Reactivity of sensorimotor oscillations is altered in children with hemiplegic cerebral palsy: A magnetoencephalographic study

Authors

  • Elina Pihko,

    Corresponding author
    1. Brain Research Unit, O.V. Lounasmaa Laboratory, Aalto University School of Science, Espoo, Finland
    • Correspondence to: Dr. Elina Pihko, Brain Research Unit, O.V. Lounasmaa Laboratory, Aalto University, PO Box 15100, 00076 Aalto, Finland. E-mail: elina.pihko@aalto.fi

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  • Päivi Nevalainen,

    1. BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland
    2. Department of Clinical Neurophysiology, Children's Hospital, Helsinki University Central Hospital and Helsinki University, Helsinki, Finland
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  • Selja Vaalto,

    1. Department of Clinical Neurophysiology, HUS Medical Imaging Center, Helsinki University Central Hospital and Helsinki University, Helsinki, Finland
    2. Department of Clinical Neurophysiology, Faculty of Health Sciences, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
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  • Kristina Laaksonen,

    1. Brain Research Unit, O.V. Lounasmaa Laboratory, Aalto University School of Science, Espoo, Finland
    2. Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland
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  • Helena Mäenpää,

    1. Department of Child Neurology, Children's Hospital, Helsinki University Central Hospital, Helsinki, Finland
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  • Leena Valanne,

    1. HUS Medical Imaging Center, Helsinki University, Helsinki, Finland
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  • Leena Lauronen

    1. Department of Clinical Neurophysiology, Children's Hospital, Helsinki University Central Hospital and Helsinki University, Helsinki, Finland
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Abstract

Cerebral palsy (CP) is characterized by difficulty in control of movement and posture due to brain damage during early development. In addition, tactile discrimination deficits are prevalent in CP. To study the function of somatosensory and motor systems in CP, we compared the reactivity of sensorimotor cortical oscillations to median nerve stimulation in 12 hemiplegic CP children vs. 12 typically developing children using magnetoencephalography. We also determined the primary cortical somatosensory and motor representation areas of the affected hand in the CP children using somatosensory-evoked magnetic fields and navigated transcranial magnetic stimulation, respectively. We hypothesized that the reactivity of the sensorimotor oscillations in alpha (10 Hz) and beta (20 Hz) bands would be altered in CP and that the beta-band reactivity would depend on the individual pattern of motor representation. Accordingly, in children with CP, suppression and rebound of both oscillations after stimulation of the contralateral hand were smaller in the lesioned than intact hemisphere. Furthermore, in two of the three children with CP having ipsilateral motor representation, the beta- but not alpha-band modulations were absent in both hemispheres after affected hand stimulation suggesting abnormal sensorimotor network interactions in these individuals. The results are consistent with widespread alterations in information processing in the sensorimotor system and complement current understanding of sensorimotor network development after early brain insults. Precise knowledge of the functional sensorimotor network organization may be useful in tailoring individual rehabilitation for people with CP. Hum Brain Mapp 35:4105–4117, 2014. © 2014 Wiley Periodicals, Inc.

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