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Hoshi H, Hirata Y, Fukasawa K, Kobayashi M, Shigihara Y. Oscillatory characteristics of resting-state magnetoencephalography reflect pathological and symptomatic conditions of cognitive impairment. Front Aging Neurosci 2024; 16:1273738. [PMID: 38352236 PMCID: PMC10861731 DOI: 10.3389/fnagi.2024.1273738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024] Open
Abstract
Background Dementia and mild cognitive impairment are characterised by symptoms of cognitive decline, which are typically assessed using neuropsychological assessments (NPAs), such as the Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB). Magnetoencephalography (MEG) is a novel clinical assessment technique that measures brain activities (summarised as oscillatory parameters), which are associated with symptoms of cognitive impairment. However, the relevance of MEG and regional cerebral blood flow (rCBF) data obtained using single-photon emission computed tomography (SPECT) has not been examined using clinical datasets. Therefore, this study aimed to investigate the relationships among MEG oscillatory parameters, clinically validated biomarkers computed from rCBF, and NPAs using outpatient data retrieved from hospital records. Methods Clinical data from 64 individuals with mixed pathological backgrounds were retrieved and analysed. MEG oscillatory parameters, including relative power (RP) from delta to high gamma bands, mean frequency, individual alpha frequency, and Shannon's spectral entropy, were computed for each cortical region. For SPECT data, three pathological parameters-'severity', 'extent', and 'ratio'-were computed using an easy z-score imaging system (eZIS). As for NPAs, the MMSE and FAB scores were retrieved. Results MEG oscillatory parameters were correlated with eZIS parameters. The eZIS parameters associated with Alzheimer's disease pathology were reflected in theta power augmentation and slower shift of the alpha peak. Moreover, MEG oscillatory parameters were found to reflect NPAs. Global slowing and loss of diversity in neural oscillatory components correlated with MMSE and FAB scores, whereas the associations between eZIS parameters and NPAs were sparse. Conclusion MEG oscillatory parameters correlated with both SPECT (i.e. eZIS) parameters and NPAs, supporting the clinical validity of MEG oscillatory parameters as pathological and symptomatic indicators. The findings indicate that various components of MEG oscillatory characteristics can provide valuable pathological and symptomatic information, making MEG data a rich resource for clinical examinations of patients with cognitive impairments. SPECT (i.e. eZIS) parameters showed no correlations with NPAs. The results contributed to a better understanding of the characteristics of electrophysiological and pathological examinations for patients with cognitive impairments, which will help to facilitate their co-use in clinical application, thereby improving patient care.
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Affiliation(s)
- Hideyuki Hoshi
- Precision Medicine Centre, Hokuto Hospital, Obihiro, Japan
| | - Yoko Hirata
- Department of Neurosurgery, Kumagaya General Hospital, Kumagaya, Japan
| | | | - Momoko Kobayashi
- Precision Medicine Centre, Kumagaya General Hospital, Kumagaya, Japan
| | - Yoshihito Shigihara
- Precision Medicine Centre, Hokuto Hospital, Obihiro, Japan
- Precision Medicine Centre, Kumagaya General Hospital, Kumagaya, Japan
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Zhang H, Wang Y, Lyu D, Li Y, Li W, Wang Q, Li Y, Qin Q, Wang X, Gong M, Jiao H, Liu W, Jia J. Cerebral blood flow in mild cognitive impairment and Alzheimer's disease: A systematic review and meta-analysis. Ageing Res Rev 2021; 71:101450. [PMID: 34419673 DOI: 10.1016/j.arr.2021.101450] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/05/2021] [Accepted: 08/17/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND Reduced cerebral blood flow (CBF) contributes to the pathophysiology of Alzheimer's disease (AD). However, it is unclear whether there is a spatial-temporal-specific pattern of changed CBF in AD progression. METHODS We systematically screened literature databases for cross-sectional and longitudinal studies reporting resting CBF or CBF velocity (CBFv) among patients with AD, mild cognitive impairment (MCI), and healthy controls (HCs). Standardised mean differences (SMDs) for CBF and mean differences (MDs) for CBFv were calculated. Quality assessments, meta-analysis, subgroup analysis, and meta-regression were subsequently performed (PROSPERO: CRD42020207548). RESULTS Overall, 244 studies comprising 13,644 participants and 60 regions were included. Compared with HCs, AD subjects had decreased resting CBF throughout the brain (SMD range: -1.87 to -0.32), especially within the posterior cingulate and temporal-parietal regions. However, MCI subjects presented decreased CBF in ten regions with modest effects (SMD range: -0.86 to -0.25), especially in the precuneus. We identified the decreased CBF in the temporal, parietal, and hippocampal regions was associated with the lower AD Mini-Mental State Examination scores. CONCLUSIONS Our findings suggest that the spatial-temporal pattern of CBF decreased from the precuneus, posterior cingulate and temporal-parietal regions to broader areas with progression from HC to MCI to AD, supporting the incorporation of CBF into the AD research framework.
