Discrepancy Between the Degree of Cognitive Impairment and Brain Imaging Abnormalities in Alzheimer’s Disease Patients Is Associated with Cognitive Reserve

2021 ◽  
pp. 1-9
Author(s):  
Tomohiko Sato ◽  
Haruo Hanyu ◽  
Yumi Koyama ◽  
Haruka Horita ◽  
Toshinori Aoki ◽  
...  

Background: In Alzheimer’s disease (AD) patients, the severity of cognitive impairment is thought to correlate with the degree of brain imaging abnormalities. However, some patients show only mild cognitive deficit, despite severe brain atrophy on magnetic resonance imaging (MRI) or marked hypoperfusion in the cerebral cortices on single-photon emission computed tomography (SPECT). This suggests that cognitive reserve (CR) can compensate for the clinical manifestations of AD in patients with extensive brain pathology. Objective: We aimed to determine whether this discrepancy between cognitive and imaging findings is associated with CR. Methods: Factors associated with the discrepancy between the degree of cognitive impairment and MRI (medial temporal lobe atrophy) and SPECT (posterior cerebral hypoperfusion) findings were analyzed in 135 patients with probable AD. Factors as proxies for CR included education, occupation, leisure activity, comorbidities, frailty, and other demographics. The discrepancy index (DI) was calculated as the difference between the degree of imaging abnormalities and the degree of cognitive dysfunction. Results: Multiple regression analysis showed that leisure activity and education were significantly associated with the discrepancy between cognitive and imaging findings. When the level of CR was determined based on leisure activity and education, the high-CR group showed a significantly larger DI than the moderate- and low-CR groups. Conclusion: The discrepancy between cognitive and imaging findings in patients with AD is associated with CR, measured using a combination of two indicators, i.e., leisure activity and education. Therefore, lifestyle interventions may delay the appearance of clinical symptoms resulting from underlying AD pathology, by increasing CR.

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Teruyuki Matsuoka ◽  
Jin Narumoto ◽  
Keisuke Shibata ◽  
Aiko Okamura ◽  
Shogo Taniguchi ◽  
...  

The aim of this study was to examine the effect of toki-shakuyaku-san (TSS) on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using single-photon emission computed tomography (SPECT). All subjects were administered TSS (7.5 g/day) for eight weeks. SPECT and evaluations using the Mini Mental State Examination (MMSE), Neuropsychiatric Inventory, and Physical Self-Maintenance Scale were performed before and after treatment with TSS. Three patients with MCI and five patients with AD completed the study. No adverse events occurred during the study period. After treatment with TSS, regional cerebral blood flow (rCBF) in the posterior cingulate was significantly higher than that before treatment. No brain region showed a significant decrease in rCBF. TSS treatment also tended to improve the score for orientation to place on the MMSE. These results suggest that TSS could be useful for treatment of MCI and AD.


