Egocentric and Allocentric Spatial Cognition in Amnestic Mild Cognitive Impairment and Early Alzheimer’s Disease

2020 ◽  
Vol 83 (4) ◽  
pp. 395-403
Author(s):  
Ritsuo Hashimoto ◽  
Momoko Uechi ◽  
Noriyo Komori

Background: Topographical disorientation is one of the early symptoms of Alzheimer’s disease (AD). The nature of this symptom, however, remains unclear. Objective: The aim of the study was to investigate egocentric and allocentric spatial cognition in patients with amnestic mild cognitive impairment (aMCI) and early AD. Participants and Methods: The participants consisted of normal healthy volunteers (n = 23), patients with aMCI (n = 26), and patients with early AD (n = 22). We administered the card placing test (CPT), in which a subject was required to recreate an array of 3 cards, each of which was randomly placed on 8 grids around the individual, before (part A) and after (part B) the individual’s rotation. With this design, the CPT can reveal an individual’s ability to represent spatial information either egocentrically (CPT-A) or allocentrically (CPT-B). A qualitative analysis of errors in performing the CPT was also conducted. Results: Compared with the controls, the aMCI patients showed significantly poorer CPT-B performance, while there was no significant difference in CPT-A performance between these 2 groups. In contrast, the AD patients demonstrated significantly poorer performance on both the CPT-A and CPT-B than the controls and aMCI patients. There was no significant difference in the profile of errors on the CPT-B between the controls and aMCI patients, whereas there was a notable difference in those on the CPT-A between the controls and AD patients and the aMCI and AD patients. Conclusion: Allocentric spatial cognition is selectively impaired in aMCI patients, while an egocentric spatial cognition is additionally impaired in AD patients.

2008 ◽  
Vol 2 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Nathalia Carollina Peruzza Marchiani ◽  
Marcio Luiz Figueredo Balthazar ◽  
Fernando Cendes ◽  
Benito Pereira Damasceno

Abstract To evaluate hippocampal volume in patients with AD and aMCI, and correlate its atrophy with verbal episodic memory performance. Methods: We studied 42 individuals older than 50 years, including 14 with amnestic mild cognitive impairment (aMCI), 14 with mild Alzheimer's disease (AD) and 14 normal controls. All individuals were submitted to the Rey auditory verbal learning test (RAVLT) to evaluate episodic memory. They were also submitted to the forward (FDS) and backward digit span (BDS) subtest of WAIS-R to evaluate working memory and attention, and to the Mini Mental State Examination (MMSE). Hippocampal volumetric measurements were performed according to anatomic guidelines from a standard protocol using high-resolution T1-inversion recovery 3-mm coronal MRI slices. Hippocampal volumes (HV) were corrected for the variation in total intracranial volume. There was no significant difference between the three groups concerning age and education. Results: On RAVLT, there was a continuum between the three groups, with AD recalling less words, controls more, and aMCI subjects showing an intermediate performance on all sub-items. We found an asymmetry between HVs, with smaller mean left HV for all groups. ANOVA and post hoc Tukey's test for comparisons of HV showed a significant difference among groups, with difference between controls and both AD and aMCI, although there was no significant difference between AD and aMCI groups. Conclusions: There was a significant correlation between hippocampal volumes and scores on RAVLT, confirming that medial temporal structures are closely associated with memory performance in normal ageing as well as in aMCI and AD.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Michael Malek-Ahmadi ◽  
Amar Patel ◽  
Marwan N. Sabbagh

Recent research has demonstrated associations between statin use, KIF6 719Arg carrier status, and cholesterol levels and amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD) patients. The association between 719Arg carrier status with homocysteine (tHcy) and c-reactive protein (CRP) levels in aMCI and AD has not been previously investigated. Data from 175 aMCI and AD patients were used for the analysis. 719Arg carriers had significantly lower levels of tHcy than noncarriers (P=0.02). No significant difference in CRP levels between 719Arg carriers and noncarriers was present (P=0.37). Logistic regression yielded no significant effect for 719Arg status on CRP [OR = 1.79 (0.85, 3.83),P=0.13] but did demonstrate a significant effect for tHcy [OR = 0.44 (0.23, 0.83),P=0.01] after adjusting for ApoEε4carrier status, age, gender, and statin use. This study is the first to explore the relationship between KIF6 719Arg carrier status with tHcy and CRP levels. 719Arg carriers were more likely to have normal tHcy levels after adjusting for ApoEε4status, age, gender, and statin use. These results suggest that the KIF6 gene might influence cardiovascular pathways associated with AD.


