Article

High Gamma Oscillations of Sensorimotor Cortex During Unilateral Movement in the Developing Brain: a MEG Study

Department of Neurology, MLC 2015, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
Brain Topography (Impact Factor: 3.47). 01/2011; 23(4):375-84. DOI: 10.1007/s10548-010-0151-0
Source: PubMed

ABSTRACT

Recent studies in adults have found consistent contralateral high gamma activities in the sensorimotor cortex during unilateral finger movement. However, no study has reported on this same phenomenon in children. We hypothesized that contralateral high gamma activities also exist in children during unilateral finger movement. Sixty normal children (6-17 years old) were studied with a 275-channel MEG system combined with synthetic aperture magnetometry (SAM). Sixty participants displayed consistently contralateral event-related synchronization (C-ERS) within high gamma band (65-150 Hz) in the primary motor cortices (M1) of both hemispheres. Interestingly, nineteen younger children displayed ipsilateral event-related synchronization (I-ERS) within the high gamma band (65-150 Hz) just during their left finger movement. Both I-ERS and C-ERS were localized in M1. The incidence of I-ERS showed a significant decrease with age. Males had significantly higher odds of having ipsilateral activity compared to females. Noteworthy, high gamma C-ERS appeared consistently, while high gamma I-ERS changed with age. The asymmetrical patterns of neuromagnetic activities in the children's brain might represent the maturational lateralization and/or specialization of motor function. In conclusion, the present results have demonstrated that contralateral high-gamma neuromagnetic activities are potential biomarkers for the accurate localization of the primary motor cortex in children. In addition, the interesting finding of the ipsilateral high-gamma neuromagnetic activities opens a new window for us to understand the developmental changes of the hemispherical functional lateralization in the motor system.

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    • "signifying a more bilateral response for the non-dominant hand, a finding that cannot be accounted for by smearing of activation. Ipsilateral MRGS has been reported previously in typicallydeveloping children for non-dominant hand movement, with decreasing incidence with age (Huo et al., 2011) and may be related to mirror movements, though we did not have bilateral hand EMG or video recording to verify this. In fMRI, ipsilateral motor cortex activation is associated with voluntary unilateral movements of the non-dominant, but not dominant, hand (Kobayashi et al., 2003). "
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    ABSTRACT: Objective: Magnetoencephalography (MEG) and a simple motor paradigm were used to study induced sensorimotor responses and their relationship to motor skills in children diagnosed with Benign Epilepsy with Centro-Temporal Spikes (BECTS). Methods: Twenty-one children with BECTS and 15 age-matched controls completed a finger abduction task in MEG; movement-related oscillatory responses were derived and contrasted between groups. A subset of children also completed psycho-behavioural assessments. Regression analyses explored the relationship of MEG responses to manual dexterity performance, and dependence upon clinical characteristics. Results: In children with BECTS, manual dexterity was below the population mean (p=.002) and three showed severe impairment. Our main significant finding was of reduced ipsilateral movement related beta desynchrony (MRBDi) in BECTS relative to the control group (p=.03) and predicted by epileptic seizure recency (p=.02), but not age, medication status, or duration of epilepsy. Laterality scores across the entire cohort indicated that less lateralised MRBD predicted better manual dexterity (p=.04). Conclusions: Altered movement-related oscillatory responses in ipsilateral motor cortex were associated with motor skill deficits in children with BECTS. These changes were more marked in those with more recent seizures. Significance: These findings may reflect differences in inter-hemispheric interactions during motor control in BECTS.
    Full-text · Article · Oct 2015 · Clinical Neurophysiology
    • "s ( ERD ) that begin up to 1 . 5 s prior to movement onset and transitions to beta synchronization ( ERS ) within 1 / 2 s of movement offset [ Cassim et al . , 2001 ; Jurkiewicz et al . , 2006 ] . Previous MEG studies have reported beta ERD and ERS in older children and adolescents with marked decreases in younger children [ Gaetz et al . , 2010 ; Huo et al . , 2011 ; Wilson et al . , 2010 ] . In the current study , we observed both mu and beta ERD in the children but with a later latency , around 200 – 250 ms prior to move - ment onset . This later ERD onset might be attributed to our use of cued movements instead of the self - paced movement para - digm employed in the previous studies ( the 3 – "
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    ABSTRACT: We examined sensorimotor brain activity associated with voluntary movements in preschool children using a customized pediatric MEG system. A videogame-like task was used to generate self-initiated right or left index finger movements in seventeen healthy right-handed subjects (8 female, ages 3.2 to 4.8 years). We successfully identified spatiotemporal patterns of movement-related brain activity in 15/17 children using beamformer source analysis and surrogate MRI spatial normalization. Readiness fields in the contralateral sensorimotor cortex began approximately 0.5 s prior to movement onset (motor field, MF), followed by transient movement-evoked fields (MEFs), similar to that observed during self-paced movements in adults, but slightly delayed and with inverted source polarities. We also observed modulation of mu (8-12 Hz) and beta (15-30 Hz) oscillations in sensorimotor cortex with movement, but with different timing and a stronger frequency band coupling compared to that observed in adults. Adult-like high-frequency (70-80 Hz) gamma bursts were detected at movement onset. All children showed activation of the right superior temporal gyrus that was independent of the side of movement, a response that has not been reported in adults. These results provide new insights into the development of movement-related brain function, for an age group in which no previous data exist. The results show that children under 5 years of age have markedly different patterns of movement-related brain activity in comparison to older children and adults, and indicate that significant maturational changes occur in the sensorimotor system between the preschool years and later childhood.
    No preview · Article · Sep 2014 · Human Brain Mapping
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    • "The stimulation presentation and response recording were accomplished with BrainX software, which was based on DirectX (Microsoft Corporation, Redmond, WA, USA) (Huo et al., 2011; Wang et al., 2010; Xiang et al., 2001, 2013). The entire procedure took about 15 min. "
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    ABSTRACT: Objective: The objective of this study was to investigate functional abnormalities of the brain in females with migraine using magnetoencephalography (MEG) and a finger-tapping task. Methods: Twenty-nine female patients with migraine (aged 16-40. years) and age- and gender-matched healthy controls were studied with an MEG system at a sampling rate of 6000. Hz. MEG recordings were performed during an attack in migraineurs with and without aura. Neuromagnetic brain activation was elicited by a finger-tapping task. The latency and amplitude of neuromagnetic responses were analyzed with averaged waveforms in the frequency range of 5-100. Hz. The Morlet wavelet and beamformers were used to analyze the spectral and spatial signatures of MEG data from subjects in two frequency ranges of 5-100 and 100-1000. Hz. Results: The latency of motor-evoked magnetic fields evoked by finger movement was significantly prolonged in migraineurs as compared with controls. Neuromagnetic spectral power in the motor cortex in migraineurs was significantly elevated. There were significantly higher odds of activation in 5-30, 100-300 and 500-700. Hz frequency ranges in the ipsilateral primary motor cortices and the supplementary motor area in migraineurs as compared with controls. Conclusions: Neuromagnetic signal abnormalities in this study suggest cortical hyperexcitability in females with migraine during migraine attack, which could be measured and analyzed with MEG signal in a frequency range of 5-1000. Hz. Significance: These findings may help to identify neurophysiological biomarkers for studying mechanisms of migraine, and may facilitate to develop new therapeutic strategies for migraine by alterations in cortical excitability.
    Full-text · Article · Apr 2014 · Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology
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