Slow wave activity in perilesional and disconnected regions during the acute stage of stroke

Poster No:

1346 

Submission Type:

Abstract Submission 

Authors:

Ilaria Mazzonetto1, Miriam Celli2, Lorenzo Pini2, Antonio Luigi Bisogno3,2, Silvia Facchini2, Andrea Zangrossi4, Ester Fusaro3, Gianluigi De Nardi2, Giorgia Adamo2, Camillo Porcaro2, Claudio Baracchini5, Anna Maria Basile6, Renzo Manara2, Maurizio Corbetta2,1,3

Institutions:

1Veneto Institute of Molecular Medicine (VIMM), Padova, Italy, 2Department of Neuroscience, University of Padova, Padova, Italy, 3Padova Neuroscience Center, University of Padova, Padova, Italy, 4Department of General Psychology, University of Padova, Padova, Italy, 5Clinica Neurologica Azienda Ospedaliera Università di Padova, Padova, Italy, 6Azienda Ospedaliera Università di Padova, Padova, Italy

First Author:

Ilaria Mazzonetto  
Veneto Institute of Molecular Medicine (VIMM)
Padova, Italy

Co-Author(s):

Miriam Celli  
Department of Neuroscience, University of Padova
Padova, Italy
Lorenzo Pini  
Department of Neuroscience, University of Padova
Padova, Italy
Antonio Luigi Bisogno  
Padova Neuroscience Center, University of Padova|Department of Neuroscience, University of Padova
Padova, Italy|Padova, Italy
Silvia Facchini  
Department of Neuroscience, University of Padova
Padova, Italy
Andrea Zangrossi  
Department of General Psychology, University of Padova
Padova, Italy
Ester Fusaro  
Padova Neuroscience Center, University of Padova
Padova, Italy
Gianluigi De Nardi  
Department of Neuroscience, University of Padova
Padova, Italy
Giorgia Adamo  
Department of Neuroscience, University of Padova
Padova, Italy
Camillo Porcaro, Associate Professor  
Department of Neuroscience, University of Padova
Padova, Italy
Claudio Baracchini  
Clinica Neurologica Azienda Ospedaliera Università di Padova
Padova, Italy
Anna Maria Basile  
Azienda Ospedaliera Università di Padova
Padova, Italy
Renzo Manara  
Department of Neuroscience, University of Padova
Padova, Italy
Maurizio Corbetta  
Department of Neuroscience, University of Padova|Veneto Institute of Molecular Medicine (VIMM)|Padova Neuroscience Center, University of Padova
Padova, Italy|Padova, Italy|Padova, Italy

Introduction:

Based on studies in both animal and human models, it is well established that stroke lesions induce a slowing of electrophysiological signals, with the effect being most pronounced near the lesion site (Gloor et al.1977, Butz et al.2014). Recent findings have further demonstrated that, in healthy sleep-deprived individuals, slow waves in specific cortical regions are associated with region-specific cognitive deficits. This study aimed to characterize the distribution of activity across different frequency bands during the acute stage and to explore whether these changes could serve as a neurophysiological marker of acute post-stroke impairments.

Methods:

We collected high-density EEG data from 54 stroke patients (mean age ± SD: 63 ± 14 years; 20 females) during the acute stage. EEG recordings were performed under resting-state conditions, with 10 minutes of eyes-closed and 10 minutes of eyes-open data acquisition. Structural anatomical images were obtained for each patient to enable lesion segmentation. Behavioral assessments included the NIHSS and OCS tests. EEG data preprocessing followed state-of-the-art methodologies, including band-pass filtering (1–45 Hz), bad channel interpolation, artifact removal using Independent Component Analysis, and average re-referencing. EEG source activity was reconstructed using subject-specific head models that accounted for lesion geometry (Vorwerk et al.2018) and eLORETA algorithm (Pascual-Marqui et al.2011). The mean absolute power in the delta (1–4 Hz), theta (5–8 Hz), alpha (9–12 Hz), and beta (13–30 Hz) bands was calculated for each region of interest (ROI) defined by the Brainnetome atlas (cortical regions) and the SUIT atlas (cerebellar regions) (Fan et al.2016, Diedrichsen 2006). For each patient, we also derived a structural indirect connectivity map. Regions were classified into three categories: (1) "perilesional" regions, intersecting a mask extending 0–2 cm from the lesion border; (2) "structurally disconnected" regions, intersecting the thresholded indirect connectivity map but not the perilesional space; and (3) "unaffected" regions. Differences in EEG power across the frequency bands among these three groups of regions were assessed using a linear mixed-effects model, with subjects included as a random effect. Finally, the relationship between EEG power in the perilesional regions across different frequency bands and behavioral performance was examined using linear regression models. To reduce the number of variables, principal component analysis was applied. Demographic variables, lesion characteristics, and treatment type were included as covariates in the analysis.

Results:

The linear mixed-effects model revealed that absolute power in the delta and theta bands during the eyes-open condition was significantly higher (p<0.05) in both "perilesional" and "structurally disconnected" regions compared to "unaffected" regions. These results remained stable when varying the threshold of the indirect connectivity map between 0.5 and 0.7. No significant differences were observed during the eyes-closed condition. Additionally, we identified a significant relationship (p<0.05) between the third principal component, primarily associated with motor deficits, and the mean power in the delta and theta bands within the perilesional space in both eyes-open and eyes-closed conditions. Specifically, higher delta and theta power were associated with more severe neurological deficits.

Conclusions:

This study effectively measured changes in slow activity within cortical perilesional and structurally disconnected regions using high-density EEG and advanced inverse problem-solving techniques. Furthermore, by establishing a connection between slow activity patterns and cognitive as well as neurological outcomes, this research offers important insights into the mechanisms driving stroke-related deficits and identifies potential biomarkers for evaluating stroke severity and informing rehabilitation strategies.

Disorders of the Nervous System:

Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 2

Modeling and Analysis Methods:

Connectivity (eg. functional, effective, structural)
EEG/MEG Modeling and Analysis 1
Task-Independent and Resting-State Analysis

Keywords:

Electroencephaolography (EEG)
Source Localization
Other - Stroke

1|2Indicates the priority used for review

Abstract Information

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Please indicate below if your study was a "resting state" or "task-activation” study.

Resting state

Healthy subjects only or patients (note that patient studies may also involve healthy subjects):

Patients

Was this research conducted in the United States?

No

Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.

Yes

Were any animal research approved by the relevant IACUC or other animal research panel? NOTE: Any animal studies without IACUC approval will be automatically rejected.

Not applicable

Please indicate which methods were used in your research:

EEG/ERP
Structural MRI
Diffusion MRI
Neuropsychological testing

For human MRI, what field strength scanner do you use?

3.0T

Provide references using APA citation style.

Gloor et al (1977). Brain lesions that produce delta waves in the EEG. Neurology 27, 326–333.
Butz et al (2014). Homeostatic structural plasticity can account for topology changes following deafferentation and focal stroke. Frontiers in Neuroanatomy. 8.
Vorwerk et al (2018). The FieldTrip‐SimBio pipeline for EEG forward solutions. BioMedical Engineering OnLine.
Pascual-Marqui et al (2011). Assessing interactions in the brain with exact low-resolution electromagnetic tomography. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 369, 3768–3784. 10.1098/rsta.2011.0081.
Fan et al (2016). The Human Brainnetome Atlas: A New Brain Atlas Based on Connectional Architecture. Cerebral Cortex, 26 (8): 3508-3526.
Diedrichsen (2006). A spatially unbiased atlas template of the human cerebellum. Neuroimage, 33, 1, p.127-138

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