Latent class analysis of attention and white matter correlation in children with attention-deficit/hyperactivity disorder

This study aimed to explore attentional patterns among children with inattentive attention-deficit/hyperactivity disorder (ADHD-I) and children with typical development (TD), using a latent class analysis (LCA). Patterns of brain connectivity were also explored. The sample comprised 29 ADHD-I and 29 TD matched children. An LCA was conducted to reclassify subjects according to their attentional performance, considering cognitive measures of attention and behavioral symptoms, regardless of group of origin. The new clusters were then compared in respect to brain white matter measurements (extracted from diffusion tensor imaging). Participants were rearranged in 2 new latent classes, according to their performance in an attention task and the results of behavioral scales, resulting in groups with more homogeneous attentional profiles. A comparison of the 2 new classes using the white matter measurements revealed increased fractional anisotropy in the left inferior fronto-occipital fasciculus and left inferior longitudinal fasciculus for the class composed by participants with a higher risk of attentional problems. The findings indicated that it was possible to observe variability regarding neuropsychological profile, accompanied by underpinning neurobiological differences, even among individuals with the same disorder subtype - inattentive ADHD. This specific data-driven clustering analysis may help to enhance understanding of the pathophysiology of the disorder's phenotypes.

Epilepsias na infância: conceitos e classificaçäo / Seizures in childhood: definition and classification

O artigo reflete uma abordagem didática sobre as epilepsias que ocorrem na infância e na adolescência, enfatizando classificaçäo e quadro clinico das crises epilépticas e das sindromes epilepticas

Serotonina sérica e síndrome de Rett / Serum serotonin and Rett syndrome

A síndrome de Rett, uma patologia neurodegenerativa que afeta meninas, caracteriza-se por uma involuçäo neuropsicomotora do desenvolvimento. Sendo o diagnóstico desta síndrome exclusivamente clínico, o presente trabalho teve como objetivo o estudo do conteúdo de serotonina sérica em crianças normais e portadoras da síndrome de Rett. A metodologia empregada para a quantificaçäo de 5HT no soro foi a cromatografia líquida de alta eficiência acoplada a detecçao eletroquímica. Os resultados obtidos mostraram uma hiperserotonemia em 81 por cento das crianças com síndrome de Rett. Verificou-se também uma correlaçäo positiva entre níveis altos de serotonina no soro e a deambulaçäo independente, mostrando que pacientes sem marcha voluntária apresentam níveis séricos maiores deste neurotransmissor. O presente trabalho sugere que o nível sérico de serotonina pode vir a ser usado como um possível marcador biológico no diagnóstico de estadiamento da síndrome de Rett.

Juvenile myoclonic epilepsy (JME): report of 12 cases

Juvenile myoclonic epilepsy is an idiopathic generalized epilepsy with age-related onset and characterized by myoclonic seizures, sometimes associated with other seizure types. We present the clinical and EEG characteristics of 12 cases out of 1,700 epileptic patients followed in the Epilepsy Section of a University Hospital. The mean age of seizure onset was 12.3 + 3.2 years (range 7-17), 8 females, 4 males; myoclonic and tonic-clonic generalized seizures were predominant (83.3 per cent). The circadian distribution of seizures was observed in 83.3 per cent (10/12). The complete seizure control occurred in 66.6 per cent (8/12) after valproate monotherapy. There was a positive family history of epilepsy in 50.0 per cent (6/12). In 50.0 per cent (6/12) of the cases the paroxysmal activity was precipitated by hyperventilation. Surprisingly we did not observe any pattern of photosensitivity in the interictal EEG recordings.