Intact Procedural Knowledge in Patients with Alzheimer's Disease: Evidence from Golf Putting.

Can Alzheimer's disease (AD) patients efficiently learn to perform a complex motor skill when relying on procedural knowledge? To address this question, the authors compared the golf-putting performance of AD patients, older adults, and younger adults in 2 different learning situations: one that promotes high error rates (thus increasing the reliance on declarative knowledge) or one that promotes low error rates (thus increasing the reliance on procedural knowledge). Motor performance was poorer overall for AD patients and older adults relative to younger adults in the high-error condition but equivalent between similar groups in the low-error condition. Also, AD patients in the low-error condition had better performance at the final putting distance relative to those in the high-error condition. This performance facilitation for AD patients likely stems from intact procedural knowledge.

Time perception in patients with dementia with Lewy bodies.

Disturbances of time perception could explain some behavioral disorders in patients with dementia with Lewy bodies (DLB), and the aim of this preliminary study was to evaluate time perception in these patients. 7 patients with DLB (mean age = 82±6,8 years) were compared to 7 cognitively normal subjects (m = 81.2±6,8 years) for spatiotemporal orientation, verbal estimation, semantic knowledge, rhythm perception and verbal time estimation. The scores on the semantic scale of temporality were statistically different between the two groups, and patients made more rhythm errors than the control sample. Moreover, a significant improvement between the first and second assessment on verbal time estimation was found in the control subjetcs but not in the patients. Time perception seems to be disturbed in patients with DLB, but more studies are required to understand this result with the behavioural disorders.

Biomarkers of vascular dysfunction and cognitive decline in patients with Alzheimer's disease: no evidence for association in elderly subjects.

BACKGROUND: Several studies have suggested that vascular dysfunction plays an important role in Alzheimer's disease. AIMS: We hypothesized that significant differences might be observed in the levels of blood endothelial biomarkers across elderly population of subjects with dementia. METHODS: We analyzed, in a prospective monocentric study, three different endothelial biomarkers, endothelial microparticles (EMPs), endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) in 132 older patients who underwent a full evaluation of a memory complaint. RESULTS: There was no difference in specific EMP, EPC or CEC levels between demented or non-demented patients, nor considering cognitive decline. DISCUSSION: Blood endothelial biomarkers may be too sensitive and it is likely that the multimorbidity observed in our patients may lead to opposite and confounding effects on endothelial biomarkers levels. CONCLUSION: Unlike younger AD patients, our results suggest that endothelial biomarkers are not valuable for the diagnosis of dementia in elderly patients.

[Link between non hypoxemic chronic obstructive pulmonary disease and executive functioning in oldest old]. / Étude du lien entre la broncho-pneumopathie obstructive non hypoxémiante et le fonctionnement exécutif de patients de plus de 75 ans.

COPD (chronic obstructive pulmonary disease) may result in cognitive disorders (mainly executive) even without hypoxemia. The aim of this descriptive study was to highlight a deficit in task-switching in non-hypoxemic patient with COPD and mild cognitive impairment (MCI) or Alzheimer disease (AD). The main judgment criterion was patients' performances on the TMTA and B. COPD patients were recruited via the database (CogDisCo) of the geriatric medicine department at Pitié Salpêtrière hospital in Paris. 7 patients had Alzheimer's disease (AD), and 11 mild cognitive impairment (MCI): they were matched for age, sex, MMSE, education level with controls subjects without COPD. There was no significant difference between the two groups. However, patients with COPD and MCI required, on average, an extra 13 seconds compared with patient without COPD for the TMTA and 18 seconds for the TMTB. Patients with COPD and AD needed, on average, an extra 63 seconds for TMTA and 97 seconds for TMTB. The number of errors for the TMTB was the same in the both groups. This preliminary study does not show statistically significant results but the time for achieving TMT was longer in the population with COPD whether AD or MCI. These results encourage us to continue with prospective studies on larger samples.

