1
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Granger SJ, Colon-Perez L, Larson MS, Bennett IJ, Phelan M, Keator DB, Janecek JT, Sathishkumar MT, Smith AP, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Reduced structural connectivity of the medial temporal lobe including the perforant path is associated with aging and verbal memory impairment. Neurobiol Aging 2023; 121:119-128. [PMID: 36434930 DOI: 10.1016/j.neurobiolaging.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 10/20/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022]
Abstract
The perforant path, the white matter bundle connecting the entorhinal cortex (ERC) with the hippocampal formation deteriorates with age-related cognitive decline. Previous investigations using diffusion-weighted MRI to quantify perforant path integrity in-vivo have been limited due to image resolution or have quantified the perforant path using methods susceptible to partial volume effects such as the tensor model and without consideration of its 3-dimensional morphology. In this investigation, we use quantitative-anisotropy informed tractography derived from ultra-high resolution diffusion imaging (ZOOMit) to investigate structural connectivity of the perforant path and other medial temporal lobe (MTL) pathways in older adults (63 to 98 years old, n = 51). We show that graph density within the MTL declines with age and is associated with lower delayed recall performance. We also show that older age and poorer delayed recall are associated with reduced streamlines connecting the ERC and dentate gyrus of the hippocampus (the putative perforant path). This work suggest that intra-MTL connectivity may new candidate biomarkers for age-related cognitive decline.
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Affiliation(s)
- Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Luis Colon-Perez
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Myra Saraí Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Ilana J Bennett
- Department of Psychology, University of California, Riverside, CA
| | - Michael Phelan
- Department of Statistics, University of California, Irvine, CA
| | - David B Keator
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA
| | - John T Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Mithra T Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Anna P Smith
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Dana Greenia
- Department of Neurology, University of California, Irvine, CA
| | - Maria M Corrada
- Department of Neurology, University of California, Irvine, CA
| | - Claudia H Kawas
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA; Department of Neurology, University of California, Irvine, CA
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA; Department of Psychiatry and Human Behavior, University of California, Irvine, CA; Department of Neurology, University of California, Irvine, CA.
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2
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Granger SJ, Colon-Perez L, Larson MS, Phelan M, Keator DB, Janecek JT, Sathishkumar MT, Smith AP, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Hippocampal dentate gyrus integrity revealed with ultrahigh resolution diffusion imaging predicts memory performance in older adults. Hippocampus 2022; 32:627-638. [PMID: 35838075 PMCID: PMC10510739 DOI: 10.1002/hipo.23456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 05/26/2022] [Accepted: 06/30/2022] [Indexed: 11/08/2022]
Abstract
Medial temporal lobe (MTL) atrophy is a core feature of age-related cognitive decline and Alzheimer's disease (AD). While regional volumes and thickness are often used as a proxy for neurodegeneration, they lack the sensitivity to serve as an accurate diagnostic test and indicate advanced neurodegeneration. Here, we used a submillimeter resolution diffusion weighted MRI sequence (ZOOMit) to quantify microstructural properties of hippocampal subfields in older adults (63-98 years old) using tensor derived measures: fractional anisotropy (FA) and mean diffusivity (MD). We demonstrate that the high-resolution sequence, and not a standard resolution sequence, identifies dissociable profiles for CA1, dentate gyrus (DG), and the collateral sulcus. Using ZOOMit, we show that advanced age is associated with increased MD of the CA1 and DG as well as decreased FA of the DG. Increased MD of the DG, reflecting decreased cellular density, mediated the relationship between age and word list recall. Further, increased MD in the DG, but not DG volume, was linked to worse spatial pattern separation. Our results demonstrate that ultrahigh-resolution diffusion imaging enables the detection of microstructural differences in hippocampal subfield integrity and will lead to novel insights into the mechanisms of age-related memory loss.
