School performance of adolescents born preterm: neuropsychological and background correlates.

In this longitudinal study the development of preterm and control children was followed from infancy until adolescence. School performance at the age of 16 in subjects born very preterm with a gestational age (GA) of

Spatial span in very prematurely born adolescents.

The working memory functions and processing speed of 35 adolescents born preterm (< or = 32 weeks of gestation) and those of 31 control adolescents were assessed at the age of 16 years. All study participants were free from major disabilities. There were no statistically significant differences in verbal IQ between the study groups. Adolescents born preterm performed less well in complex spatial span compared to their peers born full term, even when verbal IQ and processing speed were allowed to covary. Both groups performed equally well in other working memory tasks and processing speed. Gestational age was the primary contributor to spatial span performance. These results indicate a minor spatial working memory deficit in preterm born adolescents without major disability and with normal cognitive capacity. Our results are encouraging and indicate only minor neuropsychological consequences due to very preterm birth.

Increased number of febrile seizures in children born very preterm: relation of neonatal, febrile and epileptic seizures and neurological dysfunction to seizure outcome at 16 years of age.

PURPOSE: In prematurely born population, a cascade of events from initial injury in the developing brain to morbidity may be followed. The aim of our study was to assess seizures in prematurely born children from birth up to 16 years and to evaluate the contribution of different seizures, and of neurological dysfunction to the seizure outcome. METHODS: Pre- and neonatal data and data from neurodevelopmental examination at 5 years of 60 prospectively followed children born at or before 32 weeks of gestation, and of 60 matched term controls from the 2 year birth cohort were available from earlier phases of the study. Later seizure data were obtained from questionnaires at 5, 9, and 16 years, and from hospital records and parent interviews. RESULTS: In the preterm group, 16 children (27%) exhibited neonatal seizures, 10 children (17%) had seizures during febrile illness and 5 children had epilepsy. Eight children had only febrile seizures, and 3 of these had both multiple simple and complex febrile seizures and neurodevelopmental dysfunction. None of the 8 children had experienced neonatal seizures, 6 had a positive family history of seizures, but none developed epilepsy. The children with epilepsy had CP and neurocognitive problems, and all but one had experienced neonatal seizures; two of them had also had fever-induced epileptic seizures. In controls 3 children (5%) had simple febrile seizures. CONCLUSION: Children born very preterm have increased rate of febrile seizures compared to the controls. However, no cascade from initial injury via febrile seizures to epilepsy could be shown during the follow-up of 16 years. Symptomatic epilepsy in prematurely born children is characterised by neonatal seizures, major neurological disabilities and early onset of epilepsy.

Naming skills of children born preterm in comparison with their term peers at the ages of 9 and 16 years.

The linguistic abilities of children born preterm at 32 weeks' gestation or earlier at Kuopio University Hospital during 1984 to 1986 were evaluated during successive phases of a prospective study. The study protocol included the Rapid Automatic Naming test and Wechsler Intelligence Scale for Children - Revised at 9 years of age and a modified Stroop Color-Word test and the Wechsler Intelligence Scale - Revised at the age of 16 years. Fifty-one children born preterm (26 males, 25 females) and 51 age-matched and sex-matched term controls (26 males, 25 females) were studied at the age of 9 years. At the age of 16 years, 40 children born preterm (19 males, 21 females) and 31 term controls (14 males, 17 females) participated in the study. The children born preterm scored significantly lower in two naming tasks than the controls at the age of 9 years. However, there was no difference between the study groups in naming skills at the age of 16 years or in verbal IQ in either study phase. Maternal education level was not associated with naming skills. Thus, the consequences of preterm birth seem to be minor in relation to linguistic skills during school age and diminish by adolescence.

Processing of highly novel auditory events in children and adults: an event-related potential study.

In this study, the neural mechanisms of novelty detection in children and adults were examined by means of novelty-elicited event-related potentials. The gross morphology of the event-related potentials elicited by complex, novel stimuli was similar in children and adults, suggesting that processing of novel acoustic information is essentially similar across the age groups. The more frontally distributed P3 components and the larger late frontal negativities in children than in adults suggest an age-related change in activity in the frontal part of the brain. This is consistent with the findings showing that the structural maturation of the frontal cortex does not appear to be completed until late adolescence.

P3 amplitude and time-on-task effects in distractible adolescents.

OBJECTIVE: The aim of our study was to examine the role of brain activity related to stimulus evaluation processes in distractibility by analyzing the P3 event-related potential. METHODS: We studied the P3 response to target stimuli at the beginning, in the middle, and at the end of a two-tone auditory oddball task in easily distractible (n = 16) and non-distractible (n = 16) adolescents. RESULTS: Easily distractible adolescents showed enhanced frontal and reduced parietal P3 amplitude across the blocks relative to non-distractible adolescents. Also, the usual decline in P3 amplitude at the end of the task was significantly larger in distractible than in non-distractible adolescents. CONCLUSIONS: These results suggests that the P3 effects are not limited to the neuropsychiatric disorders, and that increased distractibility may be characterized by reduced amount of resources allocated to the task with continued testing. SIGNIFICANCE: The results of this study contribute to elucidation of the functional basis of distractibility.

Selective attention event-related potential effects from auditory novel stimuli in children and adults.

OBJECTIVE: We investigated differences between children and adults in selective attention. METHODS: Event-related potentials of 9 year-old children and adults were studied. Subjects performed an active dichotic novelty oddball task. We examined age-related differences in early selection by comparing non-target tones and late selection by comparing target tones in the attended and unattended channels. RESULTS: In children, an attention effect was seen on the N1 response to standard tones. For the targets, both children and adults displayed enhanced P3b amplitudes on the attended side, and in adults, an attention effect was also seen on the N2 response. In children, novelty-elicited N2 responses were larger to left ear stimuli irrespective of the direction of attention. Adults displayed enhanced novelty-elicited N2 amplitudes on the attended side. CONCLUSIONS: Developmental changes occur both in early attentional selection and target detection. Children employed efficiently the mechanisms of early selection when processing standard stimuli, whereas their processes in relation to novel stimuli were attention-independent and even varied with ear. Adults were able to maintain their attentional focus in the presence of unexpected stimuli. SIGNIFICANCE: The results of this study contribute to elucidation of the development of selective attention.

Event-related potentials to elementary auditory input in distractible adolescents.

OBJECTIVE: The aim of our study was to examine the role of brain activity related to orienting in distractibility. METHODS: Event-related potentials (ERPs) were recorded in response to intermittently presented, non-attended trains of identical auditory stimuli in otherwise healthy but easily distractible (n=16) and non-distractible (n=16) 15-to-16 year old adolescents. RESULTS: In easily distractible adolescents, the first tone in each train elicited a significantly larger N1 response than in non-distractible adolescents. A later positivity in the P3 latency range, which may be correlated with the posterior part of the orienting-related P3, was also significantly larger in distractible than in non-distractible adolescents. CONCLUSIONS: The findings of this study suggests that the susceptibility to distraction in adolescence is characterized by abnormally strong orienting response as indexed by enhanced N1 component, and that distractible adolescents allocate proportionately more attentional resources to the irrelevant stimuli as indexed by larger parietal P3 amplitude to the first stimulus of each train. SIGNIFICANCE: The results of this study contribute to elucidation of the functional basis of distractibility.