Auteur(s) : Jacques Boddaert, Marc Verny La responsabilite de la maladie d’Alzheimer (MA) dans les grandes causes de mortalite a ete suggeree par differentes etudes, et differents facteurs pejoratifs ont ete rapportes, tels que le sexe masculin, la severite initiale de la maladie, l’existence de troubles du comportement, de deambulation ou de chutes, et la presence de signes extrapyramidaux. Les donnees de la litterature sont assez variables, selon que l’on parle de debut de la maladie, et dans ce cas selon les criteres que l’on retient pour le definir, ou de date du diagnostic. De meme, l’evolutivite du declin cognitif doit etre prise en compte, comme le confirme l’etude de Hui et al. sur 354 patients avec une MA suivis sur une periode 4 ans [1]. Degre de complexite supplementaire chez le grand vieillard polypathologique, les nombreuses comorbidites associees jouent probablement un role determinant dans la survie de ces patients, et parler de survie de la MA demande une prise en compte de tous ces parametres confondants. Wolfson et al., a partir de la Canadian study of health and aging (CSHA), avaient etudie la survie de la MA en 2001 en considerant le debut de la maladie d’Alzheimer diagnostique par 3 questions de la Camdex (Cambridge examination for mental disorders of the elderly). Ces auteurs avaient rapporte une mediane de survie de 3,1 ans chez des patients âges (83 + /- 7 ans) avec MA, en utilisant des ajustements pour le biais de duree d’evolution, le sexe, le niveau d’education et l’âge au moment du diagnostic, qui restait, apres regression logistique, le facteur de plus mauvais pronostic [2]. Recemment, Larson et al. ont publie de nouveaux resultats sur le sujet [3]. Il s’agit d’une etude observationnelle prospective, a partir de 23 000 patients âges de 60 ans ou plus engages dans un programme de sante, suivis de 1987 a 1996, permettant d’etudier l’histoire naturelle de la MA dans les cas incidents. Durant la periode de l’etude, 970 patients ont ete explores pour un syndrome dementiel. Parmi eux, 521 nouveaux cas de MA ont ete diagnostiques, comprenant 431 cas probables et 90 cas de MA possible selon les criteres du DSM-III-R et NINCDS-ADRDA, avec un suivi moyen de 5,2 ± 3,1 ans. Les scores au MMS au moment du diagnostic se repartissaient en 17 % entre 25 et 30, 24 % entre 22 et 24, 30 % entre 18 et 21 et 30 % ≤ 17. Les scores relativement bas de MMS (60 % ≤ 21) sont dus aux modes de recrutement (patients entrant dans le registre s’ils recevaient des soins) et a ceux du reperage des symptomes de demence (troubles mnesiques, confusion ou deambulation...). La mediane de survie des patients a partir du diagnostic de la maladie etait influencee par de nombreux facteurs. Elle passait de 4,2 ans pour les hommes a 5,7 ans pour les femmes, confirmant le caractere pejoratif du sexe masculin. Concernant les comorbidites, cette etude soulignait le role d’une cardiopathie ischemique (p < 0,001), d’une insuffisance cardiaque (p < 0,001), du diabete (p = 0,04) et d’un antecedent d’accident vasculaire cerebral (p = 0,026) associes. Par contre, l’hypertension arterielle, consideree comme representant un facteur de declin de la MA, n’influencait pas la maladie. En analyse multivariee, ajustee pour l’âge, le sexe, l’origine ethnique, l’existence d’une cardiopathie ischemique, d’une insuffisance cardiaque et d’un diabete, le deces etait correle : 1) au score MMSE au moment du diagnostic (≤ 17 : hazard ratio 2,67 [1,94-3,66], p < 0,001) ; 2) au score DRS (entre 5,5 et 17 : hazard ratio 2,04 [1,54-2,71, p < 0,001) ; 3) aux signes frontaux (hazard ratio 1,27 [1,03-1,55], p = 0,022) ; 4) aux signes extrapyramidaux (hazard ratio 1,35 [1,03-1,76], p = 0,028) ; 5) aux troubles de l’humeur (hazard ratio 1,4 [1,12-1,76], p = 0,004), 6/ a la deambulation (hazard ratio 1,45 [1,02-2,08], p = 0,04). Le declin de plus de 5 points de MMS par an etait egalement associe a une mortalite augmentee. En comparant les resultats de l’etude aux donnees de la mortalite dans la population des Etats-Unis, les patients atteints d’une MA avaient constamment une reduction de l’esperance de vie. Les causes de deces ne sont pas rapportees. La correlation inverse entre mortalite et score au MMS reflete probablement la duree d’evolution de la maladie et l’on peut s’interroger sur l’impact d’une prise en charge globale et plus encore medicamenteuse chez ces patients. Cette etude souligne l’importance des comorbidites dans la MA du sujet âge, et est utile pour le clinicien, en particulier pour decider de la mise en place de therapeutiques lourdes. De plus, la mise en evidence de facteurs pejoratifs associes permet de cibler une population plus a risque et d’adapter au mieux surveillance et traitements. La limitation principale de cette etude concerne le mode de recrutement et le caractere non representatif de la population dans son ensemble. De nouvelles etudes, idealement en population, devront preciser la duree de vie des malades atteints d’une maladie d’Alzheimer et evaluer l’impact sur la survie des therapeutiques symptomatiques de la MA ou des traitements des comorbidites. 1. Hui JS, Wilson RS, Bennett DA, Bienias JL, Gilley DW, Evans DA. Rate of cognitive decline and mortality in Alzheimer’s disease. Neurology 2003 ; 61 : 1356-61. 2. Wolfson C, Wolfson DB, Asgharian M, M’Lan CE, Ostbye T, Rockwood K, et al. Clinical Progression of Dementia Study Group. A reevaluation of the duration of survival after the onset of dementia. N Engl J Med 2001 ; 344 : 1111- 6. 3. Larson EB, Shadlen MF, Wang L, McCormick WC, Bowen JD, Teri L, et al. Survival after initial diagnosis of Alzheimer disease. Ann Intern Med 2004 ; 140 : 501-9.

