Electroencephalogram (EEG) With or Without Transcranial Magnetic Stimulation (TMS) as Biomarkers for Post-stroke Recovery: A Narrative Review

Keser, Zafer; Buchl, Samuel C.; Seven, Nathan A.; Markota, Matej; Clark, Heather M.; Jones, David T.; Lanzino, Giuseppe; Brown, Robert D.; Worrell, Gregory A.; Lundstrom, Brian Nils

doi:10.3389/fneur.2022.827866

Cited by 21 publications

(23 citation statements)

References 126 publications

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“…Another promising method of directly and causally probe the disruptions of brain oscillatory activity induced by the impaired motor system is to observe its immediate response after a brief and local perturbation through transcranial magnetic stimulation (TMS) (12). TMS-EEG coupling has recently gained interest in the field of clinical neuroscience (13) due to its vast application opportunities as a diagnostic tool in psychiatry, neurology, and (more specifically) in stroke (11). Brain waves are the product of complex interactions between both local and remote neural oscillators (14); thus, it is commonly accepted that the TMS pulse mainly acts as a phase reset, producing stronger oscillations thereafter (15,16).…”

Section: Introductionmentioning

confidence: 99%

Brain oscillatory modes as a proxy of stroke recovery

harquel¹,

Hummel

2023

Preprint

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Stroke is the leading cause of long-term disability, making the search for successful rehabilitation treatment one of the most important public health issues. A better understanding of the neural mechanisms underlying impairment and recovery and the development of associated markers is critical for tailoring treatments to each individual patient with the ultimate goal of maximizing therapeutic outcomes. Here, we used a novel and powerful method consisting of combined transcranial magnetic stimulation (TMS) and multichannel electroencephalography (EEG) to analyze TMS-induced brain oscillations in a large cohort of 60 stroke patients from the acute to the early-chronic phase after a stroke. A data-driven parallel factor analysis (PARAFAC) approach to tensor decomposition allowed to detect brain oscillatory modes specifically centered on the θ, α and β frequency bands. In the acute stage, patients presented a general slowdown of these oscillatory modes, highlighting stroke-induced perturbations within thalamocortical processing. Furthermore, low-frequency modes evolved across stroke stages, according to the extent of motor recovery, associated with changes in GABAergic intracortical inhibition. Overall, these longitudinal changes provide novel insights into the ongoing functional reorganization of brain networks after a stroke and the underlying mechanisms. Notably, we propose that the observed α-mode decrease corresponds to a beneficial disinhibition phase between the subacute and early-chronic stages that fosters structural and functional plasticity and facilitates recovery. Monitoring this phenomenon at the individual patient level will provide critical information for phenotyping patients, developing electrophysiological biomarkers and refining therapies based on personalized excitatory/inhibitory neuromodulation using noninvasive or invasive brain stimulation techniques.

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Section: Introductionmentioning

confidence: 99%

Brain oscillatory modes as a proxy of stroke recovery

harquel¹,

Hummel

2023

Preprint

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“…Early MoCA scores have been associated with cognitive impairment in patients with ischaemic or haemorrhagic stroke, although the thresholds proposed by general normative datasets underestimated patients at risk of persistent cognitive impairments ( 21 ). In patients with stroke or traumatic acute brain injury, diffuse and/or focal slowed EEG activity ( 22 , 23 ), reduction in intra-hemispheric connectivity and impeded inter-hemispheric imbalance ( 22 ), and lower volume of hippocampus on MRI ( 24 ) have been associated with poorer cognitive functioning. However, in these patient groups also, the evidence of EEG or MRI measures on cognitive outcome prediction is scarce.…”

Section: Discussionmentioning

confidence: 99%

Predicting Long-Term Cognitive Impairments in Survivors after Cardiac Arrest: A Systematic Review

