Alzheimer Disease: Dalla Barba G

Traykov L, Marcie P, Dalla Barba G, Boller F. · INSERM Unité 324, Paris. · Rev Neurol (Paris). · Pubmed #10637937 No free full text.

Abstract: This analysis is centered on the study of cognitive disorders in Alzheimer's Disease (AD), mainly for major neuropsychological functions. We insist on the heterogeneity of the clinical picture especially in the early stages of the illness, when deficits of episodic memory and executive functions are prevalent. We consider that studying early stages of the illness is necessary to delineate the diagnostic signs, to validate the new therapeutic experiments, to predict stages of decline.

Nedjam Z, Devouche E, Dalla Barba G. · INSERM, Paris, France. · Eur J Neurol. · Pubmed #15525293 No free full text.

Abstract: We examined confabulation and performance on frontal/executive tasks in Alzheimer's disease (AD) patients and patients with a diagnosis of probable frontotemporal dementia (FTD). Twenty-two patients with probable AD, 10 patients with probable FTD and 32 normal control subjects entered the study. Executive functions were assessed with the Modified Card Sorting test; a verbal fluency test; the Cognitive Estimation test; and the Stroop test. Confabulations were assessed with a modified version of the Confabulation Battery. The Confabulation Battery included 10 questions tapping each of the following domains: Episodic Memory (memories of personal past episodes), Semantic Memory (knowledge of famous facts and famous people), and Personal Future (personal plans). The results revealed that both AD patients and FTD patients were clearly and equally impaired on tests of executive functions. Both patients' groups confabulated across the three tasks of the Confabulation Battery, but FTD patients confabulated significantly more than AD patients on Episodic Memory and Personal Future. The results failed to provide any evidence of a correlation between the performance on frontal/executive tasks and the tendency to produce confabulatory reports. According to our results, confabulation, more than a deficit of frontal/executive functions, discriminate between AD and FTD. Therefore, screening for confabulation and, possibly, for other types of memory distortions may constitute a useful additional clinical tool in order to discriminate AD from FTD.

Attali E, De Anna F, Dubois B, Dalla Barba G. · INSERM Unit 610, Pavillon Claude Bernard, Hôpital de la Salpêtrière, 47, bd de l'Hôpital, Paris, France. · Brain. · Pubmed #18829697 No free full text.

Abstract: Patients who confabulate retrieve personal habits, repeated events or over-learned information and mistake them for actually experienced, specific unique events. Although some hypotheses favour a disruption of frontal/executive functions operating at retrieval, the respective involvement of encoding and retrieval processes in confabulation is still controversial. The present study sought to investigate experimentally the involvement of encoding and retrieval processes and the interference of over-learned information in the confabulation of Alzheimer's disease patients. Twenty Alzheimer's disease patients and 20 normal controls encoded and retrieved unknown stories, well-known fairy tales (e.g. Snow White) and modified well-known fairy tales (e.g. Little Red Riding Hood is not eaten by the wolf) under three experimental conditions: (i) full attention at encoding and at retrieval; (ii) divided attention at encoding (i.e. performing an attention demanding secondary task) and full attention at retrieval; (iii) full attention at encoding and divided attention at retrieval. We found that confabulations in Alzheimer's disease patients were more frequent for the modified well-known fairy tales and when encoding was weakened by a concurrent secondary task (61%), compared with the other types of stories and experimental conditions. Confabulations in the modified fairy tales always consisted of elements of the original version of the fairy tale (e.g. Little Red Riding Hood is eaten by the wolf). This is the first experimental evidence showing that poor encoding and over-learned information are involved in confabulation in Alzheimer's disease.

De Anna F, Attali E, Freynet L, Foubert L, Laurent A, Dubois B, Dalla Barba G. · INSERM Unit 610, Paris, France. · Cortex. · Pubmed #18387559 No free full text.

Abstract: Patients with Alzheimer's disease (AD) suffer from distortions of memory. Among such distortions, intrusions in memory tests are frequently observed. In this study we describe the performance of a group of mild AD patients and a group of normal controls on the recall of three different types of stories: a previously unknown story, a well-known fairy-tale (Cinderella), and a modified well-known fairy-tale (Little Red Riding Hood is not eaten by the wolf). The aim of our study was to test the hypothesis that in patients who tend to produce intrusions, over-learned information interferes with episodic recall, i.e., the retrieval of specific, unique past episodes. AD patients produced significantly more intrusions in the recall of the modified fairy-tale compared to the recall of the two other stories. Intrusions in the recall of the modified fairy-tale always consisted of elements of the original version of the story. We suggest that in AD patients intrusions may be traced back to the interference of strongly represented, over-learned information in episodic memory recall.

Naggara O, Oppenheim C, Rieu D, Raoux N, Rodrigo S, Dalla Barba G, Meder JF. · University Paris-Descartes, Faculty of Medecine, Department of Neuroradiology, Sainte-Anne Hospital, 1 rue Cabanis, 75674 Paris, France. · Psychiatry Res. · Pubmed #16520023 No free full text.

Abstract: Our aim was to investigate the extent of white matter tissue damage in patients with early Alzheimer disease (AD) using diffusion tensor magnetic resonance imaging (DTI). Although AD pathology mainly affects cortical grey matter, previous magnetic resonance imaging (MRI) studies showed that changes also exist in the white matter (WM). However, the nature of AD-associated WM damage is still unclear. Conventional and DTI examinations (b=1000 s/mm(2), 25 directions) were obtained from 12 patients with early AD (Mini Mental State Examination [MMSE] score=27, Grober and Buschke test score=33.2, digit span score=5.6) and 12 sex- and age-matched volunteers. The right and left mean diffusivity (MD) and fractional anisotropy (FA) of several WM regions were pooled in each patient and control, and compared between the two groups. Volumes of the whole brain and degree of atrophy of the temporal lobe were compared between the two groups. In AD, MD was increased in the splenium of the corpus callosum and in the WM in the frontal and parietal lobes. FA was bilaterally decreased in the WM of the temporal lobe, the frontal lobe and the splenium compared with corresponding regions in controls. Values in other areas (occipital area, superior temporal area, cingulum, internal capsule, and genu of the corpus callosum) were not different between patients and controls. No correlations were found between the MMSE score and the anisotropy indices. Findings of DTI reveal abnormalities in the frontal and temporal WM in early AD patients. These changes are compatible with early temporal-to-frontal disconnections.

Nedjam Z, Dalla Barba G, Pillon B. · U.324 INSERM, Centre Paul Broca, Paris, France. · Cortex. · Pubmed #11059455 No free full text.

Abstract: This paper describes two patients, O.I. and B.Y., with a confabulatory syndrome. O.I. was diagnosed with probable fronto-temporal dementia, whereas B.Y. met the criteria for probable Alzheimer's disease. O.I., but not B.Y., was impaired on tests of frontal/executive functions, and performed better than B.Y. on clinical tests of memory. Both patients confabulated in episodic/autobiographical memory tasks and in personal future planning tasks. B.Y. confabulated also in a semantic memory task. It is argued that the pattern of confabulation and the cognitive profile shown by the two patients is explained better by the hypothesis proposed by Dalla Barba and co-workers (Dalla Barba et al., 1997b) than by current theories of confabulation.