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Isella V, Rosazza C, Ferri F, Gazzotti M, Impagnatiello V, Mapelli C, Morzenti S, Crivellaro C, Appollonio IM, Ferrarese C. Learning From Mistakes: Cognitive and Metabolic Correlates of Errors on Picture Naming in the Alzheimer’s Disease Spectrum. J Alzheimers Dis 2022; 87:1033-1053. [DOI: 10.3233/jad-220053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Background: Analysis of subtypes of picture naming errors produced by patients with Alzheimer’s disease (AD) have seldom been investigated yet may clarify the cognitive and neural underpinnings of naming in the AD spectrum. Objective: To elucidate the neurocognitive bases of picture naming in AD through a qualitative analysis of errors. Methods: Over 1000 naming errors produced by 70 patients with amnestic, visuospatial, linguistic, or frontal AD were correlated with general cognitive tests and with distribution of hypometabolism on FDG-PET. Results: Principal component analysis identified 1) a Visual processing factor clustering visuospatial tests and unrecognized stimuli, pure visual errors and visual-semantic errors, associated with right parieto-occipital hypometabolism; 2) a Concept-Lemma factor grouping language tests and anomias, circumlocutions, superordinates, and coordinates, correlated with left basal temporal hypometabolism; 3) a Lemma-Phonology factor including the digit span and phonological errors, linked with left temporo-parietal hypometabolism. Regression of brain metabolism on individual errors showed that errors due to impairment of basic and higher-order processing of object visual attributes or of their interaction with semantics, were related with bilateral occipital and left occipito-temporal dysfunction. Omissions and superordinates were linked to degradation of broad and basic concepts in the left basal temporal cortex. Semantic-lexical errors derived from faulty semantically- and phonologically-driven lexical retrieval in the left superior and middle temporal gyri. Generation of nonwords was underpinned by of phonological impairment within the left inferior parietal cortex. Conclusion: Analysis of individual naming errors allowed to outline a comprehensive anatomo-functional model of picture naming in classical and atypical AD.
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Affiliation(s)
- Valeria Isella
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Cristina Rosazza
- Dipartimento di Studi Umanistici (DISTUM), Università degli Studi di Urbino Carlo Bo, Urbino, Italy
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ferri
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Maria Gazzotti
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
| | | | - Cristina Mapelli
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Sabrina Morzenti
- Medical Physics, S. Gerardo Hospital, Monza, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Cinzia Crivellaro
- Nuclear Medicine, S. Gerardo Hospital, Monza, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Ildebrando M. Appollonio
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
- NeuroMI, University of Milano - Bicocca, Italy
| | - Carlo Ferrarese
- Department of Neurology, S. Gerardo Hospital, Monza, University of Milano - Bicocca, Italy
- NeuroMI, University of Milano - Bicocca, Italy
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Spect-neuropsychology correlations in very mild Alzheimer's disease and amnesic mild cognitive impairment. Arch Gerontol Geriatr 2020; 89:104085. [DOI: 10.1016/j.archger.2020.104085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 04/01/2020] [Accepted: 04/19/2020] [Indexed: 12/11/2022]
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Isella V, Rosazza C, Gazzotti M, Sala J, Morzenti S, Crivellaro C, Appollonio IM, Ferrarese C, Luzzatti C. A Metabolic Imaging Study of Lexical and Phonological Naming Errors in Alzheimer Disease. Am J Alzheimers Dis Other Demen 2020; 35:1533317520922390. [PMID: 32356456 PMCID: PMC10624092 DOI: 10.1177/1533317520922390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Patients with Alzheimer disease (AD) produce a variety of errors on confrontation naming that indicate multiple loci of impairment along the naming process in this disease. We correlated brain hypometabolism, measured with 18fluoro-deoxy-glucose positron emission tomography, with semantic and formal errors, as well as nonwords deriving from phonological errors produced in a picture-naming test by 63 patients with AD. Findings suggest that neurodegeneration leads to: (1) phonemic errors, by interfering with phonological short-term memory, or with control over retrieval of phonological or prearticulatory representations, within the left supramarginal gyrus; (2) semantic errors, by disrupting general semantic or visual-semantic representations at the level of the left posterior middle and inferior occipitotemporal cortex, respectively; (3) formal errors, by damaging the lexical-phonological output interface in the left mid-anterior segment of middle and superior temporal gyri. This topography of semantic-lexical-phonological steps of naming is in substantial agreement with dual-stream neurocognitive models of word generation.
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Affiliation(s)
- Valeria Isella
- Neurology Department, S. Gerardo Hospital, University of Milano–Bicocca, Monza, Italy
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
| | | | - Maria Gazzotti
- Department of Psychology, University of Milano–Bicocca, Monza, Italy
| | - Jessica Sala
- Department of Psychology, University of Milano–Bicocca, Monza, Italy
| | - Sabrina Morzenti
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
- Medical Physics, S. Gerardo Hospital, Monza, Italy
| | - Cinzia Crivellaro
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
- Nuclear Medicine, S. Gerardo Hospital, Monza, University of Milano–Bicocca, Italy
| | - Ildebrando Marco Appollonio
- Neurology Department, S. Gerardo Hospital, University of Milano–Bicocca, Monza, Italy
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
| | - Carlo Ferrarese
- Neurology Department, S. Gerardo Hospital, University of Milano–Bicocca, Monza, Italy
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
| | - Claudio Luzzatti
- Milan Center for Neuroscience (NeuroMI), Milan, Italy
- Department of Psychology, University of Milano–Bicocca, Monza, Italy
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Im JJ, Jeong H, Bikson M, Woods AJ, Unal G, Oh JK, Na S, Park JS, Knotkova H, Song IU, Chung YA. Effects of 6-month at-home transcranial direct current stimulation on cognition and cerebral glucose metabolism in Alzheimer's disease. Brain Stimul 2019; 12:1222-1228. [PMID: 31196835 DOI: 10.1016/j.brs.2019.06.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/09/2019] [Accepted: 06/01/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Although single or multiple sessions of transcranial direct current stimulation (tDCS) on the prefrontal cortex over a few weeks improved cognition in patients with Alzheimer's disease (AD), effects of repeated tDCS over longer period and underlying neural correlates remain to be elucidated. OBJECTIVE This study investigated changes in cognitive performances and regional cerebral metabolic rate for glucose (rCMRglc) after administration of prefrontal tDCS over 6 months in early AD patients. METHODS Patients with early AD were randomized to receive either active (n = 11) or sham tDCS (n = 7) over the dorsolateral prefrontal cortex (DLPFC) at home every day for 6 months (anode F3/cathode F4, 2 mA for 30 min). All patients underwent neuropsychological tests and brain 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) scans at baseline and 6-month follow-up. Changes in cognitive performances and rCMRglc were compared between the two groups. RESULTS Compared to sham tDCS, active tDCS improved global cognition measured with Mini-Mental State Examination (p for interaction = 0.02) and language function assessed by Boston Naming Test (p for interaction = 0.04), but not delayed recall performance. In addition, active tDCS prevented decreases in executive function at a marginal level (p for interaction < 0.10). rCMRglc in the left middle/inferior temporal gyrus was preserved in the active group, but decreased in the sham group (p for interaction < 0.001). CONCLUSIONS Daily tDCS over the DLPFC for 6 months may improve or stabilize cognition and rCMRglc in AD patients, suggesting the therapeutic potential of repeated at-home tDCS.
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Affiliation(s)
- Jooyeon Jamie Im
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Hyeonseok Jeong
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Adam J Woods
- Center for Cognitive Aging and Memory, McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, FL, USA
| | - Gozde Unal
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Jin Kyoung Oh
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Seunghee Na
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jong-Sik Park
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Helena Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA; Department of Family and Social Medicine, Albert Einstein College of Medicine, The Bronx, NY, USA
| | - In-Uk Song
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
| | - Yong-An Chung
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
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Jones SE, Idris A, Bullen JA, Miller JB, Banks SJ. Relationship between cortical thickness and fluency in the memory disorders clinic population. Neuropsychologia 2019; 129:294-301. [DOI: 10.1016/j.neuropsychologia.2019.03.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 03/16/2019] [Accepted: 03/28/2019] [Indexed: 01/18/2023]
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Montembeault M, Chapleau M, Jarret J, Boukadi M, Laforce R, Wilson MA, Rouleau I, Brambati SM. Differential language network functional connectivity alterations in Alzheimer's disease and the semantic variant of primary progressive aphasia. Cortex 2019; 117:284-298. [PMID: 31034993 DOI: 10.1016/j.cortex.2019.03.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 01/21/2019] [Accepted: 03/21/2019] [Indexed: 01/18/2023]
Abstract
Patients with Alzheimer's disease (AD) and semantic variant primary progressive aphasia (svPPA) can present with similar language impairments, mainly in naming. It has been hypothesized that these deficits are associated with different brain mechanisms in each disease, but no previous study has used a network approach to explore this hypothesis. The aim of this study was to compare resting-state functional magnetic resonance imaging (rs-fMRI) language network in AD, svPPA patients, and cognitively unimpaired elderly adults (CTRL). Therefore, 10 AD patients, 12 svPPA patients and 11 CTRL underwent rs-fMRI. Seed-based functional connectivity analyses were conducted using regions of interest in the left anterior temporal lobe (ATL), left posterior middle temporal gyrus (pMTG) and left inferior frontal gyrus (IFG), applying a voxelwise correction for gray matter volume. In AD patients, the left pMTG was the only key language region showing functional connectivity changes, mainly a reduced interhemispheric functional connectivity with its right-hemisphere counterpart, in comparison to CTRL. In svPPA patients, we observed a functional isolation of the left ATL, both decreases and increases in functional connectivity from the left pMTG and increased functional connectivity form the left IFG. Post-hoc analyses showed that naming impairments were overall associated with the functional disconnections observed across the language network. In conclusion, AD and svPPA patients present distinct language network functional connectivity profiles. In AD patients, functional connectivity changes were restricted to the left pMTG and were overall less severe in comparison to svPPA patients. Results in svPPA patients suggest decreased functional connectivity along the ventral language pathway and increased functional connectivity along the dorsal language pathway. Finally, the observed connectivity patterns are overall consistent with previously reported structural connectivity and language profiles in these patients.
