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BACKGROUND: In older adults, multidomain training that includes physical and cognitive activities has been associated with improvement of physical and cognitive health. The goal of the multisite StayFitLonger study is to assess a home-based computerised training programme, which combines physical exercises, stimulating cognitive activities and virtual coaching. METHODS: One hundred twenty-eight cognitively healthy older adults will be recruited from the community in Switzerland, Canada and Belgium. The study will comprise (1) a 26-week double-blind randomized controlled efficacy trial and (2) a 22-week pragmatic adherence sub-study. In the efficacy trial, participants will be randomly assigned to an experimental or an active control intervention. In the experimental intervention, participants will use the StayFitLonger programme, which is computerised on a tablet and provides content that combines physical activities with a focus on strength and balance, as well as divided attention, problem solving and memory training. Outcomes will be measured before and after 26 weeks of training. The primary efficacy outcome will be performance on the "Timed-Up & Go" test. Secondary outcomes will include measures of frailty, cognition, mood, fear of falling, quality of life, and activities of daily living. Age, sex, education, baseline cognition, expectation, and adherence will be used as moderators of efficacy. Following the 26-week efficacy trial, all participants will use the experimental programme meaning that participants in the control group will 'cross over' to receive the StayFitLonger programme for 22 weeks. Adherence will be measured in both groups based on dose, volume and frequency of use. In addition, participants' perception of the programme and its functionalities will be characterised through usability, acceptability and user experience. DISCUSSION: This study will determine the efficacy, adherence and participants' perception of a home-based multidomain intervention programme and its functionalities. This will allow for further development and possible commercialization of a scientifically validated training programme. TRIAL REGISTRATION: ClinicalTrials.gov , NCT04237519 Registered on January 22, 2020 - Retrospectively registered.
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Accidentes por Caídas , Actividades Cotidianas , Anciano , Bélgica , Canadá , Terapia por Ejercicio , Miedo , Humanos , Calidad de Vida , SuizaRESUMEN
BACKGROUND: Evidence-based data on prevalence and risk factors of suicidal intentions and behavior in dementia are as scarce as the data on assisted dying. The present literature review aimed on summarizing the current knowledge and provides a critical discussion of the results. METHODS: A systematic narrative literature review was performed using Medline, Cochrane Library, EMBASE, PSYNDEX, PSYCINFO, Sowiport, and Social Sciences Citation Index literature. RESULTS: Dementia as a whole does not appear to be a risk factor for suicide completion. Nonetheless some subgroups of patients with dementia apparently have an increased risk for suicidal behavior, such as patients with psychiatric comorbidities (particularly depression) and of younger age. Furthermore, a recent diagnosis of dementia, semantic dementia, and previous suicide attempts most probably elevate the risk for suicidal intentions and behavior. The impact of other potential risk factors, such as patient's cognitive impairment profile, behavioral disturbances, social isolation, or a biomarker based presymptomatic diagnosis has not yet been investigated. Assisted dying in dementia is rare but numbers seem to increase in regions where it is legally permitted. CONCLUSION: Most studies that had investigated the prevalence and risk factors for suicide in dementia had significant methodological limitations. Large prospective studies need to be conducted in order to evaluate risk factors for suicide and assisted suicide in patients with dementia and persons with very early or presymptomatic diagnoses of dementia. In clinical practice, known risk factors for suicide should be assessed in a standardized way so that appropriate action can be taken when necessary.