Survival after initial diagnosis of Alzheimer disease

Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few are practical for the current clinical environment, and the optimal priming modalities for specific clinical presentations are not known. Accordingly, developing an understanding of the various types of motor priming paradigms and their underlying neural mechanisms is an important step for therapists in neurorehabilitation. Most importantly, an understanding of the methods and their underlying mechanisms is essential for optimizing rehabilitation outcomes. The future of neurorehabilitation is likely to include these priming methods, which are delivered prior to or in conjunction with primary neurorehabilitation therapies. In this Special Interest article, we discuss those priming paradigms that are supported by the greatest amount of evidence, including (i) stimulation-based priming, (ii) motor imagery and action observation, (iii) sensory priming, (iv) movement-based priming, and (v) pharmacological priming.Video Abstract available. (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A86) for more insights from the authors.

Motor priming in neurorehabilitation.

BACKGROUND AND PURPOSE Studies have shown that adults with Alzheimer disease (AD) have gait and balance deficits; however, the focus has been on those with mild to severe disease. The purpose of this study was to determine whether balance and gait deficits are present in those with very mild AD. METHODS Thirteen adults (72.9±4.7 years old) with very mild AD and 13 age-matched (72.6±4.6 years old) and sex-matched (10 males and 3 females) participants in a control group without AD performed balance and gait tests. All participants were living in the community and independent in community ambulation. RESULTS Participants with very mild AD had shorter times in tandem stance with eyes open (P<0.001) and with eyes closed (P=0.007) compared with participants in the control group. Those with AD also took longer to complete the Timed "Up & Go" Test (P<0.001). Gait deficits were found for those with AD as demonstrated by slower velocities in the 10-m walk at a comfortable pace (P=0.029) and on an instrumented walkway (P<0.001). Stance times were longer for those with AD (P<0.001) and step length was shorter (P=0.001). There were no group differences in the 10-m walk at a fast pace. The gait velocity of participants in the control group was faster on the instrumented walkway than in the 10-m walk at a comfortable pace (P=0.031). In contrast, the gait velocity of those with AD was significantly slower on the instrumented walkway than in the 10-m walk at a comfortable pace (P=0.024). DISCUSSION Balance and gait deficits may be present in those in the very early stages of AD. Novel surfaces may affect gait speed in those with very mild AD. Identifying mobility deficits early in the progression of AD may provide an opportunity for early physical therapy intervention, thus promoting continued functional independence. CONCLUSIONS Adults in the very early stages of AD may show signs of balance and gait deficits. Recognition of these problems early with subsequent physical therapy may slow the progression of further balance and gait dysfunction.

