Disorders of Consciousness

Disorders of consciousness and pharmacotherapy: A systematic update on drugs inducing consciousness improvement

BACKGROUND

Disorders of consciousness (DOC) represent some of the least comprehended and challenging conditions within contemporary neurology. Pharmacological interventions are capable of enhancing neurotransmitter levels, synaptic plasticity and functional connectivity within consciousness networks.

OBJECTIVE

This systematic work aims to provide a comprehensive 10-year update regarding the use of drugs that may induce consciousness improvement in patients with DOC.

METHODS

A review of current literature was performed for articles published between 2014 and 2023. A study was excluded if there was a lack of data or information about pharmacological treatment in patients with DOC.

RESULTS

12 studies with a total amount of 429 patients were identified as eligible for this paper. From our data review, 2 studies with 34 patients were identified on Baclofen. The latter was identified as the most effective treatment with an 82.35 % efficacy rate. On the other hand, 2 studies with 53 patients were identified for Amantadine that also show a substantial effectiveness of 68.42 %. Zolpidem was the most widely used medication as it was employed in 6 studies with 289 patients. Nevertheless, its efficacy showed high variability among individuals resulting in a comparatively lower average efficacy rate of 18.42 %. Finally, Opioids were evaluated in two studies with 53 patients showing an efficacy of 44 %. Within this category, the effectiveness of Propofol remained inconclusive due to the lack of specific improvement data. Overall, Baclofen and Amantadine emerged as the most effective treatments for improving conditions in patients with Disorders of Consciousness DoC.

CONCLUSIONS

Over the last 10 years, amantadine and baclofen have proven to be the most promising treatments in terms of efficacy.

What Can N100 and ASSR Assess in Patients With Disorders of Consciousness?

OBJECTIVE

Auditory Evoked Potentials (AEP), particularly the N100 component and the auditory steady-state response (ASSR), have been utilized in the clinical assessment of patients with Disorders of Consciousness (DOC). However, the specific utility of these measures remains debated across studies.

METHODS

To clarify the roles of N100 and ASSR in evaluating auditory function and levels of consciousness in DOC patients, we recorded N100 and ASSR responses in 30 DOC patients and assessed their significance at the individual level through statistical analyses.

RESULTS

Our findings indicate that, compared to N100, the significance of the ASSR response appears to be a more reliable marker of auditory function. However, neither N100 nor ASSR, at both response and microstate levels, could effectively distinguish between patients diagnosed with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS). Additionally, we validated the role of ASSR using a portable EEG device in an independent cohort of 30 patients.

CONCLUSION

In summary, our results suggest that ASSR holds promise for assessing auditory function in DOC patients, but its utility in differentiating levels of consciousness may require further consideration.

SIGNIFICANCE

These findings offer valuable insights for clinicians and neuroscientists in selecting and designing objective tools for DOC assessment.

The interplay between thyrotropic axis, neurological complications, and rehabilitation outcomes in patients with traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of mortality and long-term disability, with its pathophysiology encompassing both primary mechanical damage and secondary neuroinflammatory, metabolic, and biochemical alterations. These complex mechanisms contribute to the observed heterogeneous clinical outcomes, including neuroendocrine dysfunctions, post-traumatic seizures, and disorders of consciousness (DoC). Thyroid hormones (THs) play essential roles in synaptic plasticity, neurogenesis and neuronal homeostasis, and the hypothalamic-pituitary-thyroid (HPT) axis has recently emerged as a potential acute and chronic modulator of neurological and functional recovery following TBI, thereby hinting at the potential involvement of THs in post-TBI outcomes. While evidence suggests that alterations in the HPT axis may influence susceptibility to seizures, progression of DoC, and rehabilitation outcomes, an increased blood-brain barrier permeability in concert with dysregulated deiodinase activity and expanding oxidative stress have all been proposed as mechanisms linking THs to post-TBI neurological complications. This review aims to summarize current evidence on the potential role of the thyrotropic axis in neurological and rehabilitation outcomes following TBI.

Neuromodulation and Disorders of Consciousness: Systematic Review and Pathophysiology

INTRODUCTION

Disorders of consciousness (DoC) represent a range of clinical states, affect hundreds of thousands of people in the United States, and have relatively poor outcomes. With few effective pharmacotherapies, neuromodulation has been investigated as an alternative for treating DoC. To summarize the available evidence, a systematic review of studies using various forms of neuromodulation to treat DoC was conducted.

MATERIALS AND METHODS

Adhering to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic literature review, the PubMed, Scopus, and Web of Science databases were queried to identify articles published between 1990 and 2023 in which neuromodulation was used, usually in conjunction with pharmacologic intervention, to treat or reverse DoC in humans and animals. Records were excluded if DoC (eg, unresponsive wakefulness syndrome, minimally conscious state, etc) were not the primary clinical target.

RESULTS

A total of 69 studies (58 human, 11 animal) met the inclusion criteria for the systematic review, resulting in over 1000 patients and 150 animals studied in total. Most human studies investigated deep brain stimulation (n = 15), usually of the central thalamus, and transcranial magnetic stimulation (n = 18). Transcranial direct-current stimulation (n = 15) and spinal cord stimulation (n = 6) of the dorsal column also were represented. A few studies investigated low-intensity focused ultrasound (n = 2) and median nerve stimulation (n = 2). Animal studies included primate and murine models, with nine studies involving deep brain stimulation, one using ultrasound, and one using transcranial magnetic stimulation.

DISCUSSION

While clinical outcomes were mixed and possibly confounded by natural recovery or pharmacologic interventions, deep brain stimulation appeared to facilitate greater improvements in DoC than other modalities. However, repetitive transcranial magnetic stimulation also demonstrated clinical potential with much lower invasiveness.

The impact of frequency-specific music stimulation on consciousness in patients with disorders of consciousness

Objective

This study aimed to evaluate the effects of frequency-specific music stimulation on the awareness and brain connectivity in patients with disorders of consciousness (DOC).

Methods

A total of 25 DOC patients were exposed to auditory stimulation through music at varying frequencies (low: <0.5 Hz, middle: 0.5 Hz-3.5 kHz, high: >3.5 kHz). Brain responses were assessed using Functional Near-Infrared Spectroscopy (fNIRS) to monitor objective markers of brain activity. The analysis focused on effective connectivity and coupling strength (CS) values in response to different frequency stimulations, targeting regions such as the motor and somatosensory cortices.

Results

The mean age of the patients was 49.4 years, with an average coma duration of 1.96 months. While no significant differences were observed in general brain arousal across different frequency stimuli, notable differences in effective connectivity were identified. High-frequency stimulation resulted in significantly higher CS values in the right primary motor cortex (p < 0.05), while middle-frequency stimulation showed significant effects in the right primary somatosensory cortex (p = 0.016).

Conclusion

The findings suggest that middle- and high-frequency music stimulation may enhance effective connectivity in specific brain regions, potentially contributing to the rehabilitation of DOC patients. These results indicate that frequency-specific music could stimulate motor networks and areas associated with autobiographical memory, highlighting its therapeutic potential in promoting awareness in this patient population.

Electroencephalographic differences between waking and sleeping periods in patients with prolonged disorders of consciousness at different levels of consciousness

Objective

This study aimed to explore differences in sleep electroencephalogram (EEG) patterns in individuals with prolonged disorders of consciousness, utilizing polysomnography (PSG) to assist in distinguishing between the vegetative state (VS)/unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS), thereby reducing misdiagnosis rates and enhancing the quality of medical treatment.

Methods

A total of 40 patients with prolonged disorders of consciousness (pDOC; 27 patients in the VS/UWS and 13 in the MCS) underwent polysomnography. We analyzed differential EEG indices between VS/UWS and MCS groups and performed correlation analyses between these indices and the Coma Recovery Scale-Revised (CRS-R) scores. The diagnostic accuracy of the differential indices was evaluated using receiver operating characteristic (ROC) curves.

Results

1. The fractal dimension (Higuchi's fractal dimension (HFD)) of patients in the MCS tended to be higher than that of patients in the VS/UWS across all phases, with a significant difference only in the waking phase (p < 0.05). The HFD in the waking phase was positively correlated with the CRS-R score and exhibited the highest diagnostic accuracy at 88.3%. The Teager-Kaiser energy operator (TKEO) also showed higher levels in patients in the MCS compared to those in the VS/UWS, significantly so in the NREM2 phase (p < 0.05), with a positive correlation with the CRS-R score and diagnostic accuracy of 75.2%. The δ-band power spectral density [PSD(δ)] in the patients in the MCS was lower than that in those in the VS/UWS, significantly so in the waking phase (p < 0.05), and it was negatively correlated with the CRS-R score, with diagnostic accuracy of 71.5%.

Conclusion

Polysomnography for the VS/UWS and MCS revealed significant differences, aiding in distinguishing between the two patient categories and reducing misdiagnosis rates. Notably, the HFD and PSD(δ) showed significantly better performance during wakefulness compared to sleep, while the TKEO was more prominent in the NREM2 stage. Notably, the HFD exhibited a robust correlation with the CRS-R scores, the highest diagnostic accuracy, and immense promise in the clinical diagnosis of prolonged disorders of consciousness.