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Affiliation(s)
- Steven J. Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Luis Colon-Perez
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Myra Saraí Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Michael Phelan
- UC Institute for Memory Impairments and Neurological Disorders, University of California, Irvine 92697
| | - David B. Keator
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - John T. Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Mithra T. Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Anna P. Smith
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Dana Greenia
- Department of Neurology, University of California, Irvine 92697
| | | | - Claudia H. Kawas
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
- Department of Neurology, University of California, Irvine 92697
| | - Michael A. Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
- Department of Neurology, University of California, Irvine 92697
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3
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Saute RL, Peixoto-Santos JE, Velasco TR, Leite JP. Improving surgical outcome with electric source imaging and high field magnetic resonance imaging. Seizure 2021; 90:145-154. [PMID: 33608134 DOI: 10.1016/j.seizure.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/26/2021] [Accepted: 02/04/2021] [Indexed: 12/14/2022] Open
Abstract
While most patients with focal epilepsy present with clear structural abnormalities on standard, 1.5 or 3 T MRI, some patients are MRI-negative. For those, quantitative MRI techniques, such as volumetry, voxel-based morphometry, and relaxation time measurements can aid in finding the epileptogenic focus. High-field MRI, just recently approved for clinical use by the FDA, increases the resolution and, in several publications, was shown to improve the detection of focal cortical dysplasias and mild cortical malformations. For those cases without any tissue abnormality in neuroimaging, even at 7 T, scalp EEG alone is insufficient to delimitate the epileptogenic zone. They may benefit from the use of high-density EEG, in which the increased number of electrodes helps improve spatial sampling. The spatial resolution of even low-density EEG can benefit from electric source imaging techniques, which map the source of the recorded abnormal activity, such as interictal epileptiform discharges, focal slowing, and ictal rhythm. These EEG techniques help localize the irritative, functional deficit, and seizure-onset zone, to better estimate the epileptogenic zone. Combining those technologies allows several drug-resistant cases to be submitted to surgery, increasing the odds of seizure freedom and providing a must needed hope for patients with epilepsy.
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Affiliation(s)
- Ricardo Lutzky Saute
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Brazil
| | - Jose Eduardo Peixoto-Santos
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Paulista School of Medicine, Unifesp, Brazil
| | - Tonicarlo R Velasco
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Brazil
| | - Joao Pereira Leite
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
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4
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Ferreira TA, Middlebrooks EH, Tzu WH, Neto MR, Holanda VM. Postmortem Dissections of the Papez Circuit and Nonmotor Targets for Functional Neurosurgery. World Neurosurg 2020; 144:e866-75. [DOI: 10.1016/j.wneu.2020.09.088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/16/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022]
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5
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Abstract
The gray matter of the spinal cord is the seat of somata of various types of neurons devoted to the sensory and motor activities of the limbs and trunk as well as a part of the autonomic nervous system. The volume of the spinal gray matter is an indicator of the local neuronal processing, and this can decrease due to atrophy associated with degenerative diseases and injury. Nevertheless, the absolute volume of the human spinal cord has rarely been reported, if ever. Here, we use high-resolution magnetic resonance imaging, with a cross-sectional resolution of 50 × 50 μm and a voxel size of 0.0005 mm3 to estimate the total gray and white matter volume of a post mortem human female spinal cord. Segregation of gray and white matter was accomplished using deep learning image segmentation. Furthermore, we include data from a male spinal cord of a previously published study. The gray and white matter volumes were found to be 2.87 and 11.33 mL, respectively, for the female and 3.55 and 19.33 mL, respectively, for the male. The gray and white matter profiles along the vertebral axis were found to be strikingly similar, and the volumes of the cervical, thoracic, and lumbosacral sections were almost equal.NEW & NOTEWORTHY Here, we combine high-field MRI (9.4 T) and deep learning for a post mortem reconstruction of the gray and white matter in human spinal cords. We report a minuscule total gray matter volume of 2.87 mL for a female and 3.55 mL for a male. For comparison, these volumes correspond approximately to the distal digit of the little finger.
