Jorge Alberto Oliveira

Attention deficit hyperactivity disorder and developmental coordination disorder: Two separate disorders or do they share a common etiology.

Attention deficit hyperactivity disorder (ADHD) has been described as the most prevalent behavioral disorder in children. Developmental coordination disorder (DCD) is one of the most prevalent childhood movement disorders. The overlap between the two conditions is estimated to be around 50%, with both substantially interfering with functioning and development, and leading to poorer psychosocial outcomes. This review provides an overview of the relationship between ADHD and DCD, discussing the common presenting features, etiology, neural basis, as well as associated deficits in motor functioning, attention and executive functioning. It is currently unclear which specific motor and cognitive difficulties are intrinsic to each disorder as many studies of ADHD have not been screened for DCD and vice-versa. The evidence supporting common brain underpinnings is still very limited, but studies using well defined samples have pointed to non-shared underpinnings for ADHD and DCD. The current paper suggests that ADHD and DCD are separate disorders that may require different treatment approaches.

Postprandial symptoms in dysmotility-like functional dyspepsia are not related to disturbances of gastric myoelectrical activity

Gastric dysrhythmias, such as tachy- or bradygastria, have been reported in patients with functional dyspepsia (FD), but their role in symptom production is uncertain. It is also not known whether gastric dysrhythmias in these patients can be elicited by physiological gastric distension with a meal. We investigated the relationships between symptoms after ingestion of different volumes of water following a test meal and gastric dysrhythmias in FD patients. Fourteen patients with dysmotility-like FD and 13 healthy volunteers underwent paired electrogastrography (EGG) studies. Fasted subjects ingested 150 ml of yoghurt with either 150 ml (low volume) or 300 ml (high volume) water in random order. Fasting and fed EGGs with monitoring of symptoms were performed in both studies. Ten FD patients (71.4%) reported upper abdominal discomfort and bloating after the low volume meal, but only one (7.1%) presented an abnormal EGG (dominant frequency in the 2-4-cpm range: 58%). Following the high volume meal, 7 patients (50%) had symptoms, but none had EGG abnormalities. No significant differences were found between FD patients and controls for any of the EGG variables, in any test. In FD patients with postprandial symptoms, the percentage of the EGG dominant frequency in the normal range (median, 84.6%; range, 76.0-100.0%) was similar (P>0.20) to that in those without symptoms (88.5%; 75.0-100.0%). We conclude that disturbances of gastric myoelectrical activity are unlikely to play a role in the origin of postprandial upper abdominal discomfort and bloating in dysmotility-like FD.

Risco cardiovascular e prática de atividade física em crianças e adolescentes de Muzambinho/MG: influência do gênero e da idade

INTRODUCTION AND OBJECTIVE: Cardiovascular disease begins at infancy and it has been linked to the presence of cardiovascular risk factors (CRF). Prevalence of these factors varies a lot among different Brazilian populations and has been mostly studied in big and medium size cities. Thus, this study assessed the prevalence of CRF and physical activity (PA) in children and adolescents from Muzambinho, a small city in the state of Minas Gerais. METHODS: 205 subjects (7 to 18 years - 108 males) were studied. Body weight and height, glycemia, cholesterolemia, blood pressure (BP), and PA were measured. Comparisons were made by Qui-square test. RESULTS: Obesity and altered values of BP, glycemia, and cholesterolemia were found, respectively, in 19, 11, 5 and 15% of the subjects. There was no difference between genders, while the prevalence of smokers, drinkers, altered BP, and inactivity increased with age. Seventy-nine percent of the subjects practiced community PA; 10% occupational PA; 97% physical education classes; 72% PA during school recess; and 90% leisure time PA. Ninety-two percent of them were active. Occupational PA was higher in girls, and increased with age in boys. Leisure time and during school recess PA decreased with age in both genders. CONCLUSION: Except for physical inactivity, prevalence of CRF was high, did not differ between genders, and increased with age. High levels of all kinds of PA were found; they differed between genders, and decreased with age.

Constant-Random Practice and the Adaptive Process in Motor Learning with Varying Amounts of Constant Practice

The adaptive process in motor learning was examined in terms of effects of varying amounts of constant practice performed before random practice. Participants pressed five response keys sequentially, the last one coincident with the lighting of a final visual stimulus provided by a complex coincident timing apparatus. Different visual stimulus speeds were used during the random practice. 33 children (M age = 11.6 yr.) were randomly assigned to one of three experimental groups: constant-random, constant-random 33%, and constant-random 66%. The constant-random group practiced constantly until they reached a criterion of performance stabilization — three consecutive trials within 50 msec. of error. The other two groups had additional constant practice of 33 and 66%, respectively, of the number of trials needed to achieve the stabilization criterion. All three groups performed 36 trials under random practice; in the adaptation phase, they practiced at a different visual stimulus speed adopted in the stabilization phase. Global performance measures were absolute, constant, and variable errors, and movement pattern was analyzed by relative timing and overall movement time. There was no group difference in relation to global performance measures and overall movement time. However, differences between the groups were observed on movement pattern, since constant-random 66% group changed its relative timing performance in the adaptation phase.

