Spinal cord stimulation (SCS) has emerged as a promising neuromodulatory intervention for patients with disorders of consciousness (DoC). However, the identification of optimal stimulation frequencies remains a subject of ongoing debate. Although previous electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) studies have suggested the therapeutic efficacy of 5- and 70-Hz, respectively, the integrative neurovascular mechanisms and frequency-specific network dynamics underlying these effects remain to be elucidated.

This study aims to characterize frequency-dependent network reconfiguration in DoC using simultaneous EEG-fNIRS recordings and graph theoretical analysis. By delineating distinct neurophysiological and hemodynamic signatures, our findings establish a mechanistic framework for the optimization of SCS parameters, thereby advancing personalized neuromodulation strategies for the promotion of consciousness recovery.

This prospective trial used simultaneous EEG–fNIRS and graph theory in 16 patients with DoC undergoing multifrequency SCS at 5, 20, 70, and 100 Hz to decode frequency-specific network dynamics. Our integrated EEG–fNIRS analysis revealed 3 principal advances. First, multimodal cortical mapping via a unified anatomical atlas quantified frequency-dependent network reconfiguration, generating graph-theoretical metrics (global and nodal efficiency, characteristic path length, and clustering coefficients) from source-localized EEG (delta–gamma bands) and fNIRS (oxyhemoglobin and deoxygenated) data. Second, we identified frequency-dependent neurophysiological profiles.

Five-hertz stimulation produced acute enhancement of theta-band global network efficiency coupled with elevated gamma-band nodal efficiency in the right cingulate motor area, indicating immediate frontolimbic engagement. Conversely, 70-Hz stimulation selectively evoked delayed hemodynamic responses in the visual cortices and increased occipital hemoglobin oxygenation without concomitant EEG alterations, suggesting preferential retinotopic pathway recruitment.

Multimodal EEG–fNIRS analysis elucidates frequency-specific SCS mechanisms, where 5-Hz stimulation optimizes local information integration through theta and gamma modulation, while 70-Hz enhances long-range connectivity, exposing frequency-specific neural plasticity mechanisms.

To investigate the clinical effects of time window on hyperbaric oxygen treatment (HBOT) in patients with disorders of consciousness (DOC).

All the clinical research literature regarding HBOT for DOC published between January 2000 and November 2020 were retrieved from China National Knowledge Infrastructure (CNKI), Wanfang Standards Database (WFSD) and VIP Database using Chinese key words disorders of consciousness, the vegetable state, minimally conscious state, or hyperbaric oxygen followed by a comprehensive meta-analysis.

The query gave rise to 348 results, in which 21 articles were eventually selected for meta-analysis. Among the selected 21 articles, 18 articles involved a time window comparison. All the patients were classified into < 60- (718 patients) and ≥ 60- (374 patients) day groups depending on the number of days from HBOT initiation. The Jadad scores for the included datasets were relatively low in general with 2 points as the highest score. Comparable baseline data were demonstrated in all of the articles. Datasets from different sources were pooled and analyzed, and the results suggested that the clinical curative effect rate in the treatment group was significantly higher compared with that in the control group (curative effect rate: 69.86% versus 42.30%; Z = 11.28, P = 0.000, odds ratio = 3.80, 95% CI = 3.02-4.80). Additionally, the adverse reaction rate of the < 60-day group was found to be significantly lower compared with that of the ≥ 60-day group (Z = 10.01, P = 0.000, odds ratio = 4.82, 95% CI = 3.54-6.56). The funnel diagram in articles related to curative effect analysis and time window evaluation is inverted and symmetrical, indicating that publication bias was not significant.

The clinical curative effect of the HBOT group is higher compared with that of the control group. However, the conclusions based on meta-analysis are limited because of the methodological problems of some studies. Therefore, the clinical efficacy needs to be further tested using carefully designed large sample trials (multicenter, randomized, controlled, and double-blind).