Sensory Stimulation and Music Therapy Programs for Treating Disorders of Consciousness

Musical and electrical stimulation as intervention in disorder of consciousness (DOC) patients: A randomised cross-over trial

BACKGROUND

Disorders of consciousness (DOC), i.e., unresponsive wakefulness syndrome (UWS) or vegetative state (VS) and minimally conscious state (MCS), are conditions that can arise from severe brain injury, inducing widespread functional changes. Given the damaging implications resulting from these conditions, there is an increasing need for rehabilitation treatments aimed at enhancing the level of consciousness, the quality of life, and creating new recovery perspectives for the patients. Music may represent an additional rehabilitative tool in contexts where cognition and language are severely compromised, such as among DOC patients. A further type of rehabilitation strategies for DOC patients consists of Non-Invasive Brain Stimulation techniques (NIBS), including transcranial electrical stimulation (tES), affecting neural excitability and promoting brain plasticity.

OBJECTIVE

We here propose a novel rehabilitation protocol for DOC patients that combines music-based intervention and NIBS in neurological patients. The main objectives are (i) to assess the residual neuroplastic processes in DOC patients exposed to music, (ii) to determine the putative neural modulation and the clinical outcome in DOC patients of non-pharmacological strategies, i.e., tES(control condition), and music stimulation, and (iii) to evaluate the putative positive impact of this intervention on caregiver's burden and psychological distress.

METHODS

This is a randomised cross-over trial in which a total of 30 participants will be randomly allocated to one of three different combinations of conditions: (i) Music only, (ii) tES only (control condition), (iii) Music + tES. The music intervention will consist of listening to an individually tailored playlist including familiar and self-relevant music together with fixed songs; concerning NIBS, tES will be applied for 20 minutes every day, 5 times a week, for two weeks. After these stimulations two weeks of placebo treatments will follow, with sham stimulation combined with noise for other two weeks. The primary outcomes will be clinical, i.e., based on the differences in the scores obtained on the neuropsychological tests, such as Coma Recovery Scale-Revised, and neurophysiological measures as EEG, collected pre-intervention, post-intervention and post-placebo.

DISCUSSION

This study proposes a novel rehabilitation protocol for patients with DOC including a combined intervention of music and NIBS. Considering the need for rigorous longitudinal randomised controlled trials for people with severe brain injury disease, the results of this study will be highly informative for highlighting and implementing the putative beneficial role of music and NIBS in rehabilitation treatments.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05706831, registered on January 30, 2023.

Brain activation during processing of mouth actions in patients with disorders of consciousness

In the past 2 decades, several attempts have been made to promote a correct diagnosis and possible restorative interventions in patients suffering from disorders of consciousness. Sensory stimulation has been proved to be useful in sustaining the level of arousal/awareness and to improve behavioural responsiveness with a significant effect on oro-motor functions. Recently, action observation has been proposed as a stimulation strategy in patients with disorders of consciousness, based on neurophysiological evidence that the motor cortex can be activated not only during action execution but also when actions are merely observed in the absence of motor output, or during listening to action sounds and speech. This mechanism is provided by the activity of mirror neurons. In the present study, a group of patients with disorders of consciousness (11 males, 4 females; median age: 55 years; age range: 19-74 years) underwent task-based functional MRI in which they had, in one condition, to observe and listen to the sound of mouth actions, and in another condition, to listen to verbs with motor or abstract content. In order to verify the presence of residual activation of the mirror neuron system, the brain activations of patients were compared with that of a group of healthy individuals (seven males, eight females; median age: 33.4 years; age range: 24-65 years) performing the same tasks. The results show that brain activations were lower in patients with disorders of consciousness compared with controls, except for primary auditory areas. During the audiovisual task, 5 out of 15 patients with disorders of consciousness showed only residual activation of low-level visual and auditory areas. Activation of high-level parieto-premotor areas was present in six patients. During the listening task, three patients showed only low-level activations, and six patients activated also high-level areas. Interestingly, in both tasks, one patient with a clinical diagnosis of vegetative state showed activations of high-level areas. Region of interest analysis on blood oxygen level dependent signal change in temporal, parietal and premotor cortex revealed a significant linear relation with the level of clinical functioning, assessed with coma recovery scale-revised. We propose a classification of the patient's response based on the presence of low-level and high-level activations, combined with the patient's functional level. These findings support the use of action observation and listening as possible stimulation strategies in patients with disorders of consciousness and highlight the relevance of combined methods based on functional assessment and brain imaging to provide more detailed neuroanatomical specificity about residual activated areas at both cortical and subcortical levels.

