Disorders Of Consciousness Patients Research Articles

Paradoxical markers of conscious levels: Effects of propofol on patients in disorders of consciousness.

Human consciousness is widely understood to be underpinned by rich and diverse functional networks, whose breakdown results in unconsciousness. Candidate neural correlates of anesthetic-induced unconsciousness include: (1) disrupted frontoparietal functional connectivity; (2) disrupted brain network hubs; and (3) reduced spatiotemporal complexity. However, emerging counterexamples have revealed that these markers may appear outside of the state they are associated with, challenging both their inclusion as markers of conscious level, and the theories of consciousness that rely on their evidence. In this study, we present a case series of three individuals in disorders of consciousness (DOC) who exhibit paradoxical brain responses to exposure to anesthesia. High-density electroencephalographic data were recorded from three patients with unresponsive wakefulness syndrome (UWS) while they underwent a protocol of propofol anesthesia with a targeted effect site concentration of 2 μg/ml. Network hubs and directionality of functional connectivity in the alpha frequency band (8–13 Hz), were estimated using the weighted phase lag index (wPLI) and directed phase lag index (dPLI). The spatiotemporal signal complexity was estimated using three types of Lempel-Ziv complexity (LZC). Our results illustrate that exposure to propofol anesthesia can paradoxically result in: (1) increased frontoparietal feedback-dominant connectivity; (2) posterior network hubs; and (3) increased spatiotemporal complexity. The case examples presented in this paper challenge the role of functional connectivity and spatiotemporal complexity in theories of consciousness and for the clinical evaluation of levels of human consciousness.

O131 / #859 STRUCTURAL CHANGES IN BRAINS OF PATIENTS WITH DISORDERS OF CONSCIOUSNESS TREATED WITH DEEP BRAIN STIMULATION: TRACK 2: BRAIN STIMULATION

Disorders of consciousness (DOC) are one of the major consequences after anoxic or traumatic brain injury. So far, several studies have described the regaining of consciousness in DOC patients using deep brain stimulation (DBS). However, these studies often lack detailed data on the structural and functional cerebral changes after such treatment. The aim of this study was to conduct a volumetric analysis of specific cortical and subcortical structures to determine the impact of DBS after functional recovery of DOC patients.

Multimodal prediction of residual consciousness in the intensive care unit: the CONNECT-ME study.

Functional MRI (fMRI) and EEG may reveal residual consciousness in patients with disorders of consciousness (DoC), as reflected by a rapidly expanding literature on chronic DoC. However, acute DoC is rarely investigated, although identifying residual consciousness is key to clinical decision-making in the intensive care unit (ICU). Therefore, the objective of the prospective, observational, tertiary center cohort, diagnostic phase IIb study 'Consciousness in neurocritical care cohort study using EEG and fMRI' (CONNECT-ME, NCT02644265) was to assess the accuracy of fMRI and EEG to identify residual consciousness in acute DoC in the ICU. Between April 2016 and November 2020, 87 acute DoC-patients with traumatic or non-traumatic brain injury were examined with repeated clinical assessments, fMRI and EEG. Resting-state EEG and EEG with external stimulations were evaluated by visual analysis, spectral band analysis and a Support Vector Machine (SVM) consciousness classifier. In addition, within- and between-network resting-state connectivity for canonical resting-state fMRI networks were assessed. Next, we used EEG and fMRI data at study enrollment in two different machine-learning algorithms (Random Forest and SVM with a linear kernel), to distinguish patients in a minimally conscious state or better (≥MCS) from those in coma or unresponsive wakefulness state (≤UWS), at time of study enrollment and at ICU-discharge (or before death). Prediction performances were assessed with area under the curve (AUC). Of 87 DoC-patients (mean age, 50.0 ± 18 years, 43% women), 51 (59%) were ≤ UWS and 36 (41%) were ≥ MCS at study enrollment. Thirty-one (36%) patients died in the ICU, including 28 who had life-sustaining therapy withdrawn. EEG and fMRI predicted consciousness levels at study enrollment and ICU-discharge, with maximum AUCs of 0.79 (95% CI 0.77-0.80) and 0.71 (95% CI 0.77-0.80), respectively. Models based on combined EEG and fMRI features predicted consciousness levels at study enrollment and ICU-discharge with maximum AUCs of 0.78 (95% CI 0.71-0.86) and 0.83 (95% CI 0.75-0.89), respectively, with improved positive predictive value and sensitivity. Overall, both machine-learning algorithms (SVM and Random Forest) performed equally well. In conclusion, we suggest that acute DoC prediction models in the ICU be based on a combination of fMRI and EEG features, regardless of the machine-learning algorithm used.