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Demencia/psicología , Suicidio Asistido/psicología , Intento de Suicidio/psicología , Comorbilidad , Humanos , Factores de RiesgoRESUMEN
Relying on procedural memory is a promising approach for interventions that address the cognitive difficulties found in semantic dementia. The aim of this study was to determine if procedural memory could be used to optimise learning of relevant smartphone functions in MH, a 55-year-old man with semantic dementia. The impact of learning to use specific smartphone applications, which display concepts and their semantic characteristics, on relearning useful significant concepts, was also explored in MH. This patient, who showed no deficits in procedural learning on a serial reaction time paradigm, was able to learn manipulations related to 15 smartphone functions although, because of his deficit in word comprehension, he generally needed verbal cues to clarify which functions he was asked to perform. Six months after the end of the intervention, he was still using 8 of the 15 functions regularly. However, repeated exposure to concepts through the use of two applications did not improve naming or retrieval of semantic attributes. This study showed the potential of relying on procedural memory to optimise learning of new technologies in the ecological rehabilitation of semantic dementia.
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Actividades Cotidianas , Demencia Frontotemporal/rehabilitación , Memoria a Largo Plazo , Aplicaciones Móviles/estadística & datos numéricos , Teléfono Inteligente/estadística & datos numéricos , Encéfalo/patología , Señales (Psicología) , Demencia Frontotemporal/patología , Demencia Frontotemporal/psicología , Humanos , Masculino , Persona de Mediana Edad , Destreza Motora , Pruebas Neuropsicológicas , Práctica Psicológica , Tiempo de ReacciónRESUMEN
BACKGROUND/OBJECTIVES: CAN-THUMBS UP is designed as a comprehensive and innovative fully remote program to 1) develop an interactive and compelling online Brain Health Support Program intervention, with potential to positively influence dementia literacy, self-efficacy and lifestyle risk factors; 2) enroll and retain a community-dwelling Platform Trial Cohort of individuals at risk of dementia who will participate in the intervention; 3) support an open platform trial to test a variety of multidomain interventions that might further benefit individuals at risk of dementia. This manuscript presents the Brain Health Support Program Study protocol. DESIGN/SETTING: Twelve-month prospective multi-center longitudinal study to evaluate a fully remote web-based educational intervention. Participants will subsequently be part of a Platform Trial Cohort and may be eligible to participate in further dementia prevention clinical trials. PARTICIPANTS: Three hundred fifty older adults who are cognitively unimpaired or have mild cognitive impairment, with at least 1 well established dementia risk factor. INTERVENTION: Participants engage in the Brain Health Support Program intervention for 45-weeks and complete pre/post intervention measures. This intervention is designed to convey best available evidence for dementia prevention, consists of 181 chapters within 8 modules that are progressively delivered, and is available online in English and French. The program has been developed as a collaborative effort by investigators with recognized expertise in the program's content areas, along with input from older-adult citizen advisors. MEASUREMENTS: This study utilizes adapted remote assessments with accessible technologies (e.g. videoconferencing, cognitive testing via computer and mobile phone, wearable devices to track physical activity and sleep, self-administered saliva sample collection). The primary outcome is change in dementia literacy, as measured by the Alzheimer's Disease Knowledge Scale. Secondary outcomes include change in self-efficacy; engagement using the online program; user satisfaction ratings; and evaluation of usability and acceptance. Exploratory outcomes include changes in attitudes toward dementia, modifiable risk factors, performance on the Neuropsychological Test Battery, performance on self-administered online cognitive assessments, and levels of physical activity and sleep; success of the national recruitment plan; and the distribution of age adjusted polygenic hazard scores. CONCLUSIONS: This fully remote study provides an accessible approach to research with all study activities being completed in the participants' home environment. This approach may reduce barriers to participation, provide an easier and less demanding participant experience, and reach a broader geography with recruitment from all regions of Canada. CAN-THUMBS UP represents a Canadian contribution to the global World-Wide FINGERS program (alz.org/wwfingers).
