Beyond aphasia: Altered EEG connectivity in Broca’s patients during working memory task

Gorišek, Veronika Rutar; Isoski, Vlasta Zupanc; Belič, Aleš; Manouilidou, Christina; Koritnik, Blaž; Bon, Jurij; Meglič, Nuška Pečarič; Vrabec, Matej; Žibert, Janez; Repovš, Grega; Zidar, Janez

doi:10.1016/j.bandl.2016.08.003

Cited by 9 publications

(12 citation statements)

References 40 publications

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“…All PWAs were greater than 1-year post-stroke to ensure that spontaneous recovery was not a factor in the reliability analysis. As in previous studies (e.g., Finnigan et al, 2007Finnigan et al, , 2016Leon-Carrion et al, 2009;Herron et al, 2014;Nicolo et al, 2015;Song et al, 2015;Wu et al, 2015;Gorišek et al, 2016), potential participants with a diagnosis of significant psychiatric mood disorders were excluded (including major depressive disorder or generalized anxiety disorder), but persons with self-reported symptoms of mild depression and anxiety with no clinical diagnosis were allowed to participate. All PWAs were right-handed prior to their stroke.…”

Section: Persons With Aphasiamentioning

confidence: 99%

“…Most studies of spectral EEG in individuals' post-stroke with or without aphasia do not mention mental health disorders as an exclusion criterion, so it is unclear whether individuals in their sample experience these difficulties. Those studies that do report an exclusion criterion for mental health issues range from excluding only individuals with refractory (or treatment-resistant) depression (Carrick et al, 2016), to excluding individuals who are taking specific classes of medications (such as benzodiazepines or tricyclic antidepressants, e.g., Finnigan et al, 2007), to excluding based on known (Nicolo et al, 2015;Song et al, 2015;Finnigan et al, 2016;Gorišek et al, 2016), major active (Wu et al, 2015), major pre-morbid (Leon-Carrion et al, 2009), and/or uncontrolled (Herron et al, 2014) psychiatric illness. In this study, prospective data regarding the types or severity of depression and anxiety symptoms were not collected since mental health concerns were asked about during pre-enrollment screening only.…”

Section: Limitations and Future Directionsmentioning

confidence: 99%

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Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

Dalton

Cavanagh

Richardson

2021

Front. Hum. Neurosci.

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We investigated spectral resting-state EEG in persons with chronic stroke-induced aphasia to determine its reliability, sensitivity, and relationship to functional behaviors. Resting-state EEG has not yet been characterized in this population and was selected given the demonstrated potential of resting-state investigations using other neuroimaging techniques to guide clinical decision-making. Controls and persons with chronic stroke-induced aphasia completed two EEG recording sessions, separated by approximately 1 month, as well as behavioral assessments of language, sensorimotor, and cognitive domains. Power in the classic frequency bands (delta, theta, alpha, and beta) was examined via spectral analysis of resting-state EEG data. Results suggest that power in the theta, alpha, and beta bands is reliable for use as a repeated measure. Significantly greater theta and lower beta power was observed in persons with aphasia (PWAs) than controls. Finally, in PWAs theta power negatively correlated with performance on a discourse informativeness measure, while alpha and beta power positively correlated with performance on the same measure. This indicates that spectral rsEEG slowing observed in PWAs in the chronic stage is pathological and suggests a possible avenue for directly altering brain activation to improve behavioral function. Taken together, these results suggest that spectral resting-state EEG holds promise for sensitive measurement of functioning and change in persons with chronic aphasia. Future studies investigating the utility of these measures as biomarkers of frank or latent aphasic deficits and treatment response in chronic stroke-induced aphasia are warranted.

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Section: Persons With Aphasiamentioning

confidence: 99%

Section: Limitations and Future Directionsmentioning

confidence: 99%

Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

Dalton

Cavanagh

Richardson

2021

Front. Hum. Neurosci.

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“…The asymmetry or imbalance as a result of unilateral brain injury is not only because of local lesions, but also because of the interaction of the contralesional side via the corpus callosum [27,28]. In addition, many dysfunctions after brain injury, such as motor function [27], unilateral neglect [29], and aphasia [30], are reported to be related to the interhemispheric imbalance. Neuromodulation has been shown to reestablish the balance by either increasing the excitability of the ipsilesional hemisphere or inhibiting the cortical activities in the contralesional hemisphere.…”

Section: Discussionmentioning

confidence: 99%

Simultaneously stimulating both brain hemispheres by rTMS in patients with unilateral brain lesions decreases interhemispheric asymmetry

