Acute Effects of Esketamine on the EEG Power Spectrum and Signal Complexity in Prolonged Disorders of Consciousness: A Prospective Exploratory Cohort Study.
Yi Liang, Wanning Yang, Xinxin Wang, Qianqian Ge, Jing Wang, Yiwei Chen, Bo Ma, Minyu Jian, Haiyang Liu, Jianghong He, Ruquan Han
Journal of neurosurgical anesthesiology June 15, 2026 DOI: 10.1097/ana.0000000000001124 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Prospective exploratory cohort study Peer reviewed |
|---|---|
| Sample size | 22 |
| Population | Patients with prolonged disorders of consciousness (vegetative state/unresponsive wakefulness syndrome or minimally conscious state) |
| Intervention | Esketamine |
| Dose | 0.3 mg/kg/h |
| Duration | 1-hour intravenous infusion; EEG data collected at baseline, 1 hour after infusion, and 30 minutes post-discontinuation |
| Topics | Esketamine Philosophy of mind |
| Keywords | Lempel-ziv complexity Electroencephalography Power spectral density |
| Registration | NCT06473285 |
| Key findings | Esketamine induced reorganization of EEG power spectral density and region-specific increases in signal complexity in patients with prolonged disorders of consciousness, but these neurophysiological changes were not accompanied by improvements in behavioral responsiveness. |
Abstract
Effective treatments for prolonged disorders of consciousness (pDoC) remain limited. Grounded in the entropic brain hypothesis-that psychedelic agents facilitate consciousness recovery by increasing brain complexity-this study investigated esketamine, a nonclassical psychedelic drug, and its effects on electroencephalographic (EEG) neurophysiological metrics in pDoC patients. In this prospective exploratory cohort study, 27 patients with pDoC were enrolled, and 22 with sufficient EEG signal quality were included in the final analysis. Patients were diagnosed with vegetative state/unresponsive wakefulness syndrome (VS/UWS) or a minimally conscious state (MCS). Patients received a 1-hour intravenous infusion of esketamine (0.3 mg/kg/h). EEG data were collected at baseline, 1 hour after infusion, and 30 minutes post-discontinuation. The power spectral density and Lempel-Ziv complexity (LZC) were analyzed. The study was registered at ClinicalTrials.gov (NCT06473285) on June 23, 2024. Esketamine reshaped the EEG power spectrum, suppressing global delta relative power (p_FDR=0.040) while increasing beta (p_FDR=0.040) and gamma (p_FDR=0.009) relative power. The alpha relative power increased selectively in the VS/UWS (p_FDR=0.012). The LZC increased in the parietal (P=0.030) and occipital (P=0.007) regions. In MCS patients, the increase in LZC persisted for 30 minutes post-discontinuation, most prominently in the occipital region, whereas changes in VS/UWS were transient. No behavioral improvements were observed on the Coma Recovery Scale-Revised assessments. Esketamine-induced neurophysiological alterations in patients with pDoC are characterized by reorganization of the EEG power spectral density and region-specific increases in signal complexity. However, these changes were not accompanied by improvements in behavioral responsiveness.
Comparable studies
Other observational and cohort studies on esketamine, most cited first.
Citations in the library
Cites 12
- The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs Frontiers in Human Neuroscience 2014
- LSD alters dynamic integration and segregation in the human brain. Neuroimage February 15, 2021
- Subanaesthetic ketamine and altered states of consciousness in humans British Journal of Anaesthesia April 13, 2018
- EEG oscillatory states as neuro-phenomenology of consciousness as revealed from patients in vegetative and minimally conscious states. Consciousness and Cognition March 1, 2012
- Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans. PLoS One November 23, 2020
and 7 more in the library