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International audience; : Patients with developmental amnesia usually suffer from both episodic and spatial memory deficits. DM, a developmental amnesic, was impaired in her ability to process self-motion (i.e., idiothetic) information while her ability to process external stable landmarks (i.e., allothetic) was preserved when no self-motion processing was required. On a naturalistic and incidental episodic task, DM was severely and predictably impaired on both free and cued recall tasks. Interestingly, when cued, she was more impaired at recalling spatial context than factual or temporal information. Theoretical implications of that co-occurrence of deficits and those dissociations are discussed and testable cerebral hypothesis are proposed.

International audience; OBJECTIVE: The present study directly evaluated the impact of feature sharedness on the differences between superordinate and basic-level concepts observed in semantic dementia (SD) patients. METHOD: For this purpose, we studied a group of 6 SD patients and a group of 12 matched controls using a sentence verification task in which we orthogonally manipulated feature sharedness (more vs. less shared) and concept level (basic level vs. superordinate). RESULTS: Main results showed that the superordinate advantage in SD patients was observed for more shared features but not for less shared features (p < .05, η(p)2 = .36). CONCLUSION: These results directly support the role of feature sharedness in explaining the hierarchical organization of semantic knowledge and the specific to general pattern of knowledge deterioration in SD in particular.

Resume A propos de deux observations singulieres de projection dans le passe avec une amnesie retrograde autobiographique massive de quelques mois, le cadre nosographique de l’amnesie retrograde fonctionnelle est reaborde : la particularite du stock autobiographique avec son classement temporel, la nature anatomofonctionnelle de la recherche de souvenirs personnels, l’eventualite d’un blocage d’acces volontaire a la trace mnesique et enfin l’irruption de souvenirs si precis qu’ils projettent le sujet dans le passe. Dans l’ictus amnesique, l’amnesie retrograde massive d’une periode de vie limitee peut conduire pendant l’episode a une projection dans un passe qui une fois l’ictus termine sera de nouveau oublie. Des souvenirs tres precis resurgissent, qui donnent realite a ce retour en arriere. Dans l’amnesie fonctionnelle, un meme phenomene peut se produire durablement. La dichotomie entre amnesies fonctionnelle et organique merite d’etre depassee a la lumiere de ce type d’observations.

La memoire semantique est classiquement consideree comme un systeme regroupant les connaissances generales sur le monde dont celles relatives aux objets manufactures ou biologiques. A ce jour, peu d’outils francophones permettent d’evaluer un meme ensemble d’items de facon standardisee et a travers differents formats de presentation. Pourtant, la mise en evidence des troubles plurimodaux est necessaire pour attester une atteinte des connaissances semantiques et non un trouble d’acces modalite-dependant. Dans ce but, la commission GRESEM a elabore une batterie d’evaluation des connaissances semantiques (BECS-GRECO). Cette batterie permet d’evaluer l’integrite de 40 entites (20 biologiques et 20 manufacturees) et de leurs attributs, sous deux formats (mots ecrits et dessins au trait) au moyen de 6 sous-tests. Les normes etablies aupres de 317 participants sains (âges de 20 ans a plus de 75 ans) ont ete presentees sous la forme de scores seuils. La batterie a egalement ete proposee a deux groupes de patients, l’un atteint de demence semantique et l’autre de maladie d’Alzheimer aux stades legers. A l’exception du sous-test d’appariement par identite, ce travail retrouve de bons compromis sensibilite-specificite, et souligne ainsi l’interet clinique de cette batterie pour detecter des atteintes semantiques.

Some patients with relatively selective hippocampal damage have shown proportionate recall and recognition deficits. Moreover, familiarity as well as recollection have been found to be impaired in some of these patients. In contrast, other patients with apparently similar damage presented with relatively preserved recognition despite having severely impaired recall, and some of these patients have been shown to have preserved familiarity. We report here the case of an amnesic patient who suffered bilateral hippocampal damage and temporoparietal atrophy after carbon monoxide poisoning. On tests matched for difficulty, his recall performance was more severely impaired than his recognition memory, for verbal as well as for visual materials. Moreover, he performed within the range of healthy matched subjects on nine recognition tests out of ten. In a task using the process dissociation procedure, the patient's familiarity was preserved although his recollection was impaired. These findings indicate that recall and recognition memory can be dissociated in amnesic patients with hippocampal lesions even when temporoparietal cortical atrophy is also present.

