Danielle de Souza Costa

Association between the Catechol O-Methyltransferase (COMT) Val158met Polymorphism and Different Dimensions of Impulsivity

Background Impulsivity is a multidimensional construct which has been associated with dopaminergic neurotransmission. Nonetheless, until this moment, few studies addressed the relationship between different types of impulsivity and the single nucleotide polymorphism caused by a substitution of valine (val) with methionine (met) in the 158 codon of the Catechol-o-Methyltransferase gene (COMT-val158met). The present study aimed to investigate the association between val158met COMT polymorphism and impulsive behavior measured by two neuropsychological tests. Methodology/Principal Findings We administered two neuropsychological tests, a Continuous Performance Task and the Iowa Gambling Task were applied to 195 healthy participants to characterize their levels of motor, attentional and non-planning impulsivity. Then, subjects were grouped by genotype, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional and motor impulsivity. Those participants who were homozygous for the met allele performed worse in the Iowa Gambling Task than val/val and val/met subjects. Conclusions/Significance Our results suggest that met allele of val158met COMT polymorphism is associated with poor performance in decision-making/cognitive impulsivity task. The results reinforce the hypothesis that val and met alleles of the val158met polymorphism show functional dissociation and are related to different prefrontal processes.

Normative data of the Barratt Impulsiveness Scale 11 (BIS-11) for Brazilian adults

OBJECTIVE The Barratt Impulsiveness Scale (BIS-11) is a valid and reliable instrument, and one of the most often used tools to assess impulsivity. This study assesses the performance of a large sample of adults by using a version of BIS-11 adapted to Brazilian Portuguese. METHODS We assessed 3,053 adults from eight Brazilian states. Internal consistencies and performance data were presented for two correction criteria of BIS-11: original and the two-factor score. RESULTS The associations between age, sex, region, and education and the BIS-11 scores present very small effect sizes. Therefore, we provided a percentile rank parameter for the different BIS-11 subscores considering the whole sample. Given the internal consistency of the two correction systems, we found that only the two-factor system fulfills the psychometric criteria of Cronbachs alpha (cutoff value of at least 0.6). CONCLUSION Our results support the use of the Brazilian adaptation of BIS-11 in different regions of the country as a measure of impulsivity. Since high impulsiveness is a characteristic of several dysfunctional behaviors, the establishment of normative parameters is of utmost relevance and should be extended to other age ranges and populations in future studies.

Neuropsychological impairments in elderly Neurofibromatosis type 1 patients

Cognitive performance is compromised in Neurofibromatosis type 1 (NF1) patients, but neuropsychological data including elderly NF1 are extremely sparse. We compared the cognitive performance of a small elderly NF1 group (n = 5) with an age-matched healthy control group (n = 49). NF1 group performed worse than control group on a global cognitive impairment task, verbal working memory, and visuospatial functioning. The results suggest that cognitive impairment is an important feature of NF1 across lifespan, including elderly individuals. Future studies approaching the NF1 cognitive profile might benefit from looking at the mechanisms linked to the age-related aspects of cognitive decline.

ADHD inattentive symptoms mediate the relationship between intelligence and academic performance in children aged 6-14

OBJECTIVE Fluid intelligence and the behavioral problems of attention-deficit/hyperactivity disorder (ADHD) are related to academic performance, but how this association occurs is unclear. This study aimed to assess mediation and moderation models that test possible pathways of influence between these factors. METHODS Sixty-two children with ADHD and 33 age-matched, typically developing students were evaluated with Ravens Colored Progressive Matrices and the spelling and arithmetic subtests of the Brazilian School Achievement Test. Dimensional ADHD symptomatology was reported by parents. RESULTS Our findings suggest that fluid intelligence has a significant impact on academic tests through inattention. The inattentive dimension was the principal behavioral source of influence, also accounting for the association of hyperactive-impulsive manifestations with school achievement. This cognitive-to-behavioral influence path seems to be independent of diagnosis related group, and gender, but lower socioeconomic status might increase its strength. CONCLUSION Fluid intelligence is a relevant factor in the influence of ADHD behavioral symptoms on academic performance, but its impact is indirect. Therefore, early identification of both fluid intelligence and inattentive symptoms is of the utmost importance to prevent impaired academic performance and future difficulties in functioning.

Executive Function and Academic Outcomes in Children Who Were Extremely Preterm

EF stability from 8 to 18 years of age was identified in children born EP, which was related to academic outcomes. OBJECTIVES: Cognitive and behavioral impairments of children born extremely preterm (EP) (<28 weeks’ gestation) and extremely low birth weight (ELBW) (<1000 g) may change with age. We assessed the individual stability of behavioral executive function (EF) from 8 to 18 years of age in children born EP or ELBW and their academic outcomes. METHODS: Participants comprised 180 children born EP or ELBW from a large geographic cohort. We investigated the frequency of 4 developmental groups (persistent, remitting, late-onset, and typical development) on the basis of dichotomized scores (typical versus elevated) at ages 8 and 18 years in 2 indices (the Behavioral Regulation Index [BRI] and the Metacognition Index [MCI]) of the parental form of the Behavior Rating Inventory of Executive Function. Adolescent academic outcomes were measured by using the word reading, spelling, and math computation subtests of the Wide Range Achievement Test, Fourth Edition. RESULTS: Most participants had a typical EF (BRI 61%, MCI 53%), followed by persistent (BRI 15%, MCI 16%), late-onset (BRI 12%, MCI 19%), or remitting (BRI 12%, MCI 13%) executive difficulties. Groups with executive impairments at age 18 years (persistent and late onset) had poorer academic outcomes than the typical and remitting groups. Shifting impairment categories between 8 and 18 years old was relevant to later academic outcomes. CONCLUSIONS: Most children showed stable and age-appropriate EF, although persistent and transient difficulties were observed and related to uneven academic outcomes. Studying the origins and consequences of the developmental stability of EF may contribute to the development of interventions to decrease the adverse neurodevelopmental outcomes of preterm birth.