Attention Deficit Hyperactivity Disorder and Motor Impairment: A Critical Review

Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder during childhood, affecting approximately 3–6% of school-aged children; its cardinal symptoms of high activity, impulsivity, and behavioral distractibility might be assumed to have close relationships to interferences with motor skills. A separate body of literature attests to ways that motor problems can severely impact children’s daily lives, as motor problems may occur in 30–50% of children with ADHD. This article critically reviews research on motor impairment in children with ADHD, notable differences in motor performance of individuals with ADHD compared with age-matched controls, and possible neural underpinnings of this impairment. We discuss the highly prevalent link between ADHD and developmental coordination disorder (DCD) and the lack of a clear research consensus about motor difficulties in ADHD. Despite increasing evidence and diagnostic classifications that define DCD by motor impairment, the role of ADHD symptoms in DCD has not been delineated. Similarly, while ADHD may predispose children to motor problems, it is unclear whether any such motor difficulties observed in this population are inherent to ADHD or are mediated by comorbid DCD. Future research should address the exact nature and long-term consequences of motor impairment in children with ADHD and elucidate effective treatment strategies for these disorders together and apart.

“Timing” coincidente em tarefas complexas: estudo exploratório do desempenho de adultos de diferentes idades em diferentes velocidades de estímulo visual

O objetivo desse estudo foi investigar o desempenho em uma tarefa complexa de “timing” coincidente em funcao da idade e da velocidade do estimulo visual. Os participantes foram 58 adultos voluntarios de ambos os sexos (38 adultos jovens com idades entre 19 e 23 anos e 20 adultos maduros com idades entre 35 e 50 anos). Cada grupo de adultos foi dividido em tres subgrupos de acordo com uma velocidade do estimulo visual (lenta, moderada e rapida). A tarefa consistiu em tocar cinco alvos em uma ordem pre-estabelecida em integracao a um estimulo visual. A variavel dependente foi o erro (absoluto, variavel e constante). Os dados foram analisados por meio de estatistica nao-parametrica, sendo que a ANOVA de Kruskal-Wallis apontou diferenca entre os grupos apenas no erro constante. Todavia, o teste U de Mann-Whitney, com o p ajustado com o procedimento de Bonferroni nao foi capaz de identificar entre quais grupos houve diferenca. Pode-se concluir que adultos jovens e maduros obtiveram similar desempenho em uma tarefa complexa de “timing” coincidente, independentemente da velocidade do estimulo visual.

Motor development of children with attention deficit hyperactivity disorder

OBJECTIVE To compare both global and specific domains of motor development of children with attention deficit hyperactivity disorder (ADHD) with that of typically developing children. METHODS Two hundred children (50 children with clinical diagnoses of ADHD, according to the DSM-IV-TR and 150 typically developing controls), aged 5 to 10 years, participated in this cross-sectional study. The Motor Development Scale was used to assess fine and global motricity, balance, body schema, and spatial and temporal organization. RESULTS Between-group testing revealed statistically significant differences between the ADHD and control groups for all domains. The results also revealed a deficit of nearly two years in the motor development of children with ADHD compared with the normative sample. CONCLUSION The current study shows that ADHD is associated with a delay in motor development when compared to typically developing children. The results also suggested difficulties in certain motor areas for those with ADHD. These results may point to plausible mechanisms underlying the relationship between ADHD and motor difficulties.

Health-related physical fitness children with severe and moderate developmental coordination disorder

The present study aims to examine physical fitness among children with developmental coordination disorder (DCD) with varying degrees of severity (moderate and severe - mDCD, sDCD), and a group of children without DCD (wDCD), in the city of Manaus, Brazil. Initially, 180 children aged 6-10 years old participated in this study. After being diagnosed according to the DSM-IV-TR, 63 children were then divided into three groups (21 in each group). Health-related physical fitness was measured by means of the Fitnessgram, which included several core components, namely, body composition, muscle strength and endurance, flexibility, and cardiorespiratory resistance. The results showed no statistically significant differences between both groups in any of the assessed components. However, when analyzing the results of each component according to the criteria of the Fitnessgram, we observed that, regardless of the classification group, less than half of the children achieved scores that, according to the motor tests, would classify them as having a healthy fitness. Children with sDCD, mDCD and wDCD presented similar levels of health-related physical fitness, with an unsatisfactory performance for the component strength and muscular endurance. We therefore emphasize the importance of further research in this area, more particularly when it comes to following the development of motor skills and physical fitness in children with DCD, as well as the observation of the interactions between these variables over time.

Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h2), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h2 = 0.37 ± 0.10, P < 0.05; diastolic BP: h2 = 0.39 ± 0.09, P < 0.05; TPA: h2 = 0.24 ± 0.09, P < 0.05). Significant genetic (rg) and environmental (re) correlations were detected between systolic and diastolic BP (rg = 0.67 ± 0.12 and re = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (re = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences.

The Relationship Between Motor Skills, Social Problems, and ADHD Symptomatology: Does It Vary According to Parent and Teacher Report?:

Objective: This study investigated the relationship between motor performance; attentional, hyperactive, and impulsive symptoms; and social problems. Correlations between parents’ versus teachers’ ratings of social problems and ADHD symptomatology were also examined. Method: A total of 129 children aged 9 to 12 years were included. ADHD symptoms and social problems were identified based on Conners’ Rating Scales–Revised: L, and the McCarron Assessment of Neuromuscular Development was used to assess motor skills. Results: After controlling for ADHD symptomatology, motor skills remained a significant predictor of social problems in the teacher model but not in the parent model. After controlling for motor skills, inattentive (not hyperactive-impulsive) symptoms were a significant predictor of social problems in the parent model, whereas hyperactive-impulsive (not inattentive) symptoms were a significant predictor of social problems in the teacher model. Conclusion: The findings suggested that intervention strategies should consider the interaction between symptoms and environmental contexts.