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M C Mouren

Publications and source records attributed to M C Mouren.

32 records · Page 2Linked to original sources
PubMedDate not supplied

[Symptom variations in ADHD: importance of context, development and comorbidity].

Attention-deficit hyperactivity (ADHD) is a common disorder in school-aged children and is associated with significant impairment in social and academic functioning. Its recognition is based on congruent information from different sources, because most ADHD children and adolescents are not completely aware of impairments caused by inattention and/or hyperactivity/impulsivity. Fluctuations in symptom expression may complicate the diagnosis: during clinical examination or tests sessions, ADHD symptoms may be less severe than usual or completely absent. This review examines variations in ADHD symptoms due to environmental context, internal state, circadian factors, development, psychiatric comorbidity and discusses their clinical relevance. Generally, ADHD symptoms are pervasive and identified in different areas of functioning. Despite their chronicity, they show a relative context-dependency. An unfamiliar environment or situation may lessen symptoms. The same happens in dual relations or in calm settings, when the child receives attention and positive reinforcement from the adult. On the contrary, the classroom situation with its high stimulation level (noise, visual distractors, large class size) is likely to reveal or accentuate instability, impulsivity and inattention. Independently from objective symptom fluctuations, the impact of ADHD symptoms, and their consequences on self-esteem may also vary with the degree of environmental mismatch. Recent research in experimental psychology also draws attention to the motivational state of ADHD children: preference for immediate gratification and delay aversion may explain why most of them show satisfactory attentional capacities in certain activities (for instance video games or TV), while showing impairment in school work or in other effortful tasks. The diagnosis of the full ADHD syndrome requires significant impact on functioning in at least two areas. Some children with "situational" ADHD are impaired either in school setting or exclusively at home. Manuzza et al. report long-term outcome of "situational" versus "pervasive" ADHD. School-ADHD, in opposition to home-ADHD shows similarities with the full blown syndrome, as regards proportion of anti-social personality disorder, psycho-social functioning and academic/professional achievements. Moderate seasonal variations have also been identified with less ADHD symptoms in August. This result is likely to reflect a better fit between individual characteristics and environmental demands during school holidays rather than neurobiological changes, as there are no convincing arguments for seasonal fluctuations of serotoninergic tone in ADHD. Another cause for variations in ADHD symptom expression may be the co-occurrence of a mood disorder. Relationships between early-onset mania and ADHD are discussed. The appropriate definition of prepubertal mania is still in debate; its recognition is hindered by symptom overlap and high level of comorbid conditions. Chronic emotional dysregulation with irritability and frequent temper tantrums, sometimes viewed as characteristics of early-onset mania, might reflect a--possibly severe--sub-type of ADHD rather than a prodrome of bipolarity. A marked cyclicity of symptoms, with periodic accentuation of ADHD and mood symptoms, requires careful monitoring and systematic analysis of comorbid conditions. Clarification of the complex interrelations between ADHD and bipolar disorder will be obtained from long-term studies.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

[Meta-analysis of candidate genes in attention-deficit hyperactivity disorder].

Attention-deficit hyperactivity disorder (ADHD) is a common behavioral disorder observed during childhood, detected in 3% to 5% of school-age children. The disorder is characterised by marked inattention, hyperactivity, and impulsiveness. In most cases, symptoms can be treated by catecholamine-releasing drugs, such as methylphenidate. Children with ADHD are at higher risk for substance abuse and oppositional, conduct and mood disorders. Familial and adoption studies shed light on the genetic vulnerability of ADHD. Twin studies estimated the broad heritability to range between 40% and 90%. The mode of transmission is yet unknown, but is likely polygenic. Molecular genetic studies in ADHD should contribute to a greater understanding of the pathophysiology of the disorder (genetics of the vulnerability), and could help to select a more rational type of treatment (pharmacogenetic). Family-based association studies already performed are reviewed in this manuscript. Association studies, using haplotype relative risk (HRR) or transmission disequilibrium test (TDT) have focused on candidate genes which code for proteins potentially involved in the etiopathogenesis of the disorder. Genes involved in dopamine, serotonin, and noradrenalin systems have thus been assessed for their role in core features of ADHD, such as motor overactivity, inattention, and impulsiveness. According to a meta-analysis, the DAT1 gene, an obvious candidate gene in ADHD vulnerability, does not appear to be involved (OR = 1.13, p = 0.21). On the other hand, DRD4 (OR = 1.26, p = 0.01) and DRD5 (OR = 1.4, p = 0.01) are significantly associated to ADHD according to the present meta-analysis, confirming previous ones. Recent studies showed a trend for an association between one allele of the 5-HTT (considering case-control studies) and DBH (OR = 1.27, p = 0.06) genes and ADHD, but these positive findings have to be replicated. ADHD is a complex disorder with potentially many different risk factors. Genetic and phenotypic heterogeneity could explain why some association studies are positive, whereas others are negative. For instance, different developmental pathways are likely to lead to similar clinical outcomes. More clear-cut phenotypes, such as ADHD with conduct disorder, or ADHD with bipolar disorder, could be more homogenous, the genes involved being therefore more easy to detect. These phenotypes are beginning to be specifically studied in molecular genetics. In addition, the development of pharmacogenetics could help to identify predictors of clinical response for a specific type of treatment, which would be clearly helpful in clinical practice.

Alleles↗
PubMedDate not supplied

[Lafora disease (author's transl)].

On the basis of 21 personal observations as well as those (82) from the litterature, it is concluded that the progressive myoclonic epilepsy with Lafora bodies (P.M.E.) constitutes a disease on its own. The clinical features are those described in the litterature observations and completed by some characteristics; the high frequency of visual symptoms (47 p. 100 personal cases); the relatively less bad evolution of epilepsy, perhaps in relation with use of modern drugs; the relatively moderate intensity of myoclonus which becomes complete only at the end of the evolution. From E.E.G. point of view, we can distinguish three periods: an initial one at the very onset of disease, who will show the same features as observated in primary generalized epilepsy, i.e. a well preserved background activity with superimposed generalized fast spikes and waves facilitated by the I.L.S. Then follows a period of evolutive E.E.G. (1-2 years after the onset of the disease) characterized by progressive slowing of the posterior background, enlargement of posterior slow activity and appearance of diffuse theta and delta activity. Simultaneously spikes and waves are taking less typical and bisynchronous aspect. Finally after 3 to 5 years from the onset there is a diffusely slow E.E.G. with superimposed fast multiple spikes. The E.E.G. findings in litterature usually refer only to this last period (stationary or terminal period). Occipital independent multiple spikes are frequently observed and could correlate with the visual symptoms observated in the Lafora disease. Some elements of differential diagnosis are given with respect to primary generalized epilepsy at the onset of the disease and later on with respect to dyssynergia cerebellaris myoclonica and to the progressive myoclonic epilepsy without Lafora bodies.

Adolescent↗
PubMedDate not supplied

[Gifted children. Psychological and psychopathological aspects (author's transl)].

After having tried to define the term "gifted children" the authors record the principal works devoted to this subject and the opinions, often controversial raised by the attitude in regard to exceptional children in different countries. Then, are given the means to detect gifted children as well as the characteristics in the recognition of the very young gifted children. In a third section are described the psychology and the difficulties of adaptation which these children sometimes encounter (scholastic problems, behavioral and personality problems, seldom psychotic). Finally, the orientation of gifted children can be undertaken in three ways, all of which present advantages and disadvantages: grouping in special classes, speeding up and enrichment of the programmes.

Adaptation, Psychological↗