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Affiliation(s)
- Maxime Montembeault
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Montréal, QC, Canada; Département de psychologie, Université de Montréal, Montréal, QC, Canada.
| | - Marianne Chapleau
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Montréal, QC, Canada; Département de psychologie, Université de Montréal, Montréal, QC, Canada.
| | - Julien Jarret
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Montréal, QC, Canada; Département de psychologie, Université de Montréal, Montréal, QC, Canada.
| | - Mariem Boukadi
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Montréal, QC, Canada; Département de psychologie, Université de Montréal, Montréal, QC, Canada.
| | - Robert Laforce
- Clinique Interdisciplinaire de Mémoire (CIME) du CHU de Québec, QC, Canada; Faculté de médecine, Université Laval, Québec, QC, Canada.
| | - Maximiliano A Wilson
- Faculté de médecine, Université Laval, Québec, QC, Canada; Centre de recherche CERVO, Québec, QC, Canada.
| | - Isabelle Rouleau
- Département de psychologie, Université du Québec à Montréal, Montréal, QC, Canada; Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, QC, Canada.
| | - Simona M Brambati
- Centre de recherche de l'Institut universitaire de gériatrie de Montréal, Montréal, QC, Canada; Département de psychologie, Université de Montréal, Montréal, QC, Canada.
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Course of Cognitive Functioning in Institutionalized Persons With Moderate to Severe Dementia: Evidence From the Severe Impairment Battery Short Version. J Int Neuropsychol Soc 2019; 25:204-214. [PMID: 30457078 PMCID: PMC6390392 DOI: 10.1017/s1355617718000991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVES To adequately monitor the course of cognitive functioning in persons with moderate to severe dementia, relevant cognitive tests for the advanced dementia stages are needed. We examined the ability of a test developed for the advanced dementia stages, the Severe Impairment Battery Short version (SIB-S), to measure cognitive change over time. Second, we examined type of memory impairment measured with the SIB-S in different dementia stages. METHODS Participants were institutionalized persons with moderate to severe dementia (N = 217). The SIB-S was administered at 6-month intervals during a 2-year period. Dementia severity at baseline was classified according to Global Deterioration Scale criteria. We used mixed models to evaluate the course of SIB-S total and domain scores, and whether dementia stage at baseline affected these courses. RESULTS SIB-S total scores declined significantly over time, and the course of decline differed significantly between dementia stages at baseline. Persons with moderately severe dementia declined faster in mean SIB-S total scores than persons with moderate or severe dementia. Between persons with moderate and moderately severe dementia, there was only a difference in the rate of decline of semantic items, but not episodic and non-semantic items. CONCLUSIONS Although modest floor and slight ceiling effects were noted in severe and milder cases, respectively, the SIB-S proved to be one of few available adequate measures of cognitive change in institutionalized persons with moderate to severe dementia. (JINS, 2019, 25, 204-214).
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Shaked D, Katzel LI, Seliger SL, Gullapalli RP, Davatzikos C, Erus G, Evans MK, Zonderman AB, Waldstein SR. Dorsolateral prefrontal cortex volume as a mediator between socioeconomic status and executive function. Neuropsychology 2018; 32:985-995. [PMID: 30211609 PMCID: PMC6234054 DOI: 10.1037/neu0000484] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Lower socioeconomic status (SES) is related to poorer cognitive performance, but the neural underpinnings of this relation are not fully understood. This study examined whether SES-linked decrements in executive function were mediated by smaller dorsolateral prefrontal cortex (DLPFC) volumes. Given the literature demonstrating that SES-brain relations differ by race, we examined whether race moderated these mediations. METHOD Participants were 190 socioeconomically diverse, self-identified African American (AA) and White adults from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Regional brain volumes were derived using T1-weighted MP-RAGE images. Adjusting for age and sex, moderated mediation analyses examined if the DLPFC mediated SES-executive function relations differently across racial groups. Executive function was measured using Trail Making Test part B (Trails B), Digit Span Backwards (DSB), and verbal fluency. RESULTS Moderated mediation demonstrated that DLPFC volume significantly mediated the association between SES and Trails B in Whites (lower confidence interval [CI] = 0.01; upper CI = 0.07), but not in AAs (lower CI = -0.05; upper CI = 0.01). No mediations were found for DSB or verbal fluency, although SES was related to all tests. CONCLUSION The DLPFC may be important in the association of SES and mental flexibility for White, but not AA adults. It is possible that the well-replicated advantages of high SES among Whites do not readily translate, on average, to AAs. These findings highlight the importance of brain volume for cognitive functioning, while adding to the literature on sociodemographic health disparities. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Ota K, Oishi N, Ito K, Fukuyama H. Prediction of Alzheimer's Disease in Amnestic Mild Cognitive Impairment Subtypes: Stratification Based on Imaging Biomarkers. J Alzheimers Dis 2017; 52:1385-401. [PMID: 27079727 DOI: 10.3233/jad-160145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Prediction of progression to Alzheimer's disease (AD) in amnestic mild cognitive impairment (MCI) is challenging because of its heterogeneity. OBJECTIVE To evaluate a stratification method on different cohorts and to investigate whether stratification in amnestic MCI could improve prediction accuracy. METHODS We identified 80 and 79 patients with amnestic MCI from different cohorts, respectively. They underwent baseline magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans. We performed hierarchical clustering with three imaging biomarkers: Brain volume on MRI, left hippocampus grey matter loss on MRI, and left inferior temporal gyrus glucose hypometabolism on FDG-PET. Regions-of-interest for biomarkers were defined by the Automated Anatomical Labeling atlas. We performed voxel-wise statistical parametric mapping to explore differences between clusters in patterns of grey matter loss and glucose hypometabolism. We compared time to progression using an interval-censored parametric model. We evaluated predictive performance using logistic regression. RESULTS Similar clusters were found in different cohorts. MCI1 had the healthiest biomarker profile of cognitive performance and imaging biomarkers. MCI2 had cognitive performance and MRI measures intermediate between those of nonconverters and converters. MCI3 showed the severest reduction in brain volume and left hippocampal atrophy. MCI4 showed remarkable glucose hypometabolism in the left inferior temporal gyrus, and also demonstrated significant decreases in most cognitive scores, including non-memory functions. MCI4 showed the highest risk for progression. The prediction of progression of MCI2 especially benefited from the stratification. CONCLUSION Stratification with imaging biomarkers in amnestic MCI can be a good approach for improving predictive performance.
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Affiliation(s)
- Kenichi Ota
- Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan
| | - Naoya Oishi
- Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Psychiatry, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kengo Ito
- Department of Clinical and Experimental Neuroimaging, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Hidenao Fukuyama
- Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan
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Staffaroni AM, Melrose RJ, Leskin LP, Riskin-Jones H, Harwood D, Mandelkern M, Sultzer DL. The functional neuroanatomy of verbal memory in Alzheimer’s disease: [18F]-Fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) correlates of recency and recognition memory. J Clin Exp Neuropsychol 2016; 39:682-693. [DOI: 10.1080/13803395.2016.1255312] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Adam M. Staffaroni
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Rebecca J. Melrose
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Lorraine P. Leskin
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Hannah Riskin-Jones
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Dylan Harwood
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Mark Mandelkern
- Nuclear Medicine Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Department of Physics, University of California, Irvine, CA, USA
| | - David L. Sultzer
- Brain, Behavior & Aging Research Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
- Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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Ota K, Oishi N, Ito K, Fukuyama H. Effects of imaging modalities, brain atlases and feature selection on prediction of Alzheimer's disease. J Neurosci Methods 2015; 256:168-83. [PMID: 26318777 DOI: 10.1016/j.jneumeth.2015.08.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 07/27/2015] [Accepted: 08/18/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND The choice of biomarkers for early detection of Alzheimer's disease (AD) is important for improving the accuracy of imaging-based prediction of conversion from mild cognitive impairment (MCI) to AD. The primary goal of this study was to assess the effects of imaging modalities and brain atlases on prediction. We also investigated the influence of support vector machine recursive feature elimination (SVM-RFE) on predictive performance. METHODS Eighty individuals with amnestic MCI [40 developed AD within 3 years] underwent structural magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans at baseline. Using Automated Anatomical Labeling (AAL) and LONI Probabilistic Brain Atlas (LPBA40), we extracted features representing gray matter density and relative cerebral metabolic rate for glucose in each region of interest from the baseline MRI and FDG-PET data, respectively. We used linear SVM ensemble with bagging and computed the area under the receiver operating characteristic curve (AUC) as a measure of classification performance. We performed multiple SVM-RFE to compute feature ranking. We performed analysis of variance on the mean AUCs for eight feature sets. RESULTS The interactions between atlas and modality choices were significant. The main effect of SVM-RFE was significant, but the interactions with the other factors were not significant. COMPARISON WITH EXISTING METHOD Multimodal features were found to be better than unimodal features to predict AD. FDG-PET was found to be better than MRI. CONCLUSIONS Imaging modalities and brain atlases interact with each other and affect prediction. SVM-RFE can improve the predictive accuracy when using atlas-based features.
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Affiliation(s)
- Kenichi Ota
- Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Naoya Oishi
- Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Department of Psychiatry, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
| | - Kengo Ito
- Department of Clinical and Experimental Neuroimaging, National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu-shi, Aichi 474-8511, Japan
| | - Hidenao Fukuyama
- Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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Cheungpasitporn W, Zand L, Dillon JJ, Qian Q, Leung N. Lactate clearance and metabolic aspects of continuous high-volume hemofiltration. Clin Kidney J 2015; 8:374-7. [PMID: 26251702 PMCID: PMC4515900 DOI: 10.1093/ckj/sfv045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 11/12/2022] Open
Abstract
Lactic acidosis is associated with high morbidity and mortality in hospitalized patients. Treatment of lactic acidosis is targeted on correcting the underlying causes and optimizing adequate oxygen delivery to the tissues. Even though evidence is lacking, continuous renal replacement therapy (CRRT) and dialysis have been advocated as treatments for lactic acidosis. We report a 28-year-old Caucasian male with a history of hemophagocytic lymphohistiocytosis who presented with septic shock, severe lactic acidosis and multiple organ failure. Metabolic acidosis was corrected after bicarbonate therapy and CRRT with a hemofiltration rate of 7 L/h (58 mL/kg/h). Lactate clearance was calculated to be 79 mL/min. Compared with reported rates of lactate overproduction in septic shock, the rate of lactate clearance is quite small. Our case suggests that CRRT with high-volume hemofiltration is not effective for severe lactic acidosis. Lactic acidosis alone should not be considered as a nonrenal indication for CRRT.