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Enfermedad de Alzheimer , Encéfalo , Anciano , Humanos , Canadá , Estudios Longitudinales , Estudios ProspectivosRESUMEN
The primary goal of this study was to evaluate the false recognition phenomenon in persons with frontotemporal dementia (FTD) and those with Lewy-body disease (LBD). Patients with LBD (n=10) or FTD (n=15) and their corresponding controls (n=30) were subjected to the Deese-Roediger-McDermott (DRM) paradigm to induce false recognition. Patients were first presented with items semantically related to a nonpresented critical target. The critical target was later included in a word list shown to patients to assess level of recognition. Both groups of patients showed a reduced level of false recognition of the critical target when controlling for their overall level of false alarms. This reduction was greater in persons with LBD than in those with FTD. Correlational analyses of performance on neuropsychological tests and the DRM variables indicated that the reduced DRM effect was associated with inhibition deficits in patients with LBD and with inhibition deficits and verbal memory in those with FTD. Our results support current models suggesting that these cognitive components contribute to the false recognition effect.
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Demencia Frontotemporal/fisiopatología , Enfermedad por Cuerpos de Lewy/fisiopatología , Reconocimiento en Psicología/fisiología , Aprendizaje Verbal/fisiología , Análisis de Varianza , Humanos , Inhibición Psicológica , Masculino , Pruebas NeuropsicológicasRESUMEN
BACKGROUND: Leisure activities can be both enjoyable and cognitively stimulating, and participation in such activities has been associated with reduced age-related cognitive decline. Thus, integrating stimulating leisure activities in cognitive training programs may represent a powerful and innovative approach to promote cognition in older adults at risk of dementia. The ENGAGE study is a randomized controlled, double-blind preference trial with a comprehensive cohort design that will test the efficacy and long-term impact of an intervention that combines cognitive training and cognitively stimulating leisure activities. METHODS: One hundred and forty-four older adults with a memory complaint will be recruited in Montreal and Toronto. A particular effort will be made to reach persons with low cognitive reserve. Participants will be randomly assigned to one of two conditions: cognitive + leisure training (ENGAGE-MUSIC/SPANISH) or active control (ENGAGE-DISCOVERY). The ENGAGE-MUSIC/SPANISH training will include teaching of mnemonic and attentional control strategies, casual videogames selected to train attention, and classes in music or Spanish as a second language. The ENGAGE-DISCOVERY condition will comprise psychoeducation on cognition and the brain, low-stimulating casual videogames and documentary viewing with discussions. To retain the leisure aspect of the activities, participants will be allowed to exclude either music or Spanish at study entry if they strongly dislike one of these activities. Participants randomized to ENGAGE-MUSIC/SPANISH who did not exclude any activity will be assigned to music or Spanish based on a second random assignment. Training will be provided in 24 2-h sessions over 4 months. Outcomes will be measured at baseline, at 4-month follow-up, and at 24-month follow-up. The primary outcome will be cognitive performance on a composite measure of episodic memory (delayed recall scores for words and face-name associations) measured at baseline and at the 4-month follow-up. Secondary outcomes will include a composite measure of attention (speed of processing, inhibition, dual tasking, and shifting), psychological health, activities of daily living, and brain structure and function and long-term maintenance measured at the 24-month follow-up. Information on cognitive reserve proxies (education and lifestyle questionnaires), sex and genotype (apolipoprotein (Apo)E4, brain-derived neurotrophic factor (BDNF), and catechol-O-methyltransferase (COMT)) will be collected and considered as moderators of training efficacy. DISCUSSION: This study will test whether a program combining cognitive training with stimulating leisure activities can increase cognition and reduce cognitive decline in persons at risk of dementia. TRIAL REGISTRATION: NCT03271190 . Registered on 5 September 2017.