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Yu CC, Chan HP, Ting CY. Evaluation of the Image Feature Analysis Techniques by Image Strength Fluctuation for Alzheimer’s Disease. JOURNAL OF MEDICAL IMAGING AND HEALTH INFORMATICS 2021. [DOI: 10.1166/jmihi.2021.3568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This article compares the effectiveness of both image strength fluctuation (ISF) and statistical parametric mapping (SPM), which is used for analyzing cerebral blood flow traced by single photon emission computed tomography (SPECT) in patients with Alzheimer’s disease (AD). This
is a retrospective study that uses the built-in SPECT template of the SPM software to analyze the differences in cerebral blood flow (CBF) between two groups after using the ISF and SPM software to normalize and smooth the data. Using Z score analysis, the ISF method revealed unusual fluctuations
in the range of image strength. The hot and cold areas were considered to be the difference between normal and abnormal images and the analysis of the gray intensities of cold and hot areas was used to show that cold and hot were in characteristic locations that correlate with brain functional
areas. The results of the SPM analysis revealed significantly reduced blood flow in the bilateral inferior parietal lobule, the middle or superior gyrus of the left temporal lobe, the superior gyrus and the sub-lobar insula of the right temporal lobe. The results from SPM were similar to those
obtained with the ISF and indicated the same regions (83.3%).
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Affiliation(s)
- Chang-Ching Yu
- Department of Nuclear Medicine, Kaohsiung Veterans General Hospital, Kaohsiung City, 813414, Taiwan
| | - Hung-Pin Chan
- Department of Nuclear Medicine, Kaohsiung Veterans General Hospital, Kaohsiung City, 813414, Taiwan
| | - Chien-Yi Ting
- Department of Medical Imaging and Radiology, Shu-Zen Junior College of Medicine and Management, Kaohsiung City, 821004, Taiwan
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Eguchi A, Kimura N, Aso Y, Yabuuchi K, Ishibashi M, Hori D, Sasaki Y, Nakamichi A, Uesugi S, Jikumaru M, Sumi K, Shimomura T, Matsubara E. Relationship Between the Japanese Version of the Montreal Cognitive Assessment and PET Imaging in Subjects with Mild Cognitive Impairment. Curr Alzheimer Res 2019; 16:852-860. [PMID: 31385770 DOI: 10.2174/1567205016666190805155230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 05/28/2019] [Accepted: 07/23/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND The Montreal Cognitive Assessment (MoCA) test has high sensitivity and specificity for detecting mild cognitive impairment or early dementia. How the MoCA score relates to findings of positron emission tomography imaging, however, remains unclear. OBJECTIVE This prospective study examined the relationship between the Japanese version of the MoCA (MoCA-J) test and brain amyloid deposition or cerebral glucose metabolism among subjects with mild cognitive impairment. METHODS A total of 125 subjects with mild cognitive impairment underwent the MoCA-J test, and amyloid- and 18F-fluorodeoxyglucose- positron emission tomography. Linear correlation analysis and multiple linear regression analysis were conducted to investigate the relationship between the MoCA-J score and demographic characteristics, amyloid deposition, and cerebral glucose metabolism. Moreover, Statistical Parametric Mapping 8 was used for a voxel-wise regression analysis of the MoCA-J score and cerebral glucose metabolism. RESULTS The MoCA-J score significantly correlated with age, years of education, and the Mini-Mental State Examination score. After adjusting for age, sex, and education, the MoCA-J score significantly correlated negatively with amyloid retention (β= -0.174, p= 0.031) and positively with cerebral glucose metabolism (β= 0.183, p= 0.044). Statistical Parametric Mapping showed that Japanese version of MoCA score correlated with glucose metabolism in the bilateral frontal and parietal lobes, and the left precuneus. CONCLUSION The total MoCA-J score correlated with amyloid deposition and frontal and parietal glucose metabolism in subjects with mild cognitive impairment. Our findings support the usefulness of the MoCA-J test for screening subjects at high risk for Alzheimer's disease.
