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Juskeliene V (Department of Children's Hygiene, Institute of Hygiene, Dldzioji 22, Vilnius 2024, Lithuania), Magnus P, Bakketeig L S, Dailidiene N and Jurkuvenas V. Prevalence and risk factors for asymmetric posture in preschool children aged 6–7 years. International Journal of Epidemiology 1996; 25: 1053–1059.Background Adult scoliosls can be a severe disease. Not much is known about its determinants and the predictive value of early trunk asymmetries. In Vilnius, Lithuania, a cohort study has been started among 6–7 year old children In 1994. The purpose of the present report was to estimate the prevalence of trunk asymmetry in 6–7 year old children, and the association between previous rachitis, frequent illness during childhood and reduced physical activity and trunk asymmetry. Methods The degree of asymmetry was established in 791 children in kindergartens by measuring with a ruler the distance from the seventh cervical vertebra to the lower angles of the left and the right scapulas. Rachitis and the number of illnesses were extracted from each child's medical card, whereas data on physical activity were based on questionnairesfilled in by parents and kindergarten teachers. Results In all, 46.9% of children were found to have trunk asymmetry. The odds ratio of asymmetric posture was 2.76 (95% confidence interval [Cl]: 1.62–4.72) for children with rachitis degree II compared to non-rachltic children, 3.97 (95% Cl : 2.48–6.36) for those who were ill 16–28 times (over the years) compared to those who reported fewer than nine illnesses and 2.44 (95% Cl : 1.21–4.91) for children with low physical activity level (13–22 points) as compared to children with a high level (>33 points). Conclusion These findings indicate the need for prophylactic measures to decrease the incidence of infantile rachitis, acute morbidity and to increase physical activity. The significance of the high frequency of asymmetric posture can only be assessed by a follow-up of this cohort. [ABSTRACT FROM PUBLISHER]

Brain electrophysiological activity within the low gamma frequencies (30-80 Hz) has been proposed to reflect information encoding and transfer processes. The 40-Hz auditory steady-state response (40-Hz ASSR) is frequently discussed in relation to changed cognitive processing in neuropsychiatric disorders. However, the relationship between ASSRs and cognitive functioning still remains unclear. Most of the studies assessed the single frequency ASSR, while the individual resonance frequency in the gamma range (30-60 Hz), also called individual gamma frequency (IGF), has received limited attention thus far. Nevertheless, IGF potentially might better reflect individual network characteristics than standardly utilized 40-Hz ASSRs. Here, we focused on the processing speed across different types of cognitive tasks and explored its relationship with responses at 40 Hz and at IGFs in an attempt to uncover how IGFs relate to certain aspects of cognitive functioning. We show that gamma activity is related to the performance speed on complex cognitive task tapping planning and problem solving, both when responses at 40 Hz and at IGFs were evaluated. With the individualized approach, the observed associations were found to be somewhat stronger, and the association seemed to primarily reflect individual differences in higher-order cognitive processing. These findings have important implications for the interpretation of gamma activity in neuropsychiatric disorders.

Electroencephalographic (EEG) activity in the gamma (30-80 Hz) range is related to a variety of sensory and cognitive processes which are frequently impaired in schizophrenia. Auditory steady-state response at 40-Hz (40-Hz ASSR) is utilized as an index of gamma activity and is proposed as a biomarker of schizophrenia. Nevertheless, the link between ASSRs and cognitive functions is not clear. This study explores a possible relationship between the performance on cognitive tasks and the 40-Hz ASSRs in a controlled uniform sample of young healthy males, as age and sex may have complex influence on ASSRs. Twenty-eight young healthy male volunteers participated (mean age ± SD 25.8±3.3) in the study. The 40-Hz click trains (500 ms) were presented 150 times with an inter-stimulus interval set at 700-1000 ms. The phase-locking index (PLI) and event-related power perturbation (ERSP) of the ASSR were calculated in the 200-500 ms latency range, which corresponds to the steady part of the response. The Psychology Experiment Building Language (PEBL) task battery was used to assess five cognitive subdomains: the Choice response time task, the Stroop test, the Tower of London test, the Lexical decision task and the Semantic categorisation task. Pearson's correlation coefficients were calculated to access the relationships; no multiple-test correction was applied as the tests were explorative in nature. A significant positive correlation was observed for the late-latency gamma and the mean number of steps in the Tower of London task reflecting planning and problem-solving abilities. These findings support the concept that 40-Hz ASSR might highlight top-down mechanisms which are related to cognitive functioning. Therefore, 40-Hz ASSRs can be used to explore the relationship between cognitive functioning and neurophysiological indices of brain activity., Competing Interests: The authors have declared that no competing interests exist.