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Weaver KE, Chaovalitwongse WA, Novotny EJ, Poliakov A, Grabowski TG, Ojemann JG. Local functional connectivity as a pre-surgical tool for seizure focus identification in non-lesion, focal epilepsy. Front Neurol 2013; 4:43. [PMID: 23641233 PMCID: PMC3640210 DOI: 10.3389/fneur.2013.00043] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 04/17/2013] [Indexed: 11/30/2022] Open
Abstract
Successful resection of cortical tissue engendering seizure activity is efficacious for the treatment of refractory, focal epilepsy. The pre-operative localization of the seizure focus is therefore critical to yielding positive, post-operative outcomes. In a small proportion of focal epilepsy patients presenting with normal MRI, identification of the seizure focus is significantly more challenging. We examined the capacity of resting state functional MRI (rsfMRI) to identify the seizure focus in a group of four non-lesion, focal (NLF) epilepsy individuals. We predicted that computing patterns of local functional connectivity in and around the epileptogenic zone combined with a specific reference to the corresponding region within the contralateral hemisphere would reliably predict the location of the seizure focus. We first averaged voxel-wise regional homogeneity (ReHo) across regions of interest (ROIs) from a standardized, probabilistic atlas for each NLF subject as well as 16 age- and gender-matched controls. To examine contralateral effects, we computed a ratio of the mean pair-wise correlations of all voxels within a ROI with the corresponding contralateral region (IntraRegional Connectivity – IRC). For each subject, ROIs were ranked (from lowest to highest) on ReHo, IRC, and the mean of the two values. At the group level, we observed a significant decrease in the rank for ROI harboring the seizure focus for the ReHo rankings as well as for the mean rank. At the individual level, the seizure focus ReHo rank was within bottom 10% lowest ranked ROIs for all four NLF epilepsy patients and three out of the four for the IRC rankings. However, when the two ranks were combined (averaging across ReHo and IRC ranks and scalars), the seizure focus ROI was either the lowest or second lowest ranked ROI for three out of the four epilepsy subjects. This suggests that rsfMRI may serve as an adjunct pre-surgical tool, facilitating the identification of the seizure focus in focal epilepsy.
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Affiliation(s)
- K E Weaver
- Department of Radiology, University of Washington Seattle, WA, USA ; Integrated Brain Imaging Center, University of Washington Seattle, WA, USA
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Ishak GE, Poliakov AV, Poliachik SL, Saneto RP, Novotny EJ, McDaniel S, Ojemann JG, Shaw DWW, Friedman SD. Tract-based spatial statistical analysis of diffusion tensor imaging in pediatric patients with mitochondrial disease: widespread reduction in fractional anisotropy of white matter tracts. AJNR Am J Neuroradiol 2012; 33:1726-30. [PMID: 22499843 DOI: 10.3174/ajnr.a3045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Often diagnosed at birth or in early childhood, mitochondrial disease presents with a variety of clinical symptoms, particularly in organs and tissues that require high energetic demand such as brain, heart, liver, and skeletal muscles. In a group of pediatric patients identified as having complex I or I/III deficits on muscle biopsy but with white matter tissue appearing qualitatively normal for age, we hypothesized that quantitative DTI analyses might unmask disturbance in microstructural integrity. MATERIALS AND METHODS In a retrospective study, DTI and structural MR brain imaging data from 10 pediatric patients with confirmed mitochondrial disease and 10 clinical control subjects were matched for age, sex, scanning parameters, and date of examination. Paired TBSS was performed to evaluate differences in FA, MD, and the separate diffusion direction terms (λr and λa). RESULTS In patients with mitochondrial disease, significant widespread reductions in FA values were shown in white matter tracts. Mean diffusivity values were significantly increased in patients, having a sparser distribution of affected regions compared with FA. Separate diffusion maps showed significant increase in λr and no significant changes in λa. CONCLUSIONS Despite qualitatively normal-appearing white matter tissues, patients with complex I or I/III deficiency have widespread microstructural changes measurable with quantitative DTI.
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Affiliation(s)
- G E Ishak
- Seattle Children's Hospital, Department of Radiology, 4800 Sandpoint Way, M/S R-5417, Seattle, Washington 98105, USA.
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Bai X, Guo J, Killory B, Vestal M, Berman R, Negishi M, Danielson N, Novotny EJ, Constable RT, Blumenfeld H. Resting functional connectivity between the hemispheres in childhood absence epilepsy. Neurology 2011; 76:1960-7. [PMID: 21646622 DOI: 10.1212/wnl.0b013e31821e54de] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The fundamental mechanisms by which childhood absence epilepsy (CAE) changes neural networks even between seizures remain poorly understood. During seizures, cortical and subcortical networks exhibit bihemspheric synchronous activity based on prior EEG-fMRI studies. Our aim was to investigate whether this abnormal bisynchrony may extend to the interictal period, using a blood oxygen level-dependent (BOLD) resting functional connectivity approach. METHODS EEG-fMRI data were recorded from 16 patients with CAE and 16 age- and gender-matched controls. Three analyses were performed. 1) Using 16 pairs of seizure-related regions of interest (ROI), we compared the between-hemisphere interictal resting functional connectivity of patients and controls. 2) For regions showing significantly increased interhemispheric connectivity in CAE, we then calculated connectivity to the entire brain. 3) A paired-voxel approach was performed to calculate resting functional connectivity between hemispheres without the constraint of predefined ROIs. RESULTS We found significantly increased resting functional connectivity between hemispheres in the lateral orbitofrontal cortex of patients with CAE compared to normal controls. Enhanced between-hemisphere connectivity localized to the lateral orbitofrontal cortex was confirmed by all 3 analysis methods. CONCLUSIONS Our results demonstrate abnormal increased connectivity between the hemispheres in patients with CAE in seizure-related regions, even when seizures were not occurring. These findings suggest that the lateral orbitofrontal cortex may play an important role in CAE pathophysiology, warranting further investigation. In addition, resting functional connectivity analysis may provide a promising biomarker to improve our understanding of altered brain function in CAE during the interictal period.
