Frédérique Etcharry-Bouyx

What about theory of mind after severe brain injury

Background: Behavioural changes are often reported after a severe traumatic brain injury (TBI). These changes are usually a greater burden for relatives than physical or cognitive impairments. This study investigated social cognition in TBI patients using two theory of mind (TOM) tasks. Method: The performances of 17 patients with severe TBI and 17 matched controls were compared on two tasks designed to investigate understanding of other peoples mental states: The ‘Reading the Mind in the Eyes’ test (RME) and the ‘Character Intention Task’ (CIT). TBI patients and controls were also given several executive function tasks. Results: Compared to healthy controls, patients were impaired in most executive tests and in both TOM tasks. No relationship was found between TOM and executive measures. This is consistent with Rowes position, who suggested an independence between executive functioning and social cognition. These data suggest that TBI patients may have specific social intelligence disturbances. Conclusion: Future work should employ additional tests of TOM and behavioural ratings and recruit more patients in order to complete analysis.

Unusual use of objects after unilateral brain damage. The technical reasoning model

It has been suggested that gesture engrams, conceptual knowledge and/or the ability to infer function from structure can support object use. The present paper proposes an alternative view which is based upon the idea that object use requires solely the ability to reason about technical means provided by objects. Technical means are abstract principles which are not linked with any object representation (e.g., cutting involves the opposition between dense and permeable material). The technical reasoning model predicts that the inability to perform technical reasoning should impair performance in any situation requiring the use of objects (in a conventional way or not). Twenty left brain-damaged (LBD) patients, 11 right brain-damaged (RBD) patients and 41 healthy controls were examined on experimental tests assessing the conventional use of objects (e.g., screwing a screw with a screwdriver), conceptual knowledge about object function, pantomime of object use and recognition of object utilization gestures. We also designed the Unusual Use of Objects Test, which demands unusual applications of objects to achieve a purpose for which the usually applied object is not provided (e.g., screwing a screw with a knife). The key findings are that only LBD patients have more difficulties on the Unusual Use of Objects Test than controls or RBD patients, and that the severity of their impairment is correlated with that on conventional use of objects. Correlations with tests assessing conceptual knowledge as well as with tests of pantomime of object use and recognition of object utilization gestures were weaker. These results support the technical reasoning model and question the role of conceptual knowledge and gesture engrams in object use. Since the technical reasoning model also predicts two distinct technical disorders, the discussion focuses on the existence of these disorders in regard to individual performance profiles obtained in the Unusual Use of Objects Test.

Apraxia of tool use: More evidence for the technical reasoning hypothesis

Various distinct cognitive processes such as semantic memory, executive planning or technical reasoning have been shown to support tool use. The aim of this study is to investigate the relationship between these processes. To do so, a large apraxia battery was submitted to 16 patients with left brain-damage (LBD) and aphasia and 19 healthy controls. The battery included: classical apraxia tests (Pantomime of Tool Use and Single Tool Use), familiar and novel tool use tests (Tool-Object Pairs and Sequential Mechanical Problem-Solving), semantic memory tests (Recognition of tool utilization gestures and Functional and Categorical Associations) as well as the Tower Of London. The Sequential Mechanical Problem-Solving task is a new task which permits the evaluation of pre-planning in unusual tool use situations. In this task as well as in the Tool-Object Pairs task, participants solved a tool use problem in a Choice and a No-Choice condition to examine the effect of tool selection. Globally, left brain damaged patients were impaired as compared to controls. We found high correlations in left brain damaged patients between performances on classical apraxia tests, familiar and novel tool use tests and Functional and Categorical Associations but no significant association between these performances and Tower Of London or Recognition of tool utilization gestures. Furthermore, the two conditions (Choice and No-Choice) of Tool-Object Pairs and Sequential Mechanical Problem-Solving were associated. In sum, all tasks involving tool use are strongly associated in LBD patients. Moreover, the ability to solve sequential mechanical problems does not depend on executive planning. Also, tool use appears to be associated with knowledge about object function but not with knowledge about tool manipulation. Taken together, these findings indicate that technical reasoning and, to a lesser extent, semantic memory may both play an important role in tool use.

Different constraints on grip selection in brain-damaged patients: Object use versus object transport

The present study discusses the presence of different constraints on action selection during object use versus object transport. Sixteen left brain-damaged (LBD) patients, 10 right brain-damaged (RBD) and 35 healthy controls were examined on a grip preference test consisting of a grasping-to-transport and a grasping-to-use condition. Assessment included a general praxis testing (pantomime production, object utilization gesture recognition and object use). We also reported the case of a close-head injury patient (DR) with an atypical behavioural pattern. Our results supported the different constraint hypothesis. While several LBD and RBD patients performed inappropriate grips in the grasping-to-transport condition, only two patients (L2 and DR) used inappropriate grips in the grasping-to-use condition. No correlation was found between the two conditions of the grip preference test and measures of the general praxis testing. The discussion focuses on the nature of constraints on grip selection during object use and object transport.

APP, PSEN1, and PSEN2 mutations in early-onset Alzheimer disease: A genetic screening study of familial and sporadic cases

Background Amyloid protein precursor (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2) mutations cause autosomal dominant forms of early-onset Alzheimer disease (AD-EOAD). Although these genes were identified in the 1990s, variant classification remains a challenge, highlighting the need to colligate mutations from large series. Methods and findings We report here a novel update (2012–2016) of the genetic screening of the large AD-EOAD series ascertained across 28 French hospitals from 1993 onwards, bringing the total number of families with identified mutations to n = 170. Families were included when at least two first-degree relatives suffered from early-onset Alzheimer disease (EOAD) with an age of onset (AOO) ≤65 y in two generations. Furthermore, we also screened 129 sporadic cases of Alzheimer disease with an AOO below age 51 (44% males, mean AOO = 45 ± 2 y). APP, PSEN1, or PSEN2 mutations were identified in 53 novel AD-EOAD families. Of the 129 sporadic cases screened, 17 carried a PSEN1 mutation and 1 carried an APP duplication (13%). Parental DNA was available for 10 sporadic mutation carriers, allowing us to show that the mutation had occurred de novo in each case. Thirteen mutations (12 in PSEN1 and 1 in PSEN2) identified either in familial or in sporadic cases were previously unreported. Of the 53 mutation carriers with available cerebrospinal fluid (CSF) biomarkers, 46 (87%) had all three CSF biomarkers—total tau protein (Tau), phospho-tau protein (P-Tau), and amyloid β (Aβ)42—in abnormal ranges. No mutation carrier had the three biomarkers in normal ranges. One limitation of this study is the absence of functional assessment of the possibly and probably pathogenic variants, which should help their classification. Conclusions Our findings suggest that a nonnegligible fraction of PSEN1 mutations occurs de novo, which is of high importance for genetic counseling, as PSEN1 mutational screening is currently performed in familial cases only. Among the 90 distinct mutations found in the whole sample of families and isolated cases, definite pathogenicity is currently established for only 77%, emphasizing the need to pursue the effort to classify variants.

Script representation in patients with Alzheimer's disease.

We examined script representation in 26 patients with Alzheimers disease (AD) compared to 31 healthy elderly subjects (HE). Participants were asked to sort cards describing actions belonging to eight scripts according to the script to which they belonged and according to their order of execution. Each script included actions which were low in centrality and distinctiveness (non-central actions and non-distinctive actions--NCA & NDA), and which were high in centrality (central actions--CA), distinctiveness (distinctive actions--DA), centrality and distinctiveness (central actions and distinctive action--CA & DA). These actions were presented in three conditions. In the first condition (scripts with headers--SH), the 43 actions belonging to three different scripts were given with each script header written on separate cards. The second condition (scripts without headers--SwH) used 46 actions belonging to three other scripts, but no script header was provided. In the third condition (scripts with distractor header--SDH), the 28 actions belonging to two other scripts were given with each script header and a distractor header written on separate cards. The results showed that performance of subjects with AD was significantly lower in all conditions. Overall, AD patients made significantly more sequencing errors than HE subjects. AD patients also committed significantly more sorting errors than HE subjects for all types of actions (NCA & NDA, CA, DA, CA & DA). These data are consistent with the view that AD produces impairment of both the syntactic and semantic dimensions of script representation.

Influence of Centrality and Distinctiveness of Actions on Script Sorting and Ordering in Patients With Frontal Lobe Lesions

In order to further investigate script knowledge in patients with frontal lobe lesions (FP), 30 participants with frontal brain damage, 14 controls with posterior brain damage (PC) and 30 normal controls (NC) were asked to sort script actions with various degrees of centrality and distinctiveness according to the script to which they belonged and their order of execution. Actions were given in 3 conditions: scripts with headers (SH), scripts without headers (SwH) and scripts with distractor header (SDH). Results confirmed the dual dissociation we observed in a previous study (Allain, Le Gall, Etcharry-Bouyx, Aubin, Emile, 1999). Twelve FP made numerous errors in sequencing actions regardless of the conditions, but rejected the irrelevant title. Fourteen FP made few sequencing errors but used the irrelevant title. The last 4 FP performed as well as the PC and NC in every condition. Sorting errors made by the FP mainly concerned actions with low levels of centrality and distinctiveness. These data are consistent with the view that frontal lobe lesions selectively impair the syntactic component of script representation without affecting its semantic component.

The potential of virtual reality-based training to enhance the functional autonomy of Alzheimer's disease patients in cooking activities: A single case study

ABSTRACT Impairments in performing activities of daily living occur early in the course of Alzheimers disease (AD). There is a great need to develop non-pharmacological therapeutic interventions likely to reduce dependency in everyday activities in AD patients. This study investigated whether it was possible to increase autonomy in these patients in cooking activities using interventions based on errorless learning, vanishing-cue, and virtual reality techniques. We recruited a 79-year-old woman who met NINCDS-ADRDA criteria for probable AD. She was trained in four cooking tasks for four days per task, one hour per day, in virtual and in real conditions. Outcome measures included subjective data concerning the therapeutic intervention and the experience of virtual reality, repeated assessments of training activities, neuropsychological scores, and self-esteem and quality of life measures. The results indicated that our patient could relearn some cooking activities using virtual reality techniques. Transfer to real life was also observed. Improvement of the task performance remained stable over time. This case report supports the value of a non-immersive virtual kitchen to help people with AD to relearn cooking activities.

Executive functions in clinical and preclinical Alzheimer's disease

Executive functions is an umbrella term describing a wide range of higher order processes that allow the flexible modification of thought and behaviour in response to changing cognitive or environmental contexts. Impairment of executive functions is common in neurodegenerative disorders such as Alzheimers disease. These deficits negatively affect everyday activities and hamper the ability to cope with other cognitive or behavioural disorders. In this paper, we propose a synthesis of the knowledge on executive impairments in clinical and preclinical Alzheimers disease, mostly leaning on the current studies made in this domain. We made some propositions for neuropsychological assessment of executive functions in preclinical and clinical phases of Alzheimers disease. We hope that this overview will provide a useful insight into an area that is still insufficiently explored in the field of the neuropsychology of Alzheimers disease.

Mechanical problem-solving strategies in Alzheimer's disease and semantic dementia.

OBJECTIVE The goal of this study was to explore whether the tool-use disorders observed in Alzheimers disease (AD) and semantic dementia (SD) are of the same nature as those observed in left brain-damaged (LBD) patients. Recent evidence indicates that LBD patients with apraxia of tool use encounter difficulties in solving mechanical problems, characterized by the absence of specific strategies. This pattern may show the presence of impaired mechanical knowledge, critical for both familiar and novel tool use. So, we explored the strategies followed by AD and SD patients in mechanical problem-solving tasks in order to determine whether mechanical knowledge is also impaired in these patients. METHOD We used a mechanical problem-solving task in both choice (i.e., several tools were proposed) and no-choice (i.e., only 1 tool was proposed) conditions. We analyzed quantitative data and strategy profiles. RESULTS AD patients but not SD patients met difficulties in solving mechanical problem-solving tasks. However, the key finding is that AD patients, despite their difficulties, showed strategy profiles that are similar to that of SD patients or controls. Moreover, AD patients exhibited a strategy profile distinct from the one previously observed in LBD patients. CONCLUSIONS Those observations lead us to consider that difficulties met by AD patients to solve mechanical problems or even to use familiar tools may not be caused by mechanical knowledge impairment per se. In broad terms, what we call apraxia of tool use in AD is certainly not the same as apraxia of tool use observed in LBD patients. (PsycINFO Database Record