2021 ◽  
Vol 33 (S1) ◽  
pp. 90-91
Author(s):  
Alena Sidenkova

IntroductionThe aging processes are accelerating in all regions of the world. The involvement of older people in production and social processes determines the need to maintain a high level of social and psychological adaptation, despite the progressive pathology of the brain caused by its aging. This increases the relevance of research related to the study of biological reserves of the brain and psychological and social mechanisms of human adaptation in late adulthood. The risk of developing cognitive disorders is not fatal. According to some observations, even in the hippocampal type of UKR, despite the content of amyloid in the brain, the functional and social activity of the elderly remains high. Prospective studies show that people with high cognitive reserve have a lower risk of developing dementia. Cognitive reserve is the brain’s resistance to damage. Cognitive reserve is the ability of the brain to cope with the consequences of damage caused by external influences, brain stroke, chronic brain ischemia, neurodegenerative diseases, and age-related changes. Cognitive reserve is the brain’s ability to functionally compensate for and minimize clinical manifestations of cognitive impairment. The mechanisms of cognitive reserve in normal and Alzheimer’s disease are different. In healthy older adults, a higher cognitive reserve correlates with larger brain sizes and effective strategies for performing cognitive tasks. In the early stages of Alzheimer’s disease and Alzheimer’s disease, the size of the brain decreases. But high brain activity helps preserve cognitive resources. Excessive brain activity in dementia is a compensatory mechanism. This is confirmed by the results of functional magnetic resonance imaging of the brain. Of course, the degree of brain atrophy is a predisposing factor for dementia, but it is not a mandatory factor for cognitive decline. So, the symptoms of dementia do not appear until you have crossed the critical border of damage to the brain substance. Progressive brain atrophy underlies the clinical manifestations of dementia in neurodegenerative diseases, but the correlation between the degree of brain damage and cognitive impairment is not linear.Research materials and methodsAn observational 10-year longitudinal study was conducted. In 2006, moderate cognitive impairment was found in 66 patients. The group of patients included 49 women and 49 men. Their average age in 2006 was 59.3±5.2 years. In 2006, the severity of cognitive decline was 26.2±1.9 points on the MMSE scale. This corresponds to indicators of moderate cognitive impairment. Research methods: clinical and psychopathological, psychometric, statistical. Questionnaire “Loss and acquisition of personal resources” (N. Vodopyanova, M. Stein), MMSE scale.Research resultIn 2006, amyloid was detected in the spinal fluid of all patients selected for the study group. If a patient developed dementia, they were given specific therapy. The dynamics of cognitive functions in patients was different. Mild dementia was formed in 53% of patients. Moderate dementia was formed in 10.6% of patients. Moderate cognitive impairment (pre-dementia) persisted in 36.4% of patients. Hereditary burden of dementia in patients with moderate dementia was detected 2 times more often. Back in 2006, we identified the leading sensory systems of patients. The master sensor system determines the modality of the main information flow. This is the most important part of the information that a person interacts with. This is the basis of interaction with reality. This is the basis of cognitive functions. Correlations of age-specific lesions of the corresponding sensory systems with the severity of cognitive decline were found in patients with the corresponding sensory modality (Spearman’s Correlation Coefficient-r, p<0.05): presbyacoussis – auditory r=0.667, presbyopia-visual r=0.705. The influence of psychosocial factors on the condition of patients was studied. In dementia, significant history of psychotrauma was found in 35.7%. Moderate stress was detected in the group of patients with moderate cognitive impairment in 33.3%. Moderate stress was detected in the group of patients with dementia in 83.3%. Stress of loss of life meaning was detected more often in patients with dementia 76.7%. It is important not only what stresses a person endures, but how they can cope with them. Dementia patients were statistically more likely to have unproductive coping strategies that did not help them cope adequately with stress.ConclusionsThe concept of cognitive reserve suggests possible causes of heterogeneity in the dynamics of cognitive decline in the initial stages of atrophic-degenerative brain diseases: biological causes and psychosocial causes. The concept of cognitive reserve helps to study and develop individual programs for the prevention of severe cognitive disorders.


2019 ◽  
Vol 11 (3S) ◽  
pp. 18-25 ◽  
Author(s):  
I. V. Litvinenko ◽  
A. Yu. Emelin ◽  
V. Yu. Lobzin ◽  
K. A. Kolmakova

The paper provides data on current neuroimaging techniques for diagnosing Alzheimer’s disease and vascular cognitive impairment (CN). Structural neuroimaging methods can identify potentially treatable diseases leading to dementia and assess the magnitude and localization of atrophic and cerebrovascular changes in brain tissue. Particular attention is paid to the specific signs of Alzheimer’s disease: to the visual assessment of sections and the use of various rating scales (GCA, MTA, Koedam). Vascular changes that are most significant for the development of CI are considered. A new approach to diagnosing CI is presented, by taking into account the biomarkers of amyloidosis, tauopathy, neurodegeneration, and cerebrovascular damage. The results of the authors’ own investigations using positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy, and functional magnetic resonance imaging at rest allow these techniques to be recommended for the early diagnosis of CI of different genesis.