Survival and clinical characteristics of patients with disorders of consciousness in a developing country between 2002 and 2018

OBJECTIVE

Describe the survival, sociodemographic and clinical characteristics of subjects with disorders of consciousness in a reference rehabilitation center, in a developing country.

METHODS

Patients with disorders of consciousness (DoC) caused by acquired neurological injuries, admitted between the years 2002-2018 in a neurorehabilitation center. Extracted data covered demographics, clinical details, survival time, and discharge information. Cox proportional hazard model and Kaplan-Meier analysis were used to reveal, associations with survival.

RESULT

Out of 5064 neurological cases, 159 patients were diagnosed with DoC. The demographic data showed a male dominance (65%), with an average injury age of 42 years. The most common causes were traumatic (41%), anoxic (36%), and vascular (10%), with traffic accidents accounting for 71% of traumatic injuries. The study found that 75% of patients remained in a vegetative state (VS), and 25% in a minimally conscious state (MCS), with an average survival of 2110 days.

CONCLUSION

There were no significant differences in survival days between patients in MCS and VS. Patients with traumatic injuries showed a higher survival rate than those with non-traumatic injuries. Age and etiology were identified as factors associated with a higher risk of death.

A Case Report on an Unknown Etiology Disorder of Consciousness Following Extubation Despite Thorough Evaluation

Postoperative disorders of consciousness can arise from various factors, making diagnosis challenging. This report presents a case of a disorder of consciousness that occurred after awakening from general anesthesia, in which various examinations including computed tomography (CT) and magnetic resonance imaging (MRI) were conducted, but the cause could not be identified. A man in his 60s with a history of hypertension and cerebral hemorrhage underwent revision total hip arthroplasty under general anesthesia for a left periprosthetic hip fracture. The induction and maintenance of anesthesia were uneventful. Postoperatively, anesthesia was discontinued, and the patient responded to verbal commands, opened his eyes, and was able to follow handgrip instructions, allowing for extubation. However, after moving to the recovery room, his level of consciousness decreased, reaching a Glasgow Coma Scale score of E3V1M3-4. Suspecting prolonged effects of the anesthetic agents, his condition was observed in the recovery room for approximately 30 minutes, but there was no change in his level of consciousness. CT and MRI of the head were performed, but no significant abnormalities were found. Electroencephalogram monitoring did not show any clear epileptiform activity. Gradual improvement in his level of consciousness was noted 60-120 minutes after the initial decline. Subsequently, there were no further episodes of disordered consciousness. Perioperative disorders of consciousness are challenging to diagnose due to the potential effects of anesthetic agents. Although the cause could not be identified in this case, the patient fortunately recovered consciousness without any significant sequelae.

Cognitive Effects of Transcranial Direct Current Stimulation Plus Robotic Verticalization in Minimally Conscious State

BACKGROUND AND OBJECTIVES

Transcranial direct current stimulation (tDCS) is a non-invasive therapeutic method that modulates cortical excitability and shows promising results for treating disorders of consciousness (DoCs). Robotic verticalization training (RVT) has been shown to enhance motor and cognitive recovery. This study evaluates the effects of an innovative approach combining RVT with tDCS in individuals with DoCs.

METHODS

Twenty-four subjects with DoCs, particularly those with chronic minimally conscious state (MCS) due to vascular or traumatic brain injury, participated in a quasi-randomized study at the Neurorehabilitation Unit, IRCCS Neurolesi (Messina, Italy). Participants were divided into either a control group (CG) receiving RVT alone or an experimental group (EG) receiving combined tDCS and RVT. Both groups underwent treatments five times weekly for four weeks, with tDCS/sham sessions over the dorsolateral prefrontal cortex (DLPFC) lasting 20 min before Erigo training sessions, which lasted 45 min.

RESULTS

The findings indicate that combining tDCS with Erigo® Pro RTT could lead to greater improvements in cognitive functioning and P300 latency compared to the CG.

CONCLUSIONS

These results suggest that the integrated approach of tDCS with RVT could offer significant benefits for patients with MCS, highlighting its potential to enhance cognitive recovery, such as reducing P300 latency.

The Impact of Bispectral Index Monitoring on Outcomes in Spinal Cord Stimulation for Chronic Disorders of Consciousness

Objective

To observe whether maintaining the appropriate depth of anesthesia with Bispectral Index (BIS) can improve the prognosis of Spinal Cord stimulation (SCS) implantation in patients with chronic Disorders of consciousness (DoC).

Methods

103 patients with DoC undergoing SCS implantation were reviewed, and 83 patients with DoC were included according to the standard of inclusion and exclusion Criteria. Patients were divided into a BIS group (n =45) and a non-BIS group (n =38) according to whether BIS monitoring was used during the operation. The depth of anesthesia in the BIS group was maintained between 40-60. The anesthesiologist adjusted the depth of anesthesia in the non-BIS group according to clinical experience. Relevant information such as disease course, cause, anesthesia time, and operation time were collected. Preoperative CRS-R(preoperative) score, postoperative CRS-R(24h), and postoperative CRS-R(3m) changes were collected.

Results

The CRS-R(3m) score in the BIS group was higher than that in the non-BIS group (preoperative), and the difference was statistically significant (P < 0.05). In CRS-R (24h), the BIS group was higher than the non-BIS group, and the difference was statistically significant (X2=8.787, P =0.004). The improvement of consciousness was included in the multivariate Logistic regression analysis model, and it was found that the thalamus was an independent factor affecting the improvement of consciousness (P < 0.05). During follow-up, 1 patient in the BIS group had a decrease in consciousness from MCS- to VS/ UWS and 2 patients in the non-BIS group died during follow-up.

Conclusion

Patients can be benefit in hearing in CRS-R (24h). We recommend the use of BIS to monitor the depth of anesthesia in patients with DoC to improve patient outcomes.

Prognostic Evaluation of Disorders of Consciousness by Using Resting-State fMRI: A Systematic Review

Background: This review focuses on the prognostic role of resting-state functional magnetic resonance imaging (fMRI) in disorders of consciousness (DOCs). Several studies were conducted to determine the diagnostic accuracy in DOC patients to identify prognostic markers and to understand the neural correlates of consciousness. A correct diagnosis of consciousness in unresponsive or minimally responsive patients is important for prognostic and therapeutic management. Functional connectivity is considered as an important tool for the formulation of cerebral networks; it takes into account the primary sensorimotor, language, visual and central executive areas, where fMRI studies show damage in brain connectivity in the areas of frontoparietal networks in DOC patients. Methods: The integration of neuroimaging or neurophysiological methods could improve our knowledge of the neural correlates of clinical response after an acquired brain injury. The use of MRI is widely reported in the literature in different neurological diseases. In particular, fMRI is the most widely used brain-imaging technique to investigate the neural mechanisms underlying cognition and motor function. We carried out a detailed literature search following the relevant guidelines (PRISMA), where we collected data and results on patients with disorders of consciousness from the studies performed. Results: In this review, 12 studies were selected, which showed the importance of the prognostic role of fMRI for DOCs. Conclusions: Currently there are still few studies on this topic. Future studies using fMRI are to be considered an added value for the prognosis and management of DOCs.

Perturbational complexity index in assessing responsiveness to rTMS treatment in patients with disorders of consciousness: a cross-over randomized controlled trial study

BACKGROUND

Disorders of Consciousness (DoC) caused by severe brain injuries represent a challenging clinical entity, which is easy to misdiagnosis and lacks effective treatment options. Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive neuroelectric stimulation method that shows promise in improving consciousness for DoC, especially in minimally conscious state (MCS). However, there is little evidence of its effectiveness, especially in RCT studies.

METHODS

Twenty MCS patients participated in a double-blind, randomized, crossover, sham-controlled clinical study to evaluate the safety and efficacy of rTMS for MCS. Subjects were randomized into two groups: one group received rTMS-active for 10 consecutive days (n = 10), and the other group received rTMS-sham for 10 consecutive days (n = 10). After a 10-day washout period, the two groups were crossed over and received the opposite treatment. the rTMS protocol consisted of 2,000 pulses per day in the left dorsolateral prefrontal cortex (L-DLPFC), sent at 10 Hz. The stimulation intensity was 90% of the resting motor threshold. Coma Recovery Scale Revised (CRS-R), the main evaluation index, was evaluated before and after each phase in a double-blind manner. Meanwhile RS-EEG and TMS-EEG data were acquired and relative alpha power (RAP), and perturbational complexity index based on state transitions (PCIst) were caculated.

