Browsing by Author "Hernandez, Marta"

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    High-Frequency, Low-Intensity Vibrations Increase Bone Mass and Muscle Strength in Upper Limbs, Improving Autonomy in Disabled Children
    (WILEY, 2011) Reyes, M. Loreto; Hernandez, Marta; Holmgren, Luz J.; Sanhueza, Enrique; Escobar, Raul G.
    Disuse osteoporosis in children is a progressive disease that can affect quality of life. High-frequency, low-magnitude vibration (HFLMV) acts as an anabolic signal for bone and muscle. We undertook a prospective, randomized, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of regional HFLMV in disabled children. Sixty-five children 6 to 9 year of age were randomized into three groups: placebo, 60 Hz, and 90 Hz. In the two active groups, a 0.3-g mechanical vibration was delivered to the radii and femurs for 5 minutes each day. After 6 months, the main endpoint was bone mineral density (BMD) at the ultradistal radius (UDR), 33% radii (33% R), and femoral necks (FN). Secondary endpoints were area and bone mineral content (BMC) at the UDR, 33% R, and FN; grip force of the upper and lower limbs; motor function; and PedsQL evaluation. An intention-to-treat analysis was used. Fifty-seven children (88%) completed the protocol. A significant increase was observed in the 60-Hz group relative to the other groups in BMD at the UDR (p=.011), in grip force of the upper limbs (p=.035), and in the "daily activities item" (p=.035). A mixed model to evaluate the response to intervention showed a stronger effect of 60 Hz on patients with cerebral palsy on the UDR and that between-subject variability significantly affected the response. There were no reported side effects of the intervention. This work provides evidence that regional HFLMV is an effective and safe strategy to improve bone mass, muscle strength, and possibly independence in children with motor disabilities. (C) 2011 American Society for Bone and Mineral Research.
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    Neonatal seizures and long QT Syndrome: A cardiocerebral channelopathy?
    (WILEY-BLACKWELL, 2010) Heron, Sarah E.; Hernandez, Marta; Edwards, Caitlin; Edkins, Edward; Jansen, Floor E.; Scheffer, Ingrid E.; Berkovic, Samuel F.; Mulley, John C.
    We identified a patient with electrophysiologically verified neonatal long QT syndrome (LQTS) and neonatal seizures in the presence of a controlled cardiac rhythm. To find a cause for this unusual combination of phenotypes, we tested the patient for mutations in seven ion channel genes associated with either LQTS or benign familial neonatal seizures (BFNS). Comparative genome hybridization (CGH) was done to exclude the possibility of a contiguous gene syndrome. No mutations were found in the genes (KCNQ2, KCNQ3) associated with BFNS, and CGH was negative. A previously described mutation and a known rare variant were found in the LQTS-associated genes SCN5A and KCNE2. Both are expressed in the brain, and although mutations have not been associated with epilepsy, we propose a pathophysiologic mechanism by which the combination of molecular changes may cause seizures.
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    Symptomatic Neonatal Arterial Ischemic Stroke: The International Pediatric Stroke Study
    (AMER ACAD PEDIATRICS, 2011) Kirton, Adam; Armstrong Wells, Jennifer; Chang, Taeun; de Veber, Gabrielle; Rivkin, Michael J.; Hernandez, Marta; Carpenter, Jessica; Yager, Jerome Y.; Lynch, John K.; Ferriero, Donna M.; Int Pediat Stroke Study
    BACKGROUND: Neonatal arterial ischemic stroke (AIS) has emerged as a leading cause of perinatal brain injury, cerebral palsy, and lifelong disability. The pathogenesis is poorly understood, which limits the development of treatment and prevention strategies. Multicenter studies must define epidemiology, risk factors, treatment practices, and outcomes to advance clinical trials and improve the adverse outcomes suffered by most survivors.
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    Trastornos neurológicos en niños con síndrome de Down
    (SOC MEDICA SANTIAGO, 2012) Gaete, Beatriz; Mellado, Cecilia; Hernandez, Marta
    Background: Neurological disturbances are common problems in children with Down Syndrome (DS). Aim: To determine the prevalence of neurological disorders affecting children with Down Syndrome. Patients and Methods: Review of medical records of 253 children aged from 1 day to 23 years affected with DS, attended at a public hospital and a University clinic. Results: The overall prevalence of neurological disorders was 38.7%. The most common problems were ocular motor disorders in 26% of cases and epilepsy in 12%. Conclusions: Neurological disorders are more common in children with DS than in the general population. Motor ocular disorders and epilepsy are the predominant disturbances detected. (Rev Med Chile 2012; 140: 214-219).