1997 ◽  
Vol 9 (4) ◽  
pp. 389-403 ◽  
Author(s):  
Cássio M. C. Bottino ◽  
Osvaldo P. Almeida

Recent studies indicate that neuroimaging techniques such as magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography can accurately differentiate patients with Alzheimer's disease (AD) from elderly controls. This report reviews the results of neuroimaging studies of two at-risk populations: subjects with the ε4 allele of the apolipoprotein E and those with mild cognitive impairment. The results of the work published to date indicate that the presence of the ε4 allele is a risk factor for AD and that its predictive validity can be enhanced by neuropsychological and/or neuroimaging evaluation. The results also show that patients with mild cognitive impairment display a number of structural and functional imaging abnormalities that are more pronounced in the temporal and parietal lobes. We suggest that the use of neuroimaging techniques can improve the detection of subjects early in the course of AD, although the sensitivity and the specificity of this approach still await a more detailed prospective evaluation.


2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Michael A. Meyer ◽  
Stephen A. Hudock

Posterior cortical atrophy is a rare condition first described in 1988 involving progressive degeneration and atrophy of the occipital cortex, often recognized after an unexplained homonymous hemianopsia may be discovered. We report a case in association with Alzheimer’s disease in a 77-year-old female, who underwent brain single-photon emission computed tomography as well brain positron emission tomography using Florbetapir to further evaluate progressive cognitive decline. The patient had also been followed in Ophthalmology for glaucoma, where a progressive unexplained change in her visual field maps were noted over one year consistent with a progressive right homonymous hemianopsia. This rare combination of findings in association with her dementia led to a detailed review of all her imaging studies, concluding with the surprising recognition for a clear hemi-atrophy of the primary left occipital cortex was occurring, consistent with Alzheimer’s disease affecting the primary visual cortex. Further awareness of this disease pattern is needed, as Alzheimer’s disease typically does not affect the primary visual cortex; other conditions to consider in general include Lewy Body dementia, cortico-basal degeneration and prion disease.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Tobias Gustavsson ◽  
Stina Syvänen ◽  
Paul O’Callaghan ◽  
Dag Sehlin

Abstract Background Alzheimer’s disease (AD) immunotherapy with antibodies targeting amyloid-β (Aβ) has been extensively explored in clinical trials. The aim of this study was to study the long-term brain distribution of two radiolabeled monoclonal Aβ antibody variants – RmAb158, the recombinant murine version of BAN2401, which has recently demonstrated amyloid removal and reduced cognitive decline in AD patients, and the bispecific RmAb158-scFv8D3, which has been engineered for enhanced brain uptake via transferrin receptor-mediated transcytosis. Methods A single intravenous injection of iodine-125 (125I)-labeled RmAb158-scFv8D3 or RmAb158 was administered to AD transgenic mice (tg-ArcSwe). In vivo single-photon emission computed tomography was used to investigate brain retention and intrabrain distribution of the antibodies over a period of 4 weeks. Activity in blood and brain tissue was measured ex vivo and autoradiography was performed in combination with Aβ and CD31 immunostaining to investigate the intrabrain distribution of the antibodies and their interactions with Aβ. Results Despite faster blood clearance, [125I]RmAb158-scFv8D3 displayed higher brain exposure than [125I]RmAb158 throughout the study. The brain distribution of [125I]RmAb158-scFv8D3 was more uniform and coincided with parenchymal Aβ pathology, while [125I]RmAb158 displayed a more scattered distribution pattern and accumulated in central parts of the brain at later times. Ex vivo autoradiography indicated greater vascular escape and parenchymal Aβ interactions for [125I]RmAb158-scFv8D3, whereas [125I]RmAb158 displayed retention and Aβ interactions in lateral ventricles. Conclusions The high brain uptake and uniform intrabrain distribution of RmAb158-scFv8D3 highlight the benefits of receptor-mediated transcytosis for antibody-based brain imaging. Moreover, it suggests that the alternative transport route of the bispecific antibody contributes to improved efficacy of brain-directed immunotherapy.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Hidetoshi Watari ◽  
Yutaka Shimada ◽  
Mie Matsui ◽  
Chihiro Tohda

