[Evaluation of the perspectives and experiences regarding lumbar puncture in cognitively impaired older adults over 70, their relatives and the care teams]. / Évaluation des représentations et du vécu liés à la ponction lombaire chez des patients âgés de plus de 70 ans atteints de troubles cognitifs, leurs accompagnants et les équipes soignantes.

INTRODUCTION: Lumbar puncture (LP) is an essential diagnostic procedure, which raises major concerns in older adults. Some patients may be denied LP because of the fear of complications in healthcare teams which are not familiar with the procedure. The objectives of our work were to analyze the perspectives and the experiences regarding scheduled LP in cognitively impaired older adults, as well as in their relatives, and the healthcare teams from geriatric day hospitals. METHODS: We conducted a qualitative, observational and multicentric study, based on semi-directive interviews of patients aged over 70 years with cognitive complaints undergoing a scheduled LP in a day hospital. Patients were interviewed before and after LP. Their relatives and the involved healthcare teams were also interviewed to analyze their expectations and perspectives regarding the procedure. The full interviews were transcribed and analyzed using interpretative phenomenological analysis. RESULTS: Ten patients (mean age 80.2 ± 7.2), five relatives and four healthcare teams were included. The goals and operating procedure of LP were poorly understood by several patients. Some individuals feared irreversible neurological consequences or LP-related pain, which was often overestimated with regards to the post-LP interviews. The patients' major expectation was to establish an accurate and early diagnosis of their cognitive disorder to provide optimal care plan. Relatives reported similar fears of major adverse events. They also expected an accurate diagnosis with biomarkers. The perspectives and experiences of the healthcare teams were heterogeneous, according to their level of practice of LP, but seemed in line with current scientific guidelines. CONCLUSION: This study highlighted the existence of false beliefs and poor knowledge regarding the LP procedure and its associated risks. The post-LP patients' feedbacks were better than their expectations, especially in day hospitals with solid experience in LP. Better patient information may be a key to improve our practice.

[Contribution of various MRI techniques to the characterization of Mild cognitive impairment]. / Apport de l'IRM à la caractérisation du MCI.

Mild cognitive impairment (MCI) is considered as a strong risk factor for Alzheimer's disease (AD) or other dementia syndromes. Since the last decade, numerous publications have been aimed to characterize early detectable brain changes in vivo, using more and more efficient neuroimaging techniques. This review is devoted to the brain damages detectable in MCI patients according to the MRI techniques available to date. The greatest number of studies, using structural and functional imaging, report many abnormalities principally located in the medial temporal lobe. They show, especially in this region, cortical atrophy, reduction of glucose metabolism, decrease in regional cerebral blood flew and biochemical changes. Moreover, progresses in the functional methods allow to detect brain activity during memory tasks, trying to specify whether this activity increases or decreases according to the task and the severity of cognitive impairment. The contribution of each RMI technique (morphologic, metabolic, and functional) is addressed in order to reveal how relevant they are to distinguish subjects with MCI from patients with early AD. Furthermore, their relevance to discriminate between MCI with different degrees of cognitive deficit and their power to predict the risk of conversion to AD is discussed. Finally, we review the main assumptions made to explain the underlying mechanisms of cognitive decline and present evidences in favor of dynamic compensatory processes, existence of cognitive reserve and disconnection processes. Many neuroimaging data support the pattern of installation and evolution of brain damages found in AD, reinforcing the idea that a part of amnesic MCI is probably a prodromal state of AD.