A computational method uses a simplified brain model fitted to a patient's EEG power spectrum to design personalized electrical stimulation signals. In computer simulations, these signals induce healthy-like brain activity patterns in models of people with disorders of consciousness. When the model's parameters were near a stability boundary, stimulation caused a lasting change in activity beyond the stimulation period. The approach may activate plasticity mechanisms during long-term treatment, potentially leading to sustained improvements. Further clinical adjustments and validation are needed, but the method holds promise for improving therapeutic outcomes in disorders of consciousness and may extend to other neurological conditions.
Ultrasound stimulation applied to the thalamus before or after propofol anesthesia shortened the time to recovery of consciousness in mice. Mice receiving stimulation before anesthesia regained consciousness in about 20 minutes, and those stimulated after anesthesia in about 18 minutes, compared to about 33 minutes for sham-treated mice. The stimulation directly activated neural activity in the paraventricular thalamus and indirectly in the prefrontal cortex in the 60-100 Hz frequency band. Higher correlations in neural activity between these two brain regions were observed in the 8-13 Hz band, suggesting that both structures contribute to the transition of consciousness and can be modulated by transcranial ultrasound.
Resting EEG activity typically resembles a filtered random process, and alpha band (8-13 Hz) oscillations can be modeled as independent, stochastically driven relaxation oscillators. This study tested whether changes in alpha band power and spectral slope during anesthesia with xenon and nitrous oxide—both NMDA receptor antagonists—could be explained by alterations in the distribution of alpha band damping rates. In participants receiving step-level increases of xenon (n=24) or nitrous oxide (n=20), both agents produced dose-dependent reductions in alpha power and spectral slope (15-40 Hz), accounted for by increased mean alpha band damping.