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Balance and gait of adults with very mild Alzheimer disease.

Older adults with mild cognitive impairment (MCI) and early-stage dementia have an increased risk of falling, with risks to their health and quality of life. The purpose of the current integrative review was to evaluate evidence on fall risk and fall prevention in this population. Studies were included if they examined falls or fall risk factors in older adults with MCI or early-stage dementia, or reported interventions in this population; 40 studies met criteria. Evidence supports the increased risk of falls in individuals even in the early stages of dementia or MCI, and changes in gait, balance, and fear of falling that may be related to this increased fall risk. Interventions included exercise and multifactorial interventions that demonstrated some potential to reduce falls in this population. Few studies had strong designs to provide evidence for recommendations. Further study in this area is warranted. [Res Gerontol Nurs. 2017; 10(03):139-148.].

Falls and Fall Prevention in Older Adults With Early-Stage Dementia: An Integrative Review.

OBJECTIVE: The aim of this study was to determine the rate of change in falls risk and balance and mobility performance in people with Alzheimer disease (AD) compared with those of healthy older people over a 1-yr period. DESIGN: A 1-yr follow-up study of change in levels of falls risk, balance, and mobility performance in 15 community-dwelling older people with mild to moderate AD and 15 healthy age-matched older people was conducted. Each participant completed a comprehensive assessment of balance and mobility, falls and falls risk, and level of physical activity at baseline and 1 yr later. RESULTS: The rate of increase in the number of falls and risk of falling was greater in people with AD. The rate of deterioration on a number of balance and mobility measures was also significantly greater in people with AD compared with the healthy older people. CONCLUSIONS: People with mild to moderate AD have an increased rate of decline in falls risk, balance, and mobility over a 12-mo period compared with age-matched healthy older people. Given this increased rate of decline, intermittent review of falls, balance and mobility, and interventions to address identified contributory risk factors should be considered by health practitioners. Language: en

A longitudinal study of change in falls risk and balance and mobility in healthy older people and people with Alzheimer disease

Background and purpose Individuals with Alzheimer disease (AD) have a higher risk of falls than their cognitively intact peers. This pilot study was designed to assess the feasibility and effectiveness of a small-group balance exercise program for individuals with AD in a day center environment. Methods Seven participants met the inclusion criteria: diagnosis of AD or probable AD, medical stability, and ability to walk (with or without assistive device). We used an exploratory pre- and post-test study design. Participants engaged in a functional balance exercise program in two 45-minute sessions each week for eight weeks. Balance activities were functional and concrete, and the intervention was organized into constant, blocked, massed practice. Outcome measures included Berg Balance Scale (BBS), Timed Up and Go (TUG), and gait speed (GS; self-selected and fast assessed by an instrumented walkway). Data were analyzed by comparing individual change scores with previously identified minimal detectable change scores at the 90% confidence level (MDC90). Results Pre- and post-test data were acquired for five participants (two participants withdrew). The BBS improved in all five participants, and improved > or = 6.4 points (the MDC90 for the BBS in three participants. Four participants improved their performance on the TUG, and three participants improved > or = 4.09 seconds (the MDC90 for the TUG). Self-selected GS increased > or = 9.44 cm/sec (the MDC90 for gait speed) in three participants. Two participants demonstrated post-test self-selected GS comparable with their pretest fast GS. Discussion and conclusions This pilot study suggests that a small-group functional balance intervention for individuals with AD is feasible and effective. Although participants had no explicit memory of the program, four of five improved in at least two outcome measures. Larger scale functional balance intervention studies with individuals with AD are warranted.

Jamie Michelle Drake

Papers

A small-group functional balance intervention for individuals with Alzheimer disease: a pilot study.