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Affiliation(s)
- Atsuko Eguchi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Noriyuki Kimura
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Yasuhiro Aso
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Kenichi Yabuuchi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Masato Ishibashi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Daiji Hori
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Yuuki Sasaki
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Atsuhito Nakamichi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Souhei Uesugi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Mika Jikumaru
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Kaori Sumi
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
| | - Tsuyoshi Shimomura
- Department of Neurosurgery, Oita University, Faculty of Medicine, Yufu, Oita 879-5593, Japan
| | - Etsuro Matsubara
- Department of Neurology, Faculty of Medicine, Oita University, Yufu, Oita 879-5593, Japan
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Uchida S, Kagitani F. Effect of basal forebrain stimulation on extracellular acetylcholine release and blood flow in the olfactory bulb. J Physiol Sci 2018; 68:415-423. [PMID: 28500439 PMCID: PMC10718006 DOI: 10.1007/s12576-017-0542-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/30/2017] [Indexed: 10/19/2022]
Abstract
The olfactory bulb receives cholinergic basal forebrain input, as does the neocortex; however, the in vivo physiological functions regarding the release of extracellular acetylcholine and regulation of regional blood flow in the olfactory bulb are unclear. We used in vivo microdialysis to measure the extracellular acetylcholine levels in the olfactory bulb of urethane-anesthetized rats. Focal chemical stimulation by microinjection of L-glutamate into the horizontal limb of the diagonal band of Broca (HDB) in the basal forebrain, which is the main source of cholinergic input to the olfactory bulb, increased extracellular acetylcholine release in the ipsilateral olfactory bulb. When the regional cerebral blood flow was measured using laser speckle contrast imaging, the focal chemical stimulation of the HDB did not significantly alter the blood flow in the olfactory bulb, while increases were observed in the neocortex. Our results suggest a functional difference between the olfactory bulb and neocortex regarding cerebral blood flow regulation through the release of acetylcholine by cholinergic basal forebrain input.
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Affiliation(s)
- Sae Uchida
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan.
| | - Fusako Kagitani
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan
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Berggren Å, Gustafson L, Höglund P, Johanson A. A long-term longitudinal follow-up of depressed patients treated with ECT with special focus on development of dementia. J Affect Disord 2016; 200:15-24. [PMID: 27111069 DOI: 10.1016/j.jad.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 04/11/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND In this study, the long term effects of ECT on patients with depression were investigated through repeated rCBF and EEG measures as well as clinical characteristics over several years. The aim of the investigation was to establish an association with the eventual development of dementia. METHOD A cohort of forty-nine patients (21 men and 28 women) with a mean age of 61 years underwent ECT. A subsequent evaluation from medical records and three rating-scales for diagnosis of Alzheimer´s disease (AD), fronto-temporal dementia (FTD), and for vascular dementia (VaD), revealed that 17 patients (8 men and 9 women), had developed dementia. These cases were compared to the 32 patients (13 men and 19 women), who had not developed dementia. RESULT Initially, the dementia group, compared to those without dementia, showed a lower hemispheric CBF (left side; p=.029, right side; p=.033), and a lower mean occipital EEG frequency (p=.048). After the first ECT-series, an increase in general disorientation (p=.015), personal disorientation (p=.009), and subsequently, spatial disorientation (p=.021), were seen in the dementia group. There were no differences in the clinical response or remissions after treatment in the groups. LIMITATIONS The small sample-size, which did not allow for the comparison of characteristics between different dementias. CONCLUSION Depressed older patients who later developed dementia showed lower hemispheric mean level of CBF and EEG mean frequency before ECT and higher personal and spatial disorientation following ECT.
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Affiliation(s)
- Åke Berggren
- Department of Psychology, Lund University, Lund, Sweden; Department of Anaesthesia, Blekinge Hospital, Karlskrona, Sweden; Department of Psychiatry, Clinical Sciences, Lund University, Lund, Sweden.
| | - Lars Gustafson
- Department of Geriatric Psychiatry, Clinical Sciences, Lund University, Lund, Sweden
| | - Peter Höglund
- Department of Laboratory Medicine, Clinical Chemistry & Pharmacology, Lund University, Lund, Sweden
| | - Aki Johanson
- Department of Psychology, Lund University, Lund, Sweden; Department of Psychiatry, Clinical Sciences, Lund University, Lund, Sweden
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Uchida S. Cholinergic Vasodilative System in the Cerebral Cortex: Effects of Acupuncture and Aging. J Acupunct Meridian Stud 2014; 7:173-9. [DOI: 10.1016/j.jams.2014.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 02/25/2014] [Indexed: 02/02/2023] Open
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Santos-Galduróz RF, Bueno OF, Yamaga LI, Armani F, Galduróz JCF. Influence of blood viscosity to cerebral blood flow in older humans compared to young subjects. Clin Neurophysiol 2012; 123:117-20. [DOI: 10.1016/j.clinph.2011.05.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 04/21/2011] [Accepted: 05/24/2011] [Indexed: 11/26/2022]
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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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Abstract
Cumulative evidence implicates hypertension in the pathogenesis of Alzheimer disease. Although it may not presently be possible to completely differentiate the effects of treatment and control of hypertension itself from those of the medication used to achieve such treatment goals, efforts directed at the treatment and control of hypertension can have significant public health impact.