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Affiliation(s)
| | - Ladan Zand
- Division of Nephrology and Hypertension , Mayo Clinic , Rochester, MN , USA
| | - John J Dillon
- Division of Nephrology and Hypertension , Mayo Clinic , Rochester, MN , USA
| | - Qi Qian
- Division of Nephrology and Hypertension , Mayo Clinic , Rochester, MN , USA
| | - Nelson Leung
- Division of Nephrology and Hypertension , Mayo Clinic , Rochester, MN , USA ; Division of Hematology , Mayo Clinic , Rochester, MN , USA
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Catricalà E, Della Rosa PA, Parisi L, Zippo AG, Borsa VM, Iadanza A, Castiglioni I, Falini A, Cappa SF. Functional correlates of preserved naming performance in amnestic Mild Cognitive Impairment. Neuropsychologia 2015; 76:136-52. [PMID: 25578430 DOI: 10.1016/j.neuropsychologia.2015.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/04/2015] [Accepted: 01/05/2015] [Indexed: 01/18/2023]
Abstract
Naming abilities are typically preserved in amnestic Mild Cognitive Impairment (aMCI), a condition associated with increased risk of progression to Alzheimer's disease (AD). We compared the functional correlates of covert picture naming and word reading between a group of aMCI subjects and matched controls. Unimpaired picture naming performance was associated with more extensive activations, in particular involving the parietal lobes, in the aMCI group. In addition, in the condition associated with higher processing demands (blocks of categorically homogeneous items, living items), increased activity was observed in the aMCI group, in particular in the left fusiform gyrus. Graph analysis provided further evidence of increased modularity and reduced integration for the homogenous sets in the aMCI group. The functional modifications associated with preserved performance may reflect, in the case of more demanding tasks, compensatory mechanisms for the subclinical involvement of semantic processing areas by AD pathology.
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Affiliation(s)
- Eleonora Catricalà
- Institute for Advanced Study IUSS Pavia, Palazzo del Broletto - Piazza della Vittoria n.15, 27100, Pavia, Italy.
| | - Pasquale A Della Rosa
- Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), Milan, Italy
| | - Laura Parisi
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Antonio G Zippo
- Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), Milan, Italy
| | - Virginia M Borsa
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Antonella Iadanza
- Department of Neuroradiology and CERMAC, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Isabella Castiglioni
- Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), Milan, Italy
| | - Andrea Falini
- Department of Neuroradiology and CERMAC, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Stefano F Cappa
- Institute for Advanced Study IUSS Pavia, Palazzo del Broletto - Piazza della Vittoria n.15, 27100, Pavia, Italy; Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
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Yajima K, Matsushita T, Sumitomo H, Sakurai H, Katayama T, Kanno K, Sakai M, Shigeta M, Shirabe S, Nakano T, Nishimura K, Ueki A, Kitaoka M. One-minute mental status examination for category fluency is more useful than mini-mental state examination to evaluate the reliability of insulin self-injection in elderly diabetic patients. J Diabetes Investig 2014; 5:340-4. [PMID: 24843784 PMCID: PMC4020340 DOI: 10.1111/jdi.12159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/29/2013] [Accepted: 08/18/2013] [Indexed: 11/29/2022] Open
Abstract
AIMS/INTRODUCTION We investigated the factors associated with the reliability of insulin self-injection in elderly diabetic patients receiving insulin therapy. MATERIALS AND METHODS We enrolled diabetic patients aged ≥65 years and receiving insulin therapy, and assessed their cognitive function by the mini-mental state examination and 1-min mental status examination for category fluency. We also observed their technique of insulin self-injection, and evaluated whether or not patients were able to inject insulin by themselves according to nine defined details in terms of insulin self-injection. The predictive factors for the reliability of insulin self-injection were determined by univariate and multivariate logistic regression analysis. There were 278 participants (135 males, 143 females) enrolled in the present study. RESULTS According to multivariate logistic regression analysis, only the 1-min mental status examination score was found to be a significant independent predictor of the reliability of insulin self-injection (odds ratio 0.75; 95% confidence interval 0.62-0.90; P = 0.002). CONCLUSIONS The 1-min mental status examination for category fluency can be considered more useful than mini-mental state examination to evaluate the reliability of insulin self-injection in elderly diabetic patients receiving insulin therapy.
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Affiliation(s)
- Ken Yajima
- Department of Internal MedicineFederation of National Public Service Personnel Mutual Aid AssociationsTachikawa HospitalKanagawaJapan
| | - Takaya Matsushita
- Department of Diabetology, Endocrinology and MetabolismTokyo Medical University Hachioji Medical CenterKanagawaJapan
| | - Hidetaka Sumitomo
- Division of Endocrinology and MetabolismTachikawa Sogo HospitalKanagawaJapan
| | - Hirofumi Sakurai
- Department of Geriatric MedicineTokyo Medical University HospitalKanagawaJapan
| | | | | | - Masashi Sakai
- Department of MedicineRyokufuso HospitalKanagawaJapan
| | - Masayuki Shigeta
- Division of Endocrinology and MetabolismShowa General HospitalKanagawaJapan
| | | | - Tadasumi Nakano
- Department of DiabetologyMitsubishi Kyoto HospitalKyotoJapan
| | | | - Akio Ueki
- Department of Diabetology, Endocrinology and MetabolismTokyo Medical University Hachioji Medical CenterKanagawaJapan
| | - Masafumi Kitaoka
- Division of Endocrinology and MetabolismShowa General HospitalKanagawaJapan
- Nonprofit Organization West Tokyo Diabetic AssociationTokyoJapan
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Banno K, Nakaaki S, Sato J, Torii K, Narumoto J, Miyata J, Hirono N, Furukawa TA, Mimura M, Akechi T. Neural basis of three dimensions of agitated behaviors in patients with Alzheimer disease. Neuropsychiatr Dis Treat 2014; 10:339-48. [PMID: 24600224 PMCID: PMC3933703 DOI: 10.2147/ndt.s57522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Agitated behaviors are frequently observed in patients with Alzheimer disease (AD). The neural substrate underlying the agitated behaviors in dementia is unclear. We hypothesized that different dimensions of agitated behaviors are mediated by distinct neural systems. METHODS All the patients (n=32) underwent single photon emission computed tomography (SPECT). Using the Agitated Behavior in Dementia scale, we identified the relationships between regional cerebral blood flow (rCBF) patterns and the presence of each of three dimensions of agitated behavior (physically agitated behavior, verbally agitated behavior, and psychosis symptoms) in AD patients. Statistical parametric mapping (SPM) software was used to explore these neural correlations. RESULTS Physically agitated behavior was significantly correlated with lower rCBF values in the right superior temporal gyrus (Brodmann 22) and the right inferior frontal gyrus (Brodmann 47). Verbally agitated behavior was significantly associated with lower rCBF values in the left inferior frontal gyrus (Brodmann 46, 44) and the left insula (Brodmann 13). The psychosis symptoms were significantly correlated with lower rCBF values in the right angular gyrus (Brodmann 39) and the right occipital lobe (Brodmann 19). CONCLUSION Our results support the hypothesis that three different agitated behaviors may represent distinct neural networks in AD patients.
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Affiliation(s)
- Koichi Banno
- Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Shutaro Nakaaki
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Junko Sato
- Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Katsuyoshi Torii
- Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Jin Narumoto
- Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
| | - Jun Miyata
- Department of Neuropsychiatry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | | | - Toshi A Furukawa
- Departments of Health Promotion and Human Behavior and of Clinical Epidemiology, Graduate School of Medicine/School of Public Health, Kyoto University, Kyoto, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Tatsuo Akechi
- Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Pekkala S, Wiener D, Himali JJ, Beiser AS, Obler LK, Liu Y, McKee A, Auerbach S, Seshadri S, Wolf PA, Au R. Lexical retrieval in discourse: an early indicator of Alzheimer's dementia. CLINICAL LINGUISTICS & PHONETICS 2013; 27:905-21. [PMID: 23985011 PMCID: PMC4095845 DOI: 10.3109/02699206.2013.815278] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer's disease (AD; n = 23) and a comparison group without criteria for AD (n = 24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS) and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Cross-sectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7-9 years prior to death and FAS and BNT only at 2-4 years. These results suggest that lexical-retrieval deficits in written discourse serve as an early indicator of AD.
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Affiliation(s)
- Seija Pekkala
- Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
| | | | - Jayandra J.J. Himali
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
- Boston University School of Public Health, Department of Biostatistics, Boston, MA, USA
| | - Alexa S. Beiser
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
- Boston University School of Public Health, Department of Biostatistics, Boston, MA, USA
| | - Loraine K. Obler
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- Program in Speech-Language-Hearing Sciences, City University of New York Graduate Center, NY, USA
- VA Boston Health Care System, Boston, MA, USA
| | - Yulin Liu
- The Framingham Heart Study, Framingham, MA, USA
| | - Ann McKee
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- VA Boston Health Care System, Boston, MA, USA
| | - Sanford Auerbach
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
| | - Sudha Seshadri
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
| | - Philip A. Wolf
- The Framingham Heart Study, Framingham, MA, USA
- Department of Neurology, Medicine & Public Health, Boston University School of Medicine, Boston, MA, USA
| | - Rhoda Au
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
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17
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Eastman JA, Hwang KS, Lazaris A, Chow N, Ramirez L, Babakchanian S, Woo E, Thompson PM, Apostolova LG. Cortical thickness and semantic fluency in Alzheimer's disease and mild cognitive impairment. ACTA ACUST UNITED AC 2013; 1:81-92. [PMID: 25346870 DOI: 10.7726/ajad.2013.1006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The hallmark of Alzheimer's disease (AD) is declarative memory loss, but deficits in semantic fluency are also observed. We assessed how semantic fluency relates to cortical atrophy to identify specific regions that play a role in the loss of access to semantic information. Whole-brain structural magnetic resonance imaging (MRI) data were analyzed from 9 Normal Control (NC)(M=76.7, SD=5.6), 40 Mild Cognitive Impairment (MCI) (M=74.4, SD=8.6), and 10 probable AD (M=72.4, SD=8.0) subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI). They all were administered the Category Fluency (CF) animals and vegetables tests. Poorer semantic fluency was associated with bilateral cortical atrophy of the inferior parietal lobule (Brodman areas (BA) 39 and 40) and BA 6, 8, and 9 in the frontal lobe, as well as BA 22 in the temporal lobe. More diffuse frontal associations were seen in the left hemisphere involving BA 9, 10, 32, 44, 45, and 46. Additional cortical atrophy was seen in the temporoparietal (BA 37) and the right parastriate (BA 19, 18) cortices. Associations were more diffuse for performance on vegetable fluency than animal fluency. The permutation-corrected map-wise significance for CF animals was pcorrected=0.01 for the left hemisphere, and pcorrected=0.06 for the right hemisphere. The permutation-corrected map-wise significance for CF vegetables was pcorrected=0.009 for the left hemisphere, and pcorrected=0.03 for the right hemisphere. These results demonstrate the profound effect of cortical atrophy on semantic fluency. Specifically, tapping into semantic knowledge involves the frontal lobe in addition to the language cortices of the temporoparietal region.