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Affiliation(s)
- X Bai
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06520-8018, USA
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Durazzo TS, Spencer SS, Duckrow RB, Novotny EJ, Spencer DD, Zaveri HP. Temporal distributions of seizure occurrence from various epileptogenic regions. Neurology 2008; 70:1265-71. [PMID: 18391158 DOI: 10.1212/01.wnl.0000308938.84918.3f] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The aim of this study was to determine whether seizure occurrence in partial epilepsy is under the influence of circadian rhythms and rhythmic exogenous factors, and how this influence varies according to cortical brain region. For these ends, we determined and analyzed detailed temporal distributions of seizures arising from the frontal, parietal, occipital, neocortical temporal, and mesial temporal lobes. METHODS We retrospectively analyzed intracranial EEG recordings from 131 consecutive adult subjects whose partial epilepsy was sufficiently localized for surgical resection. In all, 669 seizures were analyzed: 132 frontal, 77 parietal, 83 occipital, 217 mesial temporal, and 160 neocortical temporal. RESULTS Seizure distribution was dependent on brain region (p < 10(-9)). Nonuniform seizure distributions were observed in the parietal (p < 10(-4)), occipital (p < 10(-7)), mesial temporal (p < 0.02), and neocortical temporal lobes (p < 0.04). Occipital and parietal seizures occurred in strong gaussian-like distributions, 180 degrees out of phase relative to each other; occipital seizure occurrence peaked between 16:00 and 19:00, whereas parietal seizures peaked between 4:00 and 7:00. Frontal lobe seizures followed a unimodal distribution, peaking between 4:00 and 7:00. Seizures from the mesial temporal lobe were distributed bimodally, with the primary peak in the late afternoon between 16:00 and 19:00 and secondary peak in the morning between 7:00 and 10:00. Neocortical temporal seizures peaked slightly before the primary peak observed in the mesial temporal lobe; however, these distributions did not differ significantly. CONCLUSIONS Seizure occurrence in partial epilepsy is not random. Endogenous circadian rhythms and rhythmic exogenous factors likely play substantial roles in seizure occurrence. These roles vary considerably according to brain region. Frontal and parietal lobe seizures seem most likely to occur nocturnally, whereas occipital and temporal lobe seizures seem to have strong afternoon preferences.
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Affiliation(s)
- T S Durazzo
- Department of Neurology, Yale University, New Haven, CT 06520, USA
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Pearl PL, Gibson KM, Acosta MT, Vezina LG, Theodore WH, Rogawski MA, Novotny EJ, Gropman A, Conry JA, Berry GT, Tuchman M. Clinical spectrum of succinic semialdehyde dehydrogenase deficiency. Neurology 2003; 60:1413-7. [PMID: 12743223 DOI: 10.1212/01.wnl.0000059549.70717.80] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder affecting CNS gamma-aminobutyric acid (GABA) degradation. SSADH, in conjunction with GABA transaminase, converts GABA to succinate. In the absence of SSADH, GABA is converted to 4-OH-butyrate. The presence of 4-OH-butyrate, a highly volatile compound, may be undetected on routine organic acid analysis. Urine organic acid testing was modified at the authors' institution in 1999 to screen for the excretion of 4-OH-butyrate by selective ion monitoring gas chromatography-mass spectrometry in addition to total ion chromatography. Since then, five patients with 4-hydroxybutyric aciduria have been identified. The authors add the clinical, neuroimaging, and EEG findings from a new cohort of patients to 51 patients reported in the literature with clinical details. Ages ranged from 1 to 21 years at diagnosis. Clinical findings include mild-moderate mental retardation, disproportionate language dysfunction, hypotonia, hyporeflexia, autistic behaviors, seizures, and hallucinations. Brain MRI performed in five patients at the authors' institution revealed symmetric increased T2 signal in the globus pallidi. SSADH deficiency is an under-recognized, potentially manageable neurometabolic disorder. Urine organic acid analysis should include a sensitive method for the detection of 4-hydroxybutyrate and should be obtained from patients with mental retardation or neuropsychiatric disturbance of unknown etiology.
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Affiliation(s)
- P L Pearl
- Department of Neurology, Children's National Medical Center, George Washington University School of Health Sciences, Washington, DC 20010-2970, USA.
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de Graaf RA, Pan JW, Telang F, Lee JH, Brown P, Novotny EJ, Hetherington HP, Rothman DL. Differentiation of glucose transport in human brain gray and white matter. J Cereb Blood Flow Metab 2001; 21:483-92. [PMID: 11333358 DOI: 10.1097/00004647-200105000-00002] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Localized 1H nuclear magnetic resonance spectroscopy has been applied to determine human brain gray matter and white matter glucose transport kinetics by measuring the steady-state glucose concentration under normoglycemia and two levels of hyperglycemia. Nuclear magnetic resonance spectroscopic measurements were simultaneously performed on three 12-mL volumes, containing predominantly gray or white matter. The exact volume compositions were determined from quantitative T1 relaxation magnetic resonance images. The absolute brain glucose concentration as a function of the plasma glucose level was fitted with two kinetic transport models, based on standard (irreversible) or reversible Michaelis-Menten kinetics. The steady-state brain glucose levels were similar for cerebral gray and white matter, although the white matter levels were consistently 15% to 20% higher. The ratio of the maximum glucose transport rate, V(max), to the cerebral metabolic utilization rate of glucose, CMR(Glc), was 3.2 +/- 0.10 and 3.9 +/- 0.15 for gray matter and white matter using the standard transport model and 1.8 +/- 0.10 and 2.2 +/- 0.12 for gray matter and white matter using the reversible transport model. The Michaelis-Menten constant K(m) was 6.2 +/- 0.85 and 7.3 +/- 1.1 mmol/L for gray matter and white matter in the standard model and 1.1 +/- 0.66 and 1.7 +/- 0.88 mmol/L in the reversible model. Taking into account the threefold lower rate of CMR(Glc) in white matter, this finding suggests that blood--brain barrier glucose transport activity is lower by a similar amount in white matter. The regulation of glucose transport activity at the blood--brain barrier may be an important mechanism for maintaining glucose homeostasis throughout the cerebral cortex.
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Affiliation(s)
- R A de Graaf
- Department of Radiology, Yale University, School of Medicine, New Haven, Connecticut 06520-8043, USA
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Novotny EJ, Ariyan C, Mason GF, O'Reilly J, Haddad GG, Behar KL. Differential increase in cerebral cortical glucose oxidative metabolism during rat postnatal development is greater in vivo than in vitro. Brain Res 2001; 888:193-202. [PMID: 11150475 DOI: 10.1016/s0006-8993(00)03051-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The steady-state rate of glucose oxidation through the mitochondrial TCA cycle (V(TCA)) was measured in acid extracts of 10- and 30-day-old cerebral cortex of rats receiving [1-13C]glucose intravenously and in neocortical slices superfused in vitro with the same isotope. TCA cycle flux was determined for each age group based on metabolic modeling analysis of the isotopic turnover of cortical glutamate and lactate. The sensitivity of the calculated rates to assumed parameters in the model were also assessed. Between 10 and 30 postnatal days, V(TCA) increased by 4.3-fold (from 0.46 to 2.0 micromol g(-1) min(-1)) in the cortex in vivo, whereas only a 2-fold (from 0.17 to 0.34 micromol g(-1) min(-1)) increase was observed in neocortical slices. The much greater increase in glucose oxidative metabolism of the cortex measured in vivo over that measured in vitro as the cortex matures suggests that function-related energy demands increase during development, a process that is deficient in the slice as a result of deafferentiation and other mechanisms.
