scholarly journals Memory loss in Alzheimer's disease

2013 ◽  
Vol 15 (4) ◽  
pp. 445-454 ◽  

Loss of memory is among the first symptoms reported by patients suffering from Alzheimer's disease (AD) and by their caretakers. Working memory and long-term declarative memory are affected early during the course of the disease. The individual pattern of impaired memory functions correlates with parameters of structural or functional brain integrity. AD pathology interferes with the formation of memories from the molecular level to the framework of neural networks. The investigation of AD memory loss helps to identify the involved neural structures, such as the default mode network, the influence of epigenetic and genetic factors, such as ApoE4 status, and evolutionary aspects of human cognition. Clinically, the analysis of memory assists the definition of AD subtypes, disease grading, and prognostic predictions. Despite new AD criteria that allow the earlier diagnosis of the disease by inclusion of biomarkers derived from cerebrospinal fluid or hippocampal volume analysis, neuropsychological testing remains at the core of AD diagnosis.

2019 ◽  
Vol 216 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Audun Osland Vik-Mo ◽  
Lasse Melvaer Giil ◽  
Miguel Germán Borda ◽  
Clive Ballard ◽  
Dag Aarsland

IntroductionUnderstanding the natural course of neuropsychiatric symptoms (NPS) in dementia is important for planning patient care and trial design, but few studies have described the long-term course of NPS in individuals.MethodPrimary inclusion of 223 patients with suspected mild dementia from general practice were followed by annual assessment, including the Neuropsychiatric Inventory (NPI), for up to 12 years. Total and item NPI scores were classified as stable, relapsing, single episodic or not present based on 4.96 (s.d. 2.3) observations (98% completeness of longitudinal data) for 113 patients with Alzheimer's disease and 84 patients with LBD (68 dementia with Lewy bodies and 16 Parkinson's disease dementia).ResultsWe found that 80% had stable NPI total ≥1, 50% had stable modest NPI total ≥12 and 25% had stable NPI total ≥24 scores. Very severe NPS (≥48) were mostly single episodes, but 8% of patients with Alzheimer's disease had stable severe NPS. Patients with Alzheimer's disease and the highest 20% NPI total scores had a more stable or relapsing course of four key symptoms: aberrant motor behaviour, aggression/agitation, delusions and irritability (odds ratio 55, P < 0.001). This was not seen in LBD. Finally, 57% of patients with Alzheimer's disease and 84% of patients with LBD had reoccurring psychotic symptoms.ConclusionsWe observed a highly individual course of NPS, with most presenting as a single episode or relapsing; a stable course was less common, especially in LBD. These findings demonstrate the importance of an individualised approach (i.e. personalised medicine) in dementia care.


Ciencia Unemi ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 123
Author(s):  
Maria Alejandra Vallejo-Johnson ◽  
Patricia Marcial-Velastegui

Existen diversos estudios que proponen las causas de la Enfermedad de Alzheimer (EA), las cuales pueden ser: biológicas, genéticas, cronológicas y ambientales, dentro de ésta última se encuentra el estrés como una influencia para el inicio de dicha patología. Según las distintas teorías del estrés, el sujeto, al encontrarse frente a una situación estresante, sufre diversos cambios en su cuerpo para sobrellevar dicho acontecimiento. El cerebro es el encargado de poner al cuerpo en alerta y en marcha para actuar frente a dicho cambio. El estrés prolongado conlleva a alteraciones en las vías cerebrales, específicamente un daño neuronal del hipocampo, el cual es el encargado de los recuerdos y memoria. Éste al verse afectado, repercute en la memoria del sujeto y por lo tanto empieza a fallar; el sujeto se ve en la incapacidad para recordar y realizar distintas actividades rutinarias. Mediante la investigación documental y encuestas a profesionales de la salud, se obtuvo información tanto del estrés como de la Enfermedad de Alzheimer para luego concluir en la influencia del mismo en el origen de la enfermedad. Se concluye que el estrés perenne repercute en la muerte de neuronas del hipocampo lo que conlleva a la EA. AbstractThere are different studies that propose that the causes of Alzheimer might be biological, genetic, chronological and environmental. Within the environmental aspects, the stress influences the beginning of this pathology. There are several studies that propose the causes of Alzheimer's disease (AD), which can be: biological, genetic, chronological and environmental, within the latter is the stress that influences the beginning of this pathology. According to different theories of stress, the individual, while facing a stressful situation, experiences many changes in the body in order to deal with this situation. The brain is in charge of alerting the body to protect itself against that change. The long-term stress alters the brain pathways, producing specifically a neuronal damage in the hippocampus that is responsible for memories and memory. This affects memory and therefore individual begins to fail, and then, the person cannot remember how to do the daily routine. Through bibliographical research and surveys applied to healthcare professionals, information was obtained on both stress and Alzheimer's disease to establish the influence of that condition on the disease. The study concludes that long-term stress affects the death of neurons in the hippocampus, which leads to AD.