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Affiliation(s)
- Jennifer A Eastman
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | - Kristy S Hwang
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | | | - Nicole Chow
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | - Leslie Ramirez
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | - Sona Babakchanian
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | - Ellen Woo
- Department of Neurology, UCLA, Los Angeles, CA, USA
| | - Paul M Thompson
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
| | - Liana G Apostolova
- Department of Neurology, UCLA, Los Angeles, CA, USA ; Imaging Genetics Center, Laboratory of Neuro Imaging, UCLA, Los Angeles, CA, USA
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Nho K, Risacher SL, Crane PK, DeCarli C, Glymour MM, Habeck C, Kim S, Lee GJ, Mormino E, Mukherjee S, Shen L, West JD, Saykin AJ. Voxel and surface-based topography of memory and executive deficits in mild cognitive impairment and Alzheimer's disease. Brain Imaging Behav 2012; 6:551-67. [PMID: 23070747 PMCID: PMC3532574 DOI: 10.1007/s11682-012-9203-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Mild cognitive impairment (MCI) and Alzheimer's disease (AD) are associated with a progressive loss of cognitive abilities. In the present report, we assessed the relationship of memory and executive function with brain structure in a sample of 810 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants, including 188 AD, 396 MCI, and 226 healthy older adults (HC). Composite scores of memory (ADNI-Mem) and executive function (ADNI-Exec) were generated by applying modern psychometric theory to item-level data from ADNI's neuropsychological battery. We performed voxel-based morphometry (VBM) and surface-based association (SurfStat) analyses to evaluate relationships of ADNI-Mem and ADNI-Exec with grey matter (GM) density and cortical thickness across the whole brain in the combined sample and within diagnostic groups. We observed strong associations between ADNI-Mem and medial and lateral temporal lobe atrophy. Lower ADNI-Exec scores were associated with advanced GM and cortical atrophy across broadly distributed regions, most impressively in the bilateral parietal and temporal lobes. We also evaluated ADNI-Exec adjusted for ADNI-Mem, and found associations with GM density and cortical thickness primarily in the bilateral parietal, temporal, and frontal lobes. Within-group analyses suggest these associations are strongest in patients with MCI and AD. The present study provides insight into the spatially unbiased associations between brain atrophy and memory and executive function, and underscores the importance of structural brain changes in early cognitive decline.
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Affiliation(s)
- Kwangsik Nho
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shannon L. Risacher
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Paul K. Crane
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Charles DeCarli
- Department of Neurology and the Center for Neuroscience, School of Medicine, University of California Davis, Davis, CA, USA
| | - M. Maria Glymour
- Department of Society, Human Development and Health, Harvard School of Public Health, Boston, MA, USA
| | - Christian Habeck
- Cognitive Neuroscience Division of Taub Institute for the Study of Alzheimer’s Disease and Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Sungeun Kim
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Grace J. Lee
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Elizabeth Mormino
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, USA
| | | | - Li Shen
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John D. West
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrew J. Saykin
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
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Yoon JH, Kim H, Seo SW, Chin J, Kim JH, Lee KH, Kim YW, Park ES, Suh MK, Na DL. Dysgraphia in Korean patients with Alzheimer's disease as a manifestation of bilateral hemispheric dysfunction. J Neurol Sci 2012; 320:72-8. [DOI: 10.1016/j.jns.2012.06.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 05/14/2012] [Accepted: 06/26/2012] [Indexed: 10/28/2022]
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20
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Doi T, Shimada H, Makizako H, Yoshida D, Shimokata H, Ito K, Washimi Y, Endo H, Suzuki T. Characteristics of cognitive function in early and late stages of amnestic mild cognitive impairment. Geriatr Gerontol Int 2012; 13:83-9. [DOI: 10.1111/j.1447-0594.2012.00865.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Fornari E, Maeder P, Meuli R, Ghika J, Knyazeva MG. Demyelination of superficial white matter in early Alzheimer's disease: a magnetization transfer imaging study. Neurobiol Aging 2012; 33:428.e7-19. [DOI: 10.1016/j.neurobiolaging.2010.11.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 09/24/2010] [Accepted: 11/11/2010] [Indexed: 01/18/2023]
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The cortical neuroanatomy of neuropsychological deficits in mild cognitive impairment and Alzheimer's disease: a surface-based morphometric analysis. Neuropsychologia 2011; 49:3931-45. [PMID: 22019776 DOI: 10.1016/j.neuropsychologia.2011.10.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/10/2011] [Accepted: 10/10/2011] [Indexed: 01/18/2023]
Abstract
Patients with probable Alzheimer's disease (AD) and the amnesic form of mild cognitive impairment (aMCI) often demonstrate several types of neuropsychological deficits. These deficits are often related to cortical atrophy, induced by neuronal degradation. The purpose of this study is to investigate whether different anatomic patterns of cortical atrophy are associated with specific neuropsychological deficits. The participants were 170 patients with AD and 99 patients with aMCI. All participants underwent the Seoul Neuropsychological Screening Battery (SNSB), which includes tests that assess attention, language, visuospatial functions, verbal and visual memory, and frontal/executive functions. Cortical atrophy (thinning) was quantified by measuring the thickness of the cortical mantle across the entire brain using automated, three-dimensional magnetic resonance imaging. The relationship between cortical thickness and neuropsychological performance was analysed using stepwise multiple linear regression analyses. These analyses (corrected P<.001) showed that several specific brain regions with cortical thinning were associated with cognitive dysfunction including: digit span backward, verbal and picture recall, naming and fluency, drawing-copying, response inhibition and selective attention. Some of the other functions, however, were not associated with specific foci of cortical atrophy (digit span forward, the word reading portion of the Stroop test, word and picture recognition). Our study, involving a large sample of participants with aMCI and AD, provides support for the postulate that cortical thinning-atrophy in specific anatomic loci are pathological markers for specific forms of cognitive dysfunction.
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Melrose RJ, Campa OM, Harwood DG, Osato S, Mandelkern MA, Sultzer DL. The neural correlates of naming and fluency deficits in Alzheimer's disease: an FDG-PET study. Int J Geriatr Psychiatry 2009; 24:885-93. [PMID: 19296551 PMCID: PMC2743128 DOI: 10.1002/gps.2229] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To examine the neural processes associated with language deficits in Alzheimer's disease (AD), and in particular to elucidate the correlates of confrontation naming and word retrieval impairments. METHODS Sixty patients with probable AD were included. Confrontation naming was assessed using the number of words spontaneously named correctly on the Boston Naming Test. We recorded the number of additional words stated following phonemic cuing. We also assessed phonemic (FAS) and semantic (supermarket items) fluency. We then correlated performance on each measure with resting cortical metabolic activity using FDG-PET images. RESULTS We found that poorer ability to spontaneously name an object was associated with hypometabolism of bilateral inferior temporal lobes. In contrast, when a phonemic cue was provided, successful naming under this condition was associated with higher metabolic activity in bilateral inferior frontal gyrus (IFG), right superior frontal gyrus (SFG), left temporal, and occipital regions. Consistent with these findings, we found that poorer semantic fluency was associated with hypometabolism in regions including both IFG and temporal regions, and poorer phonemic fluency was associated with hypometabolism in only left IFG. Across analyses, measures that required cued retrieval were associated with metabolism in the left IFG, whereas measures taxing semantic knowledge were associated with metabolic rate of left temporal cortex. CONCLUSIONS Naming deficits in AD reflect compromise to temporal regions involved in the semantic knowledge network, and frontal regions involved in the controlled retrieval of information from that network.
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Affiliation(s)
- Rebecca J. Melrose
- Clinical Neurosciences Research Lab, VA Greater Los Angeles Healthcare System, Dept. of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA
| | - Olivia M. Campa
- Clinical Neurosciences Research Lab, VA Greater Los Angeles Healthcare System
| | - Dylan G. Harwood
- Clinical Neurosciences Research Lab, VA Greater Los Angeles Healthcare System, Dept. of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA
| | - Sheryl Osato
- Clinical Neurosciences Research Lab, VA Greater Los Angeles Healthcare System, Dept. of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA
| | - Mark A. Mandelkern
- Nuclear Medicine Service, VA Greater Los Angeles Healthcare System; and Dept. of Physics, University of California, Irvine
| | - David L. Sultzer
- Clinical Neurosciences Research Lab, VA Greater Los Angeles Healthcare System, Dept. of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA
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24
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Laisney M, Matuszewski V, Mézenge F, Belliard S, de la Sayette V, Eustache F, Desgranges B. The underlying mechanisms of verbal fluency deficit in frontotemporal dementia and semantic dementia. J Neurol 2009; 256:1083-94. [PMID: 19363702 DOI: 10.1007/s00415-009-5073-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 01/21/2009] [Accepted: 02/11/2009] [Indexed: 11/30/2022]
Abstract
Verbal fluency tasks are commonly used to explore semantic memory and executive functions. The aim of this study was to gain a better understanding of the cognitive and neural mechanisms underlying verbal fluency impairment in the frontal variant of frontotemporal dementia (fv-FTD) and in semantic dementia (SD). Semantic and phonemic fluency tasks were performed by 36 fv-FTD and SD patients and 18 elderly controls. We also carried out a neuropsychological investigation of semantic memory, working memory and shifting and updating processes. We performed correlative and regression analyses of fluency scores and neuropsychological data. In addition, patients underwent a resting positron emission tomography examination, and statistical parametric mapping was used to establish correlations between resting-state FDG uptake in the whole brain and fluency scores for each patient group. Both patient groups displayed impaired performances on both fluency tasks compared with controls, but with different patterns. While fv-FTD patients scored higher than SD patients on semantic fluency, their performances on the phonemic task did not differ. Correlation and regression analyses clearly demonstrated that the fv-FTD patients' performances on both fluency tasks depended on their executive abilities, while those of the SD patients were hampered by the impairment of their semantic memory store. Correlations with resting FDG uptake were consistent with the results of the cognitive study. In fv-FTD, both fluency performances were related to the metabolism of the frontal lobes, while we observed significant correlations between performances on both fluency tasks and the left temporal lobe metabolism in SD.