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Affiliation(s)
- E J Novotny
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06520, USA
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Buerstatte CR, Behar KL, Novotny EJ, Lai JC. Brain regional development of the activity of alpha-ketoglutarate dehydrogenase complex in the rat. Brain Res Dev Brain Res 2000; 125:139-45. [PMID: 11154769 DOI: 10.1016/s0165-3806(00)00134-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study was initiated to test the hypothesis that the development of alpha-ketoglutarate dehydrogenase complex (KGDHC) activity, like that of pyruvate dehydrogenase complex, is one of the late developers of tricarboxylic acid (TCA) cycle enzymes. The postnatal development of KGDHC in rat brain exhibits four distinct region-specific patterns. The age-dependent increases in olfactory bulb (OB) and hypothalamus (HYP) form one pattern: low in postnatal days (P) 2 and 4, KGDHC activity rose linearly to attain adult level at P30. The increases in mid-brain (MB) and striatum (ST) constitute a second pattern: being <40% of adult level at P2 and P4, KGDHC activity rose steeply between P10 and P17 and attained adult level by P30. The increases in cerebellum (CB), cerebral cortex (CC), and hippocampus (HIP) form a third pattern: being 25-30% of adult level at P2 and P4, KGDHC activity doubled between P10 and P17 and rose to adult level by P30. KGDHC activity development is unique in pons and medulla (PM): being >60% of the adult level at P2, it rose rapidly to adult level by P10. Thus, KGDHC activity develops earlier in phylogenetically older regions (PM) than in phylogenetically younger regions (CB, CC, HIP). Being lowest in activity among all TCA cycle enzymes, KGDHC activity in any region at any age will exert a limit on the maximum TCA cycle flux therein. The results may have functional and pathophysiological implications in control of brain glucose oxidative metabolism, energy metabolism, and neurotransmitter syntheses.
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Affiliation(s)
- C R Buerstatte
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Campus Box 8334, Pocatello, ID 83209-8334, USA
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Abstract
Glucose transporter type 1 (GLUT1) deficiency is an inborn error of glucose transport. Clinical manifestations are presumed secondary to reduced glucose transport across the blood brain barrier, and include seizures, abnormal tone, developmental delay and hypoglycorrhachia. A high index of suspicion is important as GLUT1 deficiency is a potentially treatable cause of mental retardation. We studied two affected children by continuous video-EEG in order to better understand the cause of the clinical manifestations and improvement on a ketogenic diet. The EEG was characterized by generalized paroxysmal 2-2.5 Hz spike-wave discharges, although normal EEGs were also obtained. Atypical absence seizures were the most prominent clinical seizure. Epileptiform activity and clinical seizures occurred in both children while acutely ketotic and non-ketotic, but were markedly more frequent in one child when non-ketotic. Discharges were not associated with a reduction in substrate for brain metabolism in the blood at that time. Conclusion Atypical absence seizures are common in glucose transporter type 1 deficiency and should alert the clinician to the possibility of this treatable disorder when present in a young child with developmental delay. Our data suggest that the therapeutic mechanism of the ketogenic diet in this disorder is more complicated than simply delivering ketones as an alternative substrate for brain metabolism.
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Affiliation(s)
- R G Boles
- Medical Genetics, Box 90, Childrens Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, California 90027, USA.
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Masuoka LK, Anderson AW, Gore JC, McCarthy G, Spencer DD, Novotny EJ. Functional magnetic resonance imaging identifies abnormal visual cortical function in patients with occipital lobe epilepsy. Epilepsia 1999; 40:1248-53. [PMID: 10487188 DOI: 10.1111/j.1528-1157.1999.tb00854.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine whether functional magnetic resonance imaging (fMRI) can reliably identify lateralized cortical dysfunction in patients with suspected occipital lobe epilepsy. METHODS We compared visual cortical function of 10 patients with intractable occipital lobe epilepsy with nine control subjects' fMRI. Visual stimulation by using an alternating checkerboard pattern results in transient increases in the intensity of the proton magnetic resonance signal of water in the occipital lobes during echo-planar imaging. We used these stimulus-dependent changes in signal intensity to construct functional activation maps, which we registered onto anatomic images. RESULTS After full-field stimulation, none of the patients with occipital lobe epilepsy had normal activation patterns, whereas eight of the nine control subjects had normal patterns (p = 0.001). Abnormalities consisted of either a markedly asymmetric activation pattern in six of 10 patients (p = 0.04), or a complete absence of activation in four of 10 patients (p = 0.05). The abnormal side of activation was concordant with the side of seizure onset in all six patients with asymmetric activation maps. Half-field stimulation produced less reliable results. Although more patients had abnormal activation maps than did controls with half-field stimulation (p = 0.04), the abnormal side was discordant with the side of seizure onset in three of the five patients who had markedly asymmetric activation patterns. CONCLUSIONS These results suggest that fMRI with full-field stimulation is a reliable, noninvasive method for identifying areas of abnormal visual cortical function ipsilateral to the epileptogenic region in patients with occipital lobe epilepsy.
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Affiliation(s)
- L K Masuoka
- Berlex Laboratories, Richmond, CA 94804, USA
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Abstract
PURPOSE Changes in gamma-aminobutyric acid (GABA) physiology are important in determining seizure susceptibility in the developing nervous system. Noninvasive measurements of brain GABA in adults with epilepsy have demonstrated important relations among seizure control, brain GABA levels, and changes in brain GABA with drugs designed to alter GABA metabolism. The purpose of this study was to demonstrate the changes in GABA in the occipital lobes of children with epilepsy after treatment with vigabatrin (VGB). METHODS Ten proton nuclear magnetic resonance spectroscopic (NMRS) studies were obtained on four subjects with epilepsy. The subjects were between ages 1 and 5 years. Occipital lobe GABA levels were measured before and after treatment with VGB. RESULTS Brain GABA levels increased significantly in these subjects after VGB treatment (p < 0.05, paired Student's t test). In one subject, brain GABA was decreased in the region of the epileptic focus compared with the homologous region of the opposite hemisphere. A nearly fivefold increase in GABA occurred in the epileptic region after VGB treatment in this subject. CONCLUSIONS VGB increases brain GABA levels in children with epilepsy. NMRS can be used to monitor the response of brain GABA levels to drugs known to alter GABA physiology and serve as an important tool to understand the role of GABA-mediated inhibition in pediatric epilepsies.