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Cognición , Actividades Recreativas , Trastornos de la Memoria/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Atención , Encéfalo/patología , Encéfalo/fisiopatología , Estudios de Cohortes , Método Doble Ciego , Humanos , Trastornos de la Memoria/psicología , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Proyectos de InvestigaciónRESUMEN
This article reviews how neuropsychology, in the French-speaking world, has evolved as a discipline focused on research, teaching and clinical work. The article targets the last 30 years as this corresponds to the time at which the Société de Neuropsychologie de Langue Française (French-Speaking Neuropsychological Society) was created. The review addresses how the cognitive neuropsychology approach and the advent of brain imaging have shaped the field of neuropsychology in recent years. It presents the status of the discipline in the main French-speaking countries (where neuropsychology is currently developed) including France, Belgium, Switzerland and Canada. It also analyzes a number of indicators that reflect the vitality of the discipline and its cohesion as a science and as a clinical domain. These indicators include the creation of specialized journals, organization of scientific meetings, accessibility to training programs in neuropsychology, development of discipline-oriented clinical programs, and the increase in scientific productivity. The Quebec academic environment is used as an illustration, whereby structured clinical doctoral training programs that meet national standards in neuropsychology were implemented to train clinical neuropsychologists. Finally, the authors emphasize the major role that the discipline is likely to play at different levels of society in the near future.
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Neuropsicología/tendencias , Francia , Humanos , Quebec , Investigación/tendenciasRESUMEN
In vertebrates, the majority of homeobox (HBox) genes are found in four clusters and this structural organization is believed to be of functional importance. Many HBox genes sustain their expression in the appendages of the adult newt. To further understand their regulation, the genomic loci of four newt HBox genes (two from the human HBox (HOX)-2 complex and two from the HOX-3 complex) were analysed and compared with homologous loci in other vertebrates. Notophthalmus viridescens HBox (NvHBox) genes were selected from a lambda EMBL3 library and analysed by restriction mapping and nucleotide (nt) sequencing. The nt sequences of the NvHBox genes have a very high degree of homology (more than 90%) with the human and mouse HBox genes, HOX-3.3, HOX-3.4, HOX-2.7 and HOX-2.8. The sequences flanking the HBox are also very homologous to their human and mouse counterparts. Moreover, the size of the DNA spacer separating NvHBox-3.3 from NvHBox-3.4, and NvHBox-2.7 from NvHBox-2.8 in the newt is similar in the homologous regions of the mouse and human, despite there being a C value ten times greater in the newt genome. Finally, three of these NvHBox genes are expressed in the limbs of the adult newt.
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Genes Homeobox , Familia de Multigenes , Salamandridae/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Southern Blotting , ADN , Sondas de ADN , Biblioteca Genómica , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Ácido Nucleico , Vertebrados/genéticaRESUMEN
The verbal and attentional components of working memory were examined in patients with Alzheimer's disease, normal elderlies, and young controls. Patients with Alzheimer's disease, showed a reduced span but were sensitive to word length. This is indicative of a functional rehearsal procedure. However, the effect of phonological similarity on immediate recall was smaller in patients with Alzheimer's disease and these patients showed a depressed performance in tasks of phonological analysis. There was also a significant decrement in a task that assessed the attentional component of working memory. Examination of individual patterns of performance showed that the phonological deficiency was severe in a subgroup of patients while the attentional deficit was more general.
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Envejecimiento/psicología , Enfermedad de Alzheimer/psicología , Memoria a Corto Plazo/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Percepción Auditiva/fisiología , Cognición/fisiología , Discriminación en Psicología/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Aprendizaje Verbal/fisiologíaRESUMEN
The development of vernier acuity was assessed in nine kittens using offsets in a series of square-wave gratings as stimulus targets. The kittens were tested on a jumping stand in a two-choice simultaneous discrimination paradigm, and daily thresholds were tracked with a modified staircase procedure. Vernier acuity improved gradually from initial values of 13-57' arc and reached asymptote at 1.5-5.4' arc by 70-90 days of age. The developmental function for vernier acuity is discussed in relation to physiologic development of the kitten visual system and is related to published data on the development of stereoacuity and spatial resolution in the same species.
