Do Sensory Stimulation Programs Have an Impact on Consciousness Recovery?

Multimodal acoustic-electric trigeminal nerve stimulation modulates conscious perception

Multimodal stimulation can reverse pathological neural activity and improve symptoms in neuropsychiatric diseases. Recent research shows that multimodal acoustic-electric trigeminal-nerve stimulation (TNS) (i.e., musical stimulation synchronized to electrical stimulation of the trigeminal nerve) can improve consciousness in patients with disorders of consciousness. However, the reliability and mechanism of this novel approach remain largely unknown. We explored the effects of multimodal acoustic-electric TNS in healthy human participants by assessing conscious perception before and after stimulation using behavioral and neural measures in tactile and auditory target-detection tasks. To explore the mechanisms underlying the putative effects of acoustic-electric stimulation, we fitted a biologically plausible neural network model to the neural data using dynamic causal modeling. We observed that (1) acoustic-electric stimulation improves conscious tactile perception without a concomitant change in auditory perception, (2) this improvement is caused by the interplay of the acoustic and electric stimulation rather than any of the unimodal stimulation alone, and (3) the effect of acoustic-electric stimulation on conscious perception correlates with inter-regional connection changes in a recurrent neural processing model. These results provide evidence that acoustic-electric TNS can promote conscious perception. Alterations in inter-regional cortical connections might be the mechanism by which acoustic-electric TNS achieves its consciousness benefits.

The visual stimulation in disorders of consciousness

Severe brain damage usually leads to disorders of consciousness (DOC), which include coma, unresponsive wakefulness syndrome (UWS) and a minimally conscious state (MCS). Visual stimulation is widely used, especially in the diagnosis and treatment and treatment of DOC. Researchers have indicated that tests based on visual stimulation including visual pursuit, when used in conjunction with the Coma Recovery Scale-Revised, are able to differentiate between UWS from an MCS. Recently, targeting patients' circadian rhythms has been proposed to be a possible treatment target for DOC. Indeed, light therapy has been applied in some other fields, including treating seasonal affective disorder, sleep problems, and Parkinson's disease. However, at present, although visual stimulation and light therapy are frequently used in DOC, there is still no international unified standard. Therefore, we recommend the development of an international consensus in regard to the definitions, operational criteria and assessment procedures of visual stimulation and light therapy. This review combines visual stimulation, circadian rhythm recovery, and light therapy in DOC patients and presents the mechanisms and current advances in applications related to light therapy and visual stimulation in an attempt to provide additional ideas for future research and treatment of DOC.

Implementation of Multimodal Stimulation and Physical Therapy in Improving the Level of Consciousness and Recovery in Acute Disseminated Encephalomyelitis

This case report aims to explore the use of multimodal sensory stimulation and physical therapy in rehabilitating a 30-year-old female patient with severe acute disseminated encephalomyelitis (ADEM). ADEM, characterized by autoimmune demyelination in the central nervous system, presents challenges in clinical management, particularly in cases with severe motor deficits and coordination issues. The patient's progress was measured using the Glasgow Coma Scale (GCS), Extended Glasgow Outcome Scale (GOS-E), and Coma Recovery Scale-Revised (CRS-R). The patient showed significant improvement in consciousness levels, functional status, and cognitive and neurological function. The study concludes that a collaborative approach involving both therapeutic modalities and active family participation contributed positively to the patient's recovery.

Efficacy of Multimodal Sensory Therapy in Adult Acquired Brain Injury: A Systematic Review

Adults who experience an acquired brain injury often experience disorders of consciousness, physical difficulties, and maladaptive behaviours. Multimodal sensory therapy may benefit brain injured patients, however the extent this therapy can facilitate rehabilitation is not well understood. This systematic review aimed to synthesize multimodal sensory therapy research for adults affected by acquired brain injury. PRISMA guidelines were followed and searches for work published up until July 2021 were undertaken in 5 databases, finding 1054 articles. 43 articles were included in the study. Results describe 29 studies related to coma following an acquired brain injury and 14 to no coma studies (mostly stroke). Multimodal sensory therapy was mostly used as a coma arousal technique following traumatic brain injury, finding positive effects. Multimodal sensory therapy was less applied in stroke, no coma rehabilitation, where most studies found improvement in somatosensory sensation and motor control in an affected limb. In several no coma studies, effects were maintained after several months. The most common senses stimulated in coma studies were audio (N = 30), tactile (N = 28), visual (N = 26), olfactory (N = 22), and gustatory (N = 17), while the most common senses stimulated in stroke, no coma studies were proprioception (N = 7), tactile (N = 8), and stereognosis (N = 4). Multimodal sensory therapy can be beneficial for patients, especially those in a minimally conscious state or attempting physical rehabilitation following stroke. Negative findings are infrequent in the current literature base. Multimodal sensory therapy appears to be a low-risk intervention with positive outcomes.

The Neurological Rehabilitation of Adults With Coma and Disorders of Consciousness

BACKGROUND

Severe quantitative disorders of consciousness (DoC) due to acute brain injury affect up to 47% of patients upon admission to intensive care and early rehabilitation units. Nevertheless, the rehabilitation of this vulnerable group of patients has not yet been addressed in any German-language guidelines and has only been studied in a small number of randomized clinical trials.