Prognostication in Prolonged and Chronic Disorders of Consciousness

Patients with prolonged disorders of consciousness (DOCs) longer than 28 days may continue to make significant gains and achieve functional recovery. Occasionally, this recovery trajectory may extend past 3 (for nontraumatic etiologies) and 12 months (for traumatic etiologies) into the chronic period. Prognosis is influenced by several factors including state of DOC, etiology, and demographics. There are several testing modalities that may aid prognostication under active investigation including electroencephalography, functional and anatomic magnetic resonance imaging, and event-related potentials. At this time, only one treatment (amantadine) has been routinely recommended to improve functional recovery in prolonged DOC. Given that some patients with prolonged or chronic DOC have the potential to recover both consciousness and functional status, it is important for neurologists experienced in prognostication to remain involved in their care.

Cortical responses to auditory stimulation predict the prognosis of patients with disorders of consciousness

OBJECTIVE

This study aimed to assess the prognosis of patients with disorders of consciousness (DoC) using auditory stimulation with electroencephalogram (EEG) recordings.

METHODS

We enrolled 72 patients with DoC in the study, which involved subjecting patients to auditory stimulation while EEG responses were recorded. Coma Recovery Scale-Revised (CRS-R) scores and Glasgow Outcome Scale (GOS) were determined for each patient and followed up for three months. A frequency spectrum analysis was performed on the EEG recordings. Finally, the power spectral density (PSD) index was used to predict the prognosis of patients with DoC based on a support vector machine (SVM) model.

RESULTS

Power spectral analyses revealed that the cortical response to auditory stimulation showed a decreasing trend with decreasing consciousness levels. Auditory stimulation-induced changes in absolute PSD at the delta and theta bands were positively correlated with the CRS-R and GOS scores. Furthermore, these cortical responses to auditory stimulation had a good ability to discriminate between good and poor prognoses of patients with DoC.

CONCLUSIONS

Auditory stimulation-induced changes in the PSD were highly predictive of DoC outcomes.

SIGNIFICANCE

Our findings showed that cortical responses to auditory stimulation may be an important electrophysiological indicator of prognosis in patients with DoC.

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.

Robotic Verticalization plus Music Therapy in Chronic Disorders of Consciousness: Promising Results from a Pilot Study

Background: Music stimulation is considered a valuable form of intervention in disorders of consciousness (DoC); for instance, verticalization may improve motor and cognitive recovery. Our purpose is to investigate the effects of a novel rehabilitative approach combining robotic verticalization training (RVT) with personalized music stimulation in people with DoC. Methods: Sixteen subjects affected by minimally conscious state due to traumatic brain lesions who attended our Intensive Neuro-Rehabilitation Unit were enrolled in this randomized trial. They received either music robotic verticalization (MRV) using the Erigo device plus a personalized music playlist or only RVT without music stimuli. Each treatment was performed 2 times a week for 8 consecutive weeks in addition to standard neurorehabilitation. Results: We found significant improvements in all patients’ outcomes in the experimental group (who received MRV): Coma Recovery Scale-Revised (CRS-R) (p < 0.01), Level of Cognitive Functioning (LCF) (p < 0.02), Functional Independence Measure (FIM) (p < 0.03), Functional Communication Scale (FCS) (p < 0.007), Trunk Control Test (TCT) (p = 0.05). Significant differences between the two groups were also found in the main outcome measure CRS-R (p < 0.01) but not for TCT and FIM. Conclusions: Our study supports the safety and effectiveness of RVT with the Erigo device in chronic MCS, and the achievement of better outcomes when RVT is combined with music stimulation.

