOI: 10.1016/j.siny.2005.05.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Magnetic resonance imaging (MRI) has become an essential tool for assessing the neonatal brain. Conventional imaging can detect patterns of injury that relate to the aetiology and timing of an insult and provide valuable information about prognosis. Sequences must always be adapted for the immature brain. Diffusion techniques improve the detection of ischaemic tissue and allow more accurate timing of an insult. Diffusion tensor imaging allows the assessment of tissue microstructure changes with normal development as well as in response to tissue injury. Diffusion tractography will further our understanding of the long-term effects of perinatal injuries on brain development, and when used in combination with clinical and functional imaging studies will allow the plasticity of the immature brain to be studied. MR angiography and venography are important adjuncts to the clinical examination, and when combined with perfusion studies can provide valuable information about vessel development following injury. Detailed vascular studies may detect inherent susceptibilities, which give rise to lesions in some babies but not others. The future for neonatal imaging is exciting; however, detailed and serial imaging of carefully chosen cohorts of infants coupled with long-term clinical follow-up are essential to ensure the clinical significance of any new findings.
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Affiliation(s)
- Mary A Rutherford
- Robert Steiner MR Unit, Imaging Sciences Department, Clinical Sciences Centre, Imperial College, Hammersmith Hospital, London, UK.
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24
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Brissaud O, Chateil JF, Bordessoules M, Brun M. Chemical shift imaging and localised magnetic resonance spectroscopy in full-term asphyxiated neonates. Pediatr Radiol 2005; 35:998-1005. [PMID: 15965677 DOI: 10.1007/s00247-005-1524-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Revised: 05/02/2005] [Accepted: 05/10/2005] [Indexed: 11/26/2022]
Abstract
BACKGROUND Diagnosis of brain lesions after birth anoxia-ischemia is essential for appropriate management. Clinical evaluation is not sufficient. MRI has been proven to provide useful information. OBJECTIVE To compare abnormalities observed with MRI, including diffusion-weighted imaging (DWI), localised magnetic resonance spectroscopy (MRS) and chemical shift imaging (CSI) and correlate these findings with the clinical outcome. MATERIALS AND METHODS Fourteen full-term neonates with birth asphyxia were studied. MRI, MRS and CSI were performed within the first 4 days of life. RESULTS Lesions observed with DWI were correlated with outcome, but the apparent diffusion coefficient (ADC) did improve diagnostic confidence. The mean value of Lac/Cr for the neonates with a favourable outcome was statically lower than for those who died (0.22 vs 1.04; P = 0.01). The same results were observed for the Lac/NAA ratio (0.21 vs 1.23; P = 0.01). Data obtained with localised MRS and CSI were correlated for the ratio N-acetyl-aspartate/choline, but not for the other metabolites. No correlation was found between the ADC values and the metabolite ratios. CONCLUSIONS Combination of these techniques could be helpful in our understanding of the physiopathological events occurring in neonates with asphyxia.
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Affiliation(s)
- Olivier Brissaud
- Paediatric Intensive Care Unit, Children's Hospital, Place Amélie Raba Léon, Bordeaux 33076, France.
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25
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Jissendi Tchofo P, Christophe C, David P, Metens T, Soto Ares G, Balériaux D. Apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR) in pediatric hypoxic-ischemic brain injury. J Neuroradiol 2005; 32:10-9. [PMID: 15798608 DOI: 10.1016/s0150-9861(05)83016-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND PURPOSE a review of the literature reveals the increasing interest in using Diffusion magnetic resonance imaging, with diffusion weighted images (DWI) and ADC (Apparent Diffusion Coefficient) quantitation, in pediatric hypoxic-ischemic brain injury. However, ADC and MTR (Magnetization Transfer Ratio) as quantitative tools have not been investigated together in these pathological conditions in young pediatric patients. The aim of this study was to apply a quantitative method by using ADC and MTR calculation in order to propose a reproducible quantitation of brain parenchymal lesions. METHODS we conducted a prospective study including all children presenting with suspected cerebral hypoxic-ischemic injury. 15 children were included, among them 10 males and 5 females aged from 36 weeks of gestation to 17 months with a median age of 10,5 months. All MR examinations were performed at 1.5 Tesla unit including conventional MR (T1, T2 and Inversion-recovery sequences) and DWI with ADC map. ADC and MTR ROI (region of interest) measurements were made, in the frontal subcortical and periventricular white matter (WM) as well as in the gray matter (GM=basal ganglia), and in focal lesions. RESULTS ADC and MTR values were abnormal in focal lesions and in diffuse injury with no evidence of lesion on conventional MRI and DWI. We observed a strong inverse correlation between these ADC and MTR (R=0,66 in WM; R=0,61 in GM). CONCLUSION ADC and MTR calculation may be helpful as a reproductive method to quantify the lesions and detect diffuse lesions in hypoxic-ischemic pediatric brain injury.