METHODS

In an S3 clinical practice guideline project, a systematic literature search was carried out for interventions that could improve consciousness in patients with coma, unresponsive wakefulness syndrome, or minimally conscious state after acute brain injury, and an evidence-based evaluation of these interventions was performed. Recommendations concerning diagnostic methods and medical ethics were issued by consensus.

RESULTS

Misdiagnoses are common in patients with DoC, with minimal consciousness often going unrecognized. Patients with DoC should, therefore, be repeatedly assessed with standardized instruments, particularly the Coma Recovery Scale-Revised. The literature search yielded 54 clinical trials, mostly of low quality; there were two randomized controlled clinical trials providing level 1 evidence. The best available evidence for the improvement of impaired consciousness is for the administration of amantadine (4 studies) and for anodal transcranial direct-current stimulation of the left dorsolateral prefrontal cortex in patients in the minimal conscious state (8 studies, 2 systematic reviews). Further important components of rehabilitation include positioning methods and sensory stimulation techniques such as music therapy.

CONCLUSION

For the first time, evidence-based German-language clinical practice guidelines have now become available for the neurological rehabilitation of patients with DoC.

What is a minimal clinically important difference for clinical trials in patients with disorders of consciousness? a novel probabilistic approach

Over the last 30 years, there has been a growing trend in clinical trials towards assessing novel interventions not only against the benchmark of statistical significance, but also with respect to whether they lead to clinically meaningful changes for patients. In the context of Disorders of Consciousness (DOC), despite a growing landscape of experimental interventions, there is no agreed standard as to what counts as a minimal clinically important difference (MCID). In part, this issue springs from the fact that, by definition, DOC patients are either unresponsive (i.e., in a Vegetative State; VS) or non-communicative (i.e., in a Minimally Conscious State; MCS), which renders it impossible to assess any subjective perception of benefit, one of the two core aspects of MCIDs. Here, we develop a novel approach that leverages published, international diagnostic guidelines to establish a probability-based minimal clinically important difference (pMCID), and we apply it to the most validated and frequently used scale in DOC: the Coma Recovery Scale-Revised (CRS-R). This novel method is objective (i.e., based on published criteria for patient diagnosis) and easy to recalculate as the field refines its agreed-upon criteria for diagnosis. We believe this new approach can help clinicians determine whether observed changes in patients' behavior are clinically important, even when patients cannot communicate their experiences, and can align the landscape of clinical trials in DOC with the practices in other medical fields.

Investigating the effect of implementing a sensory stimulation program by family members on delirium status of brain injury patients hospitalized in the intensive care unit: A randomized clinical trial

BACKGROUND

Delirium is the most common psychological disorder in brain injury patients hospitalized in the intensive care unit (ICU), one of the leading causes of which can be sensory deprivation or sensory overload. This study aimed to determine the effect of implementing a sensory stimulation program by family members on the delirium status of ICU-hospitalized brain injury patients.

MATERIALS AND METHODS

In this randomized controlled clinical trial, 66 brain injury patients hospitalized in the ICUs were assigned to intervention and control groups using stratified random sampling. For the intervention group, a sensory stimulation program was implemented by family members for 1 h a day during the ICU stay. The control group received routine care. Patients' delirium status was assessed daily using the confusion assessment method for the intensive care unit (CAM-ICU). Data were analyzed by the SPSS software version 22, using Chi-square, independent t-test, and Binary logistic regression model tests, at a significance level of 0.05.

RESULTS

Odds of delirium Incidence in the intervention group was 94% lower than in the control group (OR = 0.057, 95% CI 0.017, 0.19, P = 0.001). There is a significant difference between the two groups in terms of length of delirium (P = 0.001), stay in ICU (P = 0.001) and mechanical ventilation (P = 0.001). The mean of all three variables in the intervention group was lower than the control group.

CONCLUSIONS

Implementing of sensory stimulation program by the family members, as a non-pharmacological method, can reduce the incidence of delirium in brain injury patients admitted to ICU.

Optimising recovery of consciousness after coma. From bench to bedside and vice versa

BACKGROUND

Several methods have been proposed to foster recovery of consciousness in patients with disorders of consciousness (DoC).

OBJECTIVE

Critically assess pharmacological and non-pharmacological treatments for patients with chronic DoC.

METHODS

A narrative mini-review, and critical analysis of the scientific literature on the various proposed therapeutic approaches, with particular attention to level of evidence, risk-benefit ratio, and feasibility.

RESULTS AND DISCUSSION

Personalised sensory stimulation, median nerve stimulation, transcranial direct current stimulation (tDCS), amantadine and zolpidem all have favourable risk-benefit ratios and are easy to implement in clinical practice. These treatments should be proposed to every patient with chronic DoC. Comprehensive patient management should also include regular lifting, pain assessment and treatment, attempts to restore sleep and circadian rhythms, implementation of rest periods, comfort and nursing care, and a rehabilitation program with a multi-disciplinary team with expertise in this field. More invasive treatments may cause adverse effects and require further investigation to confirm preliminary, encouraging results and to better define responders' intervention parameters. Scientific studies are essential and given the severity of the disability and handicap that results from DoC, research in this area should aim to develop new therapeutic approaches.

Interventions Facilitating Recovery of Consciousness Following Traumatic Brain Injury: A Systematic Review

People who experience disorders of consciousness (DoC) following a severe traumatic brain injury (TBI) have complex rehabilitation needs addressed by occupational therapy. To examine the effectiveness of interventions to improve arousal and awareness of people with DoC following a TBI. For this systematic review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched six databases in collaboration with a research librarian. Twenty-seven studies were included and grouped thematically. Multimodal sensory stimulation, familiar voices telling structured stories, and transcranial direct current stimulation had a moderate level of evidence. Multimodal sensory stimulation had the strongest evidence in support of its use in clinical practice. Occupational therapy practitioners should administer multimodal stimuli frequently as studies reported administering these interventions at least twice daily. Occupational therapy practitioners should incorporate personally relevant, meaningful, salient stimuli into interventions when treating patients with DoC.

Randomized trial of transcutaneous auricular vagus nerve stimulation on patients with disorders of consciousness: A study protocol

Background

Transcutaneous auricular vagus nerve stimulation (taVNS) has recently been explored for the treatment of Disorders of consciousness (DoC) caused by traumatic brain injury. The evidence of taVNS during the consciousness recovery has been recently reported. However, the mechanism of taVNS in the recovery of consciousness is not clear. This study attempts to investigate the effectiveness of taVNS in DoC by means of Coma Recovery Scale-Revised (CRS-R), Magnetic resonance imaging (MRI), Electrophysiology (EEG), and Single-molecular array (Simoa).

Methods/design

Nighty patients with DoC acquired brain injury are randomized into one of three groups receiving sham taVNS or active taVNS (just left and left or right), respectively. Each of the three groups will experience a 40 days cycle (every 10 days for a small period, baseline 2 weeks, intervention 2 weeks, 40 min per day, 5 days per week, then no intervention for 2 weeks, intervention 2 weeks, 40 min per day, and 5 days per week). Primary outcomes (CRS-R) will be recorded five times during every period. Secondary outcomes will be recorded at the first and at the last period [MRI, EEG, Phosphorylated tau (P-tau), and Neurofilament light chain (NFL)]. We will take notes the adverse events and untoward effects during all cycles.

Discussion

Transcutaneous auricular vagus nerve stimulation as a painless, non-invasive, easily applied, and effective therapy was applied for treatment of patients with depression and epilepsy several decades ago. Recent progress showed that taVNS has behavioral effects in the consciousness recovery. However, there is no clinical evidence to support the effects of taVNS on brain activity. Therefore, we will design a randomized controlled trial to evaluate the effectiveness and safety of taVNS therapy for DoC, and explore neural anatomy correlated to taVNS during the consciousness recovery. Finally, this protocol also tests some biomarkers along with the recovery of consciousness.

Clinical Trial Registration

Chinese Clinical Trial Registry, ChiCTR2100045161. Registered on 9 April 2021.

Clinical Decision on Disorders of Consciousness After Acquired Brain Injury: Stepping Forward

Major advances have been made over the past few decades in identifying and managing disorders of consciousness (DOC) in patients with acquired brain injury (ABI), bringing the transformation from a conceptualized definition to a complex clinical scenario worthy of scientific exploration. Given the continuously-evolving framework of precision medicine that integrates valuable behavioral assessment tools, sophisticated neuroimaging, and electrophysiological techniques, a considerably higher diagnostic accuracy rate of DOC may now be reached. During the treatment of patients with DOC, a variety of intervention methods are available, including amantadine and transcranial direct current stimulation, which have both provided class II evidence, zolpidem, which is also of high quality, and non-invasive stimulation, which appears to be more encouraging than pharmacological therapy. However, heterogeneity is profoundly ingrained in study designs, and only rare schemes have been recommended by authoritative institutions. There is still a lack of an effective clinical protocol for managing patients with DOC following ABI. To advance future clinical studies on DOC, we present a comprehensive review of the progress in clinical identification and management as well as some challenges in the pathophysiology of DOC. We propose a preliminary clinical decision protocol, which could serve as an ideal reference tool for many medical institutions.

Behavioral intervention approaches for people with disorders of consciousness: a scoping review

PURPOSE

This review was intended to provide an overall picture of work conducted during the last decade to assess the impact of behavioral intervention strategies on people with disorders of consciousness (i.e., comatose state, vegetative state/unresponsive wakefulness, or minimally conscious state). The intervention strategies considered were those not based on music or including music as a component of the intervention package.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) checklist, a scoping review was carried out to identify and provide a synthesis of eligible studies published in English during the 2010-2021 period. Three databases (i.e., PubMed, PsycINFO, and Web of Science) were employed for the literature search.

RESULTS

Forty studies met the inclusion criteria. Those studies were grouped into three categories based on whether they assessed the effects of: (i) verbal stories/messages, (ii) multiple stimulation, and (iii) response-contingent stimulation. Then, a narrative synthesis of the studies of each of the three categories was provided to specify the types of patients involved, the intervention and assessment conditions implemented, and the outcome attained.

CONCLUSIONS

The evidence reported in most of the studies might be considered encouraging and convincing. Even so, it might be very difficult to view the evidence of the various studies cumulatively and make general/conclusive statements due to a number of differences in the intervention conditions applied.Implications for rehabilitationAn informative picture of the studies using behavioral interventions with people with disorders of consciousness is essential to any professional working in the area.Such picture can be highly useful in providing a view of the intervention strategies used for those people, of the variations existing within and across strategies, and of the evidence available.An analysis of the strategies, their implementation and their effects may provide new insights for improving those strategies and eventually increasing their impact.The individuals charged with the implementation process (e.g., family members or nurses) may have a relevant influence on the overall impact of the strategy.

Outcomes of family-centred auditory and tactile stimulation implementation on traumatic brain injured patients

AIM

To determine the outcomes of Family-centred Auditory and Tactile Stimulation Implementation on Traumatic Brain Injured Patients in Egypt.

BACKGROUND

Family engagement in the care of their relatives in the Intensive care units is limited due to patients' life-threatening conditions, in addition to the use of high technology in these settings. Auditory and tactile sensory stimulations are among the diverse sensory stimulations that have received more attention in brain injured patients than other senses as being considered safe, and effective measures.

DESIGN

A Quasi-experimental design was used to test the hypotheses of this study.

METHODS

A convenience sample of 60 adult patients suffering from Traumatic Brain Injury and admitted to the intensive care units of two University Hospitals in Egypt was included in the study. Patients were assigned into two equal groups: control and study groups (30 patients each). The auditory and tactile stimulations were provided by trained family members, once daily for 2 weeks for the study group. Whereas routine communication was provided by the family of traumatic brain injured patients in the ICU for the control group. Two tools were used for data collection; tool one, the "Glasgow Coma Scale" to assess patient's level of consciousness, and tool two the "Physiological Adverse Events Assessment" to monitor patients for the occurrence of physiological adverse events.

DATA COLLECTION

January to October 2019.

RESULTS

The implementation of an organized auditory and tactile stimulation by trained family members is associated with highly statistically significant positive effects . Patients in the study group showed a higher mean of consciousness, lower incidence rate of physiological adverse events, and a lower mean duration of ICU stay.

CONCLUSIONS

Implementation of an organized auditory and tactile stimulation by trained family members enhanced the consciousness level of comatose Traumatic Brain Injured patients, decreased the occurrence of physiological adverse events, and ICU length of stay. Thus, it is recommended for use in the daily routine nursing care of comatose Traumatic Brain Injured patients.

RELEVANCE TO CLINICAL PRACTICE

This study gives a deeper understanding of how family engagement in the care of their critically ill relative enhances their recovery and improve their level of consciousness.

Understanding, detecting, and stimulating consciousness recovery in the ICU

Coma is a medical and socioeconomic emergency. Although underfunded, research on coma and disorders of consciousness has made impressive progress. Lesion-network-mapping studies have delineated the precise brainstem regions that consistently produce coma when damaged. Functional neuroimaging has revealed how mechanisms like "communication through coherence" and "inhibition by gating" work in synergy to enable cortico-cortical processing and how this information transfer is disrupted in brain injury. On the cellular level, break-down of intracellular communication between the layer 5 pyramidal cell soma and the apical dendritic part impairs dendritic information integration, with up-stream effects on microcircuits in local neuronal populations and on large-scale fronto-parietal networks, which correlates with loss of consciousness. A breakthrough in clinical concepts occurred when fMRI, and later EEG, studies revealed that 15% of clinically unresponsive patients in acute and chronic settings are in fact awake and aware, as shown by their command following abilities revealed by brain activation during motor and locomotion imagery tasks. This condition is now termed "cognitive motor dissociation." Furthermore, epidemiological data on coma were literally non-existent until recently because of difficulties related to case ascertainment with traditional methods, but crowdsourcing of family observations enabled the first estimates of how frequent coma is in the general population (pooled annual incidence of 201 coma cases per 100,000 population in the UK and the USA). Diagnostic guidelines on coma and disorders of consciousness by the American Academy of Neurology and the European Academy of Neurology provide ambitious clinical frameworks to accommodate these achievements. As for therapy, a broad range of medical and non-medical treatment options is now being tested in increasingly larger trials; in particular, amantadine and transcranial direct current stimulation appear promising in this regard. Major international initiatives like the Curing Coma Campaign aim to raise awareness for coma and disorders of consciousness in the public, with the ultimate goal to make more brain-injured patients recover consciousness after a coma. To highlight all these accomplishments, this paper provides a comprehensive overview of recent progress and future challenges related to understanding, detecting, and stimulating consciousness recovery in the ICU.

Impact of a sensory stimulation program conducted by family members on the consciousness and pain levels of ICU patients: A mixed method study

Background

The results of several studies show the different effects of a balanced sensory stimulation program (SSP) on patients with brain injury admitted to the intensive care unit (ICU), but these effects have been less studied based on mixed and comprehensive methods.

Method

This mixed-method study involved 66 patients with brain injury admitted to the ICU who were allocated into intervention (n = 33) and control (n = 33) groups using random stratified sampling. Patients in the intervention group received a sensory stimulation program from family members for 1 h daily during ICU hospitalization, while the control group received only routine care. Patients' level of consciousness and pain intensity were measured immediately before and after the intervention using Glasgow Coma Scale (GCS) and Behavioral Pain Scale (BPS), respectively. In-depth unstructured interviews were conducted with the patients in the intervention group 3 months after discharge from the ICU. These interviews were analyzed following Graneheim and Lundman (2004) conventional content analysis method.

Results

A significant difference was found between the study groups in terms of the mean difference of GCS (P =0.001) and BPS score (P = 0.001) before and after intervention. Patients in the intervention group had a higher mean GCS and a lower mean BPS than did patients in the control group. The main themes extracted from the qualitative analysis confirmed the results obtained from the quantitative phase of the study.

Conclusion

The combination of the quantitative and qualitative findings suggested that amidst the many hardships and sufferings brain injury patients go through in the ICU, a sensory stimulation program offered by family members may have many benefits such as increased level of consciousness and reduced pain for these patients. Therefore, it is necessary to formulate a framework for this program and provide the needed facilities in order to benefit more from the capacity of such programs for ICU patients.

Sensory Stimulation for Patients With Disorders of Consciousness Following a Traumatic Brain Injury (June 2013-October 2020)

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on the effectiveness of sensory stimulation interventions to improve arousal and awareness in people with disorders of consciousness following a TBI.

Responses to stimuli in the 'snoezelen' room in unresponsive wakefulness or in minimally responsive state

BACKGROUND

Sensory stimulation in Snoezelen room increased responsiveness after brain injury and dementia.

OBJECTIVE

To explore the physiological and clinical effects of Snoezelen stimulation in persons with unresponsive wakefulness syndrome or minimally conscious state (UWS or MCS).

DESIGN

A comparative prospective observational cohort study.

METHODS

Ten patients with UWS and 25 in MCS were exposed to consecutive stimuli involving the 5 senses in a Snoezelen room. Heart rate (HR) and cerebral blood flow velocity (CBFV), and scores of the Loewenstein communication scale (LCS) were obtained before and during or after the stimuli.

RESULTS

The stimuli increased HR values and decreased left hemisphere CBFV values in patients with MCS (p < 0.05). Stimulation increased LCS scores (from 28.48 ± 6.55 to 31.13 ± 7.14; p < 0.001) in patients with MCS, but not in the UWS group. LCS gain correlated with HR and right hemisphere CBFV gains in patients with MCS (r = 0.439 and 0.636 respectively, p < 0.05).

CONCLUSIONS

Snoezelen stimulation induced immediate improvement in communication and physiological changes in patients with MSC, and had a minor physiological effect in patients with UWS. If additional studies support these findings, it will be possible to suggest that Snoezelen stimulation can affect arousal, and possibly improve functioning.

The Outcome of Neurorehabilitation Efficacy and Management of Traumatic Brain Injury

For public health professionals, traumatic brain injury (TBI) and its possible protracted repercussions are a significant source of worry. In opposed to patient neurorehabilitation with developed brain abnormalities of different etiologies, neurorehabilitation of affected persons has several distinct features. The clinical repercussions of the various types of TBI injuries will be discussed in detail in this paper. During severe TBI, the medical course frequently follows a familiar first sequence of coma, accompanied by disordered awareness, followed by agitation and forgetfulness, followed by return of function. Clinicians must be aware of common medical issues that might occur throughout the various stages of neurorehabilitation, for example, posttraumatic hydrocephalus, paroxysmal sympathetic hyperactivity and posttraumatic neuroendocrine disorders, at each step of the process. Furthermore, we address problems about the scheduling of various rehabilitation programs as well as the availability of current data for comprehensive rehabilitative neuropsychology techniques.

The Importance of Material Used in Speech Therapy: Two Case Studies in Minimally Conscious State Patients

Speech therapy can be part of the care pathway for patients recovering from comas and presenting a disorder of consciousness (DOC). Although there are no official recommendations for speech therapy follow-up, neuroscientific studies suggest that relevant stimuli may have beneficial effects on the behavioral assessment of patients with a DOC. In two case studies, we longitudinally measured (from 4 to 6 weeks) the behavior (observed in a speech therapy session or using items from the Coma Recovery Scale—Revised) of two patients in a minimally conscious state (MCS) when presenting music and/or autobiographical materials. The results highlight the importance of using relevant material during a speech therapy session and suggest that a musical context with a fast tempo could improve behavior evaluation compared to noise. This work supports the importance of adapted speech therapy for MCS patients and encourages larger studies to confirm these initial observations.

The role of plasticity in the recovery of consciousness

Disorders of consciousness (DOCs), i.e., coma, vegetative state, and minimally conscious state are the consequences of a severe brain injury that disrupts the brain ability to generate consciousness. Recovery from DOCs requires functional and structural changes in the brain. The sites where these plastic changes take place vary according to the pathophysiology of the DOC. The ascending reticular activating system of the brainstem and its complex connections with the thalamus and cortex are involved in the pathophysiology of coma. Subcortical structures, such as the striatum and globus pallidus, together with thalamocortical and corticothalamic projections, the basal forebrain, and several networks among different cortical areas are probably involved in vegetative and minimally conscious states. Some mechanisms of plasticity that allegedly operate in each of these sites to promote recovery of consciousness will be discussed in this chapter. While some mechanisms of plasticity work at a local level, others produce functional changes in complex neuronal networks, for example by entraining neuronal oscillations. The specific mechanisms of brain plasticity represent potential targets for future treatments aiming to restore consciousness in patients with severe DOCs.

Virtual Reality-Based Sensory Stimulation for Pediatric Disorders of Consciousness: A Pilot Study

OBJECTIVE

The purpose of this study was to determine whether virtual reality-based sensory stimulation has the ability to improve the level of consciousness in pediatric disorders of consciousness compared with general rehabilitation.

METHODS

Thirty subjects were divided into a virtual reality (VR) group (n = 15) and a control group (n = 15). Subjects in the VR group received both general rehabilitation and exposure to VR videos; the control group received only general rehabilitation. The Glasgow Coma Scale (GCS), Coma Recovery Scale-Revised (CRS-R), and amplitude-integrated electroencephalogram (EEG) (aEEG) were used to measure the clinical behavioral response and neuroelectrophysiology before and after the treatment. The Glasgow Outcome Scale Extended Pediatric Revised (GOS-E Peds) was used to measure the social and personal functional ability after 3 months.

RESULTS

After 2 weeks of treatment, the CRS-R and GCS improved in both groups. However, the VR group had better results than the control group in the CRS-R (p = 0.003) and GCS (p = 0.045). There were no significant differences on aEEG in the two groups after treatment. According to the GOS-E Peds, the improvement of social and personal functional ability had no significant differences in the two groups. Additionally, there were no obvious adverse reactions in the two group during the treatment.

CONCLUSIONS

This pilot study indicates potential benefit from the addition of VR to standard rehabilitation in pediatric disorders of consciousness. To further explore the efficacy of VR, a large-sample randomized controlled trial is warranted.

Virtually spatialized sounds enhance auditory processing in healthy participants and patients with a disorder of consciousness

Neuroscientific and clinical studies on auditory perception often use headphones to limit sound interference. In these conditions, sounds are perceived as internalized because they lack the sound-attributes that normally occur with a sound produced from a point in space around the listener. Without the spatial attention mechanisms that occur with localized sounds, auditory functional assessments could thus be underestimated. We hypothesize that adding virtually externalization and localization cues to sounds through headphones enhance sound discrimination in both healthy participants and patients with a disorder of consciousness (DOC). Hd-EEG was analyzed in 14 healthy participants and 18 patients while they listened to self-relevant and irrelevant stimuli in two forms: diotic (classic sound presentation with an "internalized" feeling) and convolved with a binaural room impulse response (to create an "externalized" feeling). Convolution enhanced the brains' discriminative response as well as the processing of irrelevant sounds itself, in both healthy participants and DOC patients. For the healthy participants, these effects could be associated with enhanced activation of both the dorsal (where/how) and ventral (what) auditory streams, suggesting that spatial attributes support speech discrimination. Thus, virtually spatialized sounds might "call attention to the outside world" and improve the sensitivity of assessment of brain function in DOC patients.

Music Stimulation for People with Disorders of Consciousness: A Scoping Review

Music stimulation is considered to be a valuable form of intervention for people with severe brain injuries and prolonged disorders of consciousness (i.e., unresponsive wakefulness/vegetative state or minimally conscious state). This review was intended to provide an overall picture of work conducted during the last decade to assess the impact of music on behavioral and non-behavioral responses of people with disorders of consciousness. Following the PRISMA-ScR checklist, a scoping review was carried out to identify and provide a synthesis of eligible studies published in English during the 2010–2021 period. Three databases (i.e., PubMed, PsycINFO, and Web of Science) were employed for the literature search. Thirty-four studies met the inclusion criteria. Those studies were grouped into three categories based on whether they assessed the effects of: (i) recorded music, (ii) interactive music, or (iii) response-contingent music. A narrative synthesis of the studies of each of the three categories was eventually provided. While the studies of all three categories reported fairly positive/encouraging results, several methodological questions make it difficult to draw conclusions about those results and their implications for intervention programs in daily contexts.

Clinical diagnosis guidelines and neurorestorative treatment for chronic disorders of consciousness (2021 China version)

Chronic disorders of consciousness (DOC) include the vegetative state and the minimally consciousness state. The DOC diagnosis mainly relies on the evaluation of clinical behavioral scales, electrophysiological testing, and neuroimaging examinations. No specifically effective neurorestorative methods for chronic DOC currently exist. Any valuable exploration therapies of being able to repair functions and/or structures in the consciousness loop (e.g., drugs, hyperbaric medicines, noninvasive neurostimulation, sensory and environmental stimulation, invasive neuromodulation therapy, and cell transplantation) may become effective neurorestorative strategies for chronic DOC. In the viewpoint of Neurorestoratology, this guideline proposes the diagnostic and neurorestorative therapeutic suggestions and future exploration direction for this disease following the review of the existing treatment exploration achievements for chronic DOC.

The effect of family-centered sensory and affective stimulation on comatose patients with traumatic brain injury: A systematic review and meta-analysis

BACKGROUND

Sensory stimulation has been used in the early rehabilitation of comatose patients with traumatic brain injury, but the effect of sensory stimulation involving family members is unclear.

OBJECTIVES

To evaluate the effects of family-centered sensory and affective stimulation on comatose patients with traumatic brain injury and explore the factors that affect the outcomes.

DESIGN

A systematic review with a meta-analysis.

DATA SOURCES

Electronic databases including PubMed, Web of Science, Google Scholar, Cochrane Library, CINAHL, China National Knowledge Infrastructure, and WanFang were searched from October 2019 to May 2020.

REVIEW METHODS

Two reviewers independently assessed eligibility of potential studies and extracted data. Quality of included studies was assessed according to the evaluation criteria of Cochrane Evaluation Manual 5.1.0. Outcome measures of the meta-analysis were the Glasgow Coma Scale scores, the Western Neuro Sensory Stimulation Profile scores, awakening time, and satisfaction rate. To explore whether there was a difference in the effect between variants of the intervention, variables as subgroups were time to start intervention, type of intervention, duration of each intervention, daily frequency of intervention, days of intervention, and patient's area.

RESULT

Seventeen randomized controlled trials were included in the review and meta-analysis. Most studies were of medium quality. The improvement of the Glasgow Coma Scale score is significantly greater with the intervention implemented within 24 h compared to the intervention implemented 24 h later (mean difference 3.91, 95% confidence interval 3.44-4.38 vs. mean difference 1.90, 95% confidence interval 1.69-2.12, respectively). The results of subgroup analyses show that auditory stimulation combined with tactile stimulation and multi-sensory stimulation are associated with better outcomes than a single use of auditory stimulation. Studies from Asia report more positive outcomes than those from America (mean difference 1.94, 95% confidence interval 1.73-2.16 vs. mean difference 0.44, 95% confidence interval -0.87-1.75). And the improvement of the Glasgow Coma Scale score with the stimulation performed by family members is greater than that with the stimulation implemented by nurses (mean difference 2.17, 95% confidence interval 1.67-2.66). Besides, it is associated with better awakening time, awakening rate, and satisfaction rate compared to routine care.

CONCLUSION

Early family-centered sensory and affective stimulation is more effective than routine care and nurse-implemented sensory stimulation in improving the level of consciousness and cognition of comatose patients with traumatic brain injury, and multi-sensory stimulation is more effective than single stimulation. More studies with larger sample size and high quality in different countries are warranted.

Electrophysiological and Neuroimaging Studies - During Resting State and Sensory Stimulation in Disorders of Consciousness: A Review

A severe brain injury may lead to a disorder of consciousness (DOC) such as coma, vegetative state (VS), minimally conscious state (MCS) or locked-in syndrome (LIS). Till date, the diagnosis of DOC relies only on clinical evaluation or subjective scoring systems such as Glasgow coma scale, which fails to detect subtle changes and thereby results in diagnostic errors. The high rate of misdiagnosis and inability to predict the recovery of consciousness for DOC patients have created a huge research interest in the assessment of consciousness. Researchers have explored the use of various stimulation and neuroimaging techniques to improve the diagnosis. In this article, we present the important findings of resting-state as well as sensory stimulation methods and highlight the stimuli proven to be successful in the assessment of consciousness. Primarily, we review the literature based on (a) application/non-use of stimuli (i.e., sensory stimulation/resting state-based), (b) type of stimulation used (i.e., auditory, visual, tactile, olfactory, or mental-imagery), (c) electrophysiological signal used (EEG/ERP, fMRI, PET, EMG, SCL, or ECG). Among the sensory stimulation methods, auditory stimulation has been extensively used, since it is easier to conduct for these patients. Olfactory and tactile stimulation have been less explored and need further research. Emotionally charged stimuli such as subject’s own name or narratives in a familiar voice or subject’s own face/family pictures or music result in stronger responses than neutral stimuli. Studies based on resting state analysis have employed measures like complexity, power spectral features, entropy and functional connectivity patterns to distinguish between the VS and MCS patients. Resting-state EEG and fMRI are the state-of-the-art techniques and have a huge potential in predicting the recovery of coma patients. Further, EMG and mental-imagery based studies attempt to obtain volitional responses from the VS patients and thus could detect their command-following capability. This may provide an effective means to communicate with these patients. Recent studies have employed fMRI and PET to understand the brain-activation patterns corresponding to the mental imagery. This review promotes our knowledge about the techniques used for the diagnosis of patients with DOC and attempts to provide ideas for future research.

Novel sensory paradigms for neuromodulation in disorders of consciousness in traumatic brain injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) represents a major cause of mortality and disability worldwide. In cases of severe TBI, disorders of consciousness (DoC) can occur and therapeutic options for these conditions are few and of limited efficacy. Sensory stimulation, an instrument to improve arousal and awareness, is frequently applied in the neurorehabilitation of DoC, but scientific evidence supporting its efficacy is limited. Our aim is to review the recent literature concerning novel sensory paradigms used in sensory stimulation protocols in DoC following TBI.

RECENT FINDINGS

Recent studies on sensory stimulation have investigated different types of stimulation protocols, focusing on the issue of how to demonstrate that improvements are related to the treatment applied and not to spontaneous recovery. Moreover, these studies have also shown that paraclinical tests should be useful not only to discover signs of awareness when behavioural assessment fails to do so, but also to measure the effects of sensory stimulation.

SUMMARY

Future studies about novel types of sensory stimulation, whose effects should be possibly measured through paraclinical approaches, are recommended in order to increase the probability that the proper individualized stimulation is administered for each patient.

Traditional Chinese Medicine in Emergency Treatment Mechanism and Application

Traditional Chinese medicine has usually been recognized to be efficacious to treat chronic diseases from the western point-of-view. However, there is a long history in China of applying traditional Chinese medicine in many acute and urgent medical conditions. In this review, selected methods documented in traditional Chinese medicine including blowing air to ear, nose insufflating therapy, acupuncture and moxibustion were presented as the common practices to promote consciousness recovery from coma. We aimed to explore the mechanism of these four methods with current scientific evidence, further discuss the potential of traditional Chinese medicine to be applied in emergency medicine and provide a path forward to more rigorously validate these procedures. The development of the integrated traditional Chinese medicine and western medicines provides a new therapeutic direction for the new first-aid treatment.

Sensory stimulation to improve arousal in comatose patients after traumatic brain injury: a systematic review of the literature

BACKGROUND

No standard rehabilitative treatment for coma arousal after traumatic brain injury (TBI) exists. Based on our clinical experience, we hypothesized that sensory stimulation (SS) is a promising protocol to improve outcomes in these patients.

METHODS

We performed a literature review on the progress of sensory stimulation to enhance coma arousal after traumatic brain injury. We searched the databases on Medline, Embase, and Cochrane to gain access to relevant publications using the key words "traumatic brain injury," "disorders of consciousness," "sensory stimulation," and "coma scale."

RESULTS

We included all original studies published in English with patients presenting severe disorders of consciousness due to traumatic brain injury who had received SS and whose behavioral/neural responses had been measured. We compared data on ten selected studies and analyzed the SS effects in comatose patient outcomes after TBI. Our review outlines the role of SS in patients with TBI and provides guidance for its implementation in the clinical practice.

CONCLUSIONS

The literature suggests the SS program improves coma arousal after TBI. However, high-quality clinical trials are needed to establish standard SS protocols.

Clinical Research: Auditory Stimulation in the Disorders of Consciousness

Due to the complex situation of disorder of consciousness (DOC) patients, the assessment of conscious states of these patients has become a huge challenge for a long time (Laureys et al., 2010). At present, the main clinical diagnostic method to assess the conscious state of a DOC patient is the use of a relevant behavior scale like the Coma Recovery Scale-Revised (CRS-R). In this article, we will focus on auditory stimulation and select some representative auditory stimulus, like calling names and music stimulation, to discuss the function and application of the auditory stimulus in patients with DOC and provide guidance for future research.

Usability of intravenous thiamine injection test compared with odor stick identification test for Japanese patients with severe traumatic brain injury

OBJECTIVE

Olfactory dysfunction is often observed after severe traumatic brain injury (sTBI). Its diagnosis is difficult because patients with sTBI have a communication disability following impaired consciousness and communication disorder. The intravenous thiamine injection (IT) test is one of the representative diagnostic examinations to identify dysfunction, and it is often used in medical certification for liability insurance of automobiles in Japan because it could be judged by a simple reaction. However, the extent of usefulness of the IT test in the diagnosis of olfactory dysfunction in patients with sTBI is unknown. In this study, we validated the usability of the IT test and compared the results with those of the odor stick identification test for the Japanese (OSIT-J) to evaluate the sensitivity of the IT test in patients with sTBI.

METHODS

The study enrolled 205 subjects, including 10 healthy volunteers and 195 patients with sTBI. First, we examined olfactory dysfunction in sTBI patients using OSIT-J. Subsequently, we performed the IT test among patients with olfactory dysfunction.

RESULTS

In the first part, 41 subjects, including 10 healthy volunteers, were examined by using the OSIT-J test. As a result, 28 patients were diagnosed with olfactory dysfunction (90.3%, p<0.0001), including anosmia and parosmia, compared with healthy volunteers. Among the 12 odors, garlic odor was easily recognized for patients with olfactory dysfunction. As a consequence of the IT test for 11 patients with olfactory dysfunction, four patients recognized thiamine odor, and seven patients did not. All four patients could recognize the garlic odor of OSIT-J, but 2 of the seven patients could recognize the garlic odor of OSIT-J, suggesting that the thiamine odor is linked to garlic odor (p=0.046), but not always. The detection rate of olfactory dysfunction through the IT test was 36.4%.

CONCLUSION

Our data showed that garlic odor, which is similar to thiamine odor, was easily recognizable for patients with sTBI. However, the IT test might overlook the diagnosis of olfactory dysfunction because it only identifies one odor. In addition, thiamine frequently induces angialgia. We should pay attention to the overconfidence of the IT test for patients with sTBI.

Neurorehabilitation of Traumatic Brain Injury (TBI): A Clinical Review

Traumatic brain injury (TBI) and its potential long-term consequences are of major concern for public health. Neurorehabilitation of affected individuals has some specific characteristics in contrast to neurorehabilitation of patients with acquired brain lesions of other aetiology. This review will deal with the clinical consequences of the distinct lesions of TBI. In severe TBI, clinical course often follows a typical initial sequence of coma; followed by disturbed consciousness; later, post-traumatic agitation and amnesia; and finally, recovery of function occurs. In the different phases of neurorehabilitation, physicians should be aware of typical medical complications such as paroxysmal sympathetic hyperactivity, posttraumatic hydrocephalus, and posttraumatic neuroendocrine dysfunctions. Furthermore, we address questions on timing and on existing evidence for different rehabilitation programmes and for holistic neuropsychological rehabilitation approaches.