Randomized Sham-Controlled Pilot Study of Neurocardiac Function in Patients With Acute Ischaemic Stroke Undergoing Heart Rate Variability Biofeedback

Background: Neurocardiac dysfunction worsens clinical outcome and increases mortality in stroke survivors. We hypothesized that heart rate variability (HRV) biofeedback improves neurocardiac function by modulating autonomic nervous system activity after acute ischaemic stroke (AIS).Methods: We randomly allocated (1:1) 48 acute ischaemic stroke patients to receive nine sessions of HRV- or sham biofeedback over 3 days in addition to comprehensive stroke unit care. Before and after the intervention patients were evaluated for HRV via standard deviation of normal-to-normal intervals (SDNN, primary outcome), root mean square of successive differences between normal heartbeats (RMSSD), a predominantly parasympathetic measure, and for sympathetic vasomotor and sudomotor function. Severity of autonomic symptoms was assessed via survey of autonomic symptom scale total impact score (TIS) at baseline and after 3 months.Results: We included 48 patients with acute ischaemic stroke [19 females, ages 65 (4.4), median (interquartile range)]. Treatment with HRV biofeedback increased HRV post intervention [SDNN: 43.5 (79.0) ms vs. 34.1 (45.0) ms baseline, p = 0.015; RMSSD: 46.0 (140.6) ms vs. 29.1 (52.2) ms baseline, p = 0.015] and alleviated autonomic symptoms after 3 months [TIS 3.5 (8.0) vs. 7.5 (7.0) baseline, p = 0.029], which was not seen after sham biofeedback (SDNN: p = 0.63, RMSSD: p = 0.65, TIS: 0.06). There were no changes in sympathetic vasomotor and sudomotor function (p = ns).Conclusions: Adding HRV biofeedback to standard stroke unit care led to improved neurocardiac function and sustained alleviation of autonomic symptoms after acute ischaemic stroke, which was likely mediated by a predominantly parasympathetic mechanism.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03865225.

Prospects for Using Adaptive Biofeedback to Train Musicians

The use of biofeedback (BFB) technology becomes relevant for professional training of musicians to achieve success in psychomotor function control. We compared two training approaches: 20-22 sessions of alpha-EEG/EMG biofeedback implication to increase the аlpha-2 power while reducing the tension of the forehead muscles and sham biofeedback training. Fifty student musicians (18-28 years old) were divided randomly by age, gender, performing specialty, and individual EEG alpha-peak frequency (IAPF) into two groups. Music performance, state anxiety, self-actualization, nonverbal creativity, coefficient of finger movement optimality (Ko) and the efficiency of the single training session (E1) were evaluated before and after for both types of courses. We calculated the change of the EEG power in the individually adjusted alpha-2 range in the Pz and the integrated EMG power of the surface muscles of the forehead in response to finger movement. Training with biofeedback improved music performance score, increased self-actualization, Ko, and E1 while reducing pre-stage anxiety. The students who received the sham biofeedback did not achieve such improvements. When using biofeedback, students with baseline low alpha-peak frequency (LF) showed a more significant increase in scores for music performance, Ko, and E1 than students with high alpha-peak frequency (HF). In LF students, the sessions without biofeedback did not change the studied parameters. In this pilot placebo-controlled study, we demonstrated that achieving success in the optimal musical performance training depends on the baseline genetically determined IAPF and feedback implication from the EEG alpha-2 power and forehead muscle tone.