Pain assessment during physiotherapy and noxious stimuli in patients with disorders of consciousness: A preliminary study.

ObjectivesThe primary purpose of this study is to determine whether patients with disorders of consciousness (DOC) (unresponsive wakefulness syndrome, UWS; minimally conscious state, MCS) experience pain during physiotherapy and noxious stimuli in a larger patient population.Materials and methodsThe patients’ level of consciousness was measured with the Coma Recovery Scale-Revised (CRS-R). Additionally, the Nociception Coma Scale-revised (NCS-R) was used to assess their pain response. The NCS-R total scores between UWS and MCS at baseline, physiotherapy and noxious stimulus were compared using the Mann-Whitney U test (Wilcoxon rank-sum test) and the Kruskal-Wallis H test with Bonferroni correction.ResultsThe study enrolled 93 participants. There was a statistically significant difference in NCS-R total scores between the three conditions (H = 215.25, p < 0.001). At baseline, there was no statistically significant difference between MCS and UWS (U = 378, z = –1.35, p = 0.178). While there was a statistically significant difference between MCS and UWS during physiotherapy (U = 1,362, z = –3.06, p < 0.01) and under noxious stimuli (U = 5142.5, z = –11.22, p < 0.001).ConclusionPhysiotherapy improved the activity responsiveness of DOC patients, and patients experienced less potential pain. However, some DOC patients, especially MCS patients, perceived pain under the noxious stimuli.

Short-term efficacy of music therapy combined with α binaural beat therapy in disorders of consciousness

ObjectiveTo investigate the short-term effect of music therapy combined with binaural frequency difference therapy on patients with consciousness disorder.Materials and methodsNinety patients with definite diagnosis of disorders of consciousness (DOC) were selected. These patients were randomly divided into control group, experiment 1 group and experiment 2 group, with 30 patients in each group. The control group was treated with routine clinical treatment and rehabilitation. In experiment 1 group, music therapy was added to the control group. In experimental group 2, music therapy combined with binaural α frequency difference therapy was added to the control group. All patients were assessed before and after 30 treatments. The assessment items included Glasgow Coma Scale (GCS), Coma Recovery Scale revised (CRS-R), electroencephalogram (EEG), upper somatosensory evoked potential (USEP), and brainstem auditory evoked potential (BAEP).ResultsBefore treatment, there were no significant differences in GCS score, CRS-R score, USEP, BAEP, and EEG scores among the three groups (P > 0.05). After 30 times of treatment, GCS score, CRS-R score, USEP, BAEP, and EEG scores in 3 groups were significantly higher than those before treatment (P < 0.05), and experimental group 2 >experimental group 1 >control group (P < 0.05). And the consciousness rate of experimental group 2 was better than experimental group 1, experimental group 1 was better than the control group and the difference was statistically significant (P < 0.05).ConclusionMusic therapy combined with binaural α frequency difference therapy is more effective in stimulating DOC patients.