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Affiliation(s)
- E J Novotny
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Affiliation(s)
- S R Levy
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
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13
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Abstract
A refocusing pulse train consisting of a semiselective refocusing pulse and a selective inversion pulse to obtain a pure-phase refocusing at the frequency of maximal excitation of the semiselective refocusing pulse is proposed and applied to in vivo lactate and beta-hydroxybutyrate editing using difference spectroscopy. It is shown, using both rotation matrix theory and phantom experiments, that the soft inversion pulse has to be halved to flank the semiselective pulse to obtain perfect refocusing and cancellation of interfering resonances. The editing method is used to obtain lactate and beta-hydroxybutyrate spectra from the occipital cortex of juvenile epilepsy patients before and after ketogenic diet treatment.
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Affiliation(s)
- J Shen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Abstract
Clinical neurophysiologic studies have an important role in the diagnosis and management of the patient with epilepsy. Epilepsy is a clinical diagnosis and the EEG is an important adjunct used to differentiate epileptic seizures from nonepileptic events, refine the diagnosis of epilepsy into specific seizure types and epileptic syndromes, and provide a measure of brain function. The value of the EEG is highly dependent on the clinical context in which it is being applied. In some epilepsies the interictal EEG may be diagnostic whereas in others an ictal recording may be necessary to obtain a specific diagnosis. Both the interictal and ictal EEG characteristics vary with specific seizure types and epilepsies and are described in detail in this review. The usefulness of the EEG in the management of epilepsy and in aiding in the decision to discontinue antiepileptic therapy is also discussed.
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Affiliation(s)
- E J Novotny
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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Kang PB, Novotny EJ. A two-year-old girl with acute onset of seizures and progressive encephalopathy. Curr Opin Pediatr 1997; 9:558-64. [PMID: 9425587 DOI: 10.1097/00008480-199712000-00002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- P B Kang
- Yale University, Department of Pediatrics, New Haven, CT 06520-8064, USA
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Abstract
The difference between 1H nuclear magnetic resonance (NMR) spectra obtained from the human brain during euglycemia and during hyperglycemia is depicted as well-resolved glucose peaks. The time course of these brain glucose changes during a rapid increase in plasma glucose was measured in four healthy subjects, aged 18-22 years, in five studies. Results demonstrated a significant lag in the rise of glucose with respect to plasma glucose. The fit of the integrated symmetric Michaelis-Menten model to the time course of relative glucose signals yielded an estimated plasma glucose concentration for half maximal transport, Kt, of 4.8 +/- 2.4 mM (mean +/- SD), a maximal transport rate, Tmax, of 0.80 +/- 0.45 micromol g-1 min-1, and a cerebral metabolic glucose consumption rate (CMR)glc of 0.32 +/- 0.16 micromol g-1 min-1. Assuming cerebral glucose concentration to be 1.0 micromol/g at euglycemia as measured by 13CMR, the fit of the same model to the time course of brain glucose concentrations resulted in Kt = 3.9 +/- 0.82 mM, Tmax = 1.16 +/- 0.29 micromol g-1 min-1, and CMRglc = 0.35 +/- 0.10 micromol g-1 min-1. In both cases, the resulting time course equaled that predicted from the determination of the steady-state glucose concentration by 13C NMR spectroscopy within the experimental scatter. The agreement between the two methods of determining transport kinetics suggests that glucose is distributed throughout the entire aqueous phase of the human brain, implying substantial intracellular concentration.
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Affiliation(s)
- R Gruetter
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
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Abstract
Little is known about what factors predict intractable epilepsy at the time of initial diagnosis. We performed a case-control study to identify early predictors of medically intractable epilepsy in children. Cases were children who had an average of one seizure or more a month over a 2-year period and who, during that time, had failed trials of at least three different antiepileptic drugs (AEDs). Controls were children who had epilepsy, who had been seizure-free for > or = 2 years, and who had never, before becoming seizure-free, met the definition for intractable epilepsy. Strong univariate associations were noted between intractability and several factors: infantile spasms (IS) remote symptomatic epilepsy, a history of status epilepticus (SE) before the diagnosis of epilepsy, neonatal seizures, and microcephaly. Cases were significantly younger than controls at onset (1.8 vs. 5.8 years); this was not due solely to cases with onset during the first year of life but was an association apparent throughout the age range studied. With multiple logistic regression, independent predictors of intractability were IS, odds ratio (OR) = 10.42, p = 0.03; age at onset with a decreasing risk with increasing age, OR = 0.77 per year, p less than 0.0001; remote symptomatic epilepsy, OR = 2.24, p = 0.04; and SE, OR = 3.30, p = 0.04. These findings complement those of recent cohort studies of remission of epilepsy and provide useful leads for future prospective studies of intractable epilepsy.
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Affiliation(s)
- A T Berg
- Northern Illinois University, Program in Community Health, DeKalb, Illinois, USA
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Novotny EJ, Avison MJ, Herschkowitz N, Petroff OA, Prichard JW, Seashore MR, Rothman DL. In vivo measurement of phenylalanine in human brain by proton nuclear magnetic resonance spectroscopy. Pediatr Res 1995; 37:244-9. [PMID: 7731764 DOI: 10.1203/00006450-199502000-00020] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Disorders of the CNS are the major causes of morbidity and mortality observed in untreated subjects with phenylketonuria (PKU). A method to measure cerebral concentrations of phenylalanine (Phe) in vivo would greatly enhance the ability to investigate both the pathophysiology and the efficacy of therapy of this aminoacidopathy. Twelve image-guided localized proton nuclear magnetic resonance spectroscopic studies were performed in seven subjects with PKU using pulse sequences optimized to detect the aromatic protons of Phe. Ten control studies were also performed using a 2.1-Tesla Bruker Biospec spectrometer. Plasma Phe was measured at the time of the spectroscopic examination in the PKU patients. A Phe signal was observed in all 12 studies performed on the group with PKU, and in five studies cerebral Phe concentrations were measured to be 480 to 780 mumol/g. Plasma Phe concentrations were 0.7 to 3.3 mM (10.8 to 54.8 mg/dL) in the subjects with PKU. Human cerebral Phe concentrations can be measured noninvasively using proton nuclear magnetic resonance spectroscopy. A simultaneous measure of Phe and several other cerebral metabolites is obtained with this innovative technology. Adaptations of this technique can be used to investigate PKU and other neurometabolic disorders with modifications of current clinical magnetic resonance imaging systems.