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Affiliation(s)
- Thomas Olabode Obisesan
- Division of Geriatrics, Department of Medicine, Howard University Hospital, 2041 Georgia Avenue, NW, Washington, DC 20060, USA.
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Total Mini-Mental State Examination score and regional cerebral blood flow using Z score imaging and automated ROI analysis software in subjects with memory impairment. Ann Nucl Med 2008; 22:539-42. [DOI: 10.1007/s12149-007-0148-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Accepted: 12/17/2007] [Indexed: 11/27/2022]
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Tanaka K, Yamada Y, Kobayashi Y, Sonohara K, Machida A, Nakai R, Kozaki K, Toba K. Improved cognitive function, mood and brain blood flow in single photon emission computed tomography following individual reminiscence therapy in an elderly patient with Alzheimer's disease. Geriatr Gerontol Int 2007. [DOI: 10.1111/j.1447-0594.2007.00418.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Higashi K, Rakugi H, Yu H, Moriguchi A, Shintani T, Ogihara T. Effect of kihito extract granules on cognitive function in patients with Alzheimer's-type dementia. Geriatr Gerontol Int 2007. [DOI: 10.1111/j.1447-0594.2007.00407.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Fong TG, Bogardus ST, Daftary A, Auerbach E, Blumenfeld H, Modur S, Leo-Summers L, Seibyl J, Inouye SK. Cerebral perfusion changes in older delirious patients using 99mTc HMPAO SPECT. J Gerontol A Biol Sci Med Sci 2007; 61:1294-9. [PMID: 17234823 DOI: 10.1093/gerona/61.12.1294] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prior studies describe variable cerebral blood flow changes in delirium. This study aims to investigate cerebral blood flow changes in older hospitalized patients with delirium, the population in which most cases of delirium occur. METHODS Participants included hospitalized general medical patients aged 65 years and older with documented delirium and no relevant medical conditions or preexisting abnormalities on neuroimaging prospectively studied using 99mTc HMPAO single photon emission computed tomography (SPECT) scans obtained during and after resolution of delirium. Twenty-two patients enrolled in the study, of whom six completed both scans. All participants underwent neuropsychological assessment immediately prior to SPECT scanning. SPECT images were compared across all participants during delirium; for patients completing paired scans, within-patient comparisons were made. RESULTS Visual assessment of SPECT scans revealed perfusion abnormalities in frontal (5 participants) or parietal regions (6 participants); scans were normal in 11 participants (50%). Region-of-interest analysis identified reduced blood flow (p <.01) in the left inferior frontal, right temporal, right occipital, and pontine regions. Analysis of paired scans revealed reversible abnormalities in three participants (p <.001), with decreased right parietal perfusion in two participants and increased left parietal perfusion in one participant. CONCLUSIONS The results of this study of a small group of general medical patients are suggestive that frontal or parietal cerebral perfusion abnormalities occur in delirium, and these findings need to be confirmed by future, larger studies. These results may help to improve basic understanding of delirium pathophysiology, to identify long-term changes, and to evaluate response to treatment over time.
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Affiliation(s)
- Tamara G Fong
- Department of Neurlogy, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
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Apostolova LG, Lu PH, Rogers S, Dutton RA, Hayashi KM, Toga AW, Cummings JL, Thompson PM. 3D mapping of mini-mental state examination performance in clinical and preclinical Alzheimer disease. Alzheimer Dis Assoc Disord 2007; 20:224-31. [PMID: 17132966 DOI: 10.1097/01.wad.0000213857.89613.10] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Mini-mental State Examination (MMSE) is a brief cognitive screening instrument frequently used to track Alzheimer disease (AD) progression. We investigated the structural neuroimaging correlates of MMSE performance in patients with clinical and preclinical AD. We analyzed structural magnetic resonance imaging data from 29 probable AD and 5 MCI patients who later converted to probable AD using an advanced 3D cortical mapping technique. MMSE scores were entered as covariates in a general linear model that predicted the gray matter density at each cortical surface point. The results were corrected for multiple comparisons by permutation testing. The global permutation-corrected significance for the maps linking gray matter loss and cognitive decline was P=0.005 for the left and P=0.012 for the right hemisphere. Strongest correlations between MMSE score and gray matter integrity were seen in the entorhinal, parahippocampal, precuneus, superior parietal, and subgenual cingulate/orbitofrontal cortices. Significant correlations were also seen bilaterally in the temporal, the middle frontal and the left angular and supramarginal gyri. As a global cognitive measure, MMSE depends on the integrity of widely distributed cortical areas in both brain hemispheres with left-sided predominance.