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Affiliation(s)
- Mickaël Laisney
- U 923, Inserm-EPHE-Université de Caen/Basse-Normandie, GIP Cyceron, CHU Côte de Nacre, Caen, France
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25
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Peters F, Majerus S, Collette F, Degueldre C, Del Fiore G, Laureys S, Moonen G, Salmon E. Neural substrates of phonological and lexicosemantic representations in Alzheimer's disease. Hum Brain Mapp 2009; 30:185-99. [PMID: 18095283 DOI: 10.1002/hbm.20493] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The language profile of patients suffering from Alzheimer's disease (AD) is characterized not only by lexicosemantic impairments but also by phonological deficits, as shown by an increasing number of neuropsychological studies. This study explored the functional neural correlates underlying phonological and lexicosemantic processing in AD. Using H(215)O PET functional brain imaging, a group of mild to moderate AD patients and a group of age-matched controls were asked to repeat four types of verbal stimuli: words, wordlike nonwords (WL+), non-wordlike nonwords (WL-) and simple vowels. The comparison between the different conditions allowed us to determine brain activation preferentially associated with lexicosemantic or phonological levels of language representations. When repeating words, AD patients showed decreased activity in the left temporo-parietal and inferior frontal regions relative to controls, consistent with distorted lexicosemantic representations. Brain activity was abnormally increased in the right superior temporal area during word repetition, a region more commonly associated with perceptual-phonological processing. During repetition of WL+ and WL- nonwords, AD patients showed decreased activity in the middle part of the superior temporal gyrus, presumably associated with sublexical phonological information; at the same time, AD patients showed larger activation than controls in the inferior temporal gyrus, typically associated with lexicosemantic levels of representation. Overall, the results suggest that AD patients use altered pathways to process phonological and lexicosemantic information, possibly related to a progressive loss of specialization of phonological and lexicosemantic neural networks.
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Rinka H, Yoshida T, Kubota T, Tsuruwa M, Fuke A, Yoshimoto A, Kan M, Miyazaki D, Arimoto H, Miyaichi T, Kaji A, Miyamoto S, Kuki I, Shiomi M. Hemorrhagic shock and encephalopathy syndrome--the markers for an early HSES diagnosis. BMC Pediatr 2008; 8:43. [PMID: 18922188 PMCID: PMC2577649 DOI: 10.1186/1471-2431-8-43] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2008] [Accepted: 10/16/2008] [Indexed: 01/11/2023] Open
Abstract
Background The hemorrhagic shock and encephalopathy syndrome (HSES) is a devastating disease that affects young children. The outcomes of HSES patients are often fatal or manifesting severe neurological sequelae. We reviewed the markers for an early diagnosis of HSES. Methods We examined the clinical, biological and radiological findings of 8 patients (4 months to 9 years old) who met the HSES criteria. Results Although cerebral edema, disseminated intravascular coagulopathy (DIC), and multiple organ failure were seen in all 8 cases during their clinical courses, brain computed tomography (CT) scans showed normal or only slight edema in 5 patients upon admission. All 8 patients had normal platelet counts, and none were in shock. However, they all had severe metabolic acidosis, which persisted even after 3 hours (median base excess (BE), -7.6 mmol/L). And at 6 hours after admission (BE, -5.7 mmol/L) they required mechanical ventilation. Within 12 hours after admission, fluid resuscitation and vasopressor infusion for hypotension was required. Seven of the patients had elevated liver enzymes and creatine kinase (CK) upon admission. Twenty-four hours after admission, all 8 patients needed vasopressor infusion to maintain blood pressure. Conclusion CT scan, platelet count, hemoglobin level and renal function upon admission are not useful for an early diagnosis of HSES. However, the elevated liver enzymes and CK upon admission, hypotension in the early stage after admission with refractory acid-base disturbance to fluid resuscitation and vasopressor infusion are useful markers for an early HSES diagnosis and helpful to indicate starting intensive neurological treatment.
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Affiliation(s)
- Hiroshi Rinka
- Emergency and Critical Care Medical Center, Osaka City General Hospital, Osaka, Japan.
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Fagundo AB, López S, Romero M, Guarch J, Marcos T, Salamero M. Clustering and switching in semantic fluency: predictors of the development of Alzheimer's disease. Int J Geriatr Psychiatry 2008; 23:1007-13. [PMID: 18416452 DOI: 10.1002/gps.2025] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The aims of the study are twofold: (1) to compare semantic fluency, clustering and switching performance among subjects with memory complaints, patients with Alzheimer Disease (AD), and healthy controls; and (2) to examine the clinical utility of the clustering/switching scoring system in the prediction of incident AD in subjects with memory complaints. METHODS A semantic fluency task was used to compare thirty eight subjects with memory complaints, forty two AD patients and twenty five healthy controls on the total number of words generated, clustering and switching performance. Subjects with memory complaints were followed-up for a maximum period of two years and re-evaluated. They remained in the memory complaints group (twenty eight subjects) or were defined as probable AD (ten subjects). RESULTS AD patients generated fewer correct words (p < 0.001) and showed a reduction in clustering (p = 0.008) and switching (p < 0.001). Subjects with memory complaints showed a significant reduction in correct words (p < 0.001) and clustering performance (p = 0.008) compare to controls. In the first evaluation, the subgroup of patients who converted to AD at follow up produced less correct words (p < 0.01) and smaller clusters (p = 0.007) than the subgroup who did not become demented. There were no differences in switching between these two subgroups. AD development was better predicted by cluster size than by the total number of words generated or by switching. CONCLUSIONS Subjects with memory complaints and AD patients have an alteration in both qualitative and quantitative aspects of semantic fluency. A clustering analysis could enhance the reliability of early AD diagnosis.
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Affiliation(s)
- Ana B Fagundo
- Department of Clinical Psychology, Hospital Clinic de Barcelona, Universidad de Barcelona, Barcelona, Spain
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Concept of functional imaging of memory decline in Alzheimer's disease. Methods 2008; 44:304-14. [PMID: 18374274 DOI: 10.1016/j.ymeth.2007.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 02/13/2007] [Indexed: 11/19/2022] Open
Abstract
Functional imaging methods such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) have contributed inestimably to the understanding of physiological cognitive processes in the brain in the recent decades. These techniques for the first time allowed the in vivo assessment of different features of brain function in the living human subject. It was therefore obvious to apply these methods to evaluate pathomechanisms of cognitive dysfunction in disorders such as Alzheimer's disease (AD) as well. One of the most dominant symptoms of AD is the impairment of memory. In this context, the term "memory" represents a simplification and summarizes a set of complex cognitive functions associated with encoding and retrieval of different types of information. A number of imaging studies assessed the functional changes of neuronal activity in the brain at rest and also during performance of cognitive work, with regard to specific characteristics of memory decline in AD. In the current article, basic principles of common functional imaging procedures will be explained and it will be discussed how they can be reasonably applied for the assessment of memory decline in AD. Furthermore, it will be illustrated how these imaging procedures have been employed to improve early and specific diagnosis of the disease, to understand specific pathomechanisms of memory dysfunction and associated compensatory mechanisms, and to draw reverse conclusions on physiological function of memory.
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Balik M, Waldauf P, Glocknerova K, Kusova D. Lactate-buffered dialysis in cardiogenic shock associated with severe combined lactic acidosis. Clin Kidney J 2008; 1:103-105. [PMID: 28657034 PMCID: PMC5477911 DOI: 10.1093/ndtplus/sfm054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 12/28/2007] [Indexed: 11/15/2022] Open
Abstract
The level of lactate that would serve as cut-off for contraindication of lactate buffer is so far unclear. An acute exogenous load of lactate does not affect the basal endogenous lactate production and metabolism. It is also well metabolized in patients suffering from acute renal failure and severe sepsis with a compromised haemodynamic status. We report a case of extreme lactic acidosis in a patient admitted with a combination of cardiogenic shock, uraemia and suspected accumulation of biguanide. The patient was successfully treated with lactate-buffered dialysis due to the accidental absence of the bicarbonate-buffered fluids.
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Affiliation(s)
- Martin Balik
- Department of Anaesthesia and Intensive Care, General Teaching Hospital, U nemocnice 2, Prague 2
| | - Petr Waldauf
- Department of Anaesthesia and Intensive Care, University Hospital Kralovske Vinohrady, Srobarova 50, Prague 10, Czech Republic
| | - Katerina Glocknerova
- Department of Anaesthesia and Intensive Care, University Hospital Kralovske Vinohrady, Srobarova 50, Prague 10, Czech Republic
| | - Dagmar Kusova
- Department of Anaesthesia and Intensive Care, General Teaching Hospital, U nemocnice 2, Prague 2
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Giffard B, Laisney M, Mézenge F, de la Sayette V, Eustache F, Desgranges B. The neural substrates of semantic memory deficits in early Alzheimer's disease: clues from semantic priming effects and FDG-PET. Neuropsychologia 2008; 46:1657-66. [PMID: 18325543 DOI: 10.1016/j.neuropsychologia.2007.12.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2007] [Revised: 11/26/2007] [Accepted: 12/11/2007] [Indexed: 01/18/2023]
Abstract
The neural substrates responsible for semantic dysfunction during the early stages of AD have yet to be clearly identified. After a brief overview of the literature on normal and pathological semantic memory, we describe a new approach, designed to provide fresh insights into semantic deficits in AD. We mapped the correlations between resting-state brain glucose utilisation measured by FDG-PET and semantic priming scores in a group of 17 AD patients. The priming task, which yields a particularly pure measurement of semantic memory, was composed of related pairs of words sharing an attribute relationship (e.g. tiger-stripe). The priming scores correlated positively with the metabolism of the superior temporal areas on both sides, especially the right side, and this correlation was shown to be specific to the semantic priming effect. This pattern of results is discussed in the light of recent theoretical models of semantic memory, and suggests that a dysfunction of the right superior temporal cortex may contribute to early semantic deficits, characterised by the loss of specific features of concepts in AD.