Following cerebral anoxia, EC, a 55-year-old patient, exhibited a severe and clear-cut pattern of semantic impairments without general intellectual deficit or perceptual difficulty. EC demonstrated a complex neuropsychological picture including a massive visual agnosia and a complete lack of imagery, both of which involved all categories of objects (living and non living) and a category-specific word comprehension deficit limited to animal names. Findings are discussed in the light of the theoretical frameworks currently available in the area of neuropsychology. It is argued that neither the single nor the multiple view of semantics fully succeed in providing a satisfactory account of the data and a tentative interpretation of the whole pattern of impairment is proposed in the general framework of non abstractive conceptions of meaning.

A double-blind, placebo-controlled, parallel-group, multicentre study was conducted to evaluate the efficacy of pentoxifylline (Trental) in patients with multi-infarct dementia (MID) according to DSM-III-R criteria. Men and women aged 45 years or older, with a Hachinski Ischemia Scale scoreor = 7 and a Mini Mental State Examination (MMSE) score of 10-25 at entry, and computed tomographic evidence of vascular disease were enrolled. A total of 289 patients were randomised to receive either oral pentoxifylline 400 mg t.i.d. or placebo for 9 months, and efficacy was assessed every 3 months. The primary outcome variable was the difference in scores between the two treatment groups, as measured on the Gottfries, Bråne, Steen (GBS) scale. Secondary outcome variables included the scores achieved on the Sandoz Clinical Assessment Geriatric (SCAG) scale and MMSE, and a battery of psychological and other tests. The intention-to-treat analysis for patients completing the study (n = 239) showed a statistically significant difference in the total GBS score in favour of pentoxifylline (improvement of 3.5 points, p = 0.028). A significant difference in the total GBS score in favour of pentoxifylline was even almost achieved in the intention-to-treat analysis for all evaluable patients (n = 269, improvement of 2.1 points, p = 0.065). It is concluded that treatment with pentoxifylline is beneficial for patients with MID, the global results of the GBS and SCAG scales being reinforced by significant improvements in those subscales specific for intellectual and cognitive function.

International audience; Apathy is common in aging and generally defined on the basis of three dimensions: lack of initiative, lack of interest and emotional blunting. Curiously, no study until now has examined the associations and dissociations between these dimensions in elderly people (with or without dementia). These questions were addressed in two studies. In the first study, we explored the distribution of scores and the relationships between the three dimensions of apathy in 56 patients with dementia, focusing mainly on lack of initiative and lack of interest. Apathy was hetero-evaluated with the Apathy Inventory (AI), a scale widely used to assess the apathy dimensions in aging. In the second study, given the AI's limitations, we investigated in more detail the relationship between lack of initiative and interest in 115 elderly people using a new questionnaire specifically designed to assess these two dimensions. Results showed that lack of initiative was closely related to lack of interest (Study 1). Although we used a more specific questionnaire, these facets of apathy did not constitute two separable dimensions, but reflected a common main factor of apathy in aging (Study 2). Thus, the distinction between lack of initiative and lack of interest seems questionable. Only a multifactorial approach that includes the various psychological factors involved in apathy would enable one to gain a better understanding of the different manifestations of apathy and to highlight possible dissociations between them.

International audience; Mediotemporal lobe structures are involved in both spatial processing and long-term memory. Patient M.R. suffers from amnesia, due to bilateral hippocampal lesion and temporoparietal atrophy following carbon monoxide poisoning. We compared his performance in immediate spatial memory tasks with the performance of ten healthy matched participants. Using an immediate reproduction of path, we observed a dissociation between his performance in three allocentric tasks and in five egocentric-updating tasks. His performance was always impaired on tasks requiring the use of an egocentric-updating representation but remained preserved on allocentric tasks. These results fit with the hypothesis that the hippocampus plays a role in spatial memory, but they also suggest that allocentric deficits previously observed in amnesia might actually reflect deficits in egocentric-updating processes. Furthermore, the co-occurrence of deficits in episodic long-term memory and short-term egocentric-updating representation without any short-term allocentric deficit suggests a new link between the mnemonic and navigational roles of the hippocampus. The Cognitive Map theory, the Multiple Trace theory, as well as further models linking spatial and nonspatial functions of the hippocampus are discussed.

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International audience; Apathy, defined as a reduction in voluntary goal-directed behaviors, is one of the most common behavioral symptoms encountered in Alzheimer disease (AD). However, the processes underlying the different components of apathy are still unclear. The aim of this study was to explore a particularly important aspect of executive function in daily life: multitasking [assessed with the Modified Six Elements Task (MSET)], and its relationship with apathy in AD. Sixty-seven participants (37 AD patients matched with 30 control participants) were screened using the MSET. Simultaneously, a close relative of each patient was given the Apathy Inventory, which assesses 3 distinct dimensions of apathy (lack of initiative, lack of interest, and emotional blunting). AD patients presented significantly more multitasking deficits than control participants. In addition, regression analyses revealed that the number of rule breaks on the MSET (inability to perform several tasks in a predefined time observing a number of rules) was the best predictor of apathy, and especially of lack of initiative. These results suggest that the relation between lack of initiative and multitasking has a specific character and that mechanisms underlying multitasking constitute a key component of goal-directed behaviors.

