Attention-deficit/hyperactivity disorder and brain metabolites from proton magnetic resonance spectroscopy: a systematic review and meta-analysis protocol

Abstract Despite major advances in the study of the brain, investigations on neurochemistry in vivo still lack the solid ground of more established methods, such as structural and functional magnetic resonance imaging. Proton magnetic resonance spectroscopy (MRS) is a technique that might potentially fill in this gap. Nevertheless, studies using this approach feature great methodological heterogeneity, such as varying voxel of choice, differences on emphasized metabolites, and absence of a standardized unit. In this study, we present a methodology for creating a systematic review and meta-analysis for this kind of scientific evidence using the prototypical case of attention-deficit/hyperactivity disorder. Systematic review registration: International Prospective Register of Systematic Reviews (PROSPERO), CRD42018112418.

Comparative research on brain networks of children with attention deficit hyperactivity disorder and normal children based on visual cognitive tasks / 生物医学工程学杂志

Aiming at the difference between the brain networks of children with attention deficit hyperactivity disorder (ADHD) and normal children in the task-executing state, this paper conducted a comparative study using the network features of the visual function area. Functional magnetic resonance imaging (fMRI) data of 23 children with ADHD ［age: (8.27 ± 2.77) years］ and 23 normal children ［age: (8.70 ± 2.58) years］ were obtained by the visual capture paradigm when the subjects were performing the guessing task. First, fMRI data were used to build a visual area brain function network. Then, the visual area brain function network characteristic indicators including degree distribution, average shortest path, network density, aggregation coefficient, intermediary, etc. were obtained and compared with the traditional whole brain network. Finally, support vector machines (SVM) and other classifiers in the machine learning algorithm were used to classify the feature indicators to distinguish ADHD children from normal children. In this study, visual brain function network features were used for classification, with a classification accuracy of up to 96%. Compared with the traditional method of constructing a whole brain network, the accuracy was improved by about 10%. The test results show that the use of visual area brain function network analysis can better distinguish ADHD children from normal children. This method has certain help to distinguish the brain network between ADHD children and normal children, and is helpful for the auxiliary diagnosis of ADHD children.

Computerized cognitive training in children and adolescents with attention deficit/hyperactivity disorder as add-on treatment to stimulants: feasibility study and protocol description / Treinamento cognitivo para crianças e adolescentes com transtorno de déficit de atenção/hiperatividade como tratamento complementar aos psicoestimulantes: estudo de viabilidade e descrição de protocolo

Abstract Background Cognitive training has received increasing attention as a non-pharmacological approach for the treatment of attention deficit/hyperactivity disorder (ADHD) in children and adolescents. Few studies have assessed cognitive training as add-on treatment to medication in randomized placebo controlled trials. The purpose of this preliminary study was to explore the feasibility of implementing a computerized cognitive training program for ADHD in our environment, describe its main characteristics and potential efficacy in a small pilot study. Methods Six ADHD patients aged 10-12-years old receiving stimulants and presenting residual symptoms were enrolled in a randomized clinical trial to either a standard cognitive training program or a controlled placebo condition for 12 weeks. The primary outcome was core ADHD symptoms measured using the Swanson, Nolan and Pelham Questionnaire (SNAP-IV scale). Results We faced higher resistance than expected to patient enrollment due to logistic issues to attend face-to-face sessions in the hospital and to fill the requirement of medication status and absence of some comorbidities. Both groups showed decrease in parent reported ADHD symptoms without statistical difference between them. In addition, improvements on neuropsychological tests were observed in both groups - mainly on trained tasks. Conclusions This protocol revealed the need for new strategies to better assess the effectiveness of cognitive training such as the need to implement the intervention in a school environment to have an assessment with more external validity. Given the small sample size of this pilot study, definitive conclusions on the effects of cognitive training as add-on treatment to stimulants would be premature.