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Affiliation(s)
- E J Novotny
- Department of Pediatrics, School of Medicine, Yale University, New Haven, Connecticut 06510, USA
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Mason GF, Gruetter R, Rothman DL, Behar KL, Shulman RG, Novotny EJ. Simultaneous determination of the rates of the TCA cycle, glucose utilization, alpha-ketoglutarate/glutamate exchange, and glutamine synthesis in human brain by NMR. J Cereb Blood Flow Metab 1995; 15:12-25. [PMID: 7798329 DOI: 10.1038/jcbfm.1995.2] [Citation(s) in RCA: 271] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
13C isotopic tracer data previously obtained by 13C nuclear magnetic resonance in the human brain in vivo were analyzed using a mathematical model to determine metabolic rates in a region of the human neocortex. The tricarboxylic acid (TCA) cycle rate was 0.73 +/- 0.19 mumol min-1 g-1 (mean +/- SD; n = 4). The standard deviation reflects primarily intersubject variation, since individual uncertainties were low. The rate of alpha-ketoglutarate/glutamate exchange was 57 +/- 26 mumol min-1 g-1 (n = 3), which is much greater than the TCA cycle rate; the high rate indicates that alpha-ketoglutarate and glutamate are in rapid exchange and can be treated as a single combined kinetic pool. The rate of synthesis of glutamine from glutamate was 0.47 mumol min-1 g-1 (n = 4), with 95% confidence limits of 0.139 and 3.094 mumol min-1 g-1; individual uncertainties were biased heavily toward high synthesis rates. From the TCA cycle rate the brain oxygen consumption was estimated to be 2.14 +/- 0.48 mumol min-1 g-1 (5.07 +/- 1.14 ml 100 g-1 min-1; n = 4), and the rate of brain glucose consumption was calculated to be 0.37 +/- 0.08 mumol min-1 g-1 (n = 4). The sensitivity of the model to the assumptions made was evaluated, and the calculated values were found to be unchanged as long as the assumptions remained near reported physiological values.
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Affiliation(s)
- G F Mason
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, Connecticut
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20
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Abstract
Nuclear magnetic resonance (NMR) spectroscopy permits noninvasive, serial measurements of several metabolites with important neurobiologic roles in localized brain regions in vivo. Over the last decade, this technique has been applied to investigations of both animals and humans with epilepsy. Several nuclei that include specific proton, phosphorus, and carbon isotopes provide NMR signals that measure specific compounds in vivo. This paper reviews the studies that have used these multinuclear NMR techniques to investigate the role of these methods in the diagnosis and pathogenesis of epilepsy.
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Affiliation(s)
- E J Novotny
- Yale University, School of Medicine, Department of Pediatrics, New Haven, CT 06510, USA
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21
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Gruetter R, Novotny EJ, Boulware SD, Mason GF, Rothman DL, Shulman GI, Prichard JW, Shulman RG. Localized 13C NMR spectroscopy in the human brain of amino acid labeling from D-[1-13C]glucose. J Neurochem 1994; 63:1377-85. [PMID: 7931289 DOI: 10.1046/j.1471-4159.1994.63041377.x] [Citation(s) in RCA: 205] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cerebral metabolism of D[1-13C]glucose was studied with localized 13C NMR spectroscopy during intravenous infusion of enriched [1-13C]glucose in four healthy subjects. The use of three-dimensional localization resulted in the complete elimination of triacylglycerol resonance that originated in scalp and subcutaneous fat. The sensitivity and resolution were sufficient to allow 4 min of time-resolved observation of label incorporation into the C3 and C4 resonances of glutamate and C4 of glutamine, as well as C3 of aspartate with lower time resolution. [4-13C]Glutamate labeled rapidly reaching close to maximum labeling at 60 min. The label flow into [3-13C]glutamate clearly lagged behind that of [4-13C]-glutamate and peaked at t = 110-140 min. Multiplets due to homonuclear 13C-13C coupling between the C3 and C4 peaks of the glutamate molecule were observed in vivo. Isotopomer analysis of spectra acquired between 120 and 180 min yielded a 13C isotopic fraction at C4 glutamate of 27 +/- 2% (n = 4), which was slightly less than one-half the enrichment of the C1 position of plasma glucose (63 +/- 1%), p < 0.05. By comparison with an external standard the total amount of [4-13C]glutamate was directly quantified to be 2.4 +/- 0.1 mumol/ml-brain. Together with the isotopomer data this gave a calculated brain glutamate concentration of 9.1 +/- 0.7 mumol/ml, which agrees with previous estimates of total brain glutamate concentrations. The agreement suggests that essentially all of the brain glutamate is derived from glucose in health human brain.
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Affiliation(s)
- R Gruetter
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510
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22
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Shaywitz BA, Anderson GM, Novotny EJ, Ebersole JS, Sullivan CM, Gillespie SM. Aspartame has no effect on seizures or epileptiform discharges in epileptic children. Ann Neurol 1994; 35:98-103. [PMID: 7506878 DOI: 10.1002/ana.410350115] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effects of aspartame (L-aspartyl-L-phenylalanine methyl ester; APM) on the neurological status of children with well-documented seizures were examined in a randomized, double-blind, placebo-controlled, crossover study. We report on 10 children (5 boys, 5 girls, ages 5-13 yr) who were tested for 2 weeks each on APM and placebo (single morning dose, 34 mg/kg). Seven children had generalized convulsions with 4 also having absence episodes. One child had absence seizures and 2 had complex partial seizures only. On each arm of the study, children were admitted to the hospital for a standard 21-lead electroencephalogram (EEG), continuous 24-hour cassette EEG, and determination of biochemical variables in plasma and urine. Subjects completed the Subjects Treatment Emergent Symptoms Scale (STESS) and parents the Conners Behavior Rating Scale. There were no significant differences between APM and placebo in the standard EEG or 24-hour EEG. No differences were noted for the STESS or the Conners ratings, and no differences were noted for any of the biochemical measures (except for expected increases in phenylalanine and tyrosine after APM). Our findings indicate that, in this group of vulnerable children, APM does not provoke seizures.