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Affiliation(s)
- Bénédicte Giffard
- Inserm - EPHE - Université de Caen/Basse-Normandie, U923, GIP Cyceron, CHU Côte de Nacre, 14033 Caen Cedex, France
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Piolino P, Desgranges B, Hubert V, Bernard FA, Matuszewski V, Chételat G, Baron JC, Eustache F. Reliving lifelong episodic autobiographical memories via the hippocampus: A correlative resting PET study in healthy middle-aged subjects. Hippocampus 2008; 18:445-59. [DOI: 10.1002/hipo.20406] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Apostolova LG, Lu P, Rogers S, Dutton RA, Hayashi KM, Toga AW, Cummings JL, Thompson PM. 3D mapping of language networks in clinical and pre-clinical Alzheimer's disease. BRAIN AND LANGUAGE 2008; 104:33-41. [PMID: 17485107 PMCID: PMC2211373 DOI: 10.1016/j.bandl.2007.03.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 02/13/2007] [Accepted: 03/27/2007] [Indexed: 05/15/2023]
Abstract
We investigated the associations between Boston naming and the animal fluency tests and cortical atrophy in 19 probable AD and 5 multiple domain amnestic mild cognitive impairment patients who later converted to AD. We applied a surface-based computational anatomy technique to MRI scans of the brain and then used linear regression models to detect associations between animal fluency and Boston Naming Test (BNT) performance and cortical atrophy. The global permutation-corrected significance for the maps associating BNT performance with cortical atrophy was p=.0124 for the left and p=.0196 for the right hemisphere and for the animal fluency maps p=.055 for the left and p=.073 for the right hemisphere. The degree of language impairment correlated with cortical atrophy in the left temporal and parietal lobes (BA 20, 21, 37, 39, 40, and 7), bilateral frontal lobes (BA 8, 9, and 44) and the right temporal pole (BA 38). Using a novel 3D mapping technique, we demonstrated that in AD language abilities are strongly influenced by the integrity of the perisylvian cortical regions.
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Affiliation(s)
- Liana G Apostolova
- Department of Neurology, David Geffen School of Medicine, UCLA, CA, USA.
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Salmon E, Lekeu F, Bastin C, Garraux G, Collette F. Functional imaging of cognition in Alzheimer's disease using positron emission tomography. Neuropsychologia 2007; 46:1613-23. [PMID: 18191961 DOI: 10.1016/j.neuropsychologia.2007.11.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 11/11/2007] [Accepted: 11/28/2007] [Indexed: 01/18/2023]
Abstract
Positron emission tomography in Alzheimer's disease (AD) demonstrates a metabolic decrease, predominantly in associative posterior cortices (comprising the posterior cingulate cortex), and also involving medial temporal structures and frontal regions at a lesser degree. The level of activity in this wide network is roughly correlated with dementia severity, but several confounds (such as age, education or subcortical ischemic lesions) may influence the brain-behaviour relationship. Univariate analyses allow one to segregate brain regions that are particularly closely related to specific neuropsychological performances. For example, a relationship was established between the activity in lateral associative cortices and semantic performance in AD. The role of semantic capacities (subserved by temporal or parietal regions) in episodic memory tasks was also emphasized. The residual activity in medial temporal structures was related to episodic memory abilities, as measured by free recall performance, cued recall ability and recognition accuracy. More generally, AD patients' performance on episodic memory tasks was correlated with the metabolism in several structures of Papez's circuit (including the medial temporal and posterior cingulate regions). Multivariate analyses should provide complementary information on impaired metabolic covariance in functional networks of brain regions and the consequences for AD patients' cognitive performance. More longitudinal studies are being conducted that should tell us more about the prognostic value of initial metabolic impairment and the neural correlates of progressive deterioration of cognitive performance in AD.
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Affiliation(s)
- Eric Salmon
- Cyclotron Research Centre, University of Liège, B30 Sart Tilman, 4000 Liège, Belgium.
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35
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Rauchs G, Piolino P, Mézenge F, Landeau B, Lalevée C, Pélerin A, Viader F, de la Sayette V, Eustache F, Desgranges B. Autonoetic consciousness in Alzheimer's disease: Neuropsychological and PET findings using an episodic learning and recognition task. Neurobiol Aging 2007; 28:1410-20. [PMID: 16846667 DOI: 10.1016/j.neurobiolaging.2006.06.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 06/05/2006] [Accepted: 06/07/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study aims to map in patients with mild Alzheimer's disease (AD) the correlations between resting-state brain glucose utilization measured by FDG-PET and scores reflecting autonoetic consciousness in an episodic learning and recognition task. METHODS Autonoetic consciousness, that gives a subject the conscious feeling to mentally travelling back in time to relive an event, was assessed using the Remember/Know (R/K) paradigm. RESULTS AD patients provided less R responses (reflecting autonoetic consciousness) and more K ones (indicating the involvement of noetic consciousness) than healthy controls. Correct recognitions associated with a R response correlated with the metabolism of frontal areas bilaterally whereas those associated with a K response mainly correlated with the metabolism of left parahippocampal gyrus and lateral temporal cortex. CONCLUSIONS These data show that recollection is impaired in AD and recognition is more based on a feeling of familiarity than in controls. In addition, the findings of our correlative approach indicate that the impairment of episodic memory is mainly subserved by the dysfunction of frontal areas and of the hippocampal region.
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Affiliation(s)
- Géraldine Rauchs
- Inserm-EPHE-Université de Caen E0218 and GIP Cyceron, Laboratoire de Neuropsychologie, CHU Avenue Côte de Nacre, 14033 CAEN cedex, France
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Bracco L, Bessi V, Piccini C, Mosconi L, Pupi A, Sorbi S. Metabolic correlates of executive dysfunction. J Neurol 2007; 254:1052-65. [PMID: 17385079 DOI: 10.1007/s00415-006-0488-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 10/24/2006] [Accepted: 11/04/2006] [Indexed: 01/08/2023]
Abstract
This study was designed to examine the correlations between resting-state brain glucose metabolism (CMRglc), as measured with Positron Emission Tomography and performance on executive function tasks in Alzheimer's disease (AD), while taking into account the severity of cognitive deterioration. We addressed this issue in 50 AD patients, classified as very mild (n = 22) and mild (n = 28) AD on the basis of an extensive neuropsychological battery. Thirteen healthy subjects were selected as controls for the neuropsychological measures. Statistical Parametric Mapping (SPM) was used to examine voxel-wise correlations between CMRglc and scores on selected cognitive tests of executive functions: the Stroop Test, the Trail Making Test, the Dual Task and the Phonemic Fluency, while correcting for age and global CMRglc. All analyses were done separately for the two AD subgroups. The very mild AD patients showed significant associations between Stroop and Trail Making Test scores and prefrontal regions metabolism, whereas the mild AD patients exhibited more widely distributed cognitive-metabolic correlations extending to the posterior brain regions. These data suggest that a large cortical network is implicated in executive dysfunction in AD, and that the pattern of cognitive-metabolic correlations varies according to disease severity.
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Affiliation(s)
- L Bracco
- Department of Neurological and Psychiatric Sciences, Viale Morgagni 85, 50134, Florence, Italy.
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37
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Zahn R, Garrard P, Talazko J, Gondan M, Bubrowski P, Juengling F, Slawik H, Dykierek P, Koester B, Hull M. Patterns of regional brain hypometabolism associated with knowledge of semantic features and categories in Alzheimer's disease. J Cogn Neurosci 2007; 18:2138-51. [PMID: 17129196 DOI: 10.1162/jocn.2006.18.12.2138] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The study of semantic memory in patients with Alzheimer's disease (AD) has raised important questions about the representation of conceptual knowledge in the human brain. It is still unknown whether semantic memory impairments are caused by localized damage to specialized regions or by diffuse damage to distributed representations within nonspecialized brain areas. To our knowledge, there have been no direct correlations of neuroimaging of in vivo brain function in AD with performance on tasks differentially addressing visual and functional knowledge of living and nonliving concepts. We used a semantic verification task and resting 18-fluorodeoxyglucose positron emission tomography in a group of mild to moderate AD patients to investigate this issue. The four task conditions required semantic knowledge of (1) visual, (2) functional properties of living objects, and (3) visual or (4) functional properties of nonliving objects. Visual property verification of living objects was significantly correlated with left posterior fusiform gyrus metabolism (Brodmann's area [BA] 37/19). Effects of visual and functional property verification for non-living objects largely overlapped in the left anterior temporal (BA 38/20) and bilateral premotor areas (BA 6), with the visual condition extending more into left lateral precentral areas. There were no associations with functional property verification for living concepts. Our results provide strong support for anatomically separable representations of living and nonliving concepts, as well as visual feature knowledge of living objects, and against distributed accounts of semantic memory that view visual and functional features of living and nonliving objects as distributed across a common set of brain areas.
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Ebmeier KP, Donaghey C, Dougall NJ. Neuroimaging in dementia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2005; 67:43-72. [PMID: 16291019 DOI: 10.1016/s0074-7742(05)67002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- K P Ebmeier
- Division of Psychiatry, University of Edinburgh, Kennedy Tower, Morningside Park Edinburgh EH10 5HF, United Kingdom
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Vogel A, Gade A, Stokholm J, Waldemar G. Semantic memory impairment in the earliest phases of Alzheimer's disease. Dement Geriatr Cogn Disord 2005; 19:75-81. [PMID: 15572875 DOI: 10.1159/000082352] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/09/2004] [Indexed: 11/19/2022] Open
Abstract
The presence and the nature of semantic memory dysfunction in Alzheimer's disease (AD) have been widely debated. This study aimed to determine the frequency of impaired semantic test performances in mild AD and to study whether incipient semantic impairments could be identified in predementia AD. Five short neuropsychological tests sensitive to semantic memory and easily applicable in routine practice were administered to 102 patients with mild AD (Mini-Mental State Examination score above 19), 22 predementia AD patients and 58 healthy subjects. 'Category fluency' and 'naming of famous faces' were the most frequently impaired tests in both patient groups. The study demonstrated that impairments on semantically related tests are common in mild AD and may exist prior to the clinical diagnosis. The results imply that assessment of semantic memory is relevant in the evaluation of patients with suspected AD.