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Affiliation(s)
- Simon Henmar
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Erik B Simonsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rune W Berg
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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6
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Ly M, Foley L, Manivannan A, Hitchens TK, Richardson RM, Modo M. Mesoscale diffusion magnetic resonance imaging of the ex vivo human hippocampus. Hum Brain Mapp 2020; 41:4200-4218. [PMID: 32621364 PMCID: PMC7502840 DOI: 10.1002/hbm.25119] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/01/2020] [Accepted: 06/16/2020] [Indexed: 12/21/2022] Open
Abstract
Mesoscale diffusion magnetic resonance imaging (MRI) endeavors to bridge the gap between macroscopic white matter tractography and microscopic studies investigating the cytoarchitecture of human brain tissue. To ensure a robust measurement of diffusion at the mesoscale, acquisition parameters were arrayed to investigate their effects on scalar indices (mean, radial, axial diffusivity, and fractional anisotropy) and streamlines (i.e., graphical representation of axonal tracts) in hippocampal layers. A mesoscale resolution afforded segementation of the pyramidal cell layer (CA1-4), the dentate gyrus, as well as stratum moleculare, radiatum, and oriens. Using ex vivo samples, surgically excised from patients with intractable epilepsy (n = 3), we found that shorter diffusion times (23.7 ms) with a b-value of 4,000 s/mm2 were advantageous at the mesoscale, providing a compromise between mean diffusivity and fractional anisotropy measurements. Spatial resolution and sample orientation exerted a major effect on tractography, whereas the number of diffusion gradient encoding directions minimally affected scalar indices and streamline density. A sample temperature of 15°C provided a compromise between increasing signal-to-noise ratio and increasing the diffusion properties of the tissue. Optimization of the acquisition afforded a system's view of intra- and extra-hippocampal connections. Tractography reflected histological boundaries of hippocampal layers. Individual layer connectivity was visualized, as well as streamlines emanating from individual sub-fields. The perforant path, subiculum and angular bundle demonstrated extra-hippocampal connections. Histology of the samples confirmed individual cell layers corresponding to ROIs defined on MR images. We anticipate that this ex vivo mesoscale imaging will yield novel insights into human hippocampal connectivity.
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Affiliation(s)
- Maria Ly
- Department of RadiologyUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Lesley Foley
- Department of NeurobiologyUniversity of PittsburghPittsburghPennsylvaniaUSA
| | | | - T. Kevin Hitchens
- Department of NeurobiologyUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - R. Mark Richardson
- Department of Neurological SurgeryUniversity of PittsburghPittsburghPennsylvaniaUSA
- McGowan Institute for Regenerative MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Brain InstituteUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Michel Modo
- Department of RadiologyUniversity of PittsburghPittsburghPennsylvaniaUSA
- McGowan Institute for Regenerative MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of BioengineeringUniversity of PittsburghPittsburghPennsylvaniaUSA
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7
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Böhm T, Joseph K, Kirsch M, Moroni R, Hilger A, Osenberg M, Manke I, Johnston M, Stieglitz T, Hofmann UG, Haas CA, Thiele S. Quantitative synchrotron X-ray tomography of the material-tissue interface in rat cortex implanted with neural probes. Sci Rep 2019; 9:7646. [PMID: 31113972 PMCID: PMC6529414 DOI: 10.1038/s41598-019-42544-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 04/01/2019] [Indexed: 01/13/2023] Open
Abstract
Neural probes provide many options for neuroscientific research and medical purposes. However, these implantable micro devices are not functionally stable over time due to host-probe interactions. Thus, reliable high-resolution characterization methods are required to understand local tissue changes upon implantation. In this work, synchrotron X-ray tomography is employed for the first time to image the interface between brain tissue and an implanted neural probe, showing that this 3D imaging method is capable of resolving probe and surrounding tissue at a resolution of about 1 micrometer. Unstained tissue provides sufficient contrast to identify electrode sites on the probe, cells, and blood vessels within tomograms. Exemplarily, we show that it is possible to quantify characteristics of the interaction region between probe and tissue, like the blood supply system. Our first-time study demonstrates a way for simultaneous 3D investigation of brain tissue with implanted probe, providing information beyond what was hitherto possible.