RESULTS

One-way ANOVA revealed significantly higher scores in rTMS-active treatment compared to rTMS-sham across various measures, including CRS-R total score, RAP, PCIst (all P < 0.05). Among the 20 MCS patients, 7 (35%) were identified as responders following rTMS treatment. Compared to rTMS-sham, responder scores for CRS-R, RAP, and PCIst (all P < 0.05) were significantly elevated after rTMS-active treatment. Conversely, there was no significant difference observed in non-responders. Furthermore, post-hoc analysis revealed that baseline PCIst was significantly higher in responders than non-responders. Upon a 6-month follow-up, CRS-R scores significantly increased in all 20 patients (P = 0.026). However, the responder group exhibited a more favorable prognosis compared to the non-responder group (P = 0.031).

CONCLUSIONS

Applying 10 Hz rTMS to L-DLPFC significantly increased consciousness level in MCS patients. PCIst is a neurophysiological index that has the potential to evaluate and predict therapeutic efficacy.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov , identifier: NCT05187000.

Anatomical-related factors and outcome of percutaneous short-term spinal cord stimulation electrode shift in patients with disorders of consciousness: a retrospective study

Background

Disorders of consciousness (DoC) represent a spectrum of neurological conditions that pose significant treatment challenges. Percutaneous short-term spinal cord stimulation (SCS) has emerged as a promising experimental diagnostic treatment to assess and potentially improve consciousness levels. However, the effectiveness of this intervention is frequently compromised by the shift of electrodes, particularly in the cervical region, which can negatively affect therapeutic outcomes.

Methods

This retrospective study aimed to study if electrodes shift in percutaneous short-term SCS in patients with DoC would affect the outcome. We analyzed the relationship between electrode shift length and patient outcome, as well as the correlation with various anatomical parameters, including the actual length of the cervical spine, linear length, spinal canal transverse diameter, spinal canal diameter, and C2 cone height, in a cohort of patients undergoing the procedure.

Results

Our findings revealed that in patients with better outcome, there are significant less patient with electrode shift (p = 0.019). Further, a linear correlation was found between the length of electrode shift and patients' outcome (Rho = 0.583, p = 0.002), with longer shift lengths associated with poorer outcomes. Contrary to our expectations, there was no significant association between the measured anatomical parameters and the extent of electrode shift. However, a trend was found between the actual length of the cervical spine and the shift of the electrode (p = 0.098). Notably, the shorter spinal canal transverse diameter was found to be significantly associated with better outcome in patients with DoC receiving percutaneous short-term SCS (p = 0.033).

Conclusion

These results highlight the clinical importance of electrode stability in the cervical region during SCS treatment for patients with DoC. Ensuring secure placement of electrodes may play a crucial role in enhancing patients' outcome and minimize postoperative complications. Given the lack of association with expected anatomical parameters, future research should investigate other factors that could impact electrode stability to optimize this therapeutic intervention.

Analysis of the efficacy of hyperbaric oxygen therapy for disorders of consciousness: A retrospective cohort study

OBJECTIVE

To analyze the efficacy and associated factors affecting the prognosis in patients with disturbance of consciousness after hyperbaric oxygen (HBO) treatment.

METHODS

A retrospective study was carried out on patients with disorders of consciousness (DOC) receiving HBO treatment from January to January 2022 in the Second Department of Rehabilitation Medicine of the Second Hospital of Hebei Medical University, China.

RESULTS

HBO therapy improved the Glasgow Coma Scale (GCS) and Chinese Nanjing Persistent Vegetative State Scale (CNPVSS), as well as the clinical efficacy in patients with DOC. The comparison of GCS and CNPVSS scores in patients with DOC before and after HBO treatment was all statistically significant, with 325 patients (67.1%) showing effective results and 159 patients (32.9%) having unchanged outcomes. Univariate analysis indicated that there were statistically significant differences in age, HBO intervention time, HBO treatment times, pre-treatment GCS score, and etiology and underlying diseases between the good and poor prognoses groups. Multivariate regression analysis showed that HBO intervention time ≤7 days, HBO treatment ＞ times, high GCS score before HBO treatment, and brain trauma were independent influencing factors in achieving a good prognosis for patients with DOC. Low pre-treatment GCS scores were an independent risk factor for a poor prognosis in patients with brain trauma while being male, late HBO intervention time, fewer HBO treatment times, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after a stroke. Being ≥50 years of age, late HBO intervention time, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after hypoxic-ischaemic encephalopathy.

CONCLUSION

HBO therapy can improve the GCS, CNPVSS scores and clinical efficacy in patients with DOC, and the timing of HBO intervention ≤7 days, times of HBO treatment, high pre-treatment GCS score, and brain trauma were the independent influencing factors of good prognosis in patients with DOC.

Understanding of Consciousness in Absence Seizures: A Literature Review

Absence seizures are classically associated with behavioral arrest and transient deficits in consciousness, yet substantial variability exists in the severity of the impairment. Despite several decades of research on the topic, the pathophysiology of absence seizures and the mechanisms underlying behavioral impairment remain unclear. Several rationales have been proposed including widespread cortical deactivation, reduced perception of external stimuli, and transient suspension of the default mode network, among others. This review aims to summarize the current knowledge on the neural correlates of impaired consciousness in absence seizures. We review evidence from studies using animal models of absence epilepsy, electroencephalography, functional magnetic resonance imaging, magnetoencephalography, positron emission tomography, and single photon emission computed tomography.

Touching the unconscious in the unconscious - hypnotic communication with unconscious patients

If hypnosis means contact to the unconscious to modulate psychological and physiological functions by means of suggestions, and if this is facilitated by attenuation of the critical mind, then the question arises as to whether suggestions also have an effect when waking consciousness is otherwise eliminated, namely by coma or anesthesia. A prerequisite would be perception, which actually is evidenced by reports of patients after traumatic brain injury, artificial coma, resuscitation or general anesthesia. Moreover, posttraumatic stress disorder (PTSD) frequently observed after these medical situations is hardly explainable without some sort of awareness under such conditions. Even advanced neurophysiological diagnostic cannot yet rule out consciousness or sensory processing. Especially reference to perception during unconsciousness is given by the results of a recent multicenter study on the effects of hypnotic communication with patients under controlled adequate deep general anesthesia. The observed reductions in incidence and severity of postoperative pain, opioid use, nausea and vomiting cannot be explained by the reaction of a few but only by a considerable proportion of patients. This leads to a strong plea for a more careful treatment of unconscious patients in the emergency room, operating theater or intensive care unit, for the abandonment of the restriction of therapeutic communication to awake patients, and for new aspects of communication and hypnosis research. Obviously, loss of consciousness does not protect against psychological injury, and continuation of communication is needed. But how and what to talk to unconscious patients? Generally addressing the unconscious mind with suggestions that generally exert their effects unconsciously, hypnotic communication appears to be the adequate language. Especially addressing meaningful topics, as derived from the basic psychological needs and known stressors, appears essential. With respect to negative effects by negative or missing communication or to the proposed protective and supporting effects of therapeutic communication with patients clinically rated as unconscious, the role of consciousness is secondary. For the effects of perceived signals and suggestions it does not matter whether consciousness is absent, or partial, or unrecognized present.

Establishment and validation of a bad outcomes prediction model based on EEG and clinical parameters in prolonged disorder of consciousness

Objective

This study aimed to explore the electroencephalogram (EEG) indicators and clinical factors that may lead to poor prognosis in patients with prolonged disorder of consciousness (pDOC), and establish and verify a clinical predictive model based on these factors.

Methods

This study included 134 patients suffering from prolonged disorder of consciousness enrolled in our department of neurosurgery. We collected the data of sex, age, etiology, coma recovery scales (CRS-R) score, complications, blood routine, liver function, coagulation and other laboratory tests, resting EEG data and follow-up after discharge. These patients were divided into two groups: training set (n = 107) and verification set (n = 27). These patients were divided into a training set of 107 and a validation set of 27 for this study. Univariate and multivariate regression analysis were used to determine the factors affecting the poor prognosis of pDOC and to establish nomogram model. We use the receiver operating characteristic (ROC) and calibration curves to quantitatively test the effectiveness of the training set and the verification set. In order to further verify the clinical practical value of the model, we use decision curve analysis (DCA) to evaluate the model.

Result

The results from univariate and multivariate logistic regression analyses suggested that an increased frequency of occurrence microstate A, reduced CRS-R scores at the time of admission, the presence of episodes associated with paroxysmal sympathetic hyperactivity (PSH), and decreased fibrinogen levels all function as independent prognostic factors. These factors were used to construct the nomogram. The training and verification sets had areas under the curve of 0.854 and 0.920, respectively. Calibration curves and DCA demonstrated good model performance and significant clinical benefits in both sets.

Conclusion

This study is based on the use of clinically available and low-cost clinical indicators combined with EEG to construct a highly applicable and accurate model for predicting the adverse prognosis of patients with prolonged disorder of consciousness. It provides an objective and reliable tool for clinicians to evaluate the prognosis of prolonged disorder of consciousness, and helps clinicians to provide personalized clinical care and decision-making for patients with prolonged disorder of consciousness and their families.

