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. 2021 Sep 21:2021:5664647.
doi: 10.1155/2021/5664647. eCollection 2021.

Intrahemispheric EEG: A New Perspective for Quantitative EEG Assessment in Poststroke Individuals

Rodrigo Brito  1   2 , Adriana Baltar  1   2 , Marina Berenguer-Rocha  1 , Lívia Shirahige  1   2 , Sérgio Rocha  1 , André Fonseca  3 , Daniele Piscitelli  4   5 , Kátia Monte-Silva  1   2
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Intrahemispheric EEG: A New Perspective for Quantitative EEG Assessment in Poststroke Individuals

Rodrigo Brito et al. Neural Plast. .

Abstract

The ratio between slower and faster frequencies of brain activity may change after stroke. However, few studies have used quantitative electroencephalography (qEEG) index of ratios between slower and faster frequencies such as the delta/alpha ratio (DAR) and the power ratio index (PRI; delta + theta/alpha + beta) for investigating the difference between the affected and unaffected hemisphere poststroke. Here, we proposed a new perspective for analyzing DAR and PRI within each hemisphere and investigated the motor impairment-related interhemispheric frequency oscillations. Forty-seven poststroke subjects and twelve healthy controls were included in the study. Severity of upper limb motor impairment was classified according to the Fugl-Meyer assessment in mild/moderate (n = 25) and severe (n = 22). The qEEG indexes (PRI and DAR) were computed for each hemisphere (intrahemispheric index) and for both hemispheres (cerebral index). Considering the cerebral index (DAR and PRI), our results showed a slowing in brain activity in poststroke patients when compared to healthy controls. Only the intrahemispheric PRI index was able to find significant interhemispheric differences of frequency oscillations. Despite being unable to detect interhemispheric differences, the DAR index seems to be more sensitive to detect motor impairment-related frequency oscillations. The intrahemispheric PRI index may provide insights into therapeutic approaches for interhemispheric asymmetry after stroke.

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Conflict of interest statement

The authors report no conflicts of interest.

Figures

Figure 1
Figure 1
Flowchart of the study.
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References

    1. WHO. WHO | The Atlas of Heart Disease and Stroke . WHO; 2010.
    1. Nowak D. A., Grefkes C., Ameli M., Fink G. R. Interhemispheric competition after stroke: brain stimulation to enhance recovery of function of the affected hand. Neurorehabilitation and Neural Repair . 2009;23(7):641–656. - PubMed
    1. Min Y. S., Park J. W., Jang K. E., et al. Power spectral density analysis of long-term motor recovery in patients with subacute stroke. Neurorehabilitation and Neural Repair . 2019;33(1):38–46. doi: 10.1177/1545968318818900. - DOI - PubMed
    1. van Meer M. P. A., van der Marel K., Wang K., et al. Recovery of sensorimotor function after experimental stroke correlates with restoration of resting-state interhemispheric functional connectivity. Journal of Neuroscience . 2010;30(11):3964–3972. doi: 10.1523/JNEUROSCI.5709-09.2010. - DOI - PMC - PubMed
    1. Murase N., Duque J., Mazzocchio R., Cohen L. G. Influence of interhemispheric interactions on motor function in chronic stroke. Annals of Neurology . 2004;55(3):400–409. - PubMed

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