410 - Preliminary Insights into EEG Changes Induced by non-invasive Vagus Nerve Stimulation in Acute Stroke Patients

Patients have been admitted to an inpatient acute rehabilitation unit and received around 45 minutes of taVNS during physical or occupational therapy for 5 days a week for 2 weeks (10 sessions). A resting state electroencephalogram (EEG) has been recorded just before the first session and just after the last session. The Fugl-Myer Assessment for Upper Extremity (FMA-U) and the modified Rankin Scale (mRS) for motor function assessment as well as the Montreal Cognitive Assessment (MOCA) for cognitive function assessment have been administered in parallel to EEG pre-post taVNS. 

Results:

11 patients (8 ischemic, 3 hemorrhagic strokes; aged 44–76, mean age 61.9 ± 8.4 years; 6 females) have been enrolled. Wilcoxon signed-rank tests showed significant improvements in FMA-U Total scores (p=.004) and in subscales for shoulder/arm (p=.025), wrist (p=.029), and hand (p=.017), with mean gains of 22–34%. Marginal improvement was seen on the mRS (p=.047), while MOCA scores did not change significantly (p=0.472). EEG analysis revealed decreased left frontal beta power (p=.010). Changes in frontal theta power and delta/alpha ratios in left temporal and central regions were also related with FMA coordination subscores (p< .05).

Conclusions:

The neurophysiological changes, including reduced frontal beta power and associations between frontal theta activity and coordination performance, point to engagement of cortical networks involved in motor planning and control. The combined behavioral and neural effects highlight the potential clinical value of taVNS as an adjunct to rehabilitation. Larger placebo-controlled studies are warranted to establish its therapeutic role and optimize its integration into clinical practice.