2020 ◽  
Author(s):  
Liming Zhang ◽  
Ting Shen ◽  
Hongmei An ◽  
Canxing Yuan ◽  
Jianwen Yan ◽  
...  

Abstract Background Mild cognitive impairment (MCI) is generally considered a transitional stage between normal aging and AD dementia. This study aimed to analyze the efficacy of Di-Huang-Yi-Zhi (DHYZ) formula in treating amnestic Mild Cognitive Impairment (aMCI) for the patients in high altitude area (Qinghai Tibet Plateau). Method: A total of 106 patients in Shigatse, Tibet were randomly allocated into two groups. One group were to receive DHYZ decoction (150 ml each time, twice a day), the other group were to have aniracetam capsule (200 mg each time, three times a day) ,with 53 patients in each group. Changes in neuropsychological scales including mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA), Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), the Barthel Index for activities of daily living (ADL) and TCM symptoms were detected during a 12-month treatment period. After one year follow-up, the conversion rate of AD was observed. Result There was no significant difference between the two groups in baseline characteristics and scale scores (P > 0.05). Compared with the aniracetam group, the DHYZ group showed statistically higher MMSE and MoCA score and lower TCM score at the 9-month and 12-month. In addition, the ADAS-Cog and ADL scores in DHYZ group at 12-month were lower than that in the aniracetam control group. After one year follow-up, the conversion rate of AD in DHYZ group was 10% (5/50), and aniracetam group was 15.69% (8/51). The conversion rate of AD in DHYZ group was significantly lower than that in aniracetam group. Conclusion DHYZ formula can improve the cognition behavior and global function of patients with aMCI, it can also delay the conversion to AD. This is represents a new treatment option for the patients.


2020 ◽  
Vol 17 ◽  
Author(s):  
Hyung-Ji Kim ◽  
Jae-Hong Lee ◽  
E-nae Cheong ◽  
Sung-Eun Chung ◽  
Sungyang Jo ◽  
...  

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer’s disease from Alzheimer’s disease-mimicking conditions. Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. However, a limited number of studies had been conducted this subpopulation in terms of clinical progression. Objective: We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI). Methods: This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloidnegative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET. Results: During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer’s disease-like pattern despite the lack of evidence for significant Alzheimer’s disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices. Conclusion: Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer’s diseasemimicking dementia are warranted.


2014 ◽  
Vol 11 (2) ◽  
pp. 200-205
Author(s):  
Aleksandra Klimkowicz-Mrowiec ◽  
Lukasz Krzywoszanski ◽  
Karolina Spisak ◽  
Bryan Donohue ◽  
Andrzej Szczudlik ◽  
...  

Author(s):  
Zahra Ayati ◽  
Guoyan Yang ◽  
Mohammad Hossein Ayati ◽  
Seyed Ahmad Emami ◽  
Dennis Chang

Abstract Background Saffron (stigma of Crocus sativus L.) from Iridaceae family is a well-known traditional herbal medicine that has been used for hundreds of years to treat several diseases such as depressive mood, cancer and cardiovascular disorders. Recently, anti-dementia property of saffron has been indicated. However, the effects of saffron for the management of dementia remain controversial. The aim of the present study is to explore the effectiveness and safety of saffron in treating mild cognitive impairment and dementia. Methods An electronic database search of some major English and Chinese databases was conducted until 31st May 2019 to identify relevant randomised clinical trials (RCT). The primary outcome was cognitive function and the secondary outcomes included daily living function, global clinical assessment, quality of life (QoL), psychiatric assessment and safety. Rev-Man 5.3 software was applied to perform the meta-analyses. Results A total of four RCTs were included in this review. The analysis revealed that saffron significantly improves cognitive function measured by the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) and Clinical Dementia Rating Scale-Sums of Boxes (CDR-SB), compared to placebo groups. In addition, there was no significant difference between saffron and conventional medicine, as measured by cognitive scales such as ADAS-cog and CDR-SB. Saffron improved daily living function, but the changes were not statistically significant. No serious adverse events were reported in the included studies. Conclusions Saffron may have the potential to improve cognitive function and activities of daily living in patients with Alzheimer’s disease and mild cognitive impairment (MCI). However, due to limited high-quality studies there is insufficient evidence to make any recommendations for clinical use. Further clinical trials on larger sample sizes are warranted to shed more light on its efficacy and safety.


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