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Affiliation(s)
- Thomas Böhm
- Laboratory for MEMS Applications, IMTEK Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
| | - Kevin Joseph
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Neuroelectronic Systems, Dept. of Neurosurgery, Faculty of Medicine, University Medical Center, Engesserstraße 4, 79108, Freiburg, Germany
| | - Matthias Kirsch
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Albertstraße 23, 79104, Freiburg, Germany
| | - Riko Moroni
- Laboratory for MEMS Applications, IMTEK Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany
| | - André Hilger
- Helmholtz Center Berlin for Materials and Energy, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Markus Osenberg
- Helmholtz Center Berlin for Materials and Energy, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
- Institute of Materials Science and Technology, Technical University Berlin, Hardenbergstraße 36, 10623, Berlin, Germany
| | - Ingo Manke
- Helmholtz Center Berlin for Materials and Energy, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Midori Johnston
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Experimental Epilepsy Research, Dept. of Neurosurgery, University Medical Center, Breisacher Straße 64, 79106, Freiburg, Germany
| | - Thomas Stieglitz
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Laboratory for Biomedical Microtechnology, IMTEK Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 102, 79110, Freiburg, Germany
- Bernstein Center Freiburg, Hansastraße 9a, 79104, Freiburg, Germany
| | - Ulrich G Hofmann
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Neuroelectronic Systems, Dept. of Neurosurgery, Faculty of Medicine, University Medical Center, Engesserstraße 4, 79108, Freiburg, Germany
| | - Carola A Haas
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany
- Experimental Epilepsy Research, Dept. of Neurosurgery, University Medical Center, Breisacher Straße 64, 79106, Freiburg, Germany
- Bernstein Center Freiburg, Hansastraße 9a, 79104, Freiburg, Germany
| | - Simon Thiele
- Laboratory for MEMS Applications, IMTEK Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110, Freiburg, Germany.
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, 79110, Freiburg, Germany.
- BrainLinks-BrainTools, University of Freiburg, Georges-Köhler-Allee 80, 79110, Freiburg, Germany.
- Forschungszentrum Jülich GmbH, Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Egerlandstraße 3, 91058, Erlangen, Germany.
- Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany.
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8
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Budinger TF, Bird MD. MRI and MRS of the human brain at magnetic fields of 14 T to 20 T: Technical feasibility, safety, and neuroscience horizons. Neuroimage 2018; 168:509-531. [DOI: 10.1016/j.neuroimage.2017.01.067] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/23/2017] [Accepted: 01/27/2017] [Indexed: 11/16/2022] Open
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9
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Colon-Perez LM, Tanner JJ, Couret M, Goicochea S, Mareci TH, Price CC. Cognition and connectomes in nondementia idiopathic Parkinson's disease. Netw Neurosci 2018; 2:106-124. [PMID: 29911667 PMCID: PMC5989988 DOI: 10.1162/netn_a_00027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 02/18/2017] [Accepted: 09/18/2017] [Indexed: 01/01/2023] Open
Abstract
In this study, we investigate the organization of the structural connectome in cognitively well participants with Parkinson’s disease (PD-Well; n = 31) and a subgroup of participants with Parkinson’s disease who have amnestic disturbances (PD-MI; n = 9). We explore correlations between connectome topology and vulnerable cognitive domains in Parkinson’s disease relative to non-Parkinson’s disease peers (control, n = 40). Diffusion-weighted MRI data and deterministic tractography were used to generate connectomes. Connectome topological indices under study included weighted indices of node strength, path length, clustering coefficient, and small-worldness. Relative to controls, node strength was reduced 4.99% for PD-Well (p = 0.041) and 13.2% for PD-MI (p = 0.004). We found bilateral differences in the node strength between PD-MI and controls for inferior parietal, caudal middle frontal, posterior cingulate, precentral, and rostral middle frontal. Correlations between connectome and cognitive domains of interest showed that topological indices of global connectivity negatively associated with working memory and displayed more and larger negative correlations with neuropsychological indices of memory in PD-MI than in PD-Well and controls. These findings suggest that indices of network connectivity are reduced in PD-MI relative to PD-Well and control participants. Parkinson’s disease (PD) patients with amnestic mild cognitive impairment (e.g., primary processing-speed impairments or primary memory impairments) are at greater risk of developing dementia. Recent evidence suggests that patients with PD and mild cognitive impairment present an altered connectome connectivity. In this work, we further explore the structural connectome of PD patients to provide clues to identify possible sensitive markers of disease progression, and cognitive impairment, in susceptible PD patients. We employed a weighted network framework that yields more stable topological results than the binary network framework and is robust despite graph density differences, hence it does not require thresholding to analyze the connectomes. As Supplementary Information (Colon-Perez et al., 2017), we include databases sharing the results of the network data.
