Frontiers in Systems Neuroscience
May 25, 2023
Charles Gervais, Louis-Philippe Boucher, Guillermo Martinez Villar et al.
25 citations
The healthy conscious brain is thought to operate near a critical state, balancing order and chaos for optimal information processing. This scoping review of 49 studies across seven altered states of consciousness (ASC)—including disorders of consciousness, sleep, anesthesia, epilepsy, psychedelics, delirium, and meditation—found that each category showed a deviation from this critical state. Most studies could identify a deviation but not its direction; however, a preliminary consensus indicates non-REM sleep reflects a subcritical state, epileptic seizures a supercritical state, and psychedelics are closer to criticality than normal waking consciousness. The evidence is limited and methodologically varied, but criticality may become an objective way to characterize ASC and guide treatments, such as using anesthesia or psychedelics to restore criticality in pathological brain states.
Expert review of neurotherapeutics
June 1, 2025
Rosalie Girard Pepin, Fatemeh Seyfzadeh, David Williamson et al.
7 citations
Pharmacological treatment options for disorders of consciousness (DoC), which range from coma to minimally conscious state, remain limited due to the heterogeneity of causes such as traumatic brain injury, stroke, and infections. A lack of rigorous clinical trials has led to off-label use of drugs—including dopaminergic and GABAergic agents, antidepressants, statins, and anticonvulsants—often without clear mechanistic understanding. Robust longitudinal trials are needed, prioritizing early subacute intervention and better-defined outcomes that consider immediate responses and long-term quality of life. A shift toward personalized medicine and unified functional frameworks is advocated, along with increased use of AI tools to predict treatment responses.
Annals of clinical and translational neurology
May 25, 2025
Charlotte Maschke, Loretta Norton, Catherine Duclos et al.
In patients with severe brain injury, the neurological wake-up test—a brief interruption of sedation to check responsiveness—often yields ambiguous or absent behavioral responses, limiting its prognostic value. Recording 128-channel EEG from 41 such patients during propofol sedation interruption revealed that brain responses, measured by EEG power, spatial ratios, and the spectral exponent, can show signs of waking even when behavior does not. Combining EEG with behavioral assessment improved predictions of survival, recovery of consciousness, and long-term functional outcomes, outperforming the predictions of attending physicians. EEG can complement the wake-up test to better inform clinicians, families, and treatment planning.