Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia
Objective: Logopenic variant primary progressive aphasia (lvPPA) is commonly associated with Alzheimer's disease (AD) pathology. But lvPPA patients display different cognitive and anatomical profile from the common clinical AD patients, whose verbal episodic memory is primarily affected. Report...
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Frontiers Media S.A.
2017-06-01
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Online Access: | http://journal.frontiersin.org/article/10.3389/fnins.2017.00330/full |
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Article |
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DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Khaing T. Win Khaing T. Win John Pluta Paul Yushkevich David J. Irwin Corey T. McMillan Corey T. McMillan Katya Rascovsky David Wolk David Wolk Murray Grossman Murray Grossman |
spellingShingle |
Khaing T. Win Khaing T. Win John Pluta Paul Yushkevich David J. Irwin Corey T. McMillan Corey T. McMillan Katya Rascovsky David Wolk David Wolk Murray Grossman Murray Grossman Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia Frontiers in Neuroscience logopenic primary progressive aphasia Alzheimer's disease verbal episodic memory lexical retrieval hippocampal subfields |
author_facet |
Khaing T. Win Khaing T. Win John Pluta Paul Yushkevich David J. Irwin Corey T. McMillan Corey T. McMillan Katya Rascovsky David Wolk David Wolk Murray Grossman Murray Grossman |
author_sort |
Khaing T. Win |
title |
Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia |
title_short |
Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia |
title_full |
Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia |
title_fullStr |
Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia |
title_full_unstemmed |
Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia |
title_sort |
neural correlates of verbal episodic memory and lexical retrieval in logopenic variant primary progressive aphasia |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Neuroscience |
issn |
1662-453X |
publishDate |
2017-06-01 |
description |
Objective: Logopenic variant primary progressive aphasia (lvPPA) is commonly associated with Alzheimer's disease (AD) pathology. But lvPPA patients display different cognitive and anatomical profile from the common clinical AD patients, whose verbal episodic memory is primarily affected. Reports of verbal episodic memory difficulty in lvPPA are inconsistent, and we hypothesized that their lexical retrieval impairment contributes to verbal episodic memory performance and is associated with left middle temporal gyrus atrophy.Methods: We evaluated patients with lvPPA (n = 12) displaying prominent word-finding and repetition difficulties, and a demographically-matched cohort of clinical Alzheimer's disease (AD, n = 26), and healthy seniors (n = 16). We assessed lexical retrieval with confrontation naming and verbal episodic memory with delayed free recall. Whole-brain regressions related naming and delayed free recall to gray matter atrophy. Medial temporal lobe (MTL) subfields were examined using high in-plane resolution imaging.Results: lvPPA patients had naming and delayed free recall impairments, but intact recognition memory. In lvPPA, delayed free recall was related to naming; both were associated with left middle temporal gyrus atrophy but not MTL atrophy. Despite cerebrospinal fluid evidence consistent with AD pathology, examination of MTL subfields revealed no atrophy in lvPPA. While AD patients displayed impaired delayed free recall, this deficit did not correlate with naming. Regression analyses related delayed free recall deficits in clinical AD patients to MTL subfield atrophy, and naming to left middle temporal gyrus atrophy.Conclusion: Unlike amnestic AD patients, MTL subfields were not affected in lvPPA patients. Verbal episodic memory deficit observed in lvPPA was unlikely to be due to a hippocampal-mediated mechanism but appeared to be due to poor lexical retrieval. Relative sparing of MTL volume and intact recognition memory are consistent with previous reports of hippocampal-sparing variant cases of AD pathology, where neurofibrillary tangles are disproportionately distributed in cortical areas with relative sparing of the hippocampus. This suggests that AD neuropathology in lvPPA may originate in neuronal networks outside of the MTL, which deviates from the typical Braak staging pattern of spreading pathology in clinical AD. |
topic |
logopenic primary progressive aphasia Alzheimer's disease verbal episodic memory lexical retrieval hippocampal subfields |
url |
http://journal.frontiersin.org/article/10.3389/fnins.2017.00330/full |
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doaj-9dd706f1bd694ea2af6a0f4924590f9d2020-11-24T22:26:40ZengFrontiers Media S.A.Frontiers in Neuroscience1662-453X2017-06-011110.3389/fnins.2017.00330258657Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive AphasiaKhaing T. Win0Khaing T. Win1John Pluta2Paul Yushkevich3David J. Irwin4Corey T. McMillan5Corey T. McMillan6Katya Rascovsky7David Wolk8David Wolk9Murray Grossman10Murray Grossman11Neuroscience Graduate Group, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Frontotemporal Degeneration Center, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, United StatesRadiology, Penn Imaging and Computing Science Lab, University of PennsylvaniaPhiladelphia, PA, United StatesRadiology, Penn Imaging and Computing Science Lab, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Frontotemporal Degeneration Center, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, United StatesNeuroscience Graduate Group, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Frontotemporal Degeneration Center, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Frontotemporal Degeneration Center, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, United StatesNeuroscience Graduate Group, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Memory Center, University of PennsylvaniaPhiladelphia, PA, United StatesNeuroscience Graduate Group, University of PennsylvaniaPhiladelphia, PA, United StatesNeurology, Penn Frontotemporal Degeneration Center, Perelman School of Medicine, University of PennsylvaniaPhiladelphia, PA, United StatesObjective: Logopenic variant primary progressive aphasia (lvPPA) is commonly associated with Alzheimer's disease (AD) pathology. But lvPPA patients display different cognitive and anatomical profile from the common clinical AD patients, whose verbal episodic memory is primarily affected. Reports of verbal episodic memory difficulty in lvPPA are inconsistent, and we hypothesized that their lexical retrieval impairment contributes to verbal episodic memory performance and is associated with left middle temporal gyrus atrophy.Methods: We evaluated patients with lvPPA (n = 12) displaying prominent word-finding and repetition difficulties, and a demographically-matched cohort of clinical Alzheimer's disease (AD, n = 26), and healthy seniors (n = 16). We assessed lexical retrieval with confrontation naming and verbal episodic memory with delayed free recall. Whole-brain regressions related naming and delayed free recall to gray matter atrophy. Medial temporal lobe (MTL) subfields were examined using high in-plane resolution imaging.Results: lvPPA patients had naming and delayed free recall impairments, but intact recognition memory. In lvPPA, delayed free recall was related to naming; both were associated with left middle temporal gyrus atrophy but not MTL atrophy. Despite cerebrospinal fluid evidence consistent with AD pathology, examination of MTL subfields revealed no atrophy in lvPPA. While AD patients displayed impaired delayed free recall, this deficit did not correlate with naming. Regression analyses related delayed free recall deficits in clinical AD patients to MTL subfield atrophy, and naming to left middle temporal gyrus atrophy.Conclusion: Unlike amnestic AD patients, MTL subfields were not affected in lvPPA patients. Verbal episodic memory deficit observed in lvPPA was unlikely to be due to a hippocampal-mediated mechanism but appeared to be due to poor lexical retrieval. Relative sparing of MTL volume and intact recognition memory are consistent with previous reports of hippocampal-sparing variant cases of AD pathology, where neurofibrillary tangles are disproportionately distributed in cortical areas with relative sparing of the hippocampus. This suggests that AD neuropathology in lvPPA may originate in neuronal networks outside of the MTL, which deviates from the typical Braak staging pattern of spreading pathology in clinical AD.http://journal.frontiersin.org/article/10.3389/fnins.2017.00330/fulllogopenic primary progressive aphasiaAlzheimer's diseaseverbal episodic memorylexical retrievalhippocampal subfields |