Neck muscle spasticity in patients with disorder of consciousness: a pilot study

BACKGROUND

Disorder of consciousness (DOC) is a state of prolonged altered consciousness due to severe acquired brain injury (ABI). DOC can be differentiated into coma, unresponsive wakefulness syndrome (UWS), or minimally conscious state (MCS) depending on the behavioral features observed and their relationship to the level of consciousness. Spasticity is one of the most frequently reported medical comorbidities in DOC patients. Since there is a critical lack of spasticity-focused studies and, in turn, of target treatment, we designed this pilot prospective study to evaluate cervical spine muscle spasticity and its effect on rehabilitation outcome in a large cohort of patients followed from the post-acute phase to 6 months after severe ABI.

AIM

To evaluate neck muscle spasticity and investigate its impact on neurological and functional outcome in a large cohort of adult patients with DOC followed from post-acute to 6 months after severe ABI.

DESIGN

Single-center prospective pilot study.

SETTING

Highly specialized inpatient neurorehabilitation clinic.

POPULATION

Patients with severe ABI admitted within 3 months after the acute event to our Neurorehabilitation Unit between May 21st, 2019 and April 23rd, 2020 for treatment of DOC as a part of their rehabilitation program.

METHODS

In this single-center prospective pilot study demographic data, etiology of ABI (traumatic versus non-traumatic), DOC evaluated with the revised Coma Recovery Scale (CRS-R), and neurological and functional outcome assessed respectively with the Glasgow Coma Scale (GCS) and Functional Independence Measure (FIM) were considered. During cervical examination, we assessed spasticity with the Modified Ashworth Scale (MAS), deviation of head alignment with a goniometer, and pain with the Nociception Coma Scale-Revised (NCS-R).

RESULTS

Of the 48 patients, 41.7% were diagnosed with UWS and 58.3% were in a minimally conscious state (MCS). We found spasticity of neck muscles in 91.7% of patients, with no difference in severity (assessed with MAS) between UWV and MCS. The NCS-R score at cervical spine examination was lower in UWS than MCS. Spasticity was severer in patients with traumatic brain injury (TBI) compared to non-traumatic. At multiple linear regression analysis, younger age, hemisyndrome, and tetraparesis were independent predictors of severity of neck muscle spasticity in MCS. More severe spasticity was a predictor of worse neurological and functional outcome at discharge in UWS patients, independently of the other confounding variables at admission (e.g., age, severity of brain injury, functional assessment, and pain).

CONCLUSIONS

Spasticity of neck muscles frequently develops in patients with DOC and is more severe in those after TBI. UWV and MCS have different spasticity profiles as regards risk factors and neurological and functional outcome. Severity of neck muscle spasticity in UWV patients may represent an early indicator of worse neurological and functional outcome after inpatient rehabilitation.

CLINICAL REHABILITATION IMPACT

Our findings could prompt clinicians to redefine the rehabilitation aims regarding spasticity and to estimate the functional outcome in patients undergoing intensive rehabilitation after severe ABI.

Improving Neuroplasticity through Robotic Verticalization Training in Patients with Minimally Conscious State: A Retrospective Study

In disorders of consciousness, verticalization is considered an effective type of treatment to improve motor and cognitive recovery. Our purpose is to investigate neurophysiological effects of robotic verticalization training (RVT) in patients with minimally conscious state (MCS). Thirty subjects affected by MCS due to traumatic or vascular brain injury, attending the intensive Neurorehabilitation Unit of the IRCCS Neurolesi (Messina, Italy), were included in this retrospective study. They were equally divided into two groups: the control group (CG) received traditional verticalization with a static bed and the experimental group (EG) received advanced robotic verticalization using the Erigo device. Each patient was evaluated using both clinical scales, including Levels of Cognitive Functioning (LCF) and Functional Independence Measure (FIM), and quantitative EEG pre (T0) and post each treatment (T1). The treatment lasted for eight consecutive weeks, and sessions were held three times a week, in addition to standard neurorehabilitation. In addition to a notable improvement in clinical parameters, such as functional (FIM) (p < 0.01) and cognitive (LCF) (p < 0.01) outcomes, our findings showed a significant modification in alpha and beta bands post-intervention, underscoring the promising effect of the Erigo device to influence neural plasticity and indicating a noteworthy difference between pre-post intervention. This was not observed in the CG. The observed changes in alpha and beta bands underscore the potential of the Erigo device to induce neural plasticity. The device's custom features and programming, tailored to individual patient needs, may contribute to its unique impact on brain responses.

Disorders of Consciousness Programs: Components, Organization, and Implementation

Rehabilitation of patients with disorders of consciousness (DoC) presents unique challenges requiring comprehensive and specialized care. This article reviews the components, organization, and implementation of an inpatient DoC program under the framework of recent evidence-based practice guidelines and minimum competency recommendations. The evidence and clinical applications of these recommendations are elaborated upon with the goal of offering providers a reference to translate guidelines into clinical practice.

Long-term repetitive transcranial direct current stimulation in patients with disorders of consciousness: a preliminary study

OBJECTIVES

To investigate the effects of long-term repetitive transcranial direct current stimulation on patients with DOC in the subacute phase.

METHODS

In a randomized, double-blind, controlled study, 33 patients were randomly assigned to the active or sham group, and 28 patients completed the study. Patients in the active group received anodal stimulation over the DLPFC, while patients in the sham group received placebo stimulation (20 min/day, 5 days/week, for 4 weeks). The level of consciousness among patients was assessed with the Coma Recovery Scale-Revised (CRS-R) at baseline and at the end of every week from the first to the fourth week.

RESULTS

The CRS-R scores of both the active and sham groups showed a consistent increasing trend over time; however, the treatment effect of the active group was better than that of the sham group. In addition, there was a statistically significant difference in the total CRS-R score between the two groups at weeks 1, 2, 3 and 4. Moreover, 10 patients (71.4%) in the active group and 3 patients (21.4%) in the sham group were regarded as responders.

CONCLUSION

Long-term tDCS could improve the level of consciousness of patients with DOC in the subacute stage.

Combining HD-tDCS with music stimulation for patients with prolonged disorders of consciousness: Study protocol for an RCT trial

BACKGROUND

Patients with prolonged disorders of consciousness (pDOC) pose significant challenges to healthcare workers due to their severe motor impairments and limited interaction with the environment. Non-invasive brain stimulation such as high-definition transcranial direct current stimulation (HD-tDCS) and music stimulation show promise in awakening this population.

OBJECTIVE

In this study, we present a protocol aiming at investigating the efficacy of combined HD-tDCS and music stimulation in awakening patients with pDOC through a single-blind, randomized controlled trial.

METHODS

Ninety patients with pDOC will be randomly divided into three groups: active HD-tDCS with music stimulation, active HD-tDCS, and sham HD-tDCS. All participants will receive 20 treatment sessions over a period of 10 days and the Coma Recovery Scale-Revised, Glasgow Outcome Scale and electroencephalogram will be used as assessment measures to evaluate their level of consciousness throughout the study. Adverse events and complications will be recorded during treatment. Within-group pre-post comparisons and between-group efficacy comparisons will be conducted to identify the most effective intervention approach. Statistical analysis will be performed using SPSS software with a significance level set at P < 0.05.

CONCLUSION

The pursuit of awakening therapy for patients with pDOC remains a clinical research challenge. This study protocol is designed with the aim of introducing an innovative non-pharmacological approach which combined HD-tDCS and music stimulation to facilitate the reinstatement of consciousness in patients with pDOC.

The efficacy and safety of transcutaneous auricular vagus nerve stimulation for patients with minimally conscious state: a sham-controlled randomized double-blind clinical trial

Background

Transcutaneous auricular vagus nerve stimulation (taVNS) has emerged as a potentially effective neuromodulation technique for addressing neurological disorders, including disorders of consciousness. Expanding upon our prior clinical study, which demonstrated the superior effectiveness of a 4-week taVNS treatment in patients with minimally conscious state (MCS) compared to those in a vegetative state/unresponsive wakefulness state, the aim of this investigation was to evaluate the safety and therapeutic efficacy of taVNS in individuals with MCS through a sham-controlled randomized double-blind clinical trial.

Methods

A cohort of 50 adult patients (male = 33, female = 17) diagnosed with a MCS were randomly assigned to either the active taVNS (N = 25) or sham taVNS (N = 25) groups. The treatment period lasted for 4 weeks, followed by an 8-week follow-up period. The Coma Recovery Scale-Revised (CRS-R) and Glasgow Coma Scale (GCS) were administered at baseline and weekly during the initial 4 weeks. Additionally, the Disability Rating Scale (DRS) was used to assess the patients' functional abilities via telephone at week 12. Furthermore, various neurophysiological measures, including electroencephalogram (EEG), upper-limb somatosensory evoked potentials (USEP), brainstem auditory evoked potentials (BAEP), and P300 event-related potentials (P300), were employed to monitor changes in brain activity and neural conduction pathways.

Results

The scores for the active taVNS group in the CRS-R and GCS showed greater improvement over time compared to the sham taVNS group (CRS-R: 1-week, Z = -1.248, p = 0.212; 2-week, Z = -1.090, p = 0.276; 3-week, Z = -2.017, p = 0.044; 4-week, Z = -2.267, p = 0.023. GCS: 1-week, Z = -1.325, p = 0.185; 2-week, Z = -1.245, p = 0.213; 3-week, Z = -1.848, p = 0.065; 4-week, Z = -1.990, p = 0.047). Additionally, the EEG, USEP, BAEP, and P300 also demonstrated significant improvement in the active taVNS group compared to the sham taVNS group at week 4 (EEG, Z = -2.086, p = 0.037; USEP, Z = -2.014, p = 0.044; BAEP, Z = -2.298, p = 0.022; P300 amplitude, Z = -1.974, p = 0.049; P300 latency, t = 2.275, p = 0.027). Subgroup analysis revealed that patients with MCS derived greater benefits from receiving taVNS treatment earlier (CRS-R, Disease duration ≤ 1-month, mean difference = 8.50, 95% CI = [2.22, 14.78], p = 0.027; GCS, Disease duration ≤ 1-month, mean difference = 3.58, 95% CI = [0.14, 7.03], p = 0.044). By week 12, the active taVNS group exhibited lower Disability Rating Scale (DRS) scores compared to the sham taVNS group (Z = -2.105, p = 0.035), indicating a more favorable prognosis for MCS patients who underwent taVNS. Furthermore, no significant adverse events related to taVNS were observed during treatment.

Conclusion

The findings of this study suggest that taVNS may serve as a potentially effective and safe intervention for facilitating the restoration of consciousness in individuals diagnosed with MCS. This therapeutic approach appears to enhance cerebral functioning and optimize neural conduction pathways.

Clinical trial registration

http://www.chictr.org.cn, Identifier ChiCTR2200066629.

Presumed first episode of nonconvulsive status epilepticus as the cause of postoperative disorder of consciousness following the completion of general anesthesia: A case report

Key Clinical Message

Disorder of consciousness can lead to irreversible sequelae without proper intervention. Consequently, early diagnosis and treatment are of paramount importance in patients with disorder of consciousness.

Abstract

Disorder of consciousness (DOC) has various etiologies. Here, we report a case in which DOC following general anesthesia was suspected as being due to the first episode of nonconvulsive status epilepticus (NCSE). An elderly man in his 80s underwent uneventful tumor resection surgery under general anesthesia for extramammary Paget's disease. After the procedure, he regained consciousness following anesthesia discontinuation and was extubated. Soon after extubation, however, although his respiratory status remained stable, his level of consciousness deteriorated to a Glasgow Coma Scale (GCS) score of E1V1M1. Head computed tomography and magnetic resonance imaging scans indicated no abnormal findings. Subsequently, involuntary movements were noted in his left upper limb. Suspecting an epilepsy episode, diazepam was administered, leading to an improvement in the level of consciousness (GCS: E4V5M6). Based on the improvement in consciousness after diazepam administration, we strongly suspected NCSE.

Behavioral Effects of Repetitive Transcranial Magnetic Stimulation in Disorders of Consciousness: A Systematic Review and Meta-Analysis

Traumatic brain injury, cardiac arrest, intracerebral hemorrhage, and ischemic stroke may cause disorders of consciousness (DoC). Repetitive transcranial magnetic stimulation (rTMS) has been used to promote the recovery of disorders of consciousness (DoC) patients. In this meta-analysis, we examined whether rTMS can relieve DoC patient symptoms. We searched through journal articles indexed in PubMed, the Web of Science, Embase, Scopus, and the Cochrane Library until 20 April 2023. We assessed whether studies used rTMS as an intervention and reported the pre- and post-rTMS coma recovery scale-revised (CRS-R) scores. A total of 207 patients from seven trials were included. rTMS significantly improved the recovery degree of patients; the weighted mean difference (WMD) of the change in the CRS-R score was 1.89 (95% confidence interval (CI): 1.39-2.39; p < 0.00001) in comparison with controls. The subgroup analysis showed a significant improvement in CRS-R scores in rTMS over the dorsolateral prefrontal cortex (WMD = 2.24; 95% CI: 1.55-2.92; p < 0.00001; I2 = 31%) and the primary motor cortex (WMD = 1.63; 95% CI: 0.69-2.57; p = 0.0007; I2 = 14%). Twenty-hertz rTMS significantly improved CRS-R scores in patients with DoC (WMD = 1.61; 95% CI: 0.39-2.83; p = 0.010; I2 = 31%). Furthermore, CRS-R scores in rTMS over 20 sessions significantly improved (WMD = 1.75; 95% CI: 0.95-2.55; p < 0.0001; I2 = 12%). rTMS improved the symptoms of DoC patients; however, the available evidence remains limited and inadequate.

Stimulation of vagus nerve for patients with disorders of consciousness: a systematic review

Purpose

The purpose of this study is to evaluate the efficacy and safety of stimulating the vagus nerve in patients with disorders of consciousness (DOCs).

Methods

A comprehensive systematic review was conducted, encompassing the search of databases such as PubMed, CENTRAL, EMBASE and PEDro from their inception until July 2023. Additionally, manual searches and exploration of grey literature were performed. The literature review was conducted independently by two reviewers for search strategy, selection of studies, data extraction, and judgment of evidence quality according to the American Academy of Cerebral Palsy and Developmental Medicine (AACPDM) Study Quality Scale.

Results

A total of 1,269 articles were retrieved, and 10 studies met the inclusion criteria. Among these, there were three case reports, five case series, and only two randomized controlled trials (RCTs). Preliminary studies have suggested that stimulation of vagus nerve can enhance the levels of DOCs in both vegetative state/unresponsive wakefulness state (VS/UWS) and minimally conscious state (MCS). However, due to a lack of high-quality RCTs research and evidence-based medical evidence, no definitive conclusion can be drawn regarding the intervention's effectiveness on consciousness level. Additionally, there were no significant adverse effects observed following stimulation of vagus nerve.

Conclusion

A definitive conclusion cannot be drawn from this systematic review as there was a limited number of eligible studies and low-quality evidence. The findings of this systematic review can serve as a roadmap for future research on the use of stimulation of vagus nerve to facilitate recovery from DOCs.

Multimodal communication reported by familiar caregivers to build communication capacity in persons who are minimally conscious

PURPOSE

Limited clinical and research evidence is available to support healthcare practitioners in the communication assessment and intervention of persons who are minimally conscious. This study placed a specific focus on the multimodal communication strategies familiar caregivers of persons who are minimally conscious observed, as well as the verbal and the nonverbal communication strategies they employed to build communication capacity. This may inform clinical practice as it provides valuable autobiographical information as well as familiar stimuli that may elicit responses from persons in a minimally conscious state.

METHOD

A descriptive qualitative design employing in-depth semi-structured interviews with familiar caregivers was utilised to address the purpose of the study.

RESULT

Familiar caregivers reported that they used both nonverbal and verbal communication strategies to obtain a response from persons who are minimally conscious. These caregivers also reported that these persons appeared to rely on nonverbal communication strategies to express 36 different communication functions.

CONCLUSION

Based on the findings of this study, it is clear that caregivers can be beneficial to persons who are minimally conscious, if they are able to observe and capitalise on naturally occurring multimodal communication strategies and functions. This study emphasises that familiar caregivers respect and value the dignity of persons who are minimally conscious and want to improve their communication capacity, but often lack confidence in their own communication skills.

Efficacy of non-invasive brain stimulation for disorders of consciousness: a systematic review and meta-analysis

Objective

The aim of this study is to evaluate the efficacy of non-invasive brain stimulation (NIBS) in patients with disorders of consciousness (DoC) and compare differences in efficacy between different stimulation modalities.

Methods

We searched the PubMed, Cochrane Library, Web of Science, and EMBASE databases for all studies published in English from inception to April 2023. Literature screening and quality assessment were performed independently by two investigators. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were used to evaluate the therapeutic effects of NIBS. The Cochrane Q test and I2 statistic were used to evaluate heterogeneity between studies. Subgroup analysis was performed to identify the source of heterogeneity, and differences in efficacy between different stimulation modalities were compared by Bayesian analysis.

Results

A total of 17 studies with 377 DoC patients were included. NIBS significantly improved the state of consciousness in DoC patients when compared to sham stimulation (WMD: 0.81; 95% CI: 0.46, 1.17; I2 = 78.2%, p = 0.000). When divided into subgroups according to stimulation modalities, the heterogeneity of each subgroup was significantly lower than before (I2: 0.00-30.4%, p >0.05); different stimulation modalities may be the main source of such heterogeneity. Bayesian analysis, based on different stimulation modalities, indicated that a patient's state of consciousness improved most significantly after repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC). Diagnosis-based subgroup analysis showed that NIBS significantly improved the state of consciousness in patients with a minimal consciousness state (WMD: 1.11; 95% CI: 0.37, 1.86) but not in patients with unresponsive wakefulness syndrome or a vegetative state (WMD: 0.31; 95% CI: -0.09, 0.71). Subgroup analysis based on observation time showed that single treatment did not improve the state of consciousness in DoC patients (WMD: 0.28; 95% CI: -0.27, 0.82) while multiple treatments could (WMD: 1.05; 95% CI: 0.49, 1.61). Furthermore, NIBS had long-term effects on DoC patients (WMD: 0.79; 95% CI: 0.08-1.49).

Conclusion

Available evidence suggests that the use of NIBS on patients with DoC is more effective than sham stimulation, and that rTMS of the left DLPFC may be the most prominent stimulation modality.

Prognosis prediction for impaired consciousness recovery in stroke patients using videofluoroscopic swallowing study: A retrospective observational study

Prognosis prediction of impaired consciousness is clinically important for establishing therapeutic strategies, determining a rehabilitative goal and functional outcome, and estimating rehabilitative therapy duration. In this study, we investigated the prognosis prediction value of videofluoroscopic swallowing study (VFSS) in recovery of impaired consciousness in stroke patients. Fifty-one patients with impaired consciousness who underwent VFSS during the early stage of stroke between 2017 and 2021 were recruited in this retrospective study. VFSS were performed using modified Logemann protocol, and bonorex was used as the liquid contrast medium. The penetration-aspiration scale (PAS) was graded for all patients, and they were classified into 2 groups depending on the presence of aspiration on liquid material: the aspiration-positive group with a PAS score ≥ 6, and the aspiration-negative group with a PAS score < 6. The coma recovery scale-revised (CRS-R) was used to evaluate patients' conscious state at the time of VFSS and 3 months after. Statistical analysis was performed using independent t test and Pearson's correlation. The increase in total CRS-R score from time of VFSS to 3 months later was greater in aspiration-negative group than in aspiration-positive group (P < .05). A moderate negative correlation was observed between liquid PAS score and the increase in total CRS-R score (r = -0.499, P < .05). Among 6 CRS-R subscales, a strong negative correlation was observed between liquid PAS score and the communication score increase (r = -0.563, P < .05), while moderate negative correlations were detected between liquid PAS score and the increases in auditory (r = -0.465, P < .05), motor (r = -0.372, P < .05), oromotor (r = -0.426, P < .05), and arousal (r = -0.368, P < .05) scores. We observed that patients without aspiration on videofluoroscopic swallowing study showed better recovery of impaired consciousness, and the degree of penetration and aspiration had a predictive value for impaired consciousness prognosis in the early stage of stroke.

The effect and mechanisms of music therapy on the autonomic nervous system and brain networks of patients of minimal conscious states: a randomized controlled trial

Introduction

Music therapy has been employed as an alternative treatment modality for the arousal therapy of patients with disorders of consciousness (DOC) in clinical settings. However, due to the absence of continuous quantitative measurements and the lack of a non-musical sound control group in most studies, the identification of the specific impact of music on DOC patients remains challenging. In this study, 20 patients diagnosed with minimally consciousness state (MCS) were selected, and a total of 15 patients completed the experiment.

Methods

All patients were randomly assigned to three groups: an intervention group (music therapy group, n = 5), a control group (familial auditory stimulation group, n = 5), and a standard care group (no sound stimulation group, n = 5). All three groups received 30 min of therapy five times a week for a total of 4 weeks (20 times per group, 60 times in total). Autonomic nervous system (ANS) measurements, Glasgow Coma Scale (GCS), and functional magnetic resonance-diffusion tensor imaging (fMRI-DTI) were used to measure the peripheral nervous system indicators and brain networks, and to evaluate patients' behavior levels.

Results

The results reveal that PNN50 (p = 0.0004**), TP (p = 0.0003**), VLF (p = 0.0428**), and LF/HF (p = 0.0001**) in the music group were significantly improved compared with the other two groups. Such findings suggest that the ANS of patients with MCS exhibits higher activity levels during music exposure compared to those exposed to family conversation or no auditory stimulation. In fMRI-DTI detection, due to the relative activity of ANS in the music group, the ascending reticular activation system (ARAS) in the brain network also exhibited significant nerve fiber bundle reconstruction, superior temporal gyrus (STG), transverse temporal gyrus (TTG), inferior temporal gyrus (ITG), limbic system, corpus callosum, subcorticospinal trace, thalamus and brainstem regions. In the music group, the reconstructed network topology was directed rostrally to the diencephalon's dorsal nucleus, with the brainstem's medial region serving as the hub. This network was found to be linked with the caudal corticospinal tract and the ascending lateral branch of the sensory nerve within the medulla.

Conclusion

Music therapy, as an emerging treatment for DOC, appears to be integral to the awakening of the peripheral nervous system-central nervous system based on the hypothalamic-brainstem-autonomic nervous system (HBA) axis, and is worthy of clinical promotion. The research was supported by the Beijing Science and Technology Project Foundation of China, No. Z181100001718066, and the National Key R&D Program of China No. 2022YFC3600300, No. 2022YFC3600305.

Mapping topography and network of brain injury in patients with disorders of consciousness

Background

There is a growing interest in the topography of brain regions associated with disorders of consciousness. This has caused increased research output, yielding many publications investigating the topic with varying methodologies. The objective of this study was to ascertain the topographical regions of the brain most frequently associated with disorders of consciousness.

Methods

We performed a cross-sectional text-mining analysis of disorders of consciousness studies. A text mining algorithm built in the Python programming language searched documents for anatomical brain terminology. We reviewed primary PubMed studies between January 1st 2000 to 8th February 2023 for the search query “Disorders of Consciousness.” The frequency of brain regions mentioned in these articles was recorded, ranked, then built into a graphical network. Subgroup analysis was performed by evaluating the impact on our results if analyses were based on abstracts, full-texts, or topic-modeled groups (non-negative matrix factorization was used to create subgroups of each collection based on their key topics). Brain terms were ranked by their frequency and concordance was measured between subgroups. Graphical analysis was performed to explore relationships between the anatomical regions mentioned. The PageRank algorithm (used by Google to list search results in order of relevance) was used to determine global importance of the regions.

Results

The PubMed search yielded 24,944 abstracts and 3,780 full texts. The topic-modeled subgroups contained 2015 abstracts and 283 full texts. Text Mining across all document groups concordantly ranked the thalamus the highest (Savage score = 11.716), followed by the precuneus (Savage score = 4.983), hippocampus (Savage score = 4.483). Graphical analysis had 5 clusters with the thalamus once again having the highest PageRank score (PageRank = 0.0344).

Conclusion

The thalamus, precuneus and cingulate cortex are strongly associated with disorders of consciousness, likely due to the roles they play in maintaining awareness and involvement in the default mode network, respectively. The findings also suggest that other areas of the brain like the cerebellum, cuneus, amygdala and hippocampus also share connections to consciousness should be further investigated.

Effect of Transcranial Direct Current Stimulation on Motor Recovery in Altered Conscious Patients after Traumatic Brain Injury and Cerebrovascular Accident: A Randomized Clinical Trial

Background and Purpose Altered levels of consciousness resulting from a vascular insult to the brain can vary from confusion to coma. A disruption in the function of the brain stem reticular activating system in the brain stem or both cerebral hemispheres and thalami causes coma. This study is aimed at finding the effect of transcranial direct current stimulation (tDCS) on motor recovery in altered conscious patients after traumatic brain injury and cerebrovascular accident.

Materials and Methods A total of 100 patients admitted to the neurology and neurosurgery unit of the university hospital were screened and 40 subjects who satisfied inclusion criteria were recruited and randomly divided into two groups, group A (experimental) (n = 20) and group B (control)(n = 20), by computerized randomization. Written informed consent was taken from all the caregivers before recruitment. After taking the preliminary assessment, anodal tDCS is given to the motor area (C3/C4 ipsilesional), sensory area (P3/P4 ipsilesional), and left dorsolateral prefrontal cortex (F3) according to the 10/20 electroencephalogram montage for two sessions of 20 min/day for 7 consecutive days. Routine physiotherapy was also given the same as group B.

Results At baseline, there were no significant group differences in the baseline characteristics. The groups passed the normality test. The results were tested for statistical significance between the groups by Mann–Whitney U test and by one-way analysis of variance and Tukey Honest Significant Difference for post-hoc comparison; the results were statistically different with p-value less than 0.05 with a large effect size.

Conclusion We conclude, based on the results of this study, that tDCS can be effective in motor recovery in altered consciousness patients. It is noninvasive, cost-effective with minimal contraindications, and does not interfere with other modalities in the intensive care unit. Hence, it can be administered safely under the supervision of a qualified therapist.

Effect of transcranial direct current stimulation for patients with disorders of consciousness: A systematic review and meta-analysis

Introduction

Transcranial direct current stimulation (tDCS) could potentially facilitate consciousness improvement in patients with disorders of consciousness (DOC). The aim of this study was to investigate the therapeutic efficacy of tDCS on consciousness recovery for patients with DOC.

Methods

Eight databases were systematically searched from their inception to June 2022. Quality of included studies were assessed using PEDro score and Cochrane's risk of bias assessment. All statistical analyses were performed using RevMan software. Seventeen studies with 618 patients were identified eligible for this study, and fifteen studies with sufficient data were pooled in the meta-analysis.

Results

The results of meta-analysis showed a significant effect on increasing GCS scores (MD = 1.73; 95% CI, 1.28-2.18; P < 0.01) and CRS-R scores (MD = 1.28; 95% CI = 0.56-2.00; P < 0.01) in favor of the real stimulation group as compared to sham. The results of subgroup analysis demonstrated that only more than 20 sessions of stimulation could significantly enhance the improvement of GCS scores and the CRS-R scores. Moreover, the effect of tDCS on CRS-R score improvement was predominant in patients with minimal conscious state (MCS) (MD = 1.84; 95% CI = 0.74-2.93; P < 0.01).

Conclusion

Anodal tDCS with sufficient stimulation doses appears to be an effective approach for patients with MCS, in terms of CRS-R scores.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022336958.

Transcranial Magnetic Stimulation in Disorders of Consciousness: An Update and Perspectives

Disorders of consciousness (DOC) is a state in which consciousness is affected by brain injuries, leading to dysfunction in vigilance, awareness, and behavior. DOC encompasses coma, vegetative state, and minimally conscious state based on neurobehavioral function. Currently, DOC is one of the most common neurological disorders with a rapidly increasing incidence worldwide. Therefore, DOC not only impacts the lives of individuals and their families but is also becoming a serious public health threat. Repetitive transcranial magnetic stimulation (rTMS) can stimulate electrical activity using a pulsed magnetic field in the brain, with great value in the treatment of chronic pain, neurological diseases, and mental illnesses. However, the clinical application of rTMS in patients with DOC is debatable. Herein, we report the recent main findings of the clinical therapeutics of rTMS for DOC, including its efficacy and possible mechanisms. In addition, we discuss the potential key parameters (timing, location, frequency, strength, and secession of rTMS applications) that affect the therapeutic efficiency of rTMS in patients with DOC. This review may help develop clinical guidelines for the therapeutic application of rTMS in DOC.

Establishment and evaluation of a prediction model for acute gastrointestinal injury in patients with prolonged disorder of consciousness

Objective

To establish a prediction model for acute gastrointestinal injury (AGI) in patients with prolonged disorder of consciousness (pDOC) and to evaluate and apply the prediction model. 

Methods

The clinical data of 165 patients with pDOC admitted to the hyperbaric oxygen department from January 2021 to December 2021 were retrospectively reviewed, and the patients were divided into an AGI group (n = 91) and an N-AGI group (n = 74) according to whether AGI occurred. A prediction model was built by fitting multiple independent influencing factors through logistic regression. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of the model, the Hosmer–Lemeshow (H–L) test was used to evaluate the goodness-of-fit of the model, and the ROC curve and calibration curve were drawn to evaluate the predictive performance. A nomogram was plotted to visualize the prediction model.

Results

According to the multivariate logistic regression analysis results, the prediction model was finally constructed with the CRS-R score, DAO, PCT, ALB, and I-FABP, and a nomogram was generated. The area under the ROC curve (AUC) of the prediction model was 0.931, the sensitivity was 83.5%, and the specificity was 93.2%. The data were divided into 5 groups for the H–L test (χ² = 2.54, P = 0.468 > 0.05) and into 10 groups for the H–L test (χ² = 9.98, P = 0.267 > 0.05). A calibration curve was drawn based on the test results, indicating that the prediction model has a good goodness-of-fit and good prediction stability.

Conclusion

The prediction model for AGI in pDOC patients constructed in this study can be used in clinical practice and is helpful to predict the occurrence of AGI in pDOC patients.

Thyrotropic Axis and Disorders of Consciousness in Acquired Brain Injury: A Potential Intriguing Association?

PURPOSE

A potential involvement of thyrotropic axis in influencing the state of consciousness could be hypothesized. We aimed at investigating thyroid function tests as predictors of disorders of consciousness (DoC) and relating recovery in a large cohort of patients with DoC secondary to acquired brain injury (ABI).

METHODS

This retrospective, multicenter, cohort study included 151 patients with DoC following ABI, consecutively admitted for a 6-month neurorehabilitation program. Data on etiology of brain injury, evolution of DoC, disability and rehabilitation assessments, and death during rehabilitation were collected at baseline and on discharge. Thyroid function tests (serum TSH, fT4 and fT3 levels) were assessed on admission in all patients and at final discharge in 50 patients.

RESULTS

Lower baseline TSH levels and greater TSH increments (ΔTSH) after neurorehabilitation predicted a favorable change in DoC independent of age, sex, BMI, etiology of brain injury and initial DoC subtype (TSH: OR=0.712, CI 95% 0.533-0.951, p=0.01; ΔTSH: OR=2.878, CI 95% 1.147-7.223, p=0.02). On the other hand, neither fT4 nor fT3 or their variations appeared to play any role on DoC changes after 6-months inpatient neurorehabilitation. A lower magnitude of ΔfT4 acted as a strong predictor of improved functional disability level (β=0.655, p=0.002) and cognitive functions (β=-0.671, p=0.003), implying that smaller changes in fT4 were associated with higher outcomes.

CONCLUSIONS

Serum TSH levels assessed in the subacute post-ABI phase and its variation during neurorehabilitation could represent a potential biomarker of DoC evolution, while variations in fT4 levels seem to be associated with rehabilitation and cognitive functions. Further studies are needed to investigate the mechanisms underlying these associations.

Delirium and other neuropsychiatric manifestations of COVID-19 infection in people with preexisting psychiatric disorders: a systematic review

BACKGROUND

Psychiatric disorders increase risk of neuropsychiatric disease and poor outcomes, yet little is known about the neuropsychiatric manifestations of COVID-19 in the psychiatric population. The primary objective is to synthesize neuropsychiatric outcomes of COVID-19 in people with preexisting psychiatric disorders.

METHODS

Data were collected during an ongoing review of the impact of pandemics on people with existing psychiatric disorders. All study designs and gray literature were included. Medline, PsychInfo, CINAHL, EMBASE, and MedRx were searched from inception to September 1 2020. Risk of bias was assessed using a published tool that can accommodate all study types. Two independent authors screened the studies and extracted data. Data were narratively synthesized, as there were insufficient data to meta-analyze. Evidence was appraised according to GRADE.

RESULTS

Four case reports were included, comprising 13 participants from three countries. Many large-sample, relevant papers were omitted for not reporting psychiatric history, despite reporting other comorbidities. Included participants (n = 13) were hospitalized with COVID-19 and appeared to meet criteria for delirium. Myoclonus, rigidity, and alogia were also reported. The most commonly reported preexisting psychiatric diagnoses were mood disorders, schizophrenia, and alcohol use disorder.

CONCLUSIONS

People with preexisting psychiatric disorders may experience delirium, rigidity, myoclonus, and alogia during COVID-19 infection; although higher quality and longitudinal data are needed to better understand these phenomena. Relevant COVID-19 literature does not always report psychiatric history, despite heightened neuropsychiatric vulnerability within this population.

TRIAL REGISTRATION

 PROSPERO (CRD42020179611).

Insights of neurophysiology on unconscious state using combined transcranial magnetic stimulation and electroencephalography: A systematic review

Unconscious state has been investigated in numerous studies so far, but pathophysiology of this state is not fully understood. Recently, combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) has been developed to allow for non-invasive assessment of neurophysiology in the cerebral cortex. We conducted a systematic literature search for TMS-EEG studies on human unconscious state using PubMed with cross-reference and manual searches. The initial search yielded 137 articles, and 19 of them were identified as relevant, including one article found by manual search. This review included 10 studies for unresponsive wakefulness syndrome (UWS), 9 for minimally conscious states (MCS), 5 for medication-induced unconscious states, and 6 for natural non-rapid eye movement states. These studies analyzed TMS-evoked potential to calculate perturbational complexity index (PCI) and OFF-periods. In particular, PCI was found to be a potentially useful marker to differentiate between UWS and MCS. This review demonstrated that TMS-EEG could represent a promising neuroscientific tool to investigate various unconscious states. Further TMS-EEG research may help elucidate the neural basis of unconscious state.

The effectiveness of median nerve electrical stimulation in patients with disorders of consciousness: a systematic review

OBJECTIVE

To examine the effectiveness of median nerve electrical stimulation on consciousness level in subjects with disorders of consciousness.

METHODS

Electronic databases PubMed, EMBASE, CENTRAL, and PEDro, as well as manual search and gray literature were searched from inception until May 2019. We included only randomized controlled trials. Two reviewers independently conducted the search strategy, study selection, data extraction, risk of bias assessment, and evidence judgment quality.

RESULTS

Five studies met the inclusion criteria. Overall, no clear conclusion can be drawn about the intervention's effectiveness on the level of consciousness. One study reported a benefit of the intervention on the number of hospitalization days in the intensive care unit. Furthermore, another study reported a higher percentage of patients who regained consciousness six months from the event in the experimental group.

CONCLUSION

Due to the limited number of studies that met the inclusion criteria and overall high risk of bias, it is impossible to draw a definitive conclusion. The results of this systematic review should be used to improve future research in this field.

Development of a risk scoring system for prognostication in HIV-related toxoplasma encephalitis

BACKGROUND

This study aims to evaluate specific risk factors influencing prognosis of HIV-infected patients with toxoplasma encephalitis (TE) in order to develop a prognostic risk scoring system for them.

METHODS

This is a six-center retrospective study of hospitalized HIV/TE patients. Data including six-week mortality after diagnosis, baseline characteristics, clinical features, laboratory tests and radiological characteristics of eligible patients were assimilated for risk model establishing.

RESULTS

In this study, the six-week mortality among 94 retrospective cases was 11.7% (11/94). Seven specific risk factors, viz. time from symptom onset to presentation, fever, dizziness, CD4+ T-cell counts, memory deficits, patchy brain lesions, and disorders of consciousness were calculated to be statistically associated with mortality. A criterion value of '9' was selected as the optimal cut-off value of the established model. The AUC of the ROC curve of this scoring model was 0.976 (p < 0.001). The sensitivity and specificity of the risk scoring model was 100.0 and 86.9%, respectively, which were 81.8 and 94.1% of this scoring model in the verification cohort, respectively.

CONCLUSIONS

The developed scoring system was established with simple risk factors, which also allows expeditious implementation of accurate prognostication, and appropriate therapeutic interventions in HIV-infected patients with TE.

Ethical and legal considerations related to disorders of consciousness

PURPOSE OF REVIEW

The purpose of this review is to describe ethical and legal issues that arise in the management of patients with disorders of consciousness ranging from the minimally conscious state to the coma state, as well as brain death.

RECENT FINDINGS

The recent literature highlights dilemmas created by diagnostic and prognostic uncertainties in patients with disorders of consciousness. The discussion also reveals the challenges experienced by the disability community, which includes individuals with severe brain injury who are classified as having a disorder of consciousness. We review current guidelines for management of patients with disorders of consciousness including discussions around diagnosis, prognosis, consideration of neuropalliation, and decisions around life sustaining medical treatment.

SUMMARY

In the setting of uncertainty, this review describes the utility of applying a disability rights perspective and shared decision-making process to approach medical decision-making for patients with disorders of consciousness. We outline approaches to identifying surrogate decision makers, standards for decision-making and decision-making processes, specifically addressing the concept of futility as a less useful framework for making decisions. We also highlight special considerations for research, innovative and controversial care, brain death, organ donation, and child abuse and neglect.

Decannulation and improvement of responsiveness in patients with disorders of consciousness

Decannulation is a rehabilitation milestone in patients with Disorders of Consciousness (DoC). investigate the relationship between decannulation and improvement of responsiveness (IR) in DoC. 236 tracheostomized patients with severe Acquired Brain Injury and DoC admitted in the Intensive Rehabilitation Unit were retrospectively included. They received personalized interdisciplinary rehabilitation. At discharge, IR was evaluated. The association between IR and demographic/clinical data was investigated using a logistic regression analysis, both in the Unresponsive Wakefulness Syndrome (UWS) and Minimal Consciousness State (MCS) group, divided according to their Coma Recovery Scale-Revised score at admission. In the UWS group (N = 107), only decannulation was associated with IR at discharge (OR: 5.94, CI: 2.08-16.91, p = .001). In the MCS group (N = 129) time post-injury (OR: 0.983, CI: 0.97-0.99, p = .012) and decannulation were associated with IR at discharge (OR: 17.9, CI: 6.39-50.13, p < .001). Decannulation and IR were found to be strongly related, independently from the initial clinical state. While the retrospective nature of the study could not exclude that decannulation may be a consequence of a spontaneous recovery, the obtained results may disclose its potential influence on the clinical history of patients with DoC.

Impaired consciousness due to injury of the ascending reticular activating system in a patient with bilateral pontine infarction: A case report

The ascending reticular activating system (ARAS) is known to play an essential role in maintaining arousal and consciousness. In this report, we describe the case of a patient with impaired consciousness due to injury of the ARAS after bilateral pontine infarction. A 73-year-old female patient presented with anterior chest pain to the Emergency Department of our university hospital. She was diagnosed with chronic stable angina pectoris, three-vessel disease, and chronic total occlusion of the left anterior descending artery by coronary angiography and received conservative treatment. After five days, she showed deep drowsy mentality and brain MRI revealed bilateral paramedian pontine infarction. Four weeks after the pontine infarction, she showed severely impaired consciousness, with a Glasgow Coma Scale score of 7 (eye-opening: 2, best verbal response: 2, and best motor response: 3). Coma Recovery Scale-Revised score was 10 (auditory function: 2, visual function: 3, motor function: 2, verbal function: 2, communication: 0, and arousal: 1). Results of diffusion tensor tractography (DTT) for the ARAS showed decreased neural connectivity in the left lower dorsal ARAS, both lower ventral ARAS, and both upper ARAS. To the best of our knowledge, this is the first report of injury to the ARAS in bilateral pontine infarction diagnosed by DTT. We presume that our report would provide clinicians a better understanding of the mechanism of impaired consciousness in patients with pontine infarction.

Traumatic Brain Injury: An Overview of Epidemiology, Pathophysiology, and Medical Management

Traumatic brain injury (TBI) is an acquired insult to the brain from an external mechanical force that may result in temporary or permanent impairment. The goal of this article is to provide a general review of the epidemiology, pathophysiology and medical management of adult patients with TBI for providers practicing outside the field of physical medicine and rehabilitation. The medical and rehabilitation management of moderate to severe TBI is the focus of this article, with a brief discussion of the management of mild injuries.

Animal-assisted therapy for patients in a minimally conscious state: A randomized two treatment multi-period crossover trial

Objective

To investigate if animal-assisted therapy (AAT) leads to higher consciousness in patients in a minimally conscious state during a therapy session, measured via behavioral reactions, heart rate and heart rate variability.

Methods

In a randomized two treatment multi-period crossover trial, 10 patients in a minimally conscious state participated in eight AAT sessions and eight paralleled conventional therapy sessions, leading to 78 AAT and 73 analyzed control sessions. Patients’ responses during sessions were assessed via behavioral video coding and the Basler Vegetative State Assessment (BAVESTA), heart rate and heart rate variability (SDNN, RMSSD, HF and LF). Data were analyzed with generalized linear mixed models.

Results

Patients showed more eye movements (IRR = 1.31, 95% CI: 1.23 to 1.40, p < 0.001) and active movements per tactile input during AAT compared to control sessions (IRR = 1.13, 95% CI: 1.02 to 1.25, p = 0.018). No difference was found for positive emotions. With BAVESTA, patients’ overall behavioral reactions were rated higher during AAT (b = 0.11, 95% CI: 0.01 to 0.22, p = 0.038). AAT led to significantly higher LF (b = 5.82, 95% CI: 0.55 to 11.08, p = 0.031) and lower HF (b = -5.80, 95% CI: -11.06 to -0.57, p = 0.030), while heart rate, SDNN, RMSSD did not differ.

Conclusions

Patients in a minimally conscious state showed more behavioral reactions and increased physiological arousal during AAT compared to control sessions. This might indicate increased consciousness during therapeutic sessions in the presence of an animal.

Trial registration

ClinicalTrials.gov NCT02629302.

Neuroimaging characterization of recovery of impaired consciousness in patients with disorders of consciousness

Elucidation of critical brain areas or structures that are responsible for recovery of impaired consciousness in patients with disorders of consciousness is important because it can provide information that is useful when developing therapeutic strategies for neurorehabilitation or neurointervention in patients with disorders of consciousness. In this review, studies that have demonstrated brain changes during recovery of impaired consciousness were reviewed. These studies used positron emission tomography, electroencephalography/transcranial magnetic stimulation, diffusion tensor tractography, and diffusion tensor tractography/electroencephalography. The majority of these studies reported on the importance of supratentorial areas or structures in the recovery of impaired consciousness. The important brain areas or structures that were identified were the prefrontal cortex, basal forebrain, anterior cingulate cortex, and parietal cortex. These results have a clinically important implication that these brain areas or structures can be target areas for neurorehabilitation or neurointervention in patients with disorders of consciousness. However, most of studies were case reports; therefore, further original studies involving larger numbers of patients with disorders of consciousness are warranted. In addition, more detailed information on the brain areas or structures that are relevant to the recovery of impaired consciousness is needed.

Evolution of Care for the Veterans and Active Duty Service Members with Disorders of Consciousness

The Veteran Health Administration Polytrauma Rehabilitation Center Emerging Consciousness Program (ECP) has served veterans and service members with disorders of consciousness (DOC) over the past 10 years. The ECP has evolved to meet the unique needs of this patient population, including updating admission criteria to follow evidence-based guidelines for the management of DOC, expanding the use of treatment modalities, and monitoring longitudinal outcomes. The authors review current assessment tools, medical management, and interventions and describe the current state of the ECP and how the evolution of the ECP has enhanced the care of veterans and service members with DOC.