Recollection training and transfer effects in Alzheimer's disease: effectiveness of the repetition-lag procedure.

OBJECTIVE: This study was designed to extend the use of a memory training technique, known as the repetition-lag procedure, to Alzheimer patients. The specificity of this procedure is to target the process of recollection for improvement. METHOD: A group of 12 patients were trained individually for 6h. The training procedure consisted of a series of yes/no recognition tasks in which some words were repeated throughout the test list across gradually increasing delays. Their performance was evaluated on pre-and-post tests and compared with a recognition practice group and a no contact control group. RESULTS: Initially, recollection training patients only performed accurately when the delay between repetitions consisted of one intervening word, but by the end of training their performance increased up to four-word intervals. Interestingly, these benefits generalized to other measures of memory, such as working memory, visual memory and source recognition. CONCLUSIONS: Effectiveness of the repetition-lag procedure in Alzheimer's disease is discussed.

Abnormal temporal dynamics of visual attention in Alzheimer's disease and in dementia with Lewy bodies.

Although attentional control processes are disproportionately impaired in dementia with Lewy bodies (DLB) compared with dementia of the Alzheimer type (DAT), previous studies have not compared directly the temporal dynamics of visual attention in DLB and DAT. We examined the magnitude of the attentional blink (AB) effect in these patients, to determine the degree to which each patient group exhibited a deficit in selecting and processing visual stimuli presented in rapid succession. Eighteen DAT, 15 DLB patients, and 33 elderly controls were tested in a rapid serial visual presentation task. Participants were asked to report 1 (single-target condition) or 2 target letters (dual-target condition) embedded in a sequence of digit distracters. The temporal dynamics of visual attention was examined by varying the number of intervening distracters between the 2 targets in the dual-target condition and by estimating the attentional blink effect as the decline in the ability to report the second target correctly after successfully identifying the first. Patients with DLB performed significantly worse than patients with DAT and controls in both the single and dual-targets conditions. In contrast, DAT patients showed a selective impairment in the dual-target condition as compared with controls. As predicted, we found that both patients with DAT and DLB showed a more pronounced and protracted attentional blink than controls, indicating a reduced ability to re-engage attention on the second target. Furthermore, when DAT and DLB patients were able to report the second target, they frequently failed to identify the first, an effect that was absent in elderly controls and particularly large and long-lasting in DLB patients. This study suggests that both DLB and DAT patients show abnormal temporal dynamics of visual selective attention, presumably due to a greater intertarget competition for limited processing capacity. More generally, these findings reinforce the notion that deficits of attentional control processes are more severe in DLB patients as compared with DAT patients.

[Use of nondeclarative and automatic memory processes in motor learning: how to mitigate the effects of aging]. / Utilisation des processus mnésiques non déclaratifs et automatiques dans l'apprentissage moteur: comment atténuer les effets du vieillissement.

Does normal aging inexorably lead to diminished motor learning abilities? This article provides an overview of the literature on the question, with particular emphasis on the functional dissociation between two sets of memory processes: declarative, effortful processes, and non-declarative, automatic processes. There is abundant evidence suggesting that aging does impair learning when past memories of former actions are required (episodic memory) and recollected through controlled processing (working memory). However, other studies have shown that aging does not impair learning when motor actions are performed non verbally and automatically (tapping procedural memory). These findings led us to hypothesize that one can minimize the impact of aging on the ability to learn new motor actions by favouring procedural learning. Recent data validating this hypothesis are presented. Our findings underline the importance of developing new motor learning strategies, which "bypass" declarative, effortful memory processes.

[Preservation of automatic ocular saccades in healthy elderly: alteration in patients with dementia with Lewy body]. / Longévité et robustesse de la saccade oculaire automatique chez le sujet âgé sain : atteinte dans des cas de démence à corps de Lewy.