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Affiliation(s)
- Asmus Vogel
- Memory Disorders Research Unit, Neuroscience Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
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Rodriguez G, Morbelli S, Brugnolo A, Calvini P, Girtler N, Piccardo A, Dougall NJ, Ebmeier KP, Baron JC, Nobili F. Global cognitive impairment should be taken into account in SPECT-neuropsychology correlations: the example of verbal memory in very mild Alzheimer's disease. Eur J Nucl Med Mol Imaging 2005; 32:1186-92. [PMID: 15931515 DOI: 10.1007/s00259-005-1831-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Accepted: 04/04/2005] [Indexed: 11/25/2022]
Abstract
PURPOSE To examine the impact of severity of global cognitive impairment on SPECT-neuropsychology correlations, we correlated a verbal memory test with brain perfusion in patients with very mild Alzheimer's disease (AD), taking into account the Mini-Mental State Examination (MMSE) score as an index of global cognitive impairment. METHODS Twenty-nine outpatients (mean age 78.2+/-5.5 years) affected by very mild, probable AD underwent brain SPECT with 99mTc-ethylcysteinate dimer and a word list learning test. SPM99 was used for voxel-based correlation analysis after normalisation to mean cerebellar counts (height threshold: p<0.01). In a first analysis, only age and years of education were inserted as nuisance covariates, while in a second analysis the MMSE score was inserted as well. RESULTS In the first analysis, two clusters of significant correlation were found in both hemispheres, mainly including regions of the right hemisphere, such as the inferior parietal lobule, the middle temporal gyrus and the posterior cingulate. Significant correlation in the left hemisphere was observed in the lingual lobule, the parietal precuneus and the posterior cingulate. After taking into consideration the MMSE, the largest cluster of correlation was found in the left hemisphere, including the parietal gyrus angularis, the posterior cingulate and the middle temporal gyrus. CONCLUSION The wide differences observed between the correlations achieved with and without taking into account the MMSE score indicate that severity of global cognitive impairment should be considered when searching for brain perfusion-neuropsychology correlations. In the present case, this strategy resulted in correlations that more closely matched neuropsychological models of verbal memory deficit.
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Affiliation(s)
- G Rodriguez
- Clinical Neurophysiology, Department of Endocrinological and Metabolic Sciences, University of Genoa, Viale Benedetto XV, 6, 16132, Genoa, Italy
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Nobili F, Brugnolo A, Calvini P, Copello F, De Leo C, Girtler N, Morbelli S, Piccardo A, Vitali P, Rodriguez G. Resting SPECT-neuropsychology correlation in very mild Alzheimer's disease. Clin Neurophysiol 2005; 116:364-75. [PMID: 15661114 DOI: 10.1016/j.clinph.2004.09.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2004] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the relationships between brain function and some of the most frequently impaired cognitive domains in the first stages of Alzheimer's disease (AD), we searched for correlation between the scores on 3 neuropsychological tests and brain perfusion, assessed by single photon emission computed tomography (SPECT) in patients with very mild AD. METHODS Twenty-nine consecutive outpatients (mean age 78.2+/-5.5) affected by probable AD in the very mild phase (i.e. with a score > or =20 on the mini-mental state examination, MMSE) underwent brain SPECT with (99m)Tc-ethylcisteinate dimer. For correlative purposes, word list learning (by the selective reminding test, SRT), constructional praxis test (CPT) and visual search test (VST) were chosen a priori out of an extended battery employed to diagnose AD at first patient evaluation. Voxel-based correlation analysis was achieved by statistical parametric mapping (SPM99) with a height threshold of P=0.005. Age, years of education and the MMSE score were inserted in the correlative analysis as confounding variables. RESULTS The SRT score showed correlation with brain perfusion in 3 clusters of the left hemisphere, including the post-central gyrus, the parietal precuneus, the inferior parietal lobule and the middle temporal gyrus, and in one cluster in the right hemisphere including the middle temporal gyrus and the middle occipital gyrus. The CPT score was significantly correlated with brain perfusion in the parietal precuneus and the posterior cingulate gyrus in the left hemisphere, whereas the VST score gave a significant correlation with brain perfusion in a left cluster including the parietal precuneus and the superior temporal gyrus. CONCLUSIONS Cognitive impairment in very mild AD is reflected by brain dysfunction in posterior associative areas, with peculiar topographical differences proper of each domain. The parietal precuneus was a common site of correlation of all 3 neuropsychological tests. This region, together with the posterior cingulate and the superficial posterior temporal-parietal cortex, is thought to be affected by disconnection from the mesial temporal lobe, besides being directly affected by increased oxidative stress and by atrophy as well. The impairment of these areas is thought to contribute to cognitive decline in verbal memory, constructional praxis and visual sustained attention which are indeed among the earliest signs of cognitive impairment in AD. SIGNIFICANCE Assessing the relationships between neuropsychology and brain functional imaging is a key approach to clarify the pathophysiology of cognitive failure in AD; the specificity of these findings in AD remains to be proven through comparison with correlation achieved in matched controls.
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Affiliation(s)
- Flavio Nobili
- Section of Clinical Neurophysiology (DISEM), Department of Endocrinological and Metabolic Sciences, University of Genoa, Viale Benedetto XV, 6, I-16132 Genoa, Italy.
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Zahn R, Juengling F, Bubrowski P, Jost E, Dykierek P, Talazko J, Huell M. Hemispheric asymmetries of hypometabolism associated with semantic memory impairment in Alzheimer's disease: a study using positron emission tomography with fluorodeoxyglucose-F18. Psychiatry Res 2004; 132:159-72. [PMID: 15598550 DOI: 10.1016/j.pscychresns.2004.07.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Revised: 06/11/2004] [Accepted: 07/30/2004] [Indexed: 01/18/2023]
Abstract
Considerable disagreement exists about the neuroanatomical basis of conceptual-semantic impairments observed in a subgroup of patients with Alzheimer's disease (AD) at mild to moderate stages of the disease. Several studies of groups of patients have shown correlations between focal hypometabolism or hypoperfusion in left hemispheric areas and measures of verbal semantic memory impairment in AD patients. The question remains, however, whether left hemispheric hypometabolism is sufficient to produce such impairment in the single case and whether nonverbal semantic knowledge is also affected. We used positron emission tomography (PET) with fluorodeoxyglucose-F18 (FDG), statistical parametric mapping (SPM), and tests of verbal and nonverbal semantic memory in 11 AD patients with a mean score on the Mini-Mental State Examination of 22.6 (+/-2.8). Naming impairment was significantly associated with left hemispheric asymmetry of hypometabolism on a single-case basis. Our correlation analysis showed that metabolism in left anterior temporal, posterior inferior temporal, inferior parietal and medial occipital areas (Brodmann areas: 21/38, 37, 40 and 19) correlated with both verbal and nonverbal semantic performance. We conclude that left hemispheric synaptic dysfunction, as measured by regional glucose hypometabolism, was sufficient to produce semantic impairments in our patients. The majority of areas affected in our patients with semantic impairments were involved in multimodal or supramodal (verbal and nonverbal) semantic knowledge.
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Affiliation(s)
- Roland Zahn
- Department of Psychiatry and Psychotherapy, Albert-Ludwigs-University of Freiburg, Hauptstr. 5, D-79104 Freiburg, Germany.
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Rossi AF, Khan DM, Hannan R, Bolivar J, Zaidenweber M, Burke R. Goal-directed medical therapy and point-of-care testing improve outcomes after congenital heart surgery. Intensive Care Med 2004; 31:98-104. [PMID: 15650863 DOI: 10.1007/s00134-004-2504-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Accepted: 10/25/2004] [Indexed: 01/16/2023]
Abstract
OBJECTIVE A goal-directed therapy algorithm based on serial lactate values obtained from a point-of-care testing device was utilized in an attempt to reduce the mortality of patients after congenital heart surgery. DESIGN Prospective study of patients undergoing surgery utilizing a goal-directed therapy algorithm in the postoperative period. The results of this group are compared with a historical cohort. Operative risk was determined using the RACHS-1 scoring system. SETTING A 12-bed cardiac intensive care unit (ICU) in a pediatric hospital. PATIENTS Patients undergoing surgery from July 2001 through September 2003 (group B, n=710) were compared to cohorts from June 1995 through June 2001 (group A, n=1,656). Group B patients were smaller and younger (median weight 6.2 vs 8 kg, p<0.001; median age 184 vs 327 days, p=0.004). INTERVENTIONS Beginning in July 2001, blood lactate measurements were performed serially for 24 h after heart surgery. Based on lactate values and trends, therapy was amended. MEASUREMENTS AND RESULTS Mortality was lower for group B (1.8 vs 3.7%, p=0.02). A reduction in mortality between group B and group A was noted in neonates (3.4 vs 12%, p=0.02), but not in older patients. Group B patients undergoing higher risk operations (Risk Adjustment for Congenital Heart Surgery-1 [RACHS-1] categories 3-6) had a significant reduction in mortality when compared to group A (3 vs 9%, p=0.006), no difference was noted in patients undergoing lower risk operations (RACHS-1 categories 1 and 2). CONCLUSIONS The combination of goal-directed therapy and point-of-care testing was associated with a marked decrease in mortality for patients undergoing congenital heart surgery. Improvement was greatest in the highest risk patients.
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Affiliation(s)
- Anthony F Rossi
- Cardiac Intensive Care Unit, Miami Children's Hospital, Suite 104, 3200 SW 60 Court, Miami, FL 33155, USA.
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Lee YC, Liu RS, Liao YC, Wang PN, Lin KN, Liu HC. Longitudinal Cerebral Perfusion Decrease in Mild Alzheimer’s Disease Revealed by SPECT with Statistical Parametric Mapping Method. Eur Neurol 2004; 52:42-9. [PMID: 15237252 DOI: 10.1159/000079417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2003] [Accepted: 04/13/2004] [Indexed: 11/19/2022]
Abstract
Fifteen patients with mild Alzheimer's disease received baseline and follow-up technetium-99m hexamethylpropylene amine oxime SPECT examinations paired with neuropsychological assessments, including the Cognitive Ability Screening Instruments (CASI). The differences between baseline and follow-up SPECT images were analyzed by the voxel-based paired t test of the statistical parametric mapping technique. A simple regression analysis was also conducted to analyze the correlation between CASI sub-scores and both sets of SPECT images. In comparison with baseline images, cerebral perfusion at follow-up was significantly reduced in the left superior and middle temporal gyri, right middle and inferior temporal gyri, and right fusiform gyrus. A significant correlation was demonstrated between the list-generating fluency CASI sub-score and perfusion of the left fusiform gyrus. The visual construction sub-score was significantly correlated with perfusion of the right superior and medial frontal gyri.