Family surrogate decision-makers’ perspectives in decision-making of patients with disorders of consciousness

ABSTRACT To explore and describe the experience of decision-making for patients with disorders of consciousness (DOC) from the perspectives of family surrogate decision-makers. A total of 21 face-to-face interviews with family surrogate decision-makers from a tertiary hospital in Shanghai, China were conducted from January 2021 to February 2021. Thematic analysis was used for data analysis. Four main themes were identified and were included in this study: (1) a tough choice between life and dignity, (2) a major responsibility for patient’s voice, (3) complex considerations between ethics and morals, and (4) the importance of realistic basis. The surrogate decision-making of DOC patients in China has been affected by the Chinese cultural context and several practical roots. And the family surrogate decision-makers shared their experiences of trade-offs during the decision-making process. Moreover, family surrogate decision-makers realized their serious responsibility to make a decision that would be in the best interest of DOC patients.

Functional Connectivity Increases in Response to High-Definition Transcranial Direct Current Stimulation in Patients with Chronic Disorder of Consciousness.

Highlights Functional connectivity induced by HD-tDCS in DLPFC has different trends in CRS-R score improvers and non-improvers.An increase in theta PLV in the left frontal–parietooccipital region was significantly associated with CRS-R changes.DOC patients with increased PLV of the alpha band in the intra-bifrontal region have a better prognosis than those without. High-definition transcranial direct current stimulation (HD-tDCS) has been shown to play an important role in improving consciousness in patients with disorders of consciousness (DOCs), but its neuroelectrophysiological evidence is still lacking. To better explain the electrophysiological mechanisms of the effects of HD-tDCS on patients with DOCs, 22 DOC patients underwent 10 anodal HD-tDCS sessions of the left dorsolateral prefrontal cortex (DLPFC). This study used the Coma Recovery Scale-Revised (CRS-R) to assess the level of consciousness in DOC patients. According to whether the CRS-R score increased before and after stimulation, DOC patients were divided into a responsive group and a non-responsive group. By comparing the differences in resting-state EEG functional connectivity between different frequency bands and brain regions, as well as the relationship between functional connectivity values and clinical scores, the electrophysiological mechanism of the clinical effects of HD-tDCS was further explored. The change of the phase locking value (PLV) on the theta frequency band in the left frontal–parietooccipital region was positively correlated with the change in the CRS-R scores. As the number of interventions increased, we observed that in the responsive group, the change in PLV showed an upward trend, and the increase in the PLV appeared in the left frontal–parietooccipital region at 4–8 Hz and in the intra-bifrontal region at 8–13 Hz. In the non-responsive group, although the CRS-R scores did not change after stimulation, the PLV showed a downward trend, and the decrease in the PLV appeared in the intra-bifrontal region at 8–13 Hz. In addition, at the three-month follow-up, patients with increased PLV in the intra-bifrontal region at 8–13 Hz after repeated HD-tDCS stimulation had better outcomes than those without. Repeated anodal stimulation of the left DLPFC with HD-tDCS resulted in improved consciousness in some patients with DOCs. The increase in functional connectivity in the brain regions may be associated with the improvement of related awareness after HD-tDCS and may be a predictor of better long-term outcomes.

How brain-computer interface technology may improve the diagnosis of the disorders of consciousness: A comparative study.

ObjectiveClinical assessment of consciousness relies on behavioural assessments, which have several limitations. Hence, disorder of consciousness (DOC) patients are often misdiagnosed. In this work, we aimed to compare the repetitive assessment of consciousness performed with a clinical behavioural and a Brain-Computer Interface (BCI) approach.Materials and methodsFor 7 weeks, sixteen DOC patients participated in weekly evaluations using both the Coma Recovery Scale-Revised (CRS-R) and a vibrotactile P300 BCI paradigm. To use the BCI, patients had to perform an active mental task that required detecting specific stimuli while ignoring other stimuli. We analysed the reliability and the efficacy in the detection of command following resulting from the two methodologies.ResultsOver repetitive administrations, the BCI paradigm detected command following before the CRS-R in seven patients. Four clinically unresponsive patients consistently showed command following during the BCI assessments.ConclusionBrain-Computer Interface active paradigms might contribute to the evaluation of the level of consciousness, increasing the diagnostic precision of the clinical bedside approach.SignificanceThe integration of different diagnostic methods leads to a better knowledge and care for the DOC.