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Affiliation(s)
- B A Shaywitz
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510
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23
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Chen W, Novotny EJ, Zhu XH, Rothman DL, Shulman RG. Localized 1H NMR measurement of glucose consumption in the human brain during visual stimulation. Proc Natl Acad Sci U S A 1993; 90:9896-900. [PMID: 8234332 PMCID: PMC47679 DOI: 10.1073/pnas.90.21.9896] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Spatially localized 1H NMR spectroscopy has been applied to measure changes in brain glucose concentration during 8-Hz photic stimulation. NMR spectroscopic measurements were made in a 12-cm3 volume centered on the calcarine fissure and encompassing the primary visual cortex. The average maximum change in glucose levels was 0.34 mumol.g-1 (n = 5) at 15 min; glucose level had turned toward resting level at 25 min. The glucose change was used to calculate the increase of glucose cerebral metabolic rate in the visual cortex region for individual subjects by using the Michaelis-Menten model of glucose transport on the assumption of constant transport kinetics. The glucose cerebral metabolic rate was calculated to increase over the nonstimulated rate by 22% during the first 15 min of photic stimulation. A model in which the glucose metabolic rate gradually decreases during stimulation was proposed as a possible explanation for the recovery of brain glucose and previously measured lactate concentrations to prestimulus values after 15 min.
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Affiliation(s)
- W Chen
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06510
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24
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Novotny EJ. Neonatal seizures. Semin Perinatol 1993; 17:351-6. [PMID: 8290978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- E J Novotny
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT. 06510-8064
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25
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26
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Abstract
We report two children with severe sleep-disordered breathing associated with Klippel-Feil sequence. In both patients, minor vertebral anomalies were associated with a major hindbrain anomaly. In one child, the Klippel-Feil sequence had been diagnosed previously, but the hindbrain anomaly was not recognized. Two years later, this child developed fatal obstructive sleep apnea. In the other child, neither the Klippel-Feil sequence nor hindbrain anomaly had been identified before the child's presentation with sleep-disordered breathing characterized by bradypnea and stridor. Because many of the complications of hindbrain anomalies may be amenable to neurosurgical treatment, we recommend that patients with Klippel-Feil sequence be followed for the development of sleep-disordered breathing. Sleep complaints need prompt evaluation with polysomnography, whereas neurologic signs require imaging with attention to the cervicomedullary junction. Unsuspected CNS disorders must be considered in children who present with stridor or serious respiratory disturbances during sleep.
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Affiliation(s)
- C L Rosen
- Department of Pediatrics (Sections of Respiratory Medicine and Neurology), Yale University School of Medicine, New Haven, Connecticut 06525
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27
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Gruetter R, Novotny EJ, Boulware SD, Rothman DL, Mason GF, Shulman GI, Tamborlane WV, Shulman RG. Non-invasive measurements of the cerebral steady-state glucose concentration and transport in humans by 13C nuclear magnetic resonance. Adv Exp Med Biol 1993; 331:35-40. [PMID: 8333347 DOI: 10.1007/978-1-4615-2920-0_7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- R Gruetter
- Department of Molecular Biology and Biochemistry, Yale University, New Haven, CT 06510
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28
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Petroff OA, Novotny EJ, Avison M, Rothman DL, Alger JR, Ogino T, Shulman GI, Prichard JW. Cerebral lactate turnover after electroshock: in vivo measurements by 1H/13C magnetic resonance spectroscopy. J Cereb Blood Flow Metab 1992; 12:1022-9. [PMID: 1400641 DOI: 10.1038/jcbfm.1992.139] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We reported earlier that brain activation by 10 s of cortical electroshock caused prolonged elevation of brain lactate without significant change in intracellular pH, brain high-energy phosphorylated metabolites, or blood gases. The metabolic state of the elevated lactate has been investigated in further experiments using combined, in vivo 1H-observed 13C-edited nuclear magnetic resonance spectroscopy (NMRS), homonuclear J-edited 1H-NMRS, and high-resolution 1H-NMRS of perchloric acid extracts to monitor concentrations and 13C-isotopic fractions of brain and blood lactate and glucose. We now report that electroshock-elevated lactate pool in rabbit brain approaches equilibrium with blood glucose within 1 h. There was nearly complete turnover of the raised lactate pool in brain; any pool of metabolically inactive lactate could not have been > 5% of the total. In the same experiments, blood lactate underwent < 50% turnover in 1 h. The new 1H-spectroscopic methods used for these experiments are readily adaptable for the study of human brain and may be useful in characterizing the metabolic state of elevated lactate pools associated with epilepsy, stroke, trauma, tumors, and other pathological conditions.
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Affiliation(s)
- O A Petroff
- Department of Neurology, Yale University, New Haven, Connecticut 06510
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29
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Rothman DL, Novotny EJ, Shulman GI, Howseman AM, Petroff OA, Mason G, Nixon T, Hanstock CC, Prichard JW, Shulman RG. 1H-[13C] NMR measurements of [4-13C]glutamate turnover in human brain. Proc Natl Acad Sci U S A 1992; 89:9603-6. [PMID: 1409672 PMCID: PMC50180 DOI: 10.1073/pnas.89.20.9603] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A limitation of previous methods for studying human brain glucose metabolism, such as positron emission tomography, is that metabolic steps beyond glucose uptake cannot be studied. Nuclear magnetic resonance (NMR) has the advantage of allowing the nondestructive measurement of 13C distribution in specific carbon positions of metabolites. In this study 1H-[13C] NMR spectroscopy in conjunction with volume localization was used to measure the rate of incorporation of 13C isotope from infused enriched [1-13C]glucose to human brain [4-13C]glutamate. In three studies C4 glutamate turnover time constants of 25, 20, and 17 min were measured in a 21-cm3 volume centered in the region of the visual cortex. Based on an analysis of spectrometer sensitivity the spatial resolution of the method can be improved to < 4 cm3. In conjunction with metabolic modeling and other NMR measurements this method can provide a measure of regional rates of the brain tricarboxylic acid cycle and other metabolic pathways.
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Affiliation(s)
- D L Rothman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510
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30
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Gruetter R, Rothman DL, Novotny EJ, Shulman GI, Prichard JW, Shulman RG. Detection and assignment of the glucose signal in 1H NMR difference spectra of the human brain. Magn Reson Med 1992; 27:183-8. [PMID: 1435204 DOI: 10.1002/mrm.1910270118] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The difference between 1H NMR spectra obtained during eu- and hyperglycemia exhibited well-resolved glucose peaks between 3 and 4 ppm as demonstrated by comparison with solution spectra. Estimated increases were consistent with recent 13C NMR quantitations of intracerebral glucose. Difference spectra were measured in 36-ml volumes from the human brain every 3 min.
