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Biomedical subjects

J R Valdizan

Publications and source records attributed to J R Valdizan.

3 recordsLinked to original sources
PubMed2004

[Nocturnal polysomnographic study in children with attention deficit hyperactivity disorder].

INTRODUCTION: The main symptoms of attention deficit hyperactivity disorder (ADHD) are attention deficit, hyperactivity and impulsivity. Its prevalence lies between 3 and 5% in schoolchildren. Children with ADHD can present a high prevalence rate of comorbidity. A timely diagnosis and treatment can modify the educational and psychosocial development of most of these children. A number of subjective reports (especially from parents) describe sleep disorders. The objective verification of these disorders and the exact nature of the sleep problems are still to be determined and the purpose of this study is to deal with these issues. PATIENTS AND METHODS: We studied a sample of 48 children (9 females and 39 males) with a mean age of 8 (SD: 2.59) who met DSM IV criteria. They were submitted to a general exploration as well as a neurological exploration, including their patient record, and then they were evaluated using the DSM IV, which was carried out by parents and teachers (in order to evaluate two different environments), and a nocturnal polysomnographic study. In the sample there were 26 children with predominant attention deficit type ADHD (ADHD/AD); 4 children with predominant hyperactivity impulsivity type ADHD (ADHD/H); and 18 children with combined type ADHD (ADHD/C). RESULTS: The most frequently diagnosed subtype is the attention deficit subtype. The sleep architecture of children with ADHD presents the most consistent differences as compared to normal children in an increase in the percentage of phase 3 of sleep and, consequently, an increase in the percentage of slow sleep. Epileptiform type paroxysms were observed in 16.7% of the children who presented symptoms of ADHD. The number of epileptiform paroxysms is more usual in the attention deficit subtype. CONCLUSIONS: The increase in phase 3 may be related to the alterations in noradrenaline and dopamine transmission present in children who suffer from ADHD. Some children with ADHD can have a region of the brain with intense epileptic activity, which does not trigger epileptic seizures but gives rise to behavioural disorders, learning disorders and language problems.

Adolescent↗
PubMedDate not supplied

[Face recognition in autism].

INTRODUCTION: We conducted a survey of the literature on face recognition (FR), an activity that is essential for social relations and their dynamics. Unlike the recognition of non facial objects, this type of recognition is a special process since it is based on the detection of individual features. The most characteristic clinical parameter of autistic subjects is their inability to relate socially, possibly due to the difficulty they have in processing faces, although they are more skilled at recognising objects. DEVELOPMENT: We describe the two mechanisms involved in FR, one based on features and the other referring to the whole. The latter can be further divided into overall processing that allows a whole image to be compared with another previously assimilated image, and the processing of the arrangement of a face that is recognised as a whole. These may correspond to two different neuronal pathways. During the first days of life, the newborn baby has a predilection for faces in their feature and overall aspects, and processing of the arrangement is slower. Visual development in autistic children is erratic, similar to the level of a newborn infant, and their lack of interest for human faces is apparent during the first year of life, as they look at everything as if they were objects, that is, by features. CONCLUSIONS: The analysis of the literature enabled us to determine how FR mechanisms develop in the earliest days of the infant s life. It also highlighted the importance of the integrity of the pathway that facilitates stimulation for the recognition of facial arrangement, which is altered in autistic children perhaps from the peripheral area to the cortex. Further work on peripheral pathways and the fundamental cortical connections that are affected in autistic subjects will help us to understand the inefficiency of their facial arrangement recognition system.

Autistic Disorder↗