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Affiliation(s)
| | - Jared J Tanner
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Michelle Couret
- Department of Medicine, Columbia University, New York, NY, USA
| | - Shelby Goicochea
- Department of Medicine, University of Florida, Gainesville, FL, USA
| | - Thomas H Mareci
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Catherine C Price
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
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10
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Treit S, Steve T, Gross DW, Beaulieu C. High resolution in-vivo diffusion imaging of the human hippocampus. Neuroimage 2018; 182:479-487. [PMID: 29395905 DOI: 10.1016/j.neuroimage.2018.01.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 12/13/2022] Open
Abstract
The human hippocampus is a key target of many imaging studies given its capacity for neurogenesis, role in long term potentiation and memory, and nearly ubiquitous involvement in neurological and psychiatric conditions. Diffusion tensor imaging (DTI) has detected microstructural abnormalities of the human hippocampus associated with various disorders, but acquisitions have typically been limited to low spatial resolution protocols designed for whole brain (e.g. > 2 mm isotropic, >8 mm3 voxels), limiting regional specificity and worsening partial volume effects. The purpose here was to develop a simple DTI protocol using readily available standard single-shot EPI at 3T, capable of yielding much higher spatial resolution images (1 x 1 x 1 mm3) of the human hippocampus in a 'clinically feasible' scan time of ~6 min. A thin slab of twenty 1 mm slices oriented along the long axis of the hippocampus enabled efficient coverage and a shorter repetition time, allowing more diffusion weighted images (DWIs) per slice per unit time. In combination with this strategy, a low b value of 500 s/mm2 was chosen to help overcome the very low SNR of a 1 x 1 x 1 mm3 EPI acquisition. 1 mm isotropic mean DWIs (averaged over 120-128 DWIs) showed excellent detail of the hippocampal architecture (e.g. morphology and digitations, sub-regions, stratum lacunosum moleculare - SLM) that was not readily visible on 2 mm isotropic diffusion images. Diffusion parameters within the hippocampus were consistent across subjects and fairly homogenous across sub-regions of the hippocampus (with the exception of the SLM and tail). However, it is expected that DTI parameters will be sensitive to microstructural changes associated with a number of clinical disorders (e.g. epilepsy, dementia) and that this practical, translatable approach for high resolution acquisition will facilitate localized detection of hippocampal pathology.
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Affiliation(s)
- Sarah Treit
- Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Canada
| | - Trevor Steve
- Division of Neurology, Faculty of Medicine & Dentistry, University of Alberta, Canada
| | - Donald W Gross
- Division of Neurology, Faculty of Medicine & Dentistry, University of Alberta, Canada
| | - Christian Beaulieu
- Department of Biomedical Engineering, Faculty of Medicine & Dentistry, University of Alberta, Canada.
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11
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Beaujoin J, Palomero-Gallagher N, Boumezbeur F, Axer M, Bernard J, Poupon F, Schmitz D, Mangin JF, Poupon C. Post-mortem inference of the human hippocampal connectivity and microstructure using ultra-high field diffusion MRI at 11.7 T. Brain Struct Funct 2018; 223:2157-2179. [PMID: 29387938 PMCID: PMC5968081 DOI: 10.1007/s00429-018-1617-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 01/22/2018] [Indexed: 12/11/2022]
Abstract
The human hippocampus plays a key role in memory management and is one of the first structures affected by Alzheimer's disease. Ultra-high magnetic resonance imaging provides access to its inner structure in vivo. However, gradient limitations on clinical systems hinder access to its inner connectivity and microstructure. A major target of this paper is the demonstration of diffusion MRI potential, using ultra-high field (11.7 T) and strong gradients (750 mT/m), to reveal the extra- and intra-hippocampal connectivity in addition to its microstructure. To this purpose, a multiple-shell diffusion-weighted acquisition protocol was developed to reach an ultra-high spatio-angular resolution with a good signal-to-noise ratio. The MRI data set was analyzed using analytical Q-Ball Imaging, Diffusion Tensor Imaging (DTI), and Neurite Orientation Dispersion and Density Imaging models. High Angular Resolution Diffusion Imaging estimates allowed us to obtain an accurate tractography resolving more complex fiber architecture than DTI models, and subsequently provided a map of the cross-regional connectivity. The neurite density was akin to that found in the histological literature, revealing the three hippocampal layers. Moreover, a gradient of connectivity and neurite density was observed between the anterior and the posterior part of the hippocampus. These results demonstrate that ex vivo ultra-high field/ultra-high gradients diffusion-weighted MRI allows the mapping of the inner connectivity of the human hippocampus, its microstructure, and to accurately reconstruct elements of the polysynaptic intra-hippocampal pathway using fiber tractography techniques at very high spatial/angular resolutions.