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Affiliation(s)
- R Gruetter
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
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31
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Abstract
Localized 1H NMR spectra at TE = 12 ms were obtained from cerebral cortex of human subjects using ISIS with surface suppression. The 2.29-ppm resonance was assigned to C4 glutamate with contributions from C4 glutamine and GABA using in vivo spectral editing and comparison of chemical shift with pure compounds. The measured intensity ratio between the 2.29 resonance and the creatine resonance at 3.03 ppm was in good agreement with the ratio predicted from previously reported measurements of glutamate, glutamine, and GABA concentrations in biopsied human brain tissue.
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Affiliation(s)
- D L Rothman
- Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut
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32
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Abstract
Natural abundance 13C NMR spectra obtained from 144-cm3 volumes in the human brain contained well-resolved resonances of myo-inositol after 60 min of data accumulation. A mean concentration of 7.2 +/- 0.5 mumol/g (+/- SE, n = 7) was calculated from the comparison with phantoms. 13C NMR spectroscopy thus provides a complementary role in the quantitation of metabolites also observed in the crowded 1H spectrum.
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Affiliation(s)
- R Gruetter
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
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33
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Gruetter R, Novotny EJ, Boulware SD, Rothman DL, Mason GF, Shulman GI, Shulman RG, Tamborlane WV. Direct measurement of brain glucose concentrations in humans by 13C NMR spectroscopy. Proc Natl Acad Sci U S A 1992; 89:1109-12. [PMID: 1736294 PMCID: PMC48395 DOI: 10.1073/pnas.89.3.1109] [Citation(s) in RCA: 155] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Glucose is the main fuel for energy metabolism in the normal human brain. It is generally assumed that glucose transport into the brain is not rate-limiting for metabolism. Since brain glucose concentrations cannot be determined directly by radiotracer techniques, we used 13C NMR spectroscopy after infusing enriched D-[1-13C]glucose to measure brain glucose concentrations at euglycemia and at hyperglycemia (range, 4.5-12.1 mM) in six healthy children (13-16 years old). Brain glucose concentrations averaged 1.0 +/- 0.1 mumol/ml at euglycemia (4.7 +/- 0.3 mM plasma) and 1.8-2.7 mumol/ml at hyperglycemia (7.3-12.1 mM plasma). Michaelis-Menten parameters of transport were calculated to be Kt = 6.2 +/- 1.7 mM and Tmax = 1.2 +/- 0.1 mumol/g.min from the relationship between plasma and brain glucose concentrations. The brain glucose concentrations and transport constants are consistent with transport not being rate-limiting for resting brain metabolism at plasma levels greater than 3 mM.
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Affiliation(s)
- R Gruetter
- Department of Molecular Biophysics, Yale University School of Medicine, New Haven, CT 06510
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34
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Novotny EJ. Epileptic syndromes and seizures in infants. Semin Neurol 1990; 10:366-79. [PMID: 2287831 DOI: 10.1055/s-2008-1063981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- E J Novotny
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510
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35
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Novotny EJ, Ogino T, Rothman DL, Petroff OA, Prichard JW, Shulman RG. Direct carbon versus proton heteronuclear editing of 2-13C ethanol in rabbit brain in vivo: a sensitivity comparison. Magn Reson Med 1990; 16:431-43. [PMID: 2077334 DOI: 10.1002/mrm.1910160310] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Proton NMR editing techniques were utilized to study the pharmacology of 13C-labeled ethanol in the cerebrum of the living rabbit at 4.7 T. The sensitivity of these proton spectroscopic methods was compared to direct carbon spectroscopy and a 14-fold improvement in sensitivity of 1H over 13C NMR spectroscopy was observed in vivo. This increase in sensitivity permitted the observation of the time course of the influx and afflux of this 13C-labeled compound with a time resolution of approximately 2 min per spectrum.
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Affiliation(s)
- E J Novotny
- Department of Neurology, School of Medicine, Yale University, New Haven, Connecticut 06510
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36
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Avison MJ, Herschkowitz N, Novotny EJ, Petroff OA, Rothman DL, Colombo JP, Bachmann C, Shulman RG, Prichard JW. Proton NMR observation of phenylalanine and an aromatic metabolite in the rabbit brain in vivo. Pediatr Res 1990; 27:566-70. [PMID: 2162514 DOI: 10.1203/00006450-199006000-00005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1H nuclear magnetic resonance (NMR) was used to detect directly the signal from the aromatic protons of phenylalanine (phe) in the brains of rabbits made hyperphenylalaninemic by administration of a diet high in phe and containing 0.4% alpha-methylphenylalanine. In addition to those resonances found in the region between 6.5 and 8.5 ppm in the 1H NMR spectra of control rabbits, a resonance centered at 7.37 ppm was observed in the spectra obtained from the brains of hyperphenylalaninemic rabbits in vivo or in situ postmortem. The chemical shift of this additional resonance was that expected for protons of the phenyl ring of phe. Its intensity correlated well with measurements of brain phe levels made on postmortem samples by amino acid analyzer. Both of these measurements correlated poorly with amino acid analyzer measurements of serum phe, especially at high values of the latter. High-resolution 1H NMR spectra of the brain extracts showed that in most animals an unidentified aromatic compound, possibly gamma-glutamyl-phe, was present in addition to phe. This study demonstrates the feasibility of measuring the concentration of brain phenyl and its metabolites noninvasively by 1H NMR. The method can be used for similar measurements in human brain.
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Affiliation(s)
- M J Avison
- Yale University, New Haven, Connecticut 06510
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37
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Abstract
In vivo 1H magnetic resonance spectroscopy was used to measure the cerebral ethanol concentration in the rabbit after both intraarterial and intragastric administration. There was good agreement between cerebral and blood ethanol concentrations at all times after administration by either route. Cerebral ethanol levels, measured using in vivo 1H spectroscopy, agreed well with those measured in perchloric acid extracts of brain, analyzed by both high-resolution 1H spectroscopy and gas chromatography. Ethanol may be useful as an indicator to measure cerebral blood flow by 1H spectroscopy and chemical shift-selective magnetic resonance imaging.