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Affiliation(s)
- Yi-Chung Lee
- The Neurological Institute, Taipei Veterans General Hospital, Section of Neurology, #201 Section 2 Shih-Pai Road, Shih-pai, Taipei 11217, Taiwan
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Estévez-González A, García-Sánchez C, Boltes A, Otermín P, Pascual-Sedano B, Gironell A, Kulisevsky J. Semantic knowledge of famous people in mild cognitive impairment and progression to Alzheimer's disease. Dement Geriatr Cogn Disord 2004; 17:188-95. [PMID: 14739543 DOI: 10.1159/000076355] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/28/2003] [Indexed: 11/19/2022] Open
Abstract
Patients with dementia of Alzheimer's type (DAT) show severe impairment in recognizing famous people. The aim of the current study was to investigate if this well-known memory impairment of famous faces is already present in the preclinical phase of DAT and if the famous faces test can help to differentiate patients with mild cognitive impairment (MCI) who progress to dementia and those who do not. We compared baseline performance in a task of famous face identification in a sample of 116 patients with subjective memory complaints classified in three groups: 17 participants with no evidence of cognitive impairment; 26 patients with MCI who had not developed dementia, and 27 patients with MCI who had developed probable DAT 2 years later. The remaining patients were excluded because they abandoned or did not meet the applied restrictive criteria for DAT, MCI or control. MCI patients who were diagnosed 2 years later with DAT performed significantly worse in the preclinical phase than MCI and control participants (p < 0.004). Patients with MCI but not DAT obtained intermediate results between control subjects and MCI patients who develop Alzheimer's disease. A neuropsychological task of semantic knowledge of famous people may be useful in the early diagnosis of Alzheimer's disease.
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Bollmann MD, Revelly JP, Tappy L, Berger MM, Schaller MD, Cayeux MC, Martinez A, Chioléro RL. Effect of bicarbonate and lactate buffer on glucose and lactate metabolism during hemodiafiltration in patients with multiple organ failure. Intensive Care Med 2004; 30:1103-10. [PMID: 15048552 DOI: 10.1007/s00134-004-2251-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Accepted: 02/16/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To compare the effects of sodium bicarbonate and lactate for continuous veno-venous hemodiafiltration (CVVHDF) in critically ill patients. DESIGN AND SETTINGS Prospective crossed-over controlled trial in the surgical and medical ICUs of a university hospital. PATIENTS Eight patients with multiple organ dysfunction syndrome (MODS) requiring CVVHDF. INTERVENTION Each patient received the two buffers in a randomized sequence over two consecutive days. MEASUREMENTS AND RESULTS The following variables were determined: acid-base parameters, lactate production and utilization ((13)C lactate infusion), glucose turnover (6,6(2)H(2)-glucose), gas exchange (indirect calorimetry). No side effect was observed during lactate administration. Baseline arterial acid-base variables were equal with the two buffers. Arterial lactate (2.9 versus 1.5 mmol/l), glycemia (+18%) and glucose turnover (+23%) were higher in the lactate period. Bicarbonate and glucose losses in CVVHDF were substantial, but not lactate elimination. Infusing (13)C lactate increased plasma lactate levels equally with the two buffers. Lactate clearance (7.8+/-0.8 vs 7.5+/-0.8 ml/kg per min in the bicarbonate and lactate periods) and endogenous production rates (14.0+/-2.6 vs 13.6+/-2.6 mmol/kg per min) were similar. (13)C lactate was used as a metabolic substrate, as shown by (13)CO(2) excretion. Glycemia and metabolic rate increased significantly and similarly during the two periods during lactate infusion. CONCLUSION Lactate was rapidly cleared from the blood of critically ill patients without acute liver failure requiring CVVHDF, being transformed into glucose or oxidized. Lactate did not exert undesirable effects, except moderate hyperglycemia, and achieved comparable effects on acid-base balance to bicarbonate.
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Affiliation(s)
- Marc-Daniel Bollmann
- Surgical Intensive Care Unit, University Hospital CHUV, 1011 Lausanne, Switzerland
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Kazui H, Hashimoto M, Hirono N, Mori E. Nature of personal semantic memory: evidence from Alzheimer's disease. Neuropsychologia 2003; 41:981-8. [PMID: 12667533 DOI: 10.1016/s0028-3932(02)00322-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Personal semantic memory is factual knowledge about a person's own past. Although personal semantic memory is assumed to have features of both semantic memory and episodic memory, the relationship to episodic memory and to semantic memory have not been well documented. In patients with Alzheimer's disease, episodic memory, semantic memory, and personal semantic memory are all defective. In this study, the hypothesis that defective personal semantic memory is related to both semantic and episodic memory dysfunction was tested in patients with Alzheimer's disease. Functions of episodic, semantic, and personal semantic memory were examined by using the Wechsler Memory Scale-Revised (WMS-R), subtests of the WAIS-R (Information, Vocabulary, Comprehension and Similarities), and the Family Line Test (FLT) in 62 patients who met the NINCDS/ADRDA criteria for probable Alzheimer's disease. Specific effects of episodic and semantic memory on personal semantic memory were examined by using multiple linear regression analysis with the total score of the FLT as the dependent variable and the WMS-R Delayed Recall weighted sum score and the WAIS-R Semantic Memory score (a composite of standardized scores of the four subtests) as the independent variables. Personal semantic memory function was significantly correlated with both the episodic and semantic memory functions, after controlling age, sex, educational attainment, and severity of dementia. This result supports the hypotheses that personal semantic memory has features of both episodic and semantic memory, and that semantic memory is transformed from episodic memory.
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Affiliation(s)
- Hiroaki Kazui
- Institute for Aging Brain and Cognitive Disorders, Hyogo Brain and Heart Center at Himeji, Himeji, Japan.
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Abstract
Clinical applications of PET studies for dementia are reviewed in this paper. At the mild and moderate stages of Alzheimer's disease (AD), glucose metabolism is reduced not only in the parietotemporal region but also in the posterior cingulate and precuneus. At the advanced stage of AD, there is also a metabolic reduction in the frontal region. In AD patients, glucose metabolism is relatively preserved in the pons, sensorimotor cortices, primary visual cortices, basal ganglia, thalamus and cerebellum. In patients with dementia with Lewy bodies, glucose metabolism in the primary visual cortices is reduced, and this reduction appears to be associated with the reduction pattern in AD patients. In patients with frontotemporal dementia, reduced metabolism in the frontotemporal region is the main feature of this disease, but reduced metabolism in the basal ganglia, and/or parietal metabolic reduction can be associated with the frontotemporal reduction. When corticobasal degeneration is associated with dementia, the reduction pattern of dementia is similar to the reduction pattern in AD and the hallmarks of diagnosing corticobasal degeneration associated with dementia are a reduced metabolism in the primary sensorimotor region and/or basal ganglia and an asymmetric reduction in the two hemispheres. FDG-PET is a very useful tool for the diagnosis of early AD and for the differential diagnosis of dementia. I also describe clinical applications of PET for the diagnosis of dementia in Japan.
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Affiliation(s)
- Kazunari Ishii
- Department of Radiology and Nuclear Medicine, Hyogo Brain and Heart Center, Himeji, Japan.
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Abstract
PURPOSE OF REVIEW The diagnosis of dementia rests on an improved knowledge and a better detection of early impairments, to which functional imaging can certainly contribute. RECENT FINDINGS Progress has been observed at different levels. First, the understanding of different dementias has benefited from explorations of the neural substrate of dementia symptoms and from research into new markers. Second, diverse variables (clinical, anatomical, biochemical) have been related to impaired cerebral activity in Alzheimer's disease and other dementias, and progress in image analysis and in multimodal data acquisition has allowed a better understanding of the significance of brain activity disturbances. Third, functional imaging has been applied in well-designed clinical studies, and has provided important arguments for the diagnosis of characteristic clinical syndromes in the dementias. SUMMARY The functioning of neural networks responsible for clinical symptoms in dementia remains an important research topic for functional imaging. The development of new tracers and new techniques for image processing should also improve the usefulness of brain imaging as a diagnostic tool.
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Affiliation(s)
- Eric Salmon
- Department of Neurology and Cyclotron Research Centre, University of Liege, B30 Sart Tilman, 4000 Liege, Belgium.
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Desgranges B, Baron JC, Lalevée C, Giffard B, Viader F, de La Sayette V, Eustache F. The neural substrates of episodic memory impairment in Alzheimer's disease as revealed by FDG-PET: relationship to degree of deterioration. Brain 2002; 125:1116-24. [PMID: 11960900 DOI: 10.1093/brain/awf097] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In a previous investigation, we raised the hypothesis that in Alzheimer's disease the cerebral structures implicated in episodic memory deficits may differ according to the severity of cognitive impairment. To test this hypothesis, Story Recall test scores and PET measurements of resting cerebral glucose utilization, a measure of synaptic integrity, were obtained in 40 patients. Using SPM96 (statistical parametric mapping 1996), positive correlations between the two sets of data were calculated on a voxel basis, first in the whole patient sample and then separately in the two subgroups of 20 patients differing in Mini-Mental State Examination score, i.e. those with least impaired and those with most impaired performance ('less severe' and 'more severe' subgroups, respectively). In the whole sample, significant correlations (P < 0.05, corrected for multiple tests) involved bilaterally not only several limbic structures (the hippocampal/rhinal cortex regions, posterior cingulate gyrus and retrosplenial cortex) but also, and less expectedly, some temporo-occipital association areas. However, the subgroup analysis disclosed that, in the less severe subgroup, all significant correlations (P < 0.005, uncorrected) were restricted to the parahippocampal gyrus and retrosplenial cortex, in accordance with both the distribution of changes in tau in early Alzheimer's disease and the known involvement of this network in normal and impaired memory function, while in the more severe subgroup they mainly involved the left temporal neocortex, which is known to be implicated in semantic memory. These findings suggest that, when episodic memory is mildly impaired, limbic functions are still sufficient to subserve the remaining performance, whereas with more severe memory deficit resulting from accumulated pathology the neocortical areas that are normally involved in semantic memory are recruited, perhaps as a form of (inadequate) compensatory mechanism.
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Affiliation(s)
- Béatrice Desgranges
- EMI INSERM-Unive Laboratoire de Neuropsychologie, CHU Côte de Nacre, Centre CYCERON, France.
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