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Ojo/crecimiento & desarrollo , Agudeza Visual/fisiología , Animales , GatosRESUMEN
Most previous PET studies investigating the central executive (CE) component of working memory found activation in the prefrontal cortex. However, the tasks used did not always permit to distinguish precisely the functions of the CE from the storage function of the slave systems. The aim of the present study was to isolate brain areas that subserve manipulation of information by the CE when the influence of storage function was removed. A PET activation study was performed with four cognitive tasks, crossing conditions of temporary storage and manipulation of information. The manipulation of information induced an activation in the right (BA 10/46) and left (BA 9/6) middle frontal gyrus and in the left parietal area (BA7). The interaction between the storage and manipulation conditions did not reveal any significant changes in activation. These results are in agreement with the hypothesis that CE functions are distributed between anterior and posterior brain areas, but could also reflect a simultaneous involvement of controlled (frontal) and automatic (parietal) attentional systems. In the other hand, the absence of interaction between the storage and manipulation conditions demonstrates that the CE is not necessarily related to the presence of a memory load.
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Lóbulo Frontal/fisiología , Memoria a Corto Plazo/fisiología , Lóbulo Parietal/fisiología , Adulto , Cognición/fisiología , Lóbulo Frontal/diagnóstico por imagen , Humanos , Masculino , Pruebas Neuropsicológicas , Lóbulo Parietal/diagnóstico por imagen , Tomografía Computarizada de EmisiónRESUMEN
Vernier thresholds were measured behaviourally in five cats using offsets in gratings of two spatial frequencies and in single lines. Thresholds ranged from 2.2 to 6.7', and no threshold differences were found across stimuli. These results are discussed in relationships with published spatial resolution data and are related to the optical and neural characteristics of the cat's visual system. It is concluded that if vernier acuity is a hyperacuity in cats, the improvement in grain is not of the same magnitude as it is in humans.
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Percepción de Forma/fisiología , Reconocimiento Visual de Modelos/fisiología , Agudeza Visual , Animales , Gatos , Psicofísica , Umbral Sensorial/fisiología , Percepción Espacial/fisiologíaRESUMEN
In this article, we discuss the effects of education level and age on short-term memory. The performance of young and elderly persons was compared on an adapted version of the Brown-Peterson procedure. Participants were asked to report consonant trigrams, after variable time periods, during which they performed a mental addition task or an articulation task. A control condition consisted of a no-interference task. Both age groups were divided according to individual educational level (greater or less than the median number of school years in each age group). The results revealed a significant effect of education. Moreover, the education effect interacted with the task: participants with less education were more impaired in mental addition than in articulation. However, neither the age effect nor the interactions involving age reached significance. These results indicate that education, to a greater extent than age, should be considered a determining factor of performance when interpolated tasks of high demand are used with the Brown-Peterson procedure.
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Educación , Adulto , Factores de Edad , Anciano , Envejecimiento , Femenino , Humanos , Masculino , Distribución AleatoriaRESUMEN
The purpose of this study was to assess whether older adults can inhibit irrelevant auditory information while performing a span task. In Experiment 1, young and older participants recalled seven visually presented digits while subject to three types of irrelevant noise; white noise (nonverbal), and familiar and nonfamiliar language (verbal). A baseline measure was obtained in silence. The effect of each noise was also assessed under articulatory suppression (AS). In Experiment 2, the number of digits to recall was adjusted to participants' individual span. Results show a clear irrelevant speech effect (ISE), that is, recall declines in the presence of familiar and nonfamiliar verbal noise, but is unaffected by white noise. AS negates ISE. Most important, ISE does not interact with age: older adults have no more difficulty inhibiting irrelevant auditory information than do young adults. These results are discussed relative to current theories of inhibition in aging.
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Envejecimiento/fisiología , Memoria/fisiología , Recuerdo Mental , Habla/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas NeuropsicológicasRESUMEN
We describe a brain-damaged patient with disturbed articulatory rehearsal in whom all predictions derived from a working memory model were fulfilled. The patient showed a reduced verbal span, no word-length effect on immediate recall in both the visual or the auditory modalities, no phonological similarity effect in the visual modality, and no effect of articulatory suppression. A slowed overt articulation rate provided independent evidence for disrupted articulatory rehearsal. The other components of working memory, the visuospatial scratch-pad, phonological storage system, and central executive, were functional. The selectivity of the deficit can be taken as evidence for the specific role of articulatory rehearsal in working memory.