Zhong

Zhang

et al. 2020

Preprint

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Background: Interhemispheric asymmetry is common in brains with lesions and can be an adverse factor in the recovery of patients from neurological deficits. This study aimed to investigate the influence of repetitive transcranial magnetic stimulation (rTMS) on EEG power in patients with unilateral brain lesions by simultaneously stimulating both brain hemispheres and to elucidate asymmetrical changes in neurophysiological activity induced by rTMS. Methods: Fourteen patients with unilateral brain lesions were treated with one session of 10 Hz rTMS over the vertex. Resting-state EEGs were recorded before and immediately after rTMS. The brain symmetry index (BSI), calculated from a fast Fourier transform, was used to quantify the power asymmetry in both hemispheres and paired channels over the whole frequency range and five frequency bands (delta, theta, alpha, beta and gamma bands). Results: The results indicated that rTMS significantly reduced the BSI in patients with unilateral brain lesions over the entire frequency range (t=2.767, P=0.016). Among the five frequency bands, rTMS only induced a noticeable decrease in the BSI in the delta band (t=2.254, P=0.042). An analysis of different brain regions showed that significant changes in the BSI of the alpha band were found only in the posterior parietal lobe. EEG topographic mapping was employed to identify changes in cortical oscillations across brain regions, and demonstrated a decreased power of delta oscillations in the ipsilesional hemisphere and distinct cortical oscillations in the alpha band around the parietal-occipital lobe in the contralesional hemisphere. Conclusions: When both brain hemispheres are activated simultaneously, rTMS decreases interhemispheric asymmetry primarily through reducing the delta wave in the lesioned hemisphere.

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“…The increase in theta coherences observed at F7-F8 under both the eyes-open and eyes-closed conditions is likely to reflect an increase in functionality associated with Broca's area in the inferior frontal lobes. Low theta and gamma coherences are reported in patients with Broca's aphasia wherein both phonological and working memory processes are, in combination, dysfunctional [20]. The increase in theta coherence at C3-C4 under the eyes-closed condition is also likely to reflect increased functionality of working memory associated with control of attentional and reward behaviors as is shown in rodent brain training studies targeting the anterior cingulate cortex [21].…”

Section: Behavioural Neurologymentioning

confidence: 91%

Associations of Alpha and Beta Interhemispheric EEG Coherences with Indices of Attentional Control and Academic Performance

Gorantla

Tedesco

Chandanathil

et al. 2020

Behavioural Neurology

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Introduction. Heretofore, research on optimizing academic performance has suffered from an inability to translate what is known about an individual’s learning behaviors to how effectively they are able to use the critical nodes and hubs in their cerebral cortex for learning. A previous study from our laboratory suggests that lower theta-beta ratios (TBRs) measured by EEG may be associated with higher academic performance in a medical school curriculum. Methods. In this study, we tested the hypothesis that TBR and academic performance may be correlated with EEG coherence, a measure of brain connectivity. We analyzed the interhemispheric coherences of the subjects involved in our prior study. TBR and coherence measurements were made at 19 scalp electrode recording sites and 171 electrode combinations with eyes open and closed (EO, EC). Control data were acquired during a session of acclimation to the research protocol 3 d before an initial examination in anatomy-physiology (control exam) and were repeated five weeks later, 3 d before a second exam covering different anatomy-physiology topics (comparison exam). Results. Between the control and comparison exams, beta coherences increased significantly at the frontal pole, frontal, parietal, midtemporal, posterior temporal, and occipital recording sites under the EO condition and at the inferior frontal, central, midtemporal, and posterior temporal sites under the EC condition. Alpha coherences increased significantly at the same sites and under the same EO/EC conditions as found for the beta coherences. The beta coherences were negatively correlated with the TBR and were positively correlated with the comparison exam score at the midfrontal electrode site (F3-F4) but only under the EO condition. Beta and alpha coherences at the midfrontal, inferior frontal midtemporal, posterior temporal, and occipital sites were also negatively correlated with the average TBR under the EO condition. Conclusions. Lower TBR, an indicator of attentional control, was associated with higher alpha and beta interhemispheric coherences measured with eyes open at sites overlying the frontal, temporal, and occipital cortices. Changes in EEG coherences and TBRs might be useful as neurophysiological measures of neuroplasticity and the efficacy of strategies for preventing academic underachievement and treatments for improving academic performance.

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Beyond aphasia: Altered EEG connectivity in Broca’s patients during working memory task

Cited by 9 publications

References 40 publications

Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

Simultaneously stimulating both brain hemispheres by rTMS in patients with unilateral brain lesions decreases interhemispheric asymmetry

Associations of Alpha and Beta Interhemispheric EEG Coherences with Indices of Attentional Control and Academic Performance

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