Ecological validity of the five digit test and the oral trails test.

Tests evaluating the attentional-executive system are widely used in clinical practice. However, proximity of an objective cognitive test with real-world situations (ecological validity) is not frequently investigated. The present study evaluate the association between measures of the Five Digit Test (FDT) and the Oral Trails Test (OTT) with self-reported cognitive failures in everyday life as measured by the Cognitive Failures Questionnaire (CFQ). Brazilian adults from 18-to-65 years old voluntarily performed the FDT and OTT tests and reported the frequency of cognitive failures in their everyday life through the CFQ. After controlling for the age effect, the measures of controlled attentional processes were associated with cognitive failures, yet the cognitive flexibility of both FDT and OTT accounted for by the majority of variance in most aspects of the CFQ factors. The FDT and the OTT measures were predictive of real-world problems such as cognitive failures in everyday activities/situations.

Verbal fluency in older adults with low educational level: what is the role of executive functions and processing speed?

Neuropsychological tests related to verbal fluency paradigms are among those most frequently used to assess executive functions in older adults. These tasks are quick and easy to administer and widely used for clinical assessment. However, despite their apparent simplicity, these tests involve different cognitive demands and are influenced by sociodemographic factors. Two cognitive domains are particularly related to verbal fluency performance: executive functions and processing speed. Performance on these two cognitive domains declines with age and mediates the effect of other cognitive and demographic factors on verbal fluency scores. The objective of the present report is to investigate the contribution of executive functions and processing speed on category fluency performance. We hypothesize that these two cognitive domains will be related to test performance, suggesting that verbal fluency may not be used as a unidimensional measure of executive functions. Letters to the Editor 440

Neurofibromatosis: part 2 – clinical management

Part 1 of this guideline addressed the differential diagnosis of the neurofibromatoses (NF): neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and schwannomatosis (SCH). NF shares some features such as the genetic origin of the neural tumors and cutaneous manifestations, and affects nearly 80 thousand Brazilians. Increasing scientific knowledge on NF has allowed better clinical management and reduced rate of complications and morbidity, resulting in higher quality of life for NF patients. Most medical doctors are able to perform NF diagnosis, but the wide range of clinical manifestations and the inability to predict the onset or severity of new features, consequences, or complications make NF management a real clinical challenge, requiring the support of different specialists for proper treatment and genetic counseling, especially in NF2 and SCH. The present text suggests guidelines for the clinical management of NF, with emphasis on NF1.

Cross-cultural adaptation, validity, and reliability of the Parenting Styles and Dimensions Questionnaire – Short Version (PSDQ) for use in Brazil

Objective: The Parenting Styles and Dimensions Questionnaire (PSDQ) is used worldwide to assess three styles (authoritative, authoritarian, and permissive) and seven dimensions of parenting. In this study, we adapted the short version of the PSDQ for use in Brazil and investigated its validity and reliability. Methods: Participants were 451 mothers of children aged 3 to 18 years, though sample size varied with analyses. The translation and adaptation of the PSDQ followed a rigorous methodological approach. Then, we investigated the content, criterion, and construct validity of the adapted instrument. Results: The scale content validity index (S-CVI) was considered adequate (0.97). There was evidence of internal validity, with the PSDQ dimensions showing strong correlations with their higher-order parenting styles. Confirmatory factor analysis endorsed the three-factor, second-order solution (i.e., three styles consisting of seven dimensions). The PSDQ showed convergent validity with the validated Brazilian version of the Parenting Styles Inventory (Inventário de Estilos Parentais – IEP), as well as external validity, as it was associated with several instruments measuring sociodemographic and behavioral/emotional-problem variables. Conclusion: The PSDQ is an effective and reliable psychometric instrument to assess childrearing strategies according to Baumrind’s model of parenting styles.

Use of machine learning to predict cognitive performance based on brain metabolism in Neurofibromatosis type 1

Neurofibromatosis Type 1 (NF1) can cause a wide range of cognitive deficits, but its underlying nature is still unknown. We investigated the correlation between cognitive performance and specific patterns of resting-state brain metabolism in a NF1 sample. Sixteen individuals diagnosed with NF1 underwent 18F-FDG PET/CT brain imaging followed by a neuropsychological assessment. Principal component analysis was performed on 17 measures of cognitive function and a machine learning approach based on Gaussian Process Regression was used to individually predict the components that represented most of the variance in the neuropsychological data. The accuracy of the method was estimated using leave-one-out cross-validation and its significance through permutation testing. We found that only the first component could be accurately predicted from resting state metabolism (r = 0.926, p<0.001). Multiple and heterogeneous measures contribute to the first component, mainly WISC/WAIS Procedure and Verbal IQ, verbal memory and fluency. Considering the accurate prediction of measures of neuropsychological performance based on brain metabolism in NF1 patients, this suggests an underlying metabolic pattern that relates to cognitive performance in this group.