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International audience

Semantic dementia (SD) is a syndrome of progressive loss of semantic knowledge for objects and people. International criteria propose that SD be included in the frontotemporal lobar degeneration syndromes, with progressive non-fluent aphasia and frontotemporal dementia (FTD). However, several related syndromes have been defined that clinically and conceptually share both similarities and differences with SD: fluent progressive aphasia, progressive prosopagnosia, temporal variant of FTD. In order to establish a French consensus for the diagnosis and modalities of evaluation and follow-up of SD, a working group, composed of neurologists, neuropsychologists and speech-therapists, was established by the Groupe de réflexion sur les évaluations cognitives (GRECO). New criteria were elaborated, based on clinical, neuropsychological, and imaging data. They define typical and atypical forms of SD. A diagnosis of typical SD relies on an isolated and progressive loss of semantic knowledge, attested by a deficit of word comprehension and a deficit of objects and/or people identification, with imaging showing temporal atrophy and/or hypometabolism. SD is atypical if the deficit of semantic knowledge is present only within a single modality (verbal versus visual), or if non-semantic deficits (mild and not present at onset) and/or neurological signs, are associated with the semantic loss.

Visuospatial perception is a complex ability, with various aspects. We are continuously integrating different information, like when our brain processes visual information from left and right hemisphere, in order to form a single and unitary image. The processing of visuospatial information, and more specifically its global/local aspect, has led to many studies, indicating the active involvement of the corpus callosum. Objective To study the influence of an alteration of the corpus callosum on the integration of global/local information. Methods C.M. presents an Allgrove syndrome [1] , likely a pathology of white matter fibres. This patient, with a singular neuropsychological profile, is partially impaired in global and local information integration and shows a corpus callosum alteration. This research, a case-study with a group of 6 matched control subjects, relied on a two-level approach, anatomical (MRI-DTI) and behavioural, using a hierarchical letter paradigme [2] . Results Despite all the precautions needed regarding the interpretation of our results, some specificities are emphasized: at an anatomical level, we note, for C.M., a microscopic alteration of her corpus callosum; the results from our behavioural protocol show, for C.M., a higher precedence effect, a greater sensibility to interference and a facilitation effect more important. Discussion These different results, never reported before in this pathology, indicates, for C.M., an impairment in global/local integration associated with a corpus callosum alteration. This alteration, probably part of a more global degenerative process linked to her pathology, shows the relevance of an extended neuropsychological assessment coupled to a DTI study, in order to better understand impairments generally appearing in neuropsychological rehabilitation.

Primary progressive aphasia (PPA), initially described by Mesulam, is a syndrome of progressive deterioration of language, occurring in the presenium. Several classifications have been proposed, but the most useful one distinguishes non fluent and fluent forms of PPA. Both begin by anomia. In non fluent PPA, there is a progressive reduction of language, sometimes with aggramatism and articulatory impairment, but without impairment of comprehension. Fluent PPA is characterized by preserved fluency with severe impairment of single word comprehension. It is frequently confounded with semantic dementia (SD), but some observations can be differentiated from SD. After several years, all patients become mute, and most of them develop dementia, usually of frontal lobe type. The syndrome of PPA is due to neurodegenerative brain pathology affecting mostly the perisylvian regions of the left hemisphere. In most cases, no Alzheimer type pathology was found in the brain, but tauopathy (mainly in non fluent PPA) or motor neuron disease type pathology - tau negative ubiquitin inclusions (mainly in fluent PPA). However, Alzheimer type pathology was found in a substantial number of cases.