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Affiliation(s)
- Justine Beaujoin
- CEA NeuroSpin/UNIRS, Gif-sur-Yvette, France.
- Université Paris-Saclay, Orsay, France.
- France Life Imaging, Orsay, France.
| | - Nicola Palomero-Gallagher
- Forschungszentrum Jülich, INM-1, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen, Aachen, Germany
| | - Fawzi Boumezbeur
- CEA NeuroSpin/UNIRS, Gif-sur-Yvette, France
- Université Paris-Saclay, Orsay, France
- France Life Imaging, Orsay, France
| | - Markus Axer
- Forschungszentrum Jülich, INM-1, Jülich, Germany
| | - Jeremy Bernard
- CEA NeuroSpin/UNIRS, Gif-sur-Yvette, France
- Université Paris-Saclay, Orsay, France
- France Life Imaging, Orsay, France
| | - Fabrice Poupon
- Université Paris-Saclay, Orsay, France
- France Life Imaging, Orsay, France
- CEA NeuroSpin/UNATI, Gif-sur-Yvette, France
| | | | - Jean-François Mangin
- Université Paris-Saclay, Orsay, France
- France Life Imaging, Orsay, France
- CEA NeuroSpin/UNATI, Gif-sur-Yvette, France
- CATI Neuroimaging Platform
| | - Cyril Poupon
- CEA NeuroSpin/UNIRS, Gif-sur-Yvette, France
- Université Paris-Saclay, Orsay, France
- France Life Imaging, Orsay, France
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12
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Middlebrooks EH, Quisling RG, King MA, Carney PR, Roper S, Colon-perez LM, Mareci TH. The hippocampus: detailed assessment of normative two-dimensional measurements, signal intensity, and subfield conspicuity on routine 3T T2-weighted sequences. Surg Radiol Anat 2017; 39:1149-59. [DOI: 10.1007/s00276-017-1843-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 02/28/2017] [Indexed: 10/20/2022]
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13
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Peixoto-Santos JE, Kandratavicius L, Velasco TR, Assirati JA, Carlotti CG, Scandiuzzi RC, Salmon CEG, Santos ACD, Leite JP. Individual hippocampal subfield assessment indicates that matrix macromolecules and gliosis are key elements for the increased T2 relaxation time seen in temporal lobe epilepsy. Epilepsia 2016; 58:149-159. [PMID: 27864825 DOI: 10.1111/epi.13620] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Increased T2 relaxation time is often seen in temporal lobe epilepsy (TLE) with hippocampal sclerosis. Water content directly affects the effective T2 in a voxel. Our aim was to evaluate the relation between T2 values and two molecules associated with brain water homeostasis aquaporin 4 (AQP4) and chondroitin sulfate proteoglycan (CSPG), as well as cellular populations in the hippocampal region of patients with TLE. METHODS Hippocampal T2 imaging and diffusion tensor imaging (DTI) were obtained from 42 drug-resistant patients with TLE and 20 healthy volunteers (radiologic controls, RCs). A similar protocol (ex vivo) was applied to hippocampal sections from the same TLE cases and 14 autopsy control hippocampi (histologic and radiologic controls, HRCs), and each hippocampal subfield was evaluated. Hippocampal sections from TLE cases and HRC controls were submitted to immunohistochemistry for neurons (neuron nuclei [NeuN]), reactive astrocytes (glial fibrillary acidic protein [GFAP]), activated microglia (human leukocyte antigen-D-related [HLA-DR]), polarized AQP4, and CSPG. RESULTS Patients with TLE had higher in vivo and ex vivo hippocampal T2 relaxation time. Hippocampi from epilepsy cases had lower neuron density, higher gliosis, decreased AQP4 polarization, and increased CSPG immunoreactive area. In vivo relaxation correlated with astrogliosis in the subiculum and extracellular CSPG in the hilus. Ex vivo T2 relaxation time correlated with astrogliosis in the hilus, CA4, and subiculum, and with microgliosis in CA1. The difference between in vivo and ex vivo relaxation ratio correlated with mean diffusivity and with the immunopositive area for CSPG in the hilus. SIGNIFICANCE Our data indicate that astrogliosis, microgliosis, and CSPG expression correlate with the increased T2 relaxation time seen in the hippocampi of patients with TLE.