Accuracy of EEG Biomarkers in the Detection of Clinical Outcome in Disorders of Consciousness after Severe Acquired Brain Injury: Preliminary Results of a Pilot Study Using a Machine Learning Approach.

Accurate outcome detection in neuro-rehabilitative settings is crucial for appropriate long-term rehabilitative decisions in patients with disorders of consciousness (DoC). EEG measures derived from high-density EEG can provide helpful information regarding diagnosis and recovery in DoC patients. However, the accuracy rate of EEG biomarkers to predict the clinical outcome in DoC patients is largely unknown. This study investigated the accuracy of psychophysiological biomarkers based on clinical EEG in predicting clinical outcomes in DoC patients. To this aim, we extracted a set of EEG biomarkers in 33 DoC patients with traumatic and nontraumatic etiologies and estimated their accuracy to discriminate patients’ etiologies and predict clinical outcomes 6 months after the injury. Machine learning reached an accuracy of 83.3% (sensitivity = 92.3%, specificity = 60%) with EEG-based functional connectivity predicting clinical outcome in nontraumatic patients. Furthermore, the combination of functional connectivity and dominant frequency in EEG activity best predicted clinical outcomes in traumatic patients with an accuracy of 80% (sensitivity = 85.7%, specificity = 71.4%). These results highlight the importance of functional connectivity in predicting recovery in DoC patients. Moreover, this study shows the high translational value of EEG biomarkers both in terms of feasibility and accuracy for the assessment of DoC.

Informal Caregivers of Patients with Disorders of Consciousness: a Qualitative Study of Communication Experiences and Information Needs with Physicians

Due to improvements in medicine, the figures of patients with disorders of consciousness (DoC) are increasing. Diagnostics of DoC and prognostication of rehabilitation outcome is challenging but necessary to evaluate recovery potential and to decide on treatment options. Such decisions should be made by doctors and patients’ surrogates based on medico-ethical principles. Meeting information needs and communicating effectively with caregivers as the patients´ most common surrogate-decision makers is crucial, and challenging when novel tech-nologies are introduced. This qualitative study aims to explore information needs of informal DoC caregivers, how they manage the obtained information and their perceptions and experiences with caregiver-physician communication in facilities that implemented innovative neurodiagnostics studies. In 2021, we conducted semi-structured interviews with nine caregivers of clinically stable DoC patients in two rehabilitation centers in Italy and Germany. Participants were selected based on consecutive purposeful sampling. Caregivers were recruited at the facilities after written informed consent. All interviews were recorded, transcribed verbatim and translated. For analysis, we used reflexive thematic analysis according to Braun & Clarke (2006). Caregivers experienced the conversations emotionally, generally based on the value of the information provided. They reported to seek positive information, comfort and empathy with-in the communication of results of examinations. They needed detailed information to gain a deep understanding and a clear picture of their loved-one’s condition. The results suggest a mismatch between the perspectives of caregivers and the perspectives of medical profession-als, and stress the need for more elaborate approaches to the communication of results of neu-rodiagnostics studies.

Against Futility Judgments for Patients with Prolonged Disorders of Consciousness

Against Futility Judgments for Patients with Prolonged Disorders of Consciousness

Fractal Dimension Feature as a Signature of Severity in Disorders of Consciousness: An EEG Study.