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Afasia/diagnóstico , Lesiones Encefálicas/diagnóstico , Pruebas del Lenguaje , Memoria a Corto Plazo , Habla , Afasia/etiología , Percepción Auditiva , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/psicología , Humanos , Trastornos del Lenguaje/complicaciones , Trastornos del Lenguaje/diagnóstico , Masculino , Persona de Mediana Edad , Fonética , Proyectos de Investigación , Percepción VisualRESUMEN
The case study of an autistic "savant" subject with person names hypermnesia is presented. NM's performance in memorizing person names is compared to that of normal controls, IQ-matched controls, and one overtrained control. The data show a selective hypermnesia for both the free recall of person names and the recognition of faces. Recall of common names and of biographical informations linked to faces is unremarkable. NM's hypermnesia is restricted to list learning as low performance is observed in face-name learning tasks. A comparison of the data with that of the overtrained control indicates that training is not responsible for NM's pattern of results. These findings, when combined with previous results involving proper names, demonstrate a double dissociation between proper names and other types of semantic and referential information. However, aspects of NM's performance pattern are more compatible with a network model of proper names than with a sequential model. We propose that the contextual regularity of proper names in ecological situations can be responsible for their high memorization by NM.
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Trastorno Autístico , Memoria , Adulto , Trastorno Autístico/complicaciones , Humanos , Discapacidad Intelectual/complicaciones , MasculinoRESUMEN
We present the neuropsychological study of a patient, I.R., who sustained bilateral damage to the temporal lobes and to the right frontal lobe as a result of successive brain surgeries that occurred ten years earlier. The patient is 40 years old and right-handed; she had no special training in music or in language, representing, therefore, the large majority of listeners. Her performance is compared to that of four neurologically intact subjects who are closely matched in terms of education, sex and age. In the present study, we report I.R.'s performance on various tests aiming at assessing her general cognitive functioning with a particular focus on auditory aspects. The results show that, despite extensive damage to her auditory cortex, I.R.'s speech abilities are essentially intact (see Tables 1 and 2). The only impairments that are detected in the language domain are related to a short-term memory deficit, to some abnormal sensitivity to retroactive interference in long-term memory (see Table 3) and to articulation. These difficulties do not, however, affect linguistic communication, which is obviously undisturbed I.R. is not aphasic). Similarly, I.R. does not experience any difficulty in the recognition and memorization of familiar sounds such as animal cries, traffic noises and the like (see Tables 5 and 7). In contrast, I.R. is severely impaired in most musical abilities: She can no longer discriminate nor identify melodies that were once highly familiar to her; she can no longer discriminate nor memorize novel melodies (see Table 4). Her pattern of musical losses is compatible with a basic and severe perceptual deficit that compromises access to and registration in memory systems. The observation that the auditory impairment affects music and spares language and environmental sounds refers to a neuropsychological condition that is known as music agnosia. I.R. represents, to our knowledge, the fourth case of music agnosia available in the literature (Peretz et al., 1994; Griffiths et al., 1997). The existence of such cases suggests that music processing is not mediated by a general-purpose auditory architecture but by specialized cortical subsystems. Not only does I.R. suffer from music agnosia, but she is also impaired in the discrimination and recognition of musical instruments and of human voices (see Table 5). These latter two deficits probably do not result from the music agnosic condition. Rather, they seem to reflect damage to adjacent brain areas that are specialized in timbre processing (see Peretz. et al., 1994, for the relevant discussion). It is also worth mentioning that I.R. appears to be impaired in musical expressive abilities as well: I.R. can no longer sing a single note. Thus, her losses are rather general in the musical domain, hence justifying the classification of her case as amusia. Cases of amusia without aphasia are relatively frequent in the neuropsychological literature. However, all of these reported cases are anecdotal. Thus, in the present study, special focus is given to the measurement and direct comparison of performance in the language and music domain; in both domains, task characteristics and materials were as similar as possible. To this aim, the lyrics and the tune of the same popular song excerpts were used. The musical and the spoken parts were presented separately in a primed familiarity decision task and in a memory recognition task. In both situations, I.R. performs at or close to chance when she has to deal with music, whereas she recognizes easily and performs normally on the spoken material (see Tables 6 and 7). These results clearly argue for the autonomy of music and language in the processing of auditory information.