Introduction La demence semantique se definit comme une perte progressive des connaissances semantiques, responsable d’une difficulte a identifier les objets (et/ou personnes) a partir de leur image et/ou de leur nom. La memoire au jour le jour est normale et les aspects non semantiques du langage sont theoriquement preserves. Cependant, les travaux qui ont evalue chez les patients DS l’integrite des representations lexicales pre-semantiques au moyen de la tâche de decision lexicale donnent lieu a des resultats divergents, allant d’une preservation totale a un deficit severe. L’hypothese la plus couramment avancee consiste a mettre en relation la degradation des performances en decision lexicale avec la severite des troubles semantiques. Afin de tester cette hypothese, nous avons evalue de facon systematique les performances dans cette tâche de 6 patients DS. Methode 6 patients presentant une DS selon les criteres de Neary et al (1998) ont participe a l’etude. 2 patients presentent une forme verbale pure de DS et 4 presentent une forme multimodale associant des troubles du langage a des deficits de l’identification visuelle des objets et des personnes. La severite des troubles semantiques etait attestee par la performance au Pyramid et Palm Trees test, dans sa forme verbale. La tâche de decision lexicale comportait des mots de haute et basse frequence et des non mots legaux, apparies en longueur et frequence des graphemes, presentes oralement. Resultats Les performances en decision lexicale sont variables et vont d’une preservation totale a des performances tres deficitaires. Il n’existe aucune correlation avec la severite des troubles semantiques mesures par la performance au PPTT verbal. En revanche, la performance est correlee avec le profil des troubles : la decision lexicale est tres deficitaire chez les 2 patients presentant une forme atypique (verbale pure) selon les criteres de Moreaud et al (2008), alors qu’elle est preservee dans les DS typiques (multimodales), qui presentent pourtant des deficits semantiques plus severes. Conclusion Ce resultat suggere que la forme verbale pure et la forme multimodale de demence semantique pourraient representer deux entites cliniques distinctes sous-tendues par des deficits fonctionnels differents.

The role of semantic knowledge in object utilisation is a matter of debate. It is usually presumed that access to semantic knowledge is a necessary condition for manipulation, but a few reports challenged this view. The existence of a direct, pre-semantic route from vision to action has been proposed. We report the case of a patient with a disorder of object use in everyday life, in the context of probable Alzheimers disease. This patient was also impaired when manipulating single objects. He showed a striking dissociation between impairment in object use and preserved capacity to perform symbolic and meaningless gestures. To elucidate the nature of the disorder, and to clarify the relations between semantic knowledge and object use, we systematically assessed his capacity to recognise, name, access semantic knowledge, and use 15 common objects. We found no general semantic impairment for the objects that were not correctly manipulated, and, more importantly, no difference between the semantic knowledge of objects correctly manipulated and objects incorrectly manipulated. These data, although not incompatible with the hypothesis of a direct route for action, are better accommodated by the idea of a distributed semantic memory, where different types of knowledge are represented, as proposed by Allport (Allport, D. A. Current perspectives in dysphasia, pp. 32–60. Churchill Livingstone, Edinbuirgh, 1985).

Predominant impairment or preservation of category-specific naming and comprehension is not rare in aphasics. Much less frequent is a selective inability to generate proper names. To our knowledge, only one such case has been reported after a left thalamic lesion, located in the ventral anterior nucleus, the mamillo-thalamic tractus and the genu of the internal capsule. We report a new case of selective inability to generate proper names after a left tubero-thalamic infarct. A 65-year old right-handed man presented with a selective impairment in producing proper names, both from photographs or descriptions and on tests of verbal fluency. The deficit was obvious both for persons names and for geographical names. The rest of the neuropsychological testing was remarkable only for a mild verbal amnesia, affecting only serial material (list of words), a reduced fluency for flowers, fruits and musical instruments, difficulties in learning of new words, and a dissociation between preserved learning for words on a test of learning of words and occupations (Cohen, 1990). This anomia for proper names could result from an indirect frontal-lobe dysfunction, preventing voluntary activation of the phonological representation of proper names.

Le terme de « memoire semantique » fait reference a un ensemble de connaissances sur les objets, les mots et les personnes. Plusieurs types de modeles theoriques ont ete proposes pour rendre compte de l’organisation et du format de codage de ces connaissances. L’approche la plus classique est celle que nous qualifions d’approche abstractive. Elle postule que les connaissances, issues des experiences sensorimotrices, sont recodees et stockees de maniere permanente, sous un format abstrait et amodal, au sein d’une memoire semantique distincte de la memoire episodique et separee des systemes modaux perceptifs et moteurs.D’autres modeles ont ulterieurement rejete ce point de vue en supposant que les connaissances sont, au contraire, representees de maniere distribuee dans les systemes modaux perceptifs et moteurs. Dans la lignee de ces dernieres approches, nous decrirons les modeles « non abstractifs » d’Hintzman et de Damasio qui rejettent l’hypothese de l’existence d’une memoire semantique permanente et considerent que l’evocation des connaissances sur un item donne emerge momentanement de la reactivation des traces sensorimotrices des episodes l’ayant mis en jeu.