We studied, in healthy elderly subjects (aged from 63 to 83 years) and adults (aged from 20 to 32 years), ocular saccades in two conditions: one the one hand, the gap condition, where the central target disappears; then follows a period of 200 ms during which the fixation and attention were disengaged; finally, a visual target appears in the periphery. On the other hand, the overlap condition, in which the peripheral target appears when the central target is still present, the subject should voluntarily disengage his attention and fixation to orient them toward the peripheral target. These paradigms stimulate automatic versus controlled triggering of saccades. The average saccade latency (measured by video-oculography) was longer in the elderly, and irrespectively of the condition. However, the elderly as the young subjects produced shorter latencies in the gap condition than in the overlap condition. Moreover, in the gap condition, we observed the emergence of a considerable number of reflex saccades with very short latency (between 80 and 120 ms, minimal conduction time) called "express saccades". The occurrence rate of such saccades was similar in the young and the elderly subjects. These results suggest the existence of separate circuits, one non-being sensitive to age (express saccades), the other suffering the effects of aging (controlled saccades). In another ongoing study, this methodology has been applied to patients with Lewy body dementia. The preliminary results from three patients showed an abnormal slowness of latencies, even in the gap condition expected to promote automatic and reflex saccades. Furthermore, we observed a total absence of saccades with express latency. These promising results suggest a deficit even for automatic and express saccades in these patients.

Spread deficits in initiation, speed and accuracy of horizontal and vertical automatic saccades in dementia with lewy bodies.

BACKGROUND: Mosimann et al. (2005) reported prolongation of saccade latency of prosaccades in dementia with Lewy body (DLB). The goal of this study is to go further examining all parameters, such as rates of express latency, but also accuracy and velocity of saccades, and their variability. METHODS: We examined horizontal and vertical saccades in 10 healthy elderly subjects and 10 patients with DLB. Two tasks were used: the gap (fixation target extinguishes prior to target onset) and the overlap (fixation stays on after target onset). Eye movements were recorded with the Eyelink II eye tracker. RESULTS: The main findings were: (1) as for healthy, latencies were shorter in the gap than in the overlap task (a gap effect); (2) for both tasks latency of saccades was longer for DLB patients and for all directions; (3) express latency in the gap task was absent for large majority of DLB patients while such saccades occurred frequency for controls; (4) accuracy and peak velocity were lower in DLB patients; (5) variability of all parameters was abnormally high in DLB patients. CONCLUSIONS: Abnormalities of all parameters, latency, accuracy and peak velocity reflect spread deficits in cortical-subcortical circuits involved in the triggering and execution of saccades.

Social cognition: an early impairment in dementia of the Alzheimer type.

OBJECTIVE: A core component of social functioning is the capacity to attribute mental states to others and to understand intention as psychologic cause. The hypothesis of this study was that dementia of the Alzheimer type (DAT) patients show an impaired understanding of psychologic cause although they remain able to understand physical causality. METHODS: To test this hypothesis, 20 elderly adults with DAT, 20 healthy age-matched controls, and 20 healthy young adults were presented a cartoon task requiring them to process physical or psychologic cause of events. RESULTS: Patients with DAT at onset scored significantly lower than controls when they had to reason about psychologic causation, while they did not differ for reasoning about physical causation. Consistent with these results, patients with DAT showed significantly lower scores in psychologic reasoning as compared with their scores for physical causality. Instead young and elderly healthy adults scored similarly for the 2 types of causality and the 2 groups did not differ in their scores. These results suggest that impaired understanding of intention in others may be considered as an early socio-cognitive index of onset of DAT. A post hoc division of the group of patients with DAT into 2 subgroups according to Mini Mental State (MMS) scores showed that the group with the more severe MMS scores not only had lower scores for psychologic causality but also showed impairment in reasoning about physical causality involving persons. Physical causality involving objects remained relatively preserved. CONCLUSIONS: The remarkable deficit in attribution of intention in our patients with DAT at onset and the following deterioration of their performance in reasoning about physical causality with persons may reflect progressive dysfunction of the superior temporal sulcus in Alzheimer disease.