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Affiliation(s)
- O A Petroff
- Department of Neurology, Yale University, New Haven, CT 06510
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38
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Hanstock CC, Rothman DL, Shulman RG, Novotny EJ, Petroff OA, Prichard JW. Measurement of ethanol in the human brain using NMR spectroscopy. J Stud Alcohol 1990; 51:104-7. [PMID: 2308346 DOI: 10.15288/jsa.1990.51.104] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ethanol in the human brain is readily observable by noninvasive 1H NMR spectroscopy. We have made such observations in a human subject with a time resolution per measurement of 6.5 min and volume resolution of 16 cc. The ethanol methyl proton signal is well separated from signals of other metabolites in 1H spectra from human brain and it is one of the most intense signals in such spectra when blood ethanol concentration is 0.1% (21.7 mM)--the legal definition of alcoholic intoxication in many jurisdictions. These properties, plus the fact that the ethanol signal can be further isolated from other resonances by spectral editing, open several possibilities for further investigation.
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Affiliation(s)
- C C Hanstock
- Department of Applied Sciences in Medicine, University of Alberta, Edmonton, Canada
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39
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Abstract
The mechanism of brain injury caused by excitotoxins has been explored in detail in the adult, but not the developing animal. To better define the cerebral physiologic. metabolic and pathological effects of excitotoxic damage, quisqualic acid (QA), a glutamate analogue, was injected into the parahippocampal region of the neonatal rat. Electroencephalographic monitoring showed intermittent paroxysmal discharges which persisted for more than 24 h. Metabolic alterations were consistent with disruption of membrane function with a decrease in n-acetyl aspartate and a rise in acetate. Neuropathologic examination disclosed neuronal necrosis which was maximal in the medial CA1 and hilar areas. QA produces a unique pattern of physiologic, metabolic, and pathologic alteration in the neonatal rat brain which differs from that produced by hypoxic-ischemic injury.
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Affiliation(s)
- R S Young
- Department of Pediatrics, Yale University School of Medicine, New Haven, Conn
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40
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Abstract
It is assumed that when anticonvulsants arrest seizure, there is rapid return of brain high energy phosphates and brain lactate to control values. To test this hypothesis, diazepam was administered to neonatal dogs during flurothyl-induced seizure. In vivo 31P nuclear magnetic resonance spectroscopy disclosed that diazepam quickly arrested electrographic seizure and restored brain phosphocreatine and inorganic phosphate to baseline values. In contrast, in vivo 1H nuclear magnetic resonance spectroscopic measurements showed that arrest of seizure with diazepam did not return brain lactate to control values. The sustained increase in cerebral blood flow and prolonged elevation of brain lactate, acetate, valine, and succinate in the postictal period indicate that metabolic recovery of the brain occurs over an extended period of time after the normalization of EEG, phosphocreatine, and brain pH.
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Affiliation(s)
- R S Young
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510-8064
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41
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Abstract
A newborn with multiple congenital contractures (MCC) or arthrogryposis multiplex congenita and a leukodystrophy is described. The clinical features and neurophysiological studies suggested a disorder primarily involving the central white matter. The diagnosis of connatal Pelizaeus-Merzbacher disease was made post mortem. This disorder of myelin formation should be considered in infants presenting with arthrogryposis.
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Affiliation(s)
- E J Novotny
- Department of Neurology, Stanford University Medical School, CA 94305
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42
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Abstract
It has been hypothesized that the mechanism of hypoglycemic brain damage involves energy failure or excessive accumulation of excitatory neurotransmitters. To test these hypotheses, 1H nuclear magnetic resonance spectroscopy was employed to determine brain high-energy phosphates, carbohydrates, neurotransmitters, amino acids, and fatty acids during insulin-induced hypoglycemia in the neonatal dog. Reduction in brain glucose content was associated with an increase in blood/brain lactate ratio, as well as decreases in brain glutamate, aspartate, taurine, and inositol; however, no change was observed in GABA concentration or in brain energy state. In contrast to the adult experimental animal, brain tissue injury due to hypoglycemia is minimal in the neonatal animal. The mechanism of resistance to hypoglycemic brain injury may involve modulation of the rise of excitatory amino acids and decline in inhibitory neurotransmitters and high-energy phosphates.
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Affiliation(s)
- O A Petroff
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510-8064
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43
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Abstract
Ninety-seven EEGs from 30 premature infants found to have multifocal white matter necrosis on ultrasound (US) or autopsy were reviewed retrospectively. Twenty infants had intraparenchymal echodensities on US that developed into cystic lesions, a finding consistent with periventricular leukomalacia; 8 had intraparenchymal hemorrhages; and 2 had white matter necrosis at autopsy. Four of these infants had no intraventricular hemorrhage. Positive sharp waves in the central (rolandic) regions (PRS) were identified in 22 of these 30 infants (73%) and in 0 of 30 age-matched controls (p less than 0.001). The presence of PRS on the EEG of the premature infant has a high correlation with white matter necrosis rather than with intraventricular hemorrhage. In all cases, this EEG pattern was present prior to the development of cavitations when echodensities were present on US.
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44
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Abstract
This is a clinical and neuropathological report of a 27-year-old male with partial trisomy of the long arm of chromosome 18. Severe psychomotor retardation, blindness, and epilepsy were the major clinical features. Microcephaly, an unusual diverticulum of the left occipital lobe, and severe atrophy of the visual system were the major findings on neuropathological examination.
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45
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Novotny EJ, Urich H. The coincidence of neurocutaneous melanosis and encephalofacial angiomatosis. Clin Neuropathol 1986; 5:246-51. [PMID: 3815935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The case of a 21-year-old woman who was affected by both encephalofacial angiomatosis (Sturge-Weber syndrome) and neurocutaneous melanosis is reported. Her signs and symptoms consisted of an interesting overlap of the characteristics of these two neurocutaneous syndromes with glaucoma, hydrocephalus, epilepsy, mental retardation and vascular and melanotic skin lesions observed throughout her course. The clinical diagnosis presented considerable difficulties. The simultaneous occurrence of these two disorders has not been previously reported and this is the first reported case where the cutaneous lesions and their histology, the neuropathology and the clinical features of both disorders is described in one individual.
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Abstract
We studied a kindred in which 8 members had the neuroretinopathy of Leber's disease; 14 had a progressive, generalized dystonia attributed to striatal degeneration; and 1 had both disorders. The mode of inheritance was compatible with maternal transmission. This neurologic disorder may be a mitochondrial disease.
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Novotny EJ, Eckert RE. Direct Measurement of Hole Error for Viscoelastic Fluids in Flow Between Infinite Parallel Plates. ACTA ACUST UNITED AC 1973. [DOI: 10.1122/1.549288] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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