Familiar music modulates cortical oscillatory activity after severe stroke: an EEG case series

Περίληψη

Stroke is associated with altered cortical electrical activity, characterized by increased delta and reduced alpha activity on electroencephalography (EEG). Music-based stimulation has been proposed as a strategy to modulate brain activity after stroke. However, electrophysiological responses may vary according to the extent of cerebral injury. This study aimed to examine alpha and delta EEG activity in patients with severe ischemic stroke during rest and familiar music listening. This case series included four patients in acute and subacute phases after ischemic stroke, with National Institute of Health Stroke Scale (NIHSS) scores ≥ 16. EEG recordings were obtained using an AB experimental design, consisting of a resting condition (phase A, 1.5 minutes) followed by familiar music listening (phase B, 1.5 minutes). Alpha (8-12 Hz), delta (0.5-4 Hz), and delta-alpha ratio (DAR) values were analysed. Heterogeneous electrophysiological responses were observed among patients. The two individuals with lower stroke severity demonstrated increased alpha-band activity during music listening, whereas the two patients with greater neurological impairment exhibited elevated delta activity and higher DAR values. The patient with the most severe stroke showed persistently abnormal DAR values (> 1), indicating greater cortical dysfunction. Familiar music listening was associated with differential EEG responses after stroke, with increased alpha activity and lower delta–alpha ratio in less severe cases, whereas more severe cases showed persistent delta dominance.

Keywords: Brain Activity; Alpha and delta waves; stroke; musical stimulation, EEG