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Agnosia , Percepción Auditiva , Trastornos del Conocimiento/clasificación , Música/psicología , Trastornos de la Percepción , Lóbulo Temporal , Adulto , Agnosia/clasificación , Agnosia/etiología , Afasia/etiología , Percepción Auditiva/clasificación , Percepción Auditiva/fisiología , Decorticación Cerebral/efectos adversos , Trastornos del Conocimiento/etiología , Femenino , Humanos , Pruebas Neuropsicológicas , Trastornos de la Percepción/clasificación , Trastornos de la Percepción/etiología , Percepción del Habla/fisiología , Lóbulo Temporal/fisiopatología , Lóbulo Temporal/cirugíaRESUMEN
Normal aging, as well as most of the degenerative diseases of the central nervous system characterizing old age, have an impact on cognitive abilities which are obvious as well as increasingly understood. Cognitive changes in normal ageing realize a plurality of possible patterns of cognitive disabilities. Dementias are also well known to be characterized by a plurality of cognitive impairments patterns. The different cognitive patterns are likely to be due to distinct levels of impairments of different domains of cognition, or of different components within one given domain of cognition. These differences are such that in some cases they can even realize double dissociations. The plurality of cognitive impairments patterns in normal aging and in dementia will be discussed as well as the different factors that could contribute to such a plurality. Some of these factors relate to pre-morbid characteristics of the individuals known to influence the functional organization of the brain for cognition. Others--of major importance--are related to the nature and the distribution of the pathophysiological processes underlying normal ageing or a given degenerative disease. It is also reminded that some or many of these factors can interact with more general cognitive factors, such as speed of execution. It is however suggested that, despite of their presence, these general factors partly contribute to the cognitive impairments in neurodegenerative dementia. In this case, the impact of different disease-related factors over a general cognitive factor is probably much greater than in the case of normal aging.
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Envejecimiento/psicología , Enfermedad de Alzheimer/psicología , Trastornos del Conocimiento/psicología , Cognición/fisiología , Anciano , Envejecimiento/fisiología , Enfermedad de Alzheimer/fisiopatología , Trastornos del Conocimiento/fisiopatología , HumanosRESUMEN
The aging of the population leads to increased awareness of problems associated with age-related degenerative dementias. Given that these dementias are progressive in onset, many clinicians and researchers have proposed criteria that allow for the identification of older subjects manifesting cognitive impairment, but not responding to the criteria for dementia. Our knowledge of subjects with mild cognitive impairment is limited; it is, however, established that they present a high risk of developing dementia in the future. Although it is essential to increase our comprehension of their cognitive and functional decline, the study of subjects presenting mild cognitive impairment is compromised due to the existence of numerous non-converging classifications. The goal of the present article is to conduct a critical review of the different classifications of mild cognitive impairment in the elderly in order to attempt to identify the optimal criteria, allowing for a distinction to be made between subjects with mild cognitive impairment, who remain in a stable state and those whose condition evolves to a dementia. These criteria may enable us to describe a homogenuous group of individuals presenting with different rates of dementia risk factors. We present the classifications most frequently used in clinical and research settings. After listing them according to categorial, clinical or dimensional approaches, we performed a critical analysis for each one. Depending on the diagnostic criteria applied, major variations are revealed for the prevalence of cognitive impairment and the incidence of dementia. They are explained by methodological and theoretical shortcomings that we point out and discuss (e.g., reference group, lack of diagnostic criteria or exclusion criteria, high level of subjectivity). Beyond these criticisms, we discuss the challenges to be met in order to reach the optimal identification criteria. Notably, the impact of mild cognitive impairment on daily living activities should be tested with the use of more specific questionnaires/tasks. The goal of the objective definition of cognitive impairment should be to minimize subjectivity in the diagnosis. It is also suggested that sensitive cognitive measures would be used on all aspects of cognition, while recognizing and taking into account all confounding factors (e.g., age, education level). Given the nature and consequences of mild cognitive impairment, an inter-disciplinary approach is suggested (e.g., neurobiological, psychiatric, and genetic cues). A consensus on optimal diagnostic criteria is essential to propose cognitive and pharmacological treatments for the effective prevention of ementia.