Background and Aims. We previously reported that the administration of traditional Japanese medicines, kihito (Gui-Pi-Tang in Chinese) and kamikihito (Jia-Wei-Gui-Pi-Tang in Chinese), to Alzheimer’s disease (AD) model mice improved memory impairment. There are a few reports that show kihito and kamikihito have a beneficial effect on the cognitive function of AD patients in clinical studies. However, these studies are not comparative and are retrospective studies; thus, more evidence is needed. Therefore, we conducted an open-label, crossover designed clinical trial to investigate the effect of kihito on cognitive function of AD patients. Methods. The inclusion criteria for eligible patients were as follows: (1) imaging diagnosis (magnetic resonance imaging and single-photon emission computed tomography) of AD, (2) a treatment regimen including acetylcholinesterase inhibitors (ChEIs), and (3) a Mini-Mental State Examination (MMSE) score ≥15. The exclusion criteria were as follows: (1) change in ChEI dosage, (2) memantine usage, and (3) MMSE score < 15. To prevent bias in age and baseline cognitive function, patients were divided into two groups: the first group received 2.5 g of kihito extract 3 times/day during the first half of the study (weeks 0-16) and the second group received the same dose of kihito during the second half of the study (weeks 17-32). ChEI dosage did not change during the study period. Patients underwent a cognitive function test during weeks 0, 16, and 32. Cognitive function was evaluated by Japanese versions of the Mini-Mental State Examination (MMSE-J) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS-J) test. Results. Ten patients completed the clinical trial (4 males, 6 females, average age 71.7 years). MMSE-J scores significantly increased during the kihito intake period. RBANS-J test scores had a slight improvement during the kihito intake period compared with the ChEI alone treatment period, but no significant changes were observed. Conclusion. Kihito improves cognitive function in AD patients.


2019 ◽  
Vol 34 (5) ◽  
pp. 314-321
Author(s):  
Miwako Takahashi ◽  
Tomoko Tada ◽  
Tomomi Nakamura ◽  
Keitaro Koyama ◽  
Toshimitsu Momose

This study aimed to assess efficacy and limitations of regional cerebral blood flow imaging using single-photon emission computed tomography (rCBF-SPECT) in the diagnosis of Alzheimer’s disease (AD) with amyloid-positron emission tomography (amyloid-PET). Thirteen patients, who underwent both rCBF-SPECT and amyloid-PET after clinical diagnosis of AD or mild cognitive impairment, were retrospectively identified. The rCBF-SPECTs were classified into 4 grades, from typical AD pattern to no AD pattern of hypoperfusion; amyloid-beta (Aβ) positivity was assessed by amyloid-PET. Four patients were categorized into a typical AD pattern on rCBF-SPECT, and all were Aβ+. The other 9 patients did not exhibit a typical AD pattern; however, 4 were Aβ+. The Mini-Mental State Examination score and Clinical Dementia Rating scale were not significantly different between Aβ+ and Aβ– patients. A typical AD pattern on rCBF-SPECT can reflect Aβ+; however, if not, rCBF-SPECT has a limitation to predict amyloid pathology.


1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S123-S126 ◽  
Author(s):  
H. J. Testa ◽  
J. S. Snowden ◽  
D. Neary ◽  
R. A. Shields ◽  
A. W. I. Burjan ◽  
...  

The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution [99mTc]–HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias.


2015 ◽  
Vol 39 (5-6) ◽  
pp. 360-367 ◽  
Author(s):  
Megumi Haji ◽  
Noriyuki Kimura ◽  
Takuya Hanaoka ◽  
Yasuhiro Aso ◽  
Makoto Takemaru ◽  
...  

Background: This study examined regional cerebral blood flow (rCBF) in Alzheimer's disease (AD) patients with and without subclinical hypothyroidism (SCH). Methods: Eleven AD patients with SCH and 141 AD patients without SCH underwent brain perfusion single photon emission computed tomography (SPECT). The SPECT data were analyzed by statistical parametric mapping (SPM8) and FineSRT. Results: AD patients with SCH showed a significantly decreased rCBF mainly in the temporal lobe and thalamus, whereas those without SCH showed a significantly decreased rCBF in the parietotemporal lobe and cingulate gyrus as well as the frontal lobe. Conclusion: Our findings suggest that SCH may affect cerebral perfusion in regions associated with the memory function.


Sign in / Sign up

Export Citation Format

Share Document