2020 ◽  
Author(s):  
Jianfeng Wu ◽  
Qunxi Dong ◽  
Jie Gui ◽  
Jie Zhang ◽  
Yi Su ◽  
...  

ABSTRACTBiomarker assisted preclinical/early detection and intervention in Alzheimer’s disease (AD) may be the key to therapeutic breakthroughs. One of the presymptomatic hallmarks of AD is the accumulation of beta-amyloid (Aβ) plaques in the human brain. However, current methods to detect Aβ pathology are either invasive (lumbar puncture) or quite costly and not widely available (amyloid PET). Our prior studies show that MRI-based hippocampal multivariate morphometry statistics (MMS) are an effective neurodegenerative biomarker for preclinical AD. Here we attempt to use MRI-MMS to make inferences regarding brain amyloid burden at the individual subject level. As MMS data has a larger dimension than the sample size, we propose a sparse coding algorithm, Patch Analysis-based Surface Correntropy-induced Sparse coding and max-pooling (PASCS-MP), to generate a low-dimensional representation of hippocampal morphometry for each individual subject. Then we apply these individual representations and a binary random forest classifier to predict brain Aβ positivity for each person. We test our method in two independent cohorts, 841 subjects from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and 260 subjects from the Open Access Series of Imaging Studies (OASIS). Experimental results suggest that our proposed PASCS-MP method and MMS can discriminate Aβ positivity in people with mild cognitive impairment (MCI) (Accuracy (ACC)=0.89 (ADNI)) and in cognitively unimpaired (CU) individuals (ACC=0.79 (ADNI) and ACC=0.82 (OASIS)). These results compare favorably relative to measures derived from traditional algorithms, including hippocampal volume and surface area, shape measures based on spherical harmonics (SPHARM) and our prior Patch Analysis-based Surface Sparse-coding and Max-Pooling (PASS-MP) methods.


2021 ◽  
Vol 18 ◽  
Author(s):  
Linlin Zhao ◽  
Guanghua Liu ◽  
Lingli Zhang ◽  
Yuxiang Du ◽  
Le Lei ◽  
...  

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disease which has been characterized by progressive development of long onset early disease with complicated etiology, and may cause memory loss, cognitive impairment, and behavioral changes. Physical exercise may play a preventive role in AD. In the present study, we investigated the impact of longer-term physical exercise on finger tapping of AD patient by comparing the finger tapping of AD patients and heathy controls without AD. Methods: In this study, 140 subjects who aged ≥ 60 years were enrolled. Group A consisted of 70 subjects (27 males and 43 females) without exercise habits who selected from Yangpu District (Shanghai, China). Group B consisted of 70 subjects (27 males and 43 females) who selected from Minxing District (Shanghai, China). All the subjects were right-handed as well. The subjects’ data, including subjects’ age, weight, height, Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and finger tapping frequency were measured. Results: The subjects were matched in age, weight, and height. The AD subjects’ MoCA and MMSE scores were noticeably lower than healthy subjects’ scores (P<0.001); besides, AD patients with exercise have significantly lower MoCA and MMSE scores than healthy controls with exercise (P<0.001). The finger tapping of AD subjects’ left hands was significantly lower than that of healthy subjects without AD (P<0.01), and AD subjects with exercise tapped significantly slower with left hand than healthy subjects with exercise (P<0.01). Meanwhile, AD subjects with exercise tapped significantly faster with left hand than AD subjects (P<0.05). The right hands of AD subjects tapped remarkably less than healthy subjects (P<0.01) with or without exercise. Meanwhile, subjects with exercise tapped significantly faster with right hand than healthy subjects (P<0.05), and AD subjects with exercise tapped significantly faster with right hand than AD subjects (P<0.05). Conclusion: Long-term physical exercises can improve finger tapping frequency, especially patients with AD. Finger tapping frequency may be used as an index to monitor cognitive decline in ageing AD patients.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 68-69
Author(s):  
Louise E Bennett