Asunto(s)
Trastornos del Conocimiento , Factores de Edad , Anciano , Envejecimiento , Trastornos del Conocimiento/clasificación , Trastornos del Conocimiento/diagnóstico , Humanos , Índice de Severidad de la EnfermedadRESUMEN
OBJECTIVE: The Multidomain Alzheimer Preventive Trial (MAPT study) was designed to assess the efficacy of isolated supplementation with omega-3 fatty acid, an isolated multidomain intervention (consisting of nutritional counseling, physical exercise, cognitive stimulation) or a combination of the two interventions on the change of cognitive functions in frail subjects aged 70 years and older for a period of 3 years. Ancillary neuroimaging studies were additionally implemented to evaluate the impact of interventions on cerebral metabolism (FDG PET scans) and atrophy rate (MRIs), as well as brain amyloïd deposit (AV45 PET scans). DESIGN PATIENTS: 1680 subjects (mean age: 75.3 years; female: 64.8 %), enrolled by 13 memory clinics, were randomized into one of the following four groups: omega-3 supplementation alone, multidomain intervention alone, omega-3 plus multidomain intervention, or placebo. Participants underwent cognitive, functional and biological assessments at M6, M12, M24 and M36 visits. The primary endpoint is a change of memory function at 3 years, as assessed by the Free and Cued Selective Reminding test. All participants will be followed for 2 additional years after the 3-years intervention (MAPT PLUS extension study). INTERVENTIONS: 1/Omega-3 supplementation: two soft capsules daily as a single dose, containing a total of 400 mg docosahexaenoic acid (DHA), i.e., 800 mg docosahexaenoic acid per day, for 3 years. 2/ Multidomain intervention: collective training sessions conducted in small groups (6-8 participants) in twelve 120-minute sessions over the first 2 months (two sessions a week for the first month, and one session a week the second month) then a 60-minute session per month in the following three areas: nutrition, physical activity, and cognition until the end of the 3 years. In addition to the collective sessions, individualized preventive outpatient visits exploring possible risk factors for cognitive decline are performed at baseline, M12 and M24. BASELINE POPULATION: For cognition, the mean MMSE at baseline was 28.1 (± 1.6). About 58% and 42% of participants had a CDR score equal to 0 and 0.5, respectively. Regarding mobility status, 200 (11.9%) had a 4-m gait speed lower or equal to 0.8 m/s. According to the Fried criteria, 673 (42.1%) participants were considered pre frail, and 51 (3.2%) frail. The red blood cell DHA content was 26.1 ± 8.1 µg/g. Five hundred and three participants underwent baseline MRI. AV45 PET scans were performed in 271 individuals and preliminary results showed that 38.0% had a cortical SUVR > 1.17, which gave an indication of significant brain amyloïd deposit. DISCUSSION: The MAPT trial is presently the first largest and longest multidomain preventive trial relevant to cognitive decline in older adults with subjective memory complaints. The multidomain intervention designed for the MAPT trial is likely to be easily implemented within the general population.