Danielle David

Phonological and visual processing deficits can dissociate in developmental dyslexia : Evidence from two case studies

The present study describes two Frenchteenagers with developmental reading andwriting impairments whose performance wascompared to that of chronological age andreading age matched non-dyslexic participants.Laurent conforms to the pattern of phonologicaldyslexia: he exhibits a poor performance inpseudo-word reading and spelling, producesphonologically inaccurate misspellings butreads most exception words accurately. Nicolas,in contrast, is poor in reading and spelling ofexception words but is quite good atpseudo-word spelling, suggesting that hesuffers from surface dyslexia and dysgraphia.The two participants were submitted to anextensive battery of metaphonological tasks andto two visual attentional tasks. Laurentdemonstrated poor phonemic awareness skills butgood visual processing abilities, while Nicolasshowed the reverse pattern with severedifficulties in the visual attentional tasksbut good phonemic awareness. The presentresults suggest that a visual attentionaldisorder might be found to be associated withthe pattern of developmental surface dyslexia.The present findings further show thatphonological and visual processing deficits candissociate in developmental dyslexia.

European Pentoxifylline Multi-Infarct Dementia Study

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 score > or = 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.

Are semantic errors actually semantic?: evidence from Alzheimer's disease

Patients with Alzheimers disease (AD) produce a high rate of semantic errors when naming to confrontation. This is considered to be one of the many consequences of their semantic memory deficit. However, it has been shown, in aphasic patients with focal lesions, that semantic errors could arise from impairment to any one of the levels in the naming process. To check this hypothesis in AD, we assessed in 15 patients the capacity to name and access semantic knowledge (by multiple-choice probe questions) about 14 objects presented successively in the visual, tactile, auditory, and verbal modalities. In the visual naming task, 33 errors were recorded: 26 (78.8%) were semantic and 7 (21.2%) were unrelated errors. Of the 26 semantic errors, 8 were related to a deficit of the semantic knowledge related to the item and 17 to a deficit in the retrieval of the phonological form of the word. One was associated with a deficit of access to semantic knowledge in the visual modality. The 7 unrelated errors were associated with a loss of semantic knowledge for 4 and deficit of access to the phonological form for 3. In conclusion, this study shows that semantic errors do not systematically reflect a deficit of semantic knowledge in Alzheimers disease. It also seems that unrelated errors are more frequently related to semantic deficits than semantic errors in this population.

One or Several Semantic System(S)? Maybe None: Evidence from a Case Study of Modality and Category-Specific “Semantic” Impairment

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.

Démence sémantique : réflexions d'un groupe de travail pour des critères de diagnostic en français et la constitution d'une cohorte de patients

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.

Confrontation of PDP models and dual-route models through the analysis of a case of deep dysphasia

Abstract A case study is presented of a patient, EA, who demonstrated all the defining features of deep dysphasia. His repetition disorder was associated with surface dyslexia and deep dysgraphia. EA also showed a severely restricted phonological STM. His performance in both picture confrontation naming and writing-to-dictation paralleled his performance in repetition, whereas reading aloud and oral lexical decision were not influenced by the imageability of the word input. Further testing indicated that EA did not have difficulty in either perceiving or semantically processing spoken words. An exhaustive investigation of EAs cognitive functioning was first conducted by reference to Patterson and Shewells model (1987). Such a triple-route model can account for EAs overall performance by postulating multiple functional lesions. We alternatively show that EAs language profile could be accounted for within a highly interactive model of language processing incorporating most basic principles of connection...

Superior Written Over Spoken Picture Naming in a Case of Frontotemporal Dementia

Two main hypotheses have been proposed regarding the role of phonology in written word production. According to the phonological mediation hypothesis, the retrieval of the lexical phonological representation of a word is an obligatory prerequisite to the retrieval of its spelling. Therefore, deficits to the phonological lexicon should affect both spoken and written picture naming. In contrast, the orthographic autonomy hypothesis posits that the lexical orthographic representations of words can be accessed without any necessary phonological mediation. In support of this view, cases of preserved written naming despite impaired lexical phonology have been reported following brain damage. In this report, we replicate this basic pattern of performance in case YP, a 60-year-old woman with a pattern of frontotemporal dementia. As her disease progressed, YP’s ability to write down the names of pictures remained very good despite a severe decline in oral naming. Further testing indicated that this deficit was not primarily due to an articulatory or post-lexical phonological deficit. YP’s case provides strong additional support for the orthographic autonomy hypothesis. The significance of this case with respect to the characterization of dementia syndromes is discussed.

Associative Visual Agnosia: A Case Study

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive) episodic models of memory [4].

L’aphasie du sujet âgé

Aphasia is common in elderly patients in the context of vascular or neurodegenerative disorders. In some cases, aphasia is an isolated symptom, occurring suddenly after a stroke, or developing progressively as a primary progressive aphasia. The diagnosis and treatment are then very similar in older and younger patients. Therapy may be more complicated because of the high prevalence, in older patients, of associated non linguistic symptoms (attentional and dysexecutive symptoms, behavioral and psychological symptoms or sensorial deficits), fatigability, and comprehension deficits. It may then become very difficult to recognize aphasia among all these disorders and to appreciate the physiopathology. A complete evaluation of language, cognitive functions, psychopathology, and behavior is very helpful, as are neuroimaging techniques (MRI is the most relevant). A good knowledge of classical aphasic pictures associated with stroke, Alzheimer disease or related disorders, is highly recommended. Rehabilitation must be proposed even for older patients, so far as aphasia alters the communication abilities. It must be kept in mind that associated symptoms may limit considerably the therapy.L’aphasie est un trouble frequent chez le sujet âge. Elle est le plus souvent secondaire a des lesions vasculaires ou neurodegeneratives. Il est possible de rencontrer chez les sujets âges des tableaux aphasiques isoles dont le diagnostic et la prise en charge sont les memes que chez des sujets plus jeunes. Souvent neanmoins, l’evaluation et la caracterisation semiologique des troubles sont difficiles en raison de la presence de symptomes associes non linguistiques (troubles attentionnels et dysexecutifs, troubles sensoriels, troubles thymiques, troubles comportementaux), de la fatigabilite des patients et de la plus grande frequence des troubles de comprehension. Le diagnostic positif et etiologique est en consequence rendu plus ardu. Il est alors necessaire de s’aider d’une evaluation orthophonique et neuropsychologique precise, d’une evaluation neuropsychiatrique et des moyens d’imagerie appropries (l’IRM tient une place de choix). Il importe aussi de bien connaitre la semiologie aphasique et les differents tableaux aphasiques rencontres apres une lesion vasculaire et dans le cadre des affections neurodegeneratives, Alzheimer et apparentees. Une prise en charge doit etre proposee meme chez des patients tres âges, dans la mesure ou le trouble du langage perturbe la communication. Neanmoins, cette prise en charge est souvent limitee en raison de symptomes associes.

P3-32 Etude des déficits pré-sémantiques dans la démence sémantique

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.