An accurate diagnosis of the disorder of consciousness (DOC) is essential for generating tailored treatment programs. Accurately diagnosing patients with a vegetative state (VS) and patients in a minimally conscious state (MCS), however, might be very complicated, reaching a misdiagnosis of approximately 40% if clinical scales are not carefully administered and continuously repeated. To improve diagnostic accuracy for those patients, tools such as electroencephalography (EEG) might be used in the clinical setting. Many linear indices have been developed to improve the diagnosis in DOC patients, such as spectral power in different EEG frequency bands, spectral power ratios between these bands, and the difference between eyes-closed and eyes-open conditions (i.e. alpha-blocking). On the other hand, much less has been explored using nonlinear approaches. Therefore, in this work, we aim to discriminate between MCS and VS groups using a nonlinear method called Higuchi's Fractal Dimension (HFD) and show that HFD is more sensitive than linear methods based on spectral power methods. For the sake of completeness, HFD has also been tested against another nonlinear approach widely used in EEG research, the Entropy (E). To our knowledge, this is the first time that HFD has been used in EEG data at rest to discriminate between MCS and VS patients. A comparison of Bayes factors found that differences between MCS and VS were 11 times more likely to be detected using HFD than the best performing linear method tested and almost 32 times with respect to the E. Machine learning has also been tested for HFD, reaching an accuracy of 88.6% in discriminating among VS, MCS and healthy controls. Furthermore, correlation analysis showed that HFD was more robust to outliers than spectral power methods, showing a clear positive correlation between the HFD and Coma Recovery Scale-Revised (CRS-R) values. In conclusion, our work suggests that HFD could be used as a sensitive marker to discriminate between MCS and VS patients and help decrease misdiagnosis in clinical practice when combined with commonly used clinical scales.

White matter connectometry in patients with disorders of consciousness revealed by 7-Tesla magnetic resonance imaging

White matter disruption plays an important role in disorders of consciousness (DOC). The aim of this study was to analyze the connectometry between DOC patients and healthy controls and to explore the relationship between diffusion connectometry and levels of consciousness. Fourteen patients with DOC and 13 sex- and age-matched controls were included in this study. The participants underwent diffusion magnetic resonance imaging (MRI) and T1-weighted structural MRI at 7 Tesla. Diffusion MRI connectometry was performed to investigate the differences between groups, and to subsequently study the correlation between Coma Recovery Scale-Revised (CRS-R) indexes and white matter integrity. In DOC patients, the quantitative anisotropy (QA) was significantly reduced in deep white matter tracts, whereas significantly higher QA values were found in the bilateral cerebellum compared with healthy controls. Moreover, the QA values in many tracts within the right hemisphere were higher in patients in a minimally conscious state compared to those in vegetative state/unresponsive wakefulness syndrome, which was reflected by the correlation between diffusion connectometry and CRS-R indexes. These results indicate that the cerebellum may play an important role in DOC, and the lateralization of the cerebral hemisphere in affected patients may suggest neural compensation.

Language Assessment in Patients with Disorders of Consciousness.

The assessment of residual language abilities in patients with disorders of consciousness (DoC) after severe brain injury is particularly challenging due to their limited behavioral repertoire. Moreover, associated language impairment such as receptive aphasia may lead to an underestimation of actual consciousness levels. In this review, we examine past research on the assessment of residual language processing in DoC patients, and we discuss currently available tools for identifying language-specific abilities and their prognostic value. We first highlight the need for validated and sensitive bedside behavioral assessment tools for residual language abilities in DoC patients. As regards neuroimaging and electrophysiological methods, the tasks involving higher level linguistic commands appear to be the most informative about level of consciousness and have the best prognostic value. Neuroimaging methods should be combined with the most appropriate behavioral tools in multimodal assessment protocols to assess receptive language abilities in DoC patients in the most complete and sensitive manner.

Sleep and Circadian Disturbance in Disorders of Consciousness: Current Methods and the Way towards Clinical Implementation.