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Affiliation(s)
- Liana G Apostolova
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
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Eggermont L, Swaab D, Luiten P, Scherder E. Exercise, cognition and Alzheimer's disease: More is not necessarily better. Neurosci Biobehav Rev 2006; 30:562-75. [PMID: 16359729 DOI: 10.1016/j.neubiorev.2005.10.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Revised: 09/16/2005] [Accepted: 10/27/2005] [Indexed: 01/01/2023]
Abstract
Regional hypoperfusion, associated with a reduction in cerebral metabolism, is a hallmark of Alzheimer's disease (AD) and contributes to cognitive decline. Cerebral perfusion and hence cognition can be enhanced by exercise. The present review describes first how the effects of exercise on cerebral perfusion in AD are mediated by nitric oxide (NO) and tissue-type plasminogen activator, the release of which is regulated by NO. A conclusion of clinical relevance is that exercise may not be beneficial for the cognitive functioning of all people with dementia if cardiovascular risk factors are present. The extent to which cardiovascular risk factors play a role in the selection of older people with dementia in clinical studies will be addressed in the second part of the review in which the effects of exercise on cognition are presented. Only eight relevant studies were found in the literature, emphasizing the paucity of studies in this field. Positive effects of exercise on cognition were reported in seven studies, including two that excluded and two that included patients with cardiovascular risk factors. These findings suggest that cardiovascular risk factors do not necessarily undo the beneficial effects of exercise on cognition in cognitively impaired people. Further research is called for, in view of the limitations of the clinical studies reviewed here.
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Affiliation(s)
- Laura Eggermont
- Department of Clinical Neuropsychology, Vrije Universiteit, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands.
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Salmon* E, Lespagnard* S, Marique P, Peeters F, Herholz K, Perani D, Holthoff V, Kalbe E, Anchisi D, Adam S, Collette F, Garraux G. Cerebral metabolic correlates of four dementia scales in Alzheimer’s disease. J Neurol 2005. [DOI: 10.1007/s00415-005-0961-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Salmon E, Lespagnard S, Marique P, Peeters F, Herholz K, Perani D, Holthoff V, Kalbe E, Anchisi D, Adam S, Collette F, Garraux G. Cerebral metabolic correlates of four dementia scales in Alzheimer's disease. J Neurol 2005; 252:283-90. [PMID: 16189724 DOI: 10.1007/s00415-005-0551-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2003] [Revised: 03/09/2004] [Accepted: 05/10/2004] [Indexed: 10/25/2022]
Abstract
Different scales can be used to evaluate dementia severity in Alzheimer's disease (AD). They do assess different cognitive or functional abilities, but their global scores are frequently in mutual correlation. Functional imaging provides an objective method for the staging of dementia severity. Positron emission tomography was used to assess the relationship between brain metabolism and four dementia scales that reflect a patient's global cognitive abilities (mini mental state), caregiver's evaluation of cognitive impairment (newly designed scale), daily living functioning (instrumental activities of daily living) and global dementia (clinical dementia rating). We wondered whether different clinical dementia scales would be related to severity of metabolic impairment in the same brain regions, and might reflect impairment of common cognitive processes. 225 patients with probable AD were recruited in a prospective multicentre European study. All clinical scales were related to brain metabolism in associative temporal, parietal or frontal areas. A factorial analysis demonstrated that all scales could be classified in a single factor. That factor was highly correlated to decrease of cerebral activity in bilateral parietal and temporal cortices, precuneus, and left middle frontal gyrus. This finding suggests that global scores for all scales provided similar information on the neural substrate of dementia severity. Capitalizing on the neuroimaging literature, dementia severity reflected by reduced metabolism in posterior and frontal associative areas in AD might be related to a decrease of controlled processes.
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Affiliation(s)
- E Salmon
- Cyclotron Research Centre, University of Liege, B30 Sart Tilman, 4000 Liege, Belgium.
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