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Affiliation(s)
- P Jissendi Tchofo
- Clinique de Neuroradiologie, Service de Radiologie, Hôpital Erasme, Route de Lennik 808, 1070 Bruxelles.
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26
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Rutherford M, Counsell S, Allsop J, Boardman J, Kapellou O, Larkman D, Hajnal J, Edwards D, Cowan F. Diffusion-weighted magnetic resonance imaging in term perinatal brain injury: a comparison with site of lesion and time from birth. Pediatrics 2004; 114:1004-14. [PMID: 15466098 DOI: 10.1542/peds.2004-0222] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The aim of this study was to establish a more objective method for confirming tissue injury in term neonates who present with early seizures that are believed to be hypoxic-ischemic in origin. METHODS We studied the relationship between contemporaneous diffusion-weighted magnetic resonance imaging and conventional magnetic resonance imaging in 63 symptomatic term-born neonates and 15 control term infants performed in the neonatal period. Apparent diffusion coefficients (ADC) were obtained for multiple regions of the brain. RESULTS ADC values in the 15 control infants were 1 (1-1.15) (median [range]) x 10(-3)/mm2/second in the thalami and 1.1 (1-1.3) x 10(-3)/mm2/second in the lentiform nuclei, 1.5 (1.3-1.7) x 10(-3)/mm2/second in the centrum semiovale, 1.6 (1.46-1.7) x 10(-3)/mm2/second in the anterior white matter (WM), and 1.55 (1.35-1.85) x 10(-3)/mm2/second in the posterior WM with little variation over time. ADC values were significantly reduced in the first week after severe injury to either WM or basal ganglia and thalami (BGT), but values normalized at the end of the first week and then increased during week 2. ADC values were either normal or increased in moderate BGT and WM lesions when compared with controls. ADC values < 1.1 x 10(-3)/mm2/second were always associated with WM infarction and values <0.8 x 10(-3)/mm2/second with thalamic infarction. CONCLUSION A reduced ADC soon after delivery allows the presence of tissue infarction to be confirmed at a time when conventional imaging changes may be subtle. However, as both moderate WM and BGT lesions may have normal or increased ADC values, a normal ADC value during the first week does not signify normal tissue. ADC values should always be measured in combination with visual analysis of both conventional and diffusion-weighed images for maximum detection of pathologic tissue, and the timing of the scan needs to be taken into account when interpreting the results.
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Affiliation(s)
- Mary Rutherford
- Robert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College, Hammersmith Hospital, Du Cane Rd, London W12 OHS.
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27
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Lövblad KO, Wetzel SG, Somon T, Wilhelm K, Mehdizade A, Kelekis A, El-Koussy M, El-Tatawy S, Bishof M, Schroth G, Perrig S, Lazeyras F, Sztajzel R, Terrier F, Rüfenacht D, Delavelle J. Diffusion-weighted MRI in cortical ischaemia. Neuroradiology 2004; 46:175-82. [PMID: 14749911 DOI: 10.1007/s00234-003-1133-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Accepted: 08/23/2003] [Indexed: 11/30/2022]
Abstract
We carried out MRI on 16 male and three female comatose patients, aged 2 days to 79 years, with suspected cortical ischaemia referred from our intensive care units. Using a head coil, and following standard imaging, including coronal fluid-attenuated inversion-recovery images, we performed diffusion-weighted imaging (DWI) using a whole-brain multislice single-shot echo-planar sequence with b 0 and 1000 s/mm2: 5-mm slices covering the whole brain, TR 7000 TE 106 ms, 128 x 128 pixels, field of view 250 mm, one excitation. Maps of apparent diffusion coefficients (ADC) were generated automatically. DWI showed cortical, basal ganglia and watershed-area high signal in all cases, associated with a decrease in ADC to 60- 80% of normal. DWI showed lesions not seen (40%) or underestimated (40%) on conventional T2-weighted imaging. Within 24 h of the onset of symptoms, DWI showed changes not readily detectable on T2-weighted images. The cortical high signal on DWI and the ADC changes, suggesting severe ischaemia rather than oedema, was found in areas known to be affected by cortical laminar necrosis. Extension to the brain stem and white matter was associated with a higher likelihood of death.
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Affiliation(s)
- K O Lövblad
- Unité de Neuroradiologie, Service de Radiodiagnostic, DRRI, Hôpital Cantonal Un iversitaire de Genève, 24 rue Micheli-du-Crest, 1211 Geneva 14, Switzerland.
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