The investigation of sleep in disorders of consciousness (DoC) has shown promising diagnostic and prognostic results. However, the methods employed in this field of research are diverse. This leads to confusion in the way forward for both scientific and clinical purposes. We review the literature that has investigated sleep in DoC patients and specifically outline the methodologies used next to the presented results. We highlight what knowledge we currently have and where increased efforts are needed before further clinical implementation. Specifically, the review shows that successful methods may employ a two-stage approach to sleep scoring, where one is the application of loosened standard criteria and the other a more general factor describing closeness of the electroencephalography to a healthy pattern, including a score that describes the extent to which sleep scoring criteria can be applied. This should be performed as part of a multimodal approach that also includes investigations of eye-opening/closure and that of circadian (24-hour) rhythmicity. Taken together, this puts the most promising methodologies in the field together for a comprehensive investigation. Large-scale approaches, incorporating multiple modalities and looking at individual variation, are now needed to advance our understanding of sleep in DoC and its role in diagnosis, treatment, and recovery.

Noninvasive Brain Stimulation Therapies to Promote Recovery of Consciousness: Where We Are and Where We Should Go.

Therapeutic options for patients with disorders of consciousness (DoC) are still underexplored. Noninvasive brain stimulation (NIBS) techniques modulate neural activity of targeted brain areas and hold promise for the treatment of patients with DoC. In this review, we provide a summary of published research using NIBS as therapeutic intervention for DoC patients, with a focus on (but not limited to) randomized controlled trials (RCT). We aim to identify current challenges and knowledge gaps specific to NIBS research in DoC. Furthermore, we propose possible solutions and perspectives for this field. Thus far, the most studied technique remains transcranial electrical stimulation; however, its effect remains moderate. The identified key points that NIBS researchers should focus on in future studies are (1) the lack of large-scale RCTs; (2) the importance of identifying the endotypes of responders; and (3) the optimization of stimulation parameters to maximize the benefits of NIBS.

Heterologous COVID-19 Booster Vaccination in the Chronic Disorder of Consciousness: A Pilot Study.

Significant anti-spike protein receptor-binding domain (S-RBD) antibody responses have been demonstrated in patients with chronic disorder of consciousness (DOC) completing a COVID-19 vaccine regime with BNT162b2 (Pfizer–BioNTech). We now provide further prospective data on the immunogenicity of these patients followed by heterologous booster injection with mRNA-1273 (Moderna). These patients were compared with two different demographically comparable healthcare workers (HCW) groups who underwent homologous booster injection with BNT162b2 vaccine or heterologous booster injection with mRNA-1273. Antibody responses were evaluated at 21 days after the administration of the booster dose of vaccination. Results: No severe adverse reactions were reported after each type of vaccination. Heterologous boosting with mRNA-1273 elicited a higher increase of S-RBD IgG levels than homologous boosting with BNT162b2 both in DOC patients and HCW who had previously received two doses of BNT162b2. No significant difference was detected between DOC and HCW patients who received heterologous boosting. Conclusions: Despite the small sample size, our preliminary results suggest that heterologous boosting with mRNA-1273, following initial vaccination with BNT162b2, is safe and tends to be more immunogenic than homologous boosting, either in fragile people or in healthy controls.

Whole-brain modelling identifies distinct but convergent paths to unconsciousness in anaesthesia and disorders of consciousness

The human brain entertains rich spatiotemporal dynamics, which are drastically reconfigured when consciousness is lost due to anaesthesia or disorders of consciousness (DOC). Here, we sought to identify the neurobiological mechanisms that explain how transient pharmacological intervention and chronic neuroanatomical injury can lead to common reconfigurations of neural activity. We developed and systematically perturbed a neurobiologically realistic model of whole-brain haemodynamic signals. By incorporating PET data about the cortical distribution of GABA receptors, our computational model reveals a key role of spatially-specific local inhibition for reproducing the functional MRI activity observed during anaesthesia with the GABA-ergic agent propofol. Additionally, incorporating diffusion MRI data obtained from DOC patients reveals that the dynamics that characterise loss of consciousness can also emerge from randomised neuroanatomical connectivity. Our results generalise between anaesthesia and DOC datasets, demonstrating how increased inhibition and connectome perturbation represent distinct neurobiological paths towards the characteristic activity of the unconscious brain.