Abstract Alzheimer’s disease, resulting from the over-expression of amyloid precursor protein (APP) and accumulation of plaques comprising the APP-derived amyloid beta (Aβ), is a diagnostic and pathological brain feature of Alzheimer’s disease (AD). For older, predisposed people, accumulation of Aβ plaque in the brain precedes symptoms of memory loss by decades. There is a growing consensus that over-expression of APP may also reflect a defense response against infection, via the antibiotic effects of Aβ, which becomes toxic when Aβ peptides cannot be cleared from the brain. These scenarios permit two possible pathways of potential intervention from whey proteins mediated by lactoferrin and hydrolyzed whey proteins. In particular, the interference of fibril assembly whey-derived peptides can promote opportunity for clearance of aggregating forms of Aβ, while the anti-microbial activity of whey proteins such as lactoferrin have potential to suppress the activity of microbes (and viruses) and collectively manage the progress of AD. This presentation will explain the individual potential benefits of whey peptides and lactoferrin, based on available evidence. More research is required to determine if a synergistic effect might be possible from this therapeutic combination.


1991 ◽  
Vol 4 (4) ◽  
pp. 225-233
Author(s):  
Edith V. Sullivan

The most common clinical sign of Alzheimer's disease (AD) is progressive memory loss. Presented here is a case of AD who, despite ultimate profound dementia with severe amnesia, showed retention of a perseverative response she developed during 26 encounters, over 4.5 years, with the Brown–Peterson distractor test. From Test 9 onwards, she responded from the first distractor-filled trial with one consonant trigram, appearing in none of the seven test forms given her. At Test 26, she could not repeat heard trigrams yet faithfully responded with her perseverative trigram. The trigram, ostensibly declarative information, apparently became part and parcel of the task's procedure. Although perseveration is a form of impairment probably resulting from Alzheimer pathology involving frontal and parietal cortex, it may also reflect a form of preserved memory, albeit distorted, supported by posterior cortical regions spared in AD.


2020 ◽  
Vol 31 (3) ◽  
pp. 245-268 ◽  
Author(s):  
Diana Marcela Cuestas Torres ◽  
Fernando P. Cardenas

AbstractThe strength and efficiency of synaptic connections are affected by the environment or the experience of the individual. This property, called synaptic plasticity, is directly related to memory and learning processes and has been modeled at the cellular level. These types of cellular memory and learning models include specific stimulation protocols that generate a long-term strengthening of the synapses, called long-term potentiation, or a weakening of the said long-term synapses, called long-term depression. Although, for decades, researchers have believed that the main cause of the cognitive deficit that characterizes Alzheimer’s disease (AD) and aging was the loss of neurons, the hypothesis of an imbalance in the cellular and molecular mechanisms of synaptic plasticity underlying this deficit is currently widely accepted. An understanding of the molecular and cellular changes underlying the process of synaptic plasticity during the development of AD and aging will direct future studies to specific targets, resulting in the development of much more efficient and specific therapeutic strategies. In this review, we classify, discuss, and describe the main findings related to changes in the neurophysiological mechanisms of synaptic plasticity in excitatory synapses underlying AD and aging. In addition, we suggest possible mechanisms in which aging can become a high-risk factor for the development of AD and how its development could be prevented or slowed.


2019 ◽  
Vol 16 (11) ◽  
pp. 975-985
Author(s):  
Martin Vyhnálek ◽  
Hana Marková ◽  
Jan Laczó ◽  
Rossana De Beni ◽  
Santo Di Nuovo

Memory impairment has been considered as one of the earliest clinical hallmarks of Alzheimer’s disease. This paper summarizes recent progress in the assessment of memory impairment in predementia stages. New promising approaches of memory assessment include evaluation of longitudinal cognitive changes, assessment of long-term memory loss, evaluation of subjective cognitive concerns and testing of other memory modalities, such as spatial memory. In addition, we describe new challenging memory tests based on memory binding paradigms that have been recently developed and are currently being validated.


Author(s):  
Theresa König ◽  
Elisabeth Stögmann

SummaryAlzheimer’s disease (AD) is the leading cause of neurodegeneration in the elderly and is clinically characterized by slowly progressing cognitive decline, which most commonly affects episodic memory function. This eventually leads to difficulties in activities of daily living. Biomarker studies show that the underlying pathology of AD begins 20 years before clinical symptoms. This results in the need to define specific targets and preclinical stages in order to address the problems of this disease at an earlier point in time. Genetic studies are indispensable for gaining insight into the etiology of neurodegenerative diseases and can play a major role in the early definition of the individual disease risk. This review provides an overview of the currently known genetic features of AD.


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