Physical activity and mild cognitive impairment and Alzheimer's disease.
ABSTRACT Regular physical activity undoubtedly has many health benefits for all age groups. In the past decade, researchers and clinicians have begun to focus their attention on whether physical activity also can improve health outcomes of older adults who experience mild cognitive impairment (MCI) or dementia. This ongoing question is gaining relevance in light of the aging of the world population and with it the rise of age-related conditions, such as cognitive impairment. Not surprisingly, physical activity is among the potential protective lifestyle factors mentioned when strategies to delay or prevent dementia are discussed. The first large-scale multidomain intervention trials are under way to put this to the test. This review aims to give an overview of recent trials of physical activity in patients with MCI or dementia.
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ABSTRACT: Several models of neural compensation in healthy aging have been suggested to explain brain activity that aids to sustain cognitive function. Applying recently suggested criteria of "attempted" and "successful" compensation, we reviewed existing literature on compensatory mechanisms in preclinical Huntington's disease (HD) and amnestic mild cognitive impairment (aMCI). Both disorders constitute early stages of neurodegeneration ideal for examining compensatory mechanisms and developing targeted interventions. We strived to clarify whether compensation criteria derived from healthy aging populations can be applied to early neurodegeneration. To concentrate on the close coupling of cognitive performance and brain activity, we exclusively addressed task fMRI studies. First, we found evidence for parallels in compensatory mechanisms between healthy aging and neurodegenerative disease. Several studies fulfilled criteria of attempted compensation, while reports of successful compensation were largely absent, which made it difficult to conclude on. Second, comparing working memory studies in preclinical HD and aMCI, we identified similar compensatory patterns across neurodegenerative disorders in lateral and medial prefrontal cortex. Such patterns included an inverted U-shaped relationship of neurodegeneration and compensatory activity spanning from preclinical to manifest disease. Due to the lack of studies systematically targeting all criteria of compensation, we propose an exemplary study design, including the manipulation of compensating brain areas by brain stimulation. Furthermore, we delineate the benefits of targeted interventions by non-invasive brain stimulation, as well as of unspecific interventions such as physical activity or cognitive training. Unambiguously detecting compensation in early neurodegenerative disease will help tailor interventions aiming at sustained overall functioning and delayed clinical disease onset.Frontiers in Psychiatry 01/2014; 5:132.
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ABSTRACT: IntroductionThere is increasing evidence to support the benefits of physical activity on cognition in older adults. This paper describes (i) the attitudes, beliefs and barriers towards physical activity of older adults with and without cognitive impairment and (ii) their opinion of the attributes of the ideal physical activity program.Methods Thematic analysis of focus groups and individual interviews with 50 older adults with no cognitive impairment, subjective memory complaints, mild cognitive impairment and Alzheimer's disease was performed.ResultsConsistent with previous research in cognitively intact older adults, most participants, irrespective of cognitive status, had a positive attitude towards physical activity and believed it was beneficial both generally and for cognition. There was a preference for physical activity programs to be suggested by advertising and general practitioners (GPs), undertaken in a group setting, and beliefs that they should be tailored to individual's needs and preferences, and should be affordable according to their income. Participants with cognitive impairment cited specific barriers including “memory” and “lack of companion” as well as preferring “accessible” settings and “simple/light/safe” activities.DiscussionThese findings provide useful data, particularly from participants with cognitive impairment, with whom there has been little research to date. This could contribute to efforts to translate the growing research evidence of the benefits of physical activity for brain health into effective community programs.Asia-Pacific Psychiatry 06/2014; 6(2). · 0.47 Impact Factor
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ABSTRACT: INTRODUCTION: Regular exercise induces recurrent increases in cerebrovascular perfusion. In peripheral arteries, such episodic increases in perfusion are responsible for improvement in arterial function and health. We examined the hypothesis that exercise during water immersion augments cerebral blood flow velocity compared to intensity-matched land-based exercise. METHODS: Fifteen normotensive participants were recruited (26±4yrs, 24.3±1.9kg/m). We continuously assessed mean arterial blood pressure (MAP), heart rate (HR), stroke volume, oxygen consumption and blood flow velocities through the middle and posterior cerebral arteries before, during and after 20-min bouts of water- and land-based stepping exercise of matched intensity. The order in which the exercise conditions were performed was randomized between subjects. Water-based exercise was performed in 30°C water to the level of the right atrium. RESULTS: The water- and land-based exercise bouts were closely matched for oxygen consumption [13.3ml.kg.min (95% CI=12.2, 14.6) vs. 13.5ml.kg.min (95% CI=12.1, 14.8); P=0.89] and HR [95bpm (95% CI=90, 101) vs. 96bpm (95% CI=91, 102); P=0.65]. Compared with land-based exercise, water-based exercise induced an increase in middle cerebral artery blood flow velocity [74cm/s (95% CI=66, 81) vs. 67cm/s (95% CI=60, 74) P<0.001], posterior cerebral artery blood flow velocity [47cm/s (95% CI=40, 53) vs. 43cm/s (95% CI=37, 49) P<0.001], MAP [106mmHg (95% CI=100, 111) vs. 101mmHg (95% CI=95, 106) P<0.001] and partial pressure of expired CO2 (P≤0.001). CONCLUSION: Our findings suggest that water-based exercise augments cerebrovascular blood flow, relative to land-based exercise of a similar intensity, in healthy humans.Medicine and science in sports and exercise 06/2014; · 4.48 Impact Factor