Glimmerveen

Verhulst

Verbunt

et al. 2023

JRM

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Objective: International guidelines recommend early screening for identification of patients who are at risk of long-term cognitive impairments after cardiac arrest. However, information about predictors is not provided. A systematic review of the literature was performed to identify early predictors of long-term cognitive outcome after cardiac arrest.Methods: Scopus and PubMed were systematically searched to identify studies on early predictors of long-term cognitive outcome in patients after cardiac arrest. The population included adult cardiac arrest survivors and potential early predictors were demographics, early cognitive screening scores, imaging measures, electroencephalographic measures, and levels of blood biomarkers. Two investigators reviewed studies for relevance, extracted data and assessed risk of bias.Results: Five articles were included. Risk of bias was assessed as low or moderate. Most detected longterm cognitive impairments were in the domain of memory. Coma duration (2 studies), early cognitive impairments by the self-developed clinical Bedside Neuropsychological Test Battery (BNTB) screener (2 studies), and high S-100B levels on day 3 (2 studies) were the most prominent identified determinants of cognitive impairment on the group level. On the individual patient level, a score on the BNTB of ≤ 94.5 predicted cognitive impairments at 6 months after cardiac arrest (1 study without external validation). Studies on brain imaging and electroencephalography are lacking. Conclusion: Early bedside cognitive screening can contribute to prediction of long-term cognitive impairment after cardiac arrest. Evidence is scarce for S-100B levels and coma duration and absent for measures derived from brain imaging and electroencephalography. LAY ABSTRACTSurvival rates of patients after cardiac arrest have increased significantly over the past decades. However, many cardiac arrest survivors have impairments in different domains of thinking (memory, attention, and executive functions, such as planning). Early identification of survivors at risk of such impairments could guide personalized rehabilitation. However, such predictors are currently unavailable. This study reviewed the literature to identify possible early predictors for patients at risk of long-term impairments in thinking. A short, early, bedside test to screen domains of thinking during hospital admission may help to predict long-term impairments. Certain blood markers and a long duration of coma have also been associated with long-term impairments of thinking, but the evidence is weak. There are no studies on brain imaging and electroencephalography in this context.

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“…A recent review suggested that compensatory activity in the non-lesioned hemisphere leads mostly to unfavorable outcomes and further aggravated inter-hemispheric imbalance. Balanced inter-hemispheric activity with increased intrahemispheric coherence in the lesioned networks correlates with improved post-stroke recovery ( 59 ). According to one longitudinal fMRI study, the right hemisphere's contribution to recovery from stroke-induced aphasia was relatively small, and the recovery was more likely driven by the left frontotemporal networks that had previously engaged in speech and cognition ( 60 ).…”

Section: Discussionmentioning

confidence: 99%

Alteration of network connectivity in stroke patients with apraxia of speech after tDCS: A randomized controlled study

Zhao

Zhang

et al. 2022

Front. Neurol.

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Objective: This study aimed to examine the changes in the functional connectivity of the cortical speech articulation network after anodal transcranial direct current stimulation (A-tDCS) over the left lip region of the primary motor cortex (M ) in subacute post-stroke patients with apraxia of speech (AoS), and the e ect of A-tDCS on AoS.Methods: A total of patients with post-stroke AoS were randomized into two groups and received A-tDCS over the left lip region of M (tDCS group)/ sham tDCS (control group) as well as speech and language therapy two times per day for days. Before and after the treatment, the AoS assessments and electroencephalogram (EEG) were evaluated. The cortical interconnections were measured using the EEG non-linear index of cross approximate entropy (C-ApEn).Results: The analysis of EEG showed that, after the treatment, the activated connectivity was all in the left hemisphere, and not only regions in the speech articulation network but also in the dorsal lateral prefrontal cortex (DLPFC) in the domain-general network were activated in the tDCS group. In contrast, the connectivity was confined to the right hemisphere and between bilateral DLPFC and bilateral inferior frontal gyrus (IFG) in the control group. In AoS assessments, the tDCS group improved significantly more than the control group in four of the five subtests. The results of multivariate linear regression analyses showed that only the group was significantly associated with the improvement of word repetition (P = .). Conclusion:A-tDCS over the left lip region of M coupled with speech therapy could upregulate the connectivity of both speech-specific and domain-general networks in the left hemisphere. The improved articulation performance in patients with post-stroke AoS might be related to the enhanced connectivity of networks in the left hemisphere induced by tDCS.

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Electroencephalogram (EEG) With or Without Transcranial Magnetic Stimulation (TMS) as Biomarkers for Post-stroke Recovery: A Narrative Review

Cited by 21 publications

References 126 publications

Brain oscillatory modes as a proxy of stroke recovery

Brain oscillatory modes as a proxy of stroke recovery

Predicting Long-Term Cognitive Impairments in Survivors after Cardiac Arrest: A Systematic Review

Alteration of network connectivity in stroke patients with apraxia of speech after tDCS: A randomized controlled study

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