Résumé
Le déclin cognitif joue un rôle important dans le concept de fragilité de la personne âgée. Il est physiologique s’il est mineur et limité aux capacités attentionnelles et à la vitesse de traitement des informations, pathologique s’il induit un trouble cognitif léger ou un syndrome démentiel. La cognition est influencée par de multiples facteurs organiques et psychologiques pouvant s’intégrer à des maladies neurodégénératives ou neurovasculaires, à des comorbidités ou à l’iatrogénie, chacun de ces facteurs pouvant participer à d’autres composantes du syndrome de fragilité. La phase prédémentielle induite par la plupart des maladies neurodégénératives, telles la maladie d’Alzheimer ou la maladie à corps de Lewy, est associée à un risque de décompensation brutale d’un statut cognitif fragile illustrée par une confusion. Cette confusion représente alors un véritable marqueur de fragilité cognitive. Cette diminution de la réserve cognitive doit être repérée afin de mettre en place les mesures de prévention secondaire, en particulier de la dépendance et des symptômes comportementaux.
Abstract
Cognitive decline plays a fundamental role in the concept of frailty in the elderly. This decline is physiological if it is only minor and limited to attention span capacity and the speed at which information is processed; however, it becomes pathological when it leads to slight cognitive issues or dementia. Cognition is influenced by a number of organic and psychological factors, which can be associated with neurodegenerative or neurovascular diseases, with comorbidities or iatrogenic effects; each one of these factors possibly contributing to other components of frailty syndrome. The pre-dementia phase, brought about by the majority of neurodegenerative diseases such as Alzheimer’s or Dementia with Lewy Bodies, is associated with a risk of sudden decompensation in fragile cognitive status which is illustrated by confusion. This confusion thus represents a true marker for cognitive frailty. This reduction in cognitive reserve must be identified so as to implement secondary prevention measures, specifically concerning dependency and behavioural symptoms.
Références
Fried LP, Tangen CM, Walston J, et al (2001) Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci 56(3):M146–M156
Rockwood K, Fox RA, Stolee P, et al (1994) Frailty in elderly people: an evolving concept. CMAJ 150(4):489–495
Murphy M, O’Leary E (2010) Depression, cognitive reserve and memory performance in older adults. Int J Geriatr Psychiatry 25(7):665–671
Voineskos AN, Rajji TK, Lobaugh NJ, et al (2012) Age-related decline in white matter tract integrity and cognitive performance: a DTI tractography and structural equation modeling study. Neurobiol Aging 33(1):21–34
Salthouse TA (2009) When does age-related cognitive decline begin? Neurobiol Aging 30(4):507–514
Raz N, Rodrigue KM (2006) Differential aging of the brain: patterns, cognitive correlates and modifiers. Neurosci Biobehav Rev 30(6):730–748
Raz N, Ghisletta P, Rodrigue KM, et al (2010) Trajectories of brain aging in middle-aged and older adults: regional and individual differences. Neuroimage 51(2):501–511
Mezuk B, Edwards L, Lohman M, et al (2011) Depression and frailty in later life: a synthetic review. Int J Geriatr Psychiatry [Epub ahead of print]
Geerlings MI, den Heijer T, Koustaal PJ, et al (2008) History of depression, depressive symptoms, and medial temporal lobe atrophy and the risk of Alzheimer disease. Neurology 70(15):1258–1264
Aarsland D, Pahlhagen S, Ballard CG, et al (2012) Depression in Parkinson disease-epidemiology, mechanisms and management. Nat Rev Neurol 8(1):35–47
Jack CR Jr, Albert M, Knopman DS, et al (2011) Introduction to revised criteria for the diagnosis of Alzheimer’s disease: National Institute on Aging and the Alzheimer’s Association workgroup. Alzheimers Dement 7(3):257–262
Jack CR Jr, Knopman DS, Jagust WJ, et al (2010) Hypothetical model of dynamic biomarkers of the Alzheimer’s pathological cascade. Lancet Neurol 9(1):119–128
McKhann GM, Knopman DS, Chertkow H, et al (2011) The diagnosis of dementia due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement 7(3):263–269
McKeith IG, Dickson DW, Lowe J, et al (2005) Diagnosis and management of dementia with Lewy bodies: third report of the DLB Consortium. Neurology 65(12):1863–1872
Pohjasvaara T, Mantyla R, Ylikoski R, et al (2000) Comparison of different clinical criteria (DSM-III, ADDTC, ICD-10, NINDSAIREN, DSM-IV) for the diagnosis of vascular dementia. National Institute of Neurological Disorders and Stroke-Association internationale pour la recherche et l’enseignement en neurosciences. Stroke 31(12):2952–2957
Jones RN, Fong TG, Metzzer E, et al (2010) Aging, brain disease, and reserve: implications for delirium. Am J Geriatr Psychiatry 18(2):117–127
Solfrizzi V, Frisardi V, Capurso C, et al (2009) Whole-diet approach: working on a criterion validity for age-related cognitive decline and mild cognitive impairment. J Am Geriatr Soc 57(10):1944–1946
Carter CS, Leeuwenburgh C, Daniels M, et al (2009) Influence of calorie restriction on measures of age-related cognitive decline: role of increased physical activity. J Gerontol A Biol Sci Med Sci 64(8):850–859
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Krolak-Salmon, P. Cognition et fragilité chez la personne âgée. cah. année gerontol. 4, 13–16 (2012). https://doi.org/10.1007/s12612-012-0257-y
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12612-012-0257-y