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Affiliation(s)
- Jose Eduardo Peixoto-Santos
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Ludmyla Kandratavicius
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Tonicarlo Rodrigues Velasco
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Joao Alberto Assirati
- Department of Surgery and Anatomy, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Carlos Gilberto Carlotti
- Department of Surgery and Anatomy, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Renata Caldo Scandiuzzi
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Carlos Ernesto Garrido Salmon
- Department of Physics and Mathematics, Faculty of Philosophy, Science and Languages of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Antonio Carlos Dos Santos
- Department of Internal Medicine, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Joao Pereira Leite
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
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14
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Robinson JL, Salibi N, Deshpande G. Functional connectivity of the left and right hippocampi: Evidence for functional lateralization along the long-axis using meta-analytic approaches and ultra-high field functional neuroimaging. Neuroimage 2016; 135:64-78. [DOI: 10.1016/j.neuroimage.2016.04.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 01/31/2016] [Accepted: 04/09/2016] [Indexed: 12/17/2022] Open
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15
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Budinger TF, Bird MD, Frydman L, Long JR, Mareci TH, Rooney WD, Rosen B, Schenck JF, Schepkin VD, Sherry AD, Sodickson DK, Springer CS, Thulborn KR, Uğurbil K, Wald LL. Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale. MAGMA 2016; 29:617-39. [PMID: 27194154 PMCID: PMC5538368 DOI: 10.1007/s10334-016-0561-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 12/16/2022]
Abstract
An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to 20 T has been underway since 2012. This initiative has been supported by 22 interested participants from the USA and Europe, of which 15 are authors of this review. Advances in high temperature superconductor materials, advances in cryocooling engineering, prospects for non-persistent mode stable magnets, and experiences gained from large-bore, high-field magnet engineering for the nuclear fusion endeavors support the feasibility of a human brain MRI and MRS system with 1 ppm homogeneity over at least a 16-cm diameter volume and a bore size of 68 cm. Twelve neuroscience opportunities are presented as well as an analysis of the biophysical and physiological effects to be investigated before exposing human subjects to the high fields of 14 T and beyond.
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Affiliation(s)
- Thomas F Budinger
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA.
| | - Mark D Bird
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Lucio Frydman
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Weizmann Institute, Rehovot, Israel
| | - Joanna R Long
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Thomas H Mareci
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | | | - Bruce Rosen
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
| | - John F Schenck
- General Electric Corporate Research, Schenectady, NY, USA
| | - Victor D Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - A Dean Sherry
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | | | | | | | - Lawrence L Wald
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
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16
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Martinoni M, Berti PP, Marucci G, Rubboli G, Volpi L, Riguzzi P, Marliani F, Toni F, Bisulli F, Tinuper P, Michelucci R, Baruzzi A, Giulioni M. Pathology-Based Approach to Seizure Outcome After Surgery for Pharmacoresistant Medial Temporal Lobe Epilepsy. World Neurosurg 2016; 90:448-453. [PMID: 26968448 DOI: 10.1016/j.wneu.2016.02.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 02/14/2016] [Accepted: 02/15/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND Hippocampal sclerosis (HS) is the most common cause of drug-resistant medial temporal lobe epilepsy (MTLE). Structural abnormalities such as HS, granule cell pathology (GCP), and focal cortical dysplasia (FCD) have been classified histopathologically, possibly allowing a more accurate assessment of prognostic seizure and neuropsychologic outcomes. We correlated seizure outcome with comprehensive temporal lobe pathologic findings, identified according to the most recent classification systems of HS, GCP, and FCD. METHODS All the 83 patients who underwent anterior temporal lobectomy (ATL) for drug-resistant MTLE and with a proven diagnosis of HS between April 2001 and May 2014 were collected. Patients were divided in 2 main groups: 1) isolated HS with/without GCP (HS +/- GCP); and 2) HS associated with FCD with/without GCP (HS+FCD +/- GCP). Patients were followed up at least 1 year, and seizure outcome was reported in accordance with Engel classification. RESULTS Group I: HS +/- GCP: Statistical analysis confirmed a better outcome in HS + GCP patients than in HS-no GCP (P < 0.05). Moreover, a better outcome for the patients affected by GCP type I was observed (P < 0.05). Group II: HS+FCD +/- GCP: Patients with HS variant type I presented a better seizure outcome than the patients with HS type II (Engel class IA HS type I vs. type II: 69% vs. 40%). CONCLUSIONS A pathology-based approach to epilepsy surgery might improve the interpretation of the results, could predict which cases will enjoy a better seizure outcome, and could help to the comprehension of the causes of failures.