Smart Textiles for Improved Quality of Life and Cognitive Assessment

Smart textiles can be used as innovative solutions to amuse, meaningfully engage, comfort, entertain, stimulate, and to overall improve the quality of life for people living in care homes with dementia or its precursor mild cognitive impairment (MCI). This concept paper presents a smart textile prototype to both entertain and monitor/assess the behavior of the relevant clients. The prototype includes physical computing components for music playing and simple interaction, but additionally games and data logging systems, to determine baselines of activity and interaction. Using microelectronics, light-emitting diodes (LEDs) and capacitive touch sensors woven into a fabric, the study demonstrates the kinds of augmentations possible over the normal manipulation of the traditional non-smart activity apron by incorporating light and sound effects as feedback when patients interact with different regions of the textile. A data logging system will record the patient’s behavioral patterns. This would include the location, frequency, and time of the patient’s activities within the different textile areas. The textile will be placed across the laps of the resident, which they then play with, permitting the development of a behavioral profile through the gamification of cognitive tests. This concept paper outlines the development of a prototype sensor system and highlights the challenges related to its use in a care home setting. The research implements a wide range of functionality through a novel architecture involving loosely coupling and concentrating artifacts on the top layer and technology on the bottom layer. Components in a loosely coupled system can be replaced with alternative implementations that provide the same services, and so this gives the solution the best flexibility. The literature shows that existing architectures that are strongly coupled result in difficulties modeling different individuals without incurring significant costs.

Therapies to Restore Consciousness in Patients with Severe Brain Injuries: A Gap Analysis and Future Directions

Background/Objective

For patients with disorders of consciousness (DoC) and their families, the search for new therapies has been a source of hope and frustration. Almost all clinical trials in patients with DoC have been limited by small sample sizes, lack of placebo groups, and use of heterogeneous outcome measures. As a result, few therapies have strong evidence to support their use; amantadine is the only therapy recommended by current clinical guidelines, specifically for patients with DoC caused by severe traumatic brain injury. To foster and advance development of consciousness-promoting therapies for patients with DoC, the Curing Coma Campaign convened a Coma Science Work Group to perform a gap analysis.

Methods

We consider five classes of therapies: (1) pharmacologic; (2) electromagnetic; (3) mechanical; (4) sensory; and (5) regenerative. For each class of therapy, we summarize the state of the science, identify gaps in knowledge, and suggest future directions for therapy development.

Results

Knowledge gaps in all five therapeutic classes can be attributed to the lack of: (1) a unifying conceptual framework for evaluating therapeutic mechanisms of action; (2) large-scale randomized controlled trials; and (3) pharmacodynamic biomarkers that measure subclinical therapeutic effects in early-phase trials. To address these gaps, we propose a precision medicine approach in which clinical trials selectively enroll patients based upon their physiological receptivity to targeted therapies, and therapeutic effects are measured by complementary behavioral, neuroimaging, and electrophysiologic endpoints.

Conclusions

This personalized approach can be realized through rigorous clinical trial design and international collaboration, both of which will be essential for advancing the development of new therapies and ultimately improving the lives of patients with DoC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01227-y.

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.

Recovery from disorders of consciousness: mechanisms, prognosis and emerging therapies

Substantial progress has been made over the past two decades in detecting, predicting and promoting recovery of consciousness in patients with disorders of consciousness (DoC) caused by severe brain injuries. Advanced neuroimaging and electrophysiological techniques have revealed new insights into the biological mechanisms underlying recovery of consciousness and have enabled the identification of preserved brain networks in patients who seem unresponsive, thus raising hope for more accurate diagnosis and prognosis. Emerging evidence suggests that covert consciousness, or cognitive motor dissociation (CMD), is present in up to 15-20% of patients with DoC and that detection of CMD in the intensive care unit can predict functional recovery at 1 year post injury. Although fundamental questions remain about which patients with DoC have the potential for recovery, novel pharmacological and electrophysiological therapies have shown the potential to reactivate injured neural networks and promote re-emergence of consciousness. In this Review, we focus on mechanisms of recovery from DoC in the acute and subacute-to-chronic stages, and we discuss recent progress in detecting and predicting recovery of consciousness. We also describe the developments in pharmacological and electrophysiological therapies that are creating new opportunities to improve the lives of patients with DoC.

Positive effects of music therapist's selected auditory stimulation on the autonomic nervous system of patients with disorder of consciousness: a randomized controlled trial

The current randomