Cognitive impairment in amyotrophic lateral sclerosis (ALS) is characterized by deficits on tests of executive functions however the contribution of processing speed is unknown. By contrast, multiple sclerosis (MS) is a disorder in which slowed processing speed is regarded as the core deficit, however, methodology is often confounded by tasks which depend on motor speed. MRI studies have revealed multi-system cerebral involvement in ALS, with evidence of reduced white matter volume and integrity in predominantly frontotemporal regions. The current study had two aims. Firstly, to investigate whether cognitive impairments in ALS and MS are due to executive dysfunction or slowed processing speed, independent of motor dysfunction. Secondly, to investigate the relationship between specific cognitive impairments and the integrity of distinct white matter tracts in ALS. Twenty-nine ALS patients, twenty-five MS patients, and matched healthy control groups were administered a dual task paradigm and processing speed tasks in which stimulus presentation times were manipulated. In addition background measures of executive functioning, working memory, verbal memory, and language were administered. White matter integrity was investigated using region-of-interest (ROI) and tract based spatial statistics (TBSS) analyses of diffusion MRI data. ALS patients did not show impairments in tests of processing speed, but deficits were revealed in the dual task, as well as background tests of executive functioning, working memory, and verbal memory. MS patients also exhibited deficits in the dual task as well as background tests of executive functioning, working memory, and verbal memory. However, in contrast to ALS patients, a processing speed deficit was also observed in MS. ROI analyses revealed significant differences in fractional anisotropy (FA) and mean diffusivity (<D>) between ALS patients and healthy controls. Reduced integrity was observed in the corticospinal tracts and prefrontal and temporal white matter tracts including uncinate fasciculus, inferior longitudinal fasciculus, and regions of the cingulum. Significant differences also emerged in the white matter underlying the superior, medial and inferior frontal gyri, and the temporal gyri. Similar group differences were found in the TBSS analyses; ALS patients displayed prominent changes in the corticospinal tract and corpus callosum as well as extensive changes in prefrontal and temporal tracts and association fibres. Correlations between task performance and ROI parameters revealed that dual task performance was associated with FA in the middle frontal gyrus white matter while letter fluency indices correlated with FA in the corpus callosum and corticospinal tracts. Furthermore, verbal memory performance correlated with FA in the inferior longitudinal fasciculus and working memory performance correlated with <D> in uncinate fasciculus and hippocampal portion of the cingulum. Correlations with TBSS revealed significant associations between letter fluency indices and FA in the corticospinal tracts and anterior corpus callosum. The current study demonstrates that cognitive impairment in ALS is not due to slowed processing speed. Moreover dual task deficits are related to distinct prefrontal tract involvement in ALS, whilst fluency deficits may reflect decreasing callosal integrity. Deficits in working memory and verbal memory are related to white matter changes in fibre bundles connecting prefrontal, temporal, and limbic structures.

The evidence suggesting Attention-Deficit/Hyperactivity Disorder (ADHD) has neurodevelopmental roots with specific impairment in executive functioning continues to grow. However, no known study to date has explored the relationship between adult males with a diagnosis of ADHD and performance on a measure of executive functioning, the Delis-Kaplan Executive Function System (DKEFS). The current investigation attempted to explore (1) whether adult males with ADHD show an overall pattern of executive dysfunction as measured by the DKEFS, (2) potential group differences on both level-of-performance and process-oriented measure scores, and (3) the clinical utility of the DKEFS in diagnosing ADHD in adult males. A sample of 37 adults with ADHD was compared to a community sample of equal size. Multivariate statistical analysis yielded significant group differences despite intellectual advantage by the study group. In addition, analysis of individual measures revealed patterns which were not initially predicted based upon current theories of ADHD. Overall, however, no clinically significant impairments emerged, as defined by scores at least one standard deviation below the mean. These findings and potential clinical implications are discussed with recommendations for future research.

This study furthers our understanding of the impact of executive dysfunction on everyday activities in stroke survivors. A classification system was developed to analyze a wide range of behaviours performed by 14 stroke survivors and 12 matched controls on the Baycrest Multiple Errands Test, a task requiring participants to buy specific items and collect certain information on the main floor of the hospital. The event recorder was used to code the occurrences and frequencies of behaviours performed by participants. Results demonstrated that participants with stroke performed significantly more task specific relevant inefficient behaviours (p < .05) and non-task specific irrelevant behaviours (p < .10) compared to controls. This study indicates the importance of performing a detailed analysis of behaviours performed to better understand the impact of ED in everyday life.

This study furthers our understanding of the impact of executive dysfunction on everyday activities in stroke survivors. A classification system was developed to analyze a wide range of behaviours performed by 14 stroke survivors and 12 matched controls on the Baycrest Multiple Errands Test, a task requiring participants to buy specific items and collect certain information on the main floor of the hospital. The event recorder was used to code the occurrences and frequencies of behaviours performed by participants. Results demonstrated that participants with stroke performed significantly more task specific relevant inefficient behaviours (p < .05) and non-task specific irrelevant behaviours (p < .10) compared to controls. This study indicates the importance of performing a detailed analysis of behaviours performed to better understand the impact of ED in everyday life.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19889号 / 医博第4138号 / 新制||医||1016(附属図書館) / 32966 / 京都大学大学院医学研究科医学専攻 / (主査)教授 古川 壽亮, 教授 髙橋 良輔, 教授 富樫 かおり / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Une étude récente rapporte que des participants souffrant de cauchemars idiopathiques fréquents (CIF) produisaient plus d’erreurs de persévération sur une tâche de fluence verbale (TFV) que des participants contrôle (CTL) (Simor et al., 2012). Cela suggère une dysfonction exécutive chez les participants CIF, soutenant le modèle des cauchemars Affective Network Dysfunction (AND). Notre objectif était de reproduire cette trouvaille auprès d’une cohorte francophone. Des TFV lexicale et sémantique ont été administrées à 23 participants avec CIF et à 16 CTL. Contrairement aux attentes, le groupe CIF n’affichait pas plus de persévération (p=.87). L’absence de reproduction pourrait infirmer la suggestion d’une dysfonction exécutive liée au CIF, toutefois des différences méthodologiques entre les études et les complexités de la TFV peuvent jouer un rôle dans le décalage entre les études. Nous suggérons que l’étude future des déficits exécutifs liés aux CIF emploie des tâches neuropsychologiques non linguistiques empiriquement associées au sommeil paradoxal. / A recent study reported that individuals suffering from frequent idiopathic nightmares (NMs) produced more perseveration errors on a verbal fluency task (VFT) than did control participants (CTLs) (Simor et al., 2012). These findings suggest executive dysfunction in NM sufferers and support the Affective Network Dysfunction (AND) model relating NM production. We sought to replicate these results in a French speaking cohort. Lexical and semantic VFTs were administered to 23 participants with frequent NMs, and to 16 CTLs with few NMs. Contrary to expectations, groups did not exhibit more fluency perseveration errors (p=.87). Though failure to replicate may indicate that NM sufferers do not have an executive dysfunction, methodological differences between studies and challenges inherent to the use of the VFT may also play a role in the discrepancy between studies. Future study of executive deficits in NM participants should be measured by non linguistic-dependant neuropsychological tasks empirically linked to REM sleep.

Many of the shifts in our identity are as surprising as they are inevitable. As with our bodies and our minds, it’s easy to forget that our identities are in a constant state of change — that is, until a situation forces us to face ourselves and examine who we’ve become. For adolescents, college students included, reckonings with their sense of self come frequently; they feel seismic each time they occur. My thesis will be a short screenplay in which the central character is recovering from severe executive dysfunction, the impairment of basic skills that include working memory, mental flexibility, and inhibitory control. She will confront the question at the heart of the Ship of Theseus: have I changed enough that I am now an entirely different person than I used to be? And if so, what now? As part of the story development process, I viewed films that told compelling stories about the impact physical changes can have one one's identity. I intend for my screenplay to explore the ability of a change in mental health to do the same.

No description available.

Résumé : Pour assister efficacement les personnes en perte d'autonomie dans le contexte des habitats intelligents, il est essentiel d'identifier les difficultés auxquelles ces personnes sont confrontées dans leur quotidien. L'objectif de ce travail est d'observer les processus exécutifs durant les activités de la vie quotidienne, ainsi que leur dysfonctionnement lors du vieillissement cognitif (normal ou lié à la maladie d'Alzheimer), puis d'élaborer un modèle théorique et informatique capable de simuler les comportements observés. Une phase d'observation et de qualification des processus de contrôle exécutif (capacités de régulation de l'action, de correction et d'adaptation lors de situations imprévues) a d'abord été réalisée, dornnant lieu à la spécification d'un modèle théorique fondé sur le modèle de contrôle attentionnel de l'action de Norman et Shallice. Le modèle théorique a ensuite été implémenté informatiquement et permet de simuler une activité quotidienne spécifique. // Abstract : In order to assist patients who are loosing their autonomy, smart homes and cognitive assistance systems have to be based on a good knowledge of people's disorders and on the difficulties they are likely to encounter in daily life. The specific objective of this PhD is to observe executive processes involved in the completion of daily activities and their impairment during ageing and dementia of the Alzheimer's type, and then to design both theoretical and computational models which are able to generate the observed behaviours. An observation and a qualification phase, allowing to observe executive control processes (action regulation, correction and adaptation when unexpected situations occur) have been first realized, leading to the specification of a theoretical model based on the Norman and Shallice model. This theoretical model has then been implemented to obtain a computational model, which allows the simulation of a specific activity of daily living.

Contexte : Les fonctions exécutives (FE) du syndrome de Gilles de la Tourette (SGT) demeurent à ce jour un sujet complexe. Les études tentent d’élucider l’implication des tics sur le fonctionnement cognitif, mais notent des résultats contradictoires. Ceux-ci seraient occasionnés par plusieurs facteurs, mais principalement par les comorbidités, incluant la dépression. Les risques de développer des symptômes dépressifs sont de 76 % dans la population du SGT. Toutefois, les études qui mettent en évidence un profil des fonctions exécutives à l’aide d’un questionnaire auto administré, tout en considérant les effets de la dépression, demeurent pratiquement absentes pour cette population. Ainsi, il est pertinent d’étudier ce sujet à l’aide d’un outil sensible aux atteintes exécutives afin de considérer ce besoin et d’édifier un portrait global du trouble. Objectifs : Le premier objectif sera de valider les relations entre les symptômes SGT, les symptômes dépressifs sous-cliniques (SDSC) et les sous-facteurs du BRIEF. Le deuxième objectif consiste à confirmer la nature des liens entre les évaluations du BRIEF-A et les différences entre les groupes atteints du SGT ou de tics chroniques (TC) avec ou sans SDSC et un groupe contrôle. Le troisième objectif vise à extraire un profil typique pour discriminer les groupes avec le BRIEF-A. Participants : Un groupe de 28 contrôles, 15 SGT ou TC et 16 SGT ou TC avec SDSC ont été recrutés. Ceux-ci ont été appariés selon l’âge et le sexe. Procédure : Le questionnaire auto-évalué et rapporté par les proches du BRIEF-A, l’inventaire de dépression de Beck (BDI), l’inventaire d’anxiété de Beck (BAI) et le YGTSS (Yale Global Tic Severity Score) ont été administrés. Résultats : Les résultats de l’ANOVA et des tests Welch, ainsi que les analyses de la fonction discriminante effectuées, révèlent un domaine caractérisant le SGT ou TC-SDSC soit l’inhibition. Conclusion : Le BRIEF-A permet de distinguer un profil exécutif propre aux personnes SGT ou TC avec SDSC. Les atteintes associées à l’inhibition seraient, en majeure partie, reliées aux SDSC et refléteraient une catégorie d’individu parmi la population SGT ayant développé une prédisposition à une dépression présentant une agitation psychomotrice. / Background: The executive functions (EF) of Gilles de la Tourette’s syndrome (TS) remain a complex subject to this day. Indeed, studies attempt to elucidate the implication of tics on cognitive functioning note mixed results. Several factors could influence these results, including significant comorbidities like depression. The chances of developing depressive symptoms in the TS population is as high as 76%. However, studies that highlight a profile of executive functions with a self-administered questionnaire and consider the effects of depression remain practically absent for this population. Thus, it is relevant to study this question using a tool sensitive to executive impairment to address this need and build a global portrait of the disorder. Objectives: The first objective will validate the relationships between TS symptoms, subclinical depressive symptoms (SCDS) and BRIEF sub-factors. The second objective is to confirm the nature of the BRIEF-A assessments and the differences between groups with TS or chronic tic (CT), TS or TC with SCDS and a control group based on BRIEF subfactors, TS symptoms and SCDS. The third objective is to extract a general profile to discriminate groups with the BRIEF-A. Participants: A group of 28 controls, 15 SGT or TC and 16 SGT or TC- SCDS, were recruited. They were matched by age and sex. Procedure: The BRIEF-A, a self-report version as well as the informant version, Beck’s Depression Inventory (BDI), Beck’s Anxiety Inventory (BAI) and the YGTSS (Yale Global Tic Severity Score) were administered. Results: The results of the ANOVA and the Welch, as well as the discriminant function analysis performed in the two versions of the BRIEF-A, reveal a domain that may characterize SGT or TC- SCDS: inhibition. Conclusion: The BRIEF-A makes it possible to distinguish a specific executive profile highlighting SGT or TC people with SCDS. The impairments measured in the executive function related to inhibition are mainly due to SCDS and could reflect a category of individuals among the SGT population with a predisposition to depression and psychomotor agitation.