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Affiliation(s)
- Matteo Martinoni
- IRCCS Institute of Neurological Science of Bologna, Division of Neurosurgery, Bellaria Hospital, Bologna, Italy.
| | - Pier Paolo Berti
- IRCCS Institute of Neurological Science of Bologna, Division of Neurosurgery, Bellaria Hospital, Bologna, Italy
| | - Gianluca Marucci
- Section of Pathology, "M. Malpighi," Bellaria Hospital, Azienda USL-IRCCS Institute of Neurological Sciences, Bologna, Italy
| | - Guido Rubboli
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Danish Epilepsy Centre, Dianalund, Denmark
| | - Lilia Volpi
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy
| | - Patrizia Riguzzi
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy
| | - Federica Marliani
- IRCCS Institute of Neurological Science of Bologna, Division of Neuroradiology, Bellaria Hospital, Bologna, Italy
| | - Francesco Toni
- IRCCS Institute of Neurological Science of Bologna, Division of Neuroradiology, Bellaria Hospital, Bologna, Italy
| | - Francesca Bisulli
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Paolo Tinuper
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Roberto Michelucci
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy
| | - Agostino Baruzzi
- IRCCS Institute of Neurological Science of Bologna, Division of Neurology, Bellaria Hospital, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Marco Giulioni
- IRCCS Institute of Neurological Science of Bologna, Division of Neurosurgery, Bellaria Hospital, Bologna, Italy
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17
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Solomon E, Liberman G, Nissan N, Frydman L. Robust diffusion tensor imaging by spatiotemporal encoding: Principles and in vivo demonstrations. Magn Reson Med 2016; 77:1124-1133. [PMID: 26968710 DOI: 10.1002/mrm.26197] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/11/2016] [Accepted: 02/11/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE Evaluate the usefulness of single-shot and of interleaved spatiotemporally encoded (SPEN) methods to perform diffusion tensor imaging (DTI) under various preclinical and clinical settings. METHODS A formalism for analyzing SPEN DTI data is presented, tailored to account for the spatially dependent b-matrix weightings introduced by the sequence's use of swept pulses acting while in the presence of field gradients. Using these b-matrix calculations, SPEN's ability to deliver DTI measurements was tested on phantoms as well as ex vivo and in vivo. In the latter case, DTI involved scans on mice brains and on human lactating breasts. RESULTS For both ex vivo and in vivo investigations, SPEN data proved less sensitive to distortions arising from Bo field inhomogeneities and from eddy currents, than conventional single-shot alternatives. Further resolution enhancement could be achieved using referenceless methods for interleaved SPEN data acquisitions. CONCLUSION The robustness of SPEN-based sequences vis-à-vis field instabilities and heterogeneities, enables the implementation of DTI experiments with good sensitivity and resolution even in challenging environments in both preclinical and clinical settings. Magn Reson Med 77:1124-1133, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Eddy Solomon
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Gilad Liberman
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Noam Nissan
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel.,Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Lucio Frydman
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel
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