Abstract Details

Title Signs of Electro-cortical Disconnection revealed by Hd-EEG in Acute Stroke Patients: a Case Study.

Topic Epilepsy/Clinical Neurophysiology (EEG)

Presentation(s) P10 - Poster Session 10 (8:00 AM-9:00 AM)

Poster/Presentation
Number 9-010

Objective To assess electro-cortical disconnection induced by stroke lesions in two patients with Hd-EEG study.

Background There are overwhelming evidences that stroke lesions induce local and remote effects beyond the site of the primary anatomical damage. These networks effects have been studied mainly via neuroimaging techniques. However, little is known about the electrocortical disconnection caused by acute stroke. Moreover, the spatial resolution has been limited by the adoption of standard EEG.

Design/Methods

128 channels Hd-EEG was recorded in two acute stroke patients (Patient 1 and Patient 2) in awake state. Patient 1 presented with aphasia and neglect in ischemic stroke involving left insula, temporal and parietal lobe. Patient 2 had mild left side paresis with evidence of extensive hypoperfusion and small multiple ischemic infarcts in right ICA occlusion. Raw data were pre-processed in MATLAB using AMICA in EEGLAB. Power spectra analysis was performed on delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (12-25 Hz) frequencies at whole-brain level and within each hemisphere. Values were then compared between the two hemispheres (lesioned vs not lesioned) using a t-test analysis (p<0.05).

Results Patient 1 had not only higher delta and theta power over temporo-parietal and posterior frontal regions but also absence of alpha power over posterior occipital regions. In addition to high delta and theta activity over a broad region including frontal and temporo-parietal areas in the hypo-perfused hemisphere, Hd-EEG in Patient 2 showed abnormal delta activity over contralateral frontal regions.

Conclusions Our findings point to the presence of electro-cortical disconnection that extends the focal lesion borders. Both patients had either delta activity or loss of alpha power in regions distant from the location of the primary local damage/hypoperfusion that was characterized by slowing. Hd-EEG may reveal network disruption in acute stroke patients in a novel and complementary way compared to neuroimaging.

Authors/Disclosures
Elena Monai, MD (University of Wisconsin-Madison) PRESENTER	Dr. Monai has nothing to disclose.
	No disclosure on file
Klevest Gjini (University of Wisconsin - Madison)	Klevest Gjini has nothing to disclose.
Aaron F. Struck, MD (Washington University in St. Louis)	The institution of Dr. Struck has received research support from Ceribell.
Melanie Boly, MD (UW Medical Foundation Centennial Bldg)	Dr. Boly has nothing to disclose.

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