Resumo Introdução O treinamento cognitivo tem recebido atenção especial como abordagem não medicamentosa para o tratamento do transtorno de déficit de atenção/hiperatividade (TDAH) em crianças e adolescentes. Poucos estudos avaliaram o treinamento cognitivo como abordagem complementar à medicação em ensaios clínicos randomizados controlados por placebo. O objetivo deste estudo foi explorar a viabilidade para a implementação de um programa de treinamento cognitivo computadorizado, descrever suas características principais e potencial eficácia em um pequeno estudo piloto. Métodos Seis pacientes com TDAH entre 10-12 anos de idade, em uso de psicoestimulantes e apresentando sintomas residuais, foram recrutados e randomizados para um dos dois grupos (treinamento cognitivo ou placebo) por 12 semanas. O desfecho principal foram os sintomas nucleares do TDAH avaliados através do Questionário de Swanson, Nolan e Pelham (SNAP-IV). Resultados Encontramos maior resistência do que a esperada no recrutamento dos pacientes em função de problemas logísticos para atender às sessões presenciais no hospital assim como para preencherem os critérios de status medicamentoso e ausência de algumas comorbidades. Ambos os grupos apresentaram diminuição nos escores dos sintomas de TDAH reportados pelos pais, mas sem diferença estatística entre eles. Além disso, foi observada melhora nos testes neuropsicológicos em ambos os grupos - principalmente nas tarefas treinadas pelo programa. Conclusão Este protocolo revelou a necessidade de novas estratégias para melhor avaliar a eficácia do treinamento cognitivo tal como a necessidade de implementar a intervenção no ambiente escolar a fim de obter uma avaliação com maior validade externa. Devido ao pequeno tamanho amostral deste estudo, conclusões definitivas sobre os efeitos do treinamento cognitivo como abordagem complementar aos psicoestimulantes seriam prematuras.

Community survey of attention-deficit/hyperactivity disorder among primary school pupils in Benin City, Nigeria

Background: Attention-deficit/hyperactivity disorder (ADHD) is a common childhood neuro-developmental condition with early onset. ADHD affects children worldwide. However, there is a variation in the prevalence across different countries. In Nigeria, there is paucity of information on the prevalence. To provide the relevant information, a cross-sectional study was conducted between February and August 2006 among 1473 public primary school pupils aged 6-12 years selected systematically among pupils in Egor Local Government Area of Edo State. Materials and Methods: All the 1473 pupils were screened with the Disruptive Behavior Disorder (DBD) Rating Scale to identify children who had ADHD symptoms as contained in the DSM -IV. Such children were compared with randomly selected controls. The academic records of both the groups were also compared. Results: The prevalence of ADHD was 7.6%. The prevalence was higher in boys (9.4%) when compared to girls (5.5%) (P = 0.003). Of the three different subtypes of ADHD, the predominantly inattentive subtype (ADHD-I) was the most prevalent (47.3% of the ADHD population) followed by the combined type (ADHD-C; 31.3%), while the least prevalent was the hyperactive/impulsive subtype (ADHD-HI; 21.4%). There was no statistically significant difference in the prevalence of ADHD amongst the different age cohorts. Conclusion: The prevalence of ADHD was relatively high when compared to the figures available for other countries. For this reason, there is a need to pay increased attention to this condition in Nigeria. Community screening under the umbrella of the School Health Program could be of assistance

Methylphenidate increased regional cerebral blood flow in subjects with attention deficit/hyperactivity disorder

The regional cerebral blood flow (rCBF) responses to methylphenidate (MPH) treatment were examined in children with attention deficit/hyperactivity disorder (ADHD). Thirty-two male children, diagnosed with ADHD by the DSM-IV diagnostic criteria, other behavioral assessment scales and neuropsychological battery, were studied using 99mTc-HMPAO-single photon emission computed tomography (SPECT). Subjects were studied before and after MPH treatment. First, using an image subtraction method, we obtained a NDR parametric image of each patient and found increased cerebral blood flow in the frontal lobes, caudate nuclei and thalamic areas after treatment. When the changes in SPECT and clinical response were compared, the matching rate, sensitivity and specificity between them were found to be 77.1, 80.0 and 79.2%, respectively. Second, three transaxial brain slices delineating anatomically defined regions of interest (ROI) at 20, 40, and 60mm above the orbitomeatal line (OML) were used, with the average number of counts for each region of interest normalized to the area of the cerebellar maximal uptake. The left and right prefrontal areas, and caudate and thalamic areas showed significant increases in rCBF after MPH treatment. These findings suggested MPH could affect the function of the fronto-striato-thalamic circuit, which is known as the pathophysiologic site of ADHD and could be used to correct the underlying brain dysfunction of ADHD.