Quantitative EEG and prognosis for recovery in post-stroke patients: The effect of lesion laterality

Piergiuseppe Liuzzi; Antonello Grippo; Alessandro Sodero; Chiara Castagnoli; Ilaria Pellegrini; Rachele Burali; Tanita Toci; Teresa Barretta; Andrea Mannini; Bahia Hakiki; Claudio Macchi; Francesco Lolli; Francesca Cecchi

doi:10.1016/j.neucli.2024.102952

Quantitative EEG and prognosis for recovery in post-stroke patients: The effect of lesion laterality

Neurophysiol Clin. 2024 Feb 28;54(3):102952. doi: 10.1016/j.neucli.2024.102952. Online ahead of print.

Affiliations

¹ IRCCS Fondazione Don Carlo Gnocchi ONLUS, Via Di Scandicci 269, Firenze, Italy; Scuola Superiore Sant'Anna, Istituto di BioRobotica, Viale Rinaldo Piaggio 34, Pontedera, Italy. Electronic address: pliuzzi@dongnocchi.it.
² IRCCS Fondazione Don Carlo Gnocchi ONLUS, Via Di Scandicci 269, Firenze, Italy.
³ IRCCS Fondazione Don Carlo Gnocchi ONLUS, Via Di Scandicci 269, Firenze, Italy; Università di Firenze, Dipartimento di Medicina Sperimentale e Clinica, Largo Brambilla 3, Firenze, Italy.
⁴ Università degli Studi di Firenze, Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Viale Morgagni 50, Firenze, Italy.
⁵ IRCCS Fondazione Don Carlo Gnocchi ONLUS, Via Di Scandicci 269, Firenze, Italy; Università degli Studi di Firenze, Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Viale Morgagni 50, Firenze, Italy.

PMID: 38422721
DOI: 10.1016/j.neucli.2024.102952

Abstract

Objective: There is emerging confidence that quantitative EEG (qEEG) has the potential to inform clinical decision-making and guide individualized rehabilitation after stroke, but consensus on the best EEG biomarkers is needed for translation to clinical practice. This study investigates the spatial qEEG spectral and symmetry distribution in patients with a left/right hemispheric stroke, to evaluate their side-specific prognostic power in post-acute rehabilitation outcome.

Methods: Resting-state 19-channel EEG recordings were collected with clinical information on admission to intensive inpatient rehabilitation (within 30 days post stroke), and six months post stroke. After preprocessing, spectral (Delta-to-Alpha Ratio, DAR) and symmetry (pairwise and hemispheric Brain Symmetry Index) features were extracted. Patients were divided into Affected Right and Left (AR/AL) groups, according to the location of their lesion. Within each group, DAR was compared between homologous electrode pairs and the pairwise difference between pairs was compared across pairs in the scalp. Then, the prognostic power of qEEG admission metrics was evaluated by performing correlations between admission metrics and discharge mBI values.

Results: Fifty-two patients with hemorrhagic or ischemic stroke (20 females, 38.5 %, median age 76 years [IQR = 22]) were included in the study. DAR was significantly higher in the affected hemisphere for both AR and AL groups, and, a higher frontal (to posterior) asymmetry was found independent of the side of the lesion. DAR was found to be a prognostic marker of 6-months modified Barthel Index (mBI) only for the AL group, while hemispheric asymmetry did not correlate with follow-up outcomes in either group.

Discussion: While the presence of EEG abnormalities in the affected hemisphere of a stroke is well recognized, we have shown that the extent of DAR abnormalities seen correlates with disability at 6 months post stroke, but only for left hemispheric lesions. Routine prognostic evaluation, in addition to motor and functional scales, can add information concerning neuro-prognostication and reveal neurophysiological abnormalities to be assessed during rehabilitation.

Keywords: Brain symmetry; Neurorehabilitation; Quantitative EEG; Stroke.