On the recovery of disorders of consciousness under intrathecal baclofen administration for severe spasticity-An observational study.

BackgroundOccasionally, patients show dramatic recovery from disorders of consciousness (DOC) under intrathecal baclofen (ITB), an established treatment option for severe supraspinal spasticity. Anecdotal explanations for ITB‐related recovery of cognition include modulation of afferent impulses at the spinal level, thereby reducing spasticity‐related proprioceptive information overload within cortico–thalamo–cortical connections.ObjectiveIn this retrospective patient chart analysis, we assessed whether a reduction in spasticity would be associated with an increase in Coma Recovery Scale revised (CRS‐R) scores in a larger sample of patients than previously published.MethodsFrom a hospital‐based ITB treatment register, we extracted data from 26 patients with DOC and severe supraspinal spasticity who improved by >2 points on the Coma Recovery Scale revised (CRS‐R) within 6 months after ITB treatment initiation. We assessed Modified Ashworth scale (MAS) scores and CRS‐R scores on admission (PRE) and 3 and 6 months after initiation of ITB treatment (3M, 6M). We performed correlation analysis of the scores and their respective changes (PRE to 3M, 3M to 6M). We also correlated the time from acute event until ITB initiation to CRS‐R scores at 3M and 6M.ResultsITB led to significant improvement in spasticity based on MAS scores, which did not correlate to the improvements seen in CRS‐R total and subscale scores. Daily ITB dose did neither correlate to MAS scores nor to CRS‐total scores in the whole patient group, but after 3 months, ITB dose correlated to some CRS‐R subscale scores in some patient subgroups. Time until ITB treatment did not correlate to CRS‐R scores later on.ConclusionsOur data confirm that ITB may exert beneficial effects in selected DOC patients with respect to improved cognitive functions, which, however, do not correlate to its antispastic effect. The lack of correlation between time to ITB and CRS‐R outcome, but significant CRS‐R improvements following pump implantation, renders spontaneous remissions unlikely and leaves room for alternative pharmacological mechanisms.

Trigeminal nerve stimulation for disorders of consciousness

According to previous case reports, trigeminal nerve stimulation (TNS) can be successfully used to wake a non-responsive unconscious patient. However, no studies have comprehensively investigated the effect of TNS on patients with disorders of consciousness (DOC). Therefore, the present study aimed to assess the safety and efficacy of TNS in DOC patients recruited at the First Affiliated Hospital of Nanchang University. We used Coma Recovery Scale-Revised (CRS-R) scores to assess patients at baseline and after 1–4 weeks of TNS. The patients were further followed up for 4 weeks after the last stimulation to evaluate the safety of the procedure. The participant group comprised 21 DOC patients with an acquired brain injury who were more than 3 months post-injury. The participants were 44.29 ± 12.55 years old and 5.52 ± 1.83 months post-DOC onset, and included 12 patients who were in a vegetative state or had unresponsive wakefulness syndrome and 9 patients who were in a minimally conscious state. Compared with CRS-R scores at baseline, those at weeks 4 and 8 showed no significant improvements in any of the DOC patients. Nonetheless, CRS-R scores improved throughout the study period in 8 out of the 21 DOC patients. Among those with improved scores, two patients in a minimally conscious state had improved CRS-R scores at week 4, while five had improved scores at 4 weeks later. Only one patient with vegetative state/unresponsive wakefulness syndrome had recovered to a minimally conscious state at week 4. Importantly, no obvious treatment-related adverse events were considered to be related to TNS. Taken together, these data provide early evidence that TNS may be an effective and safe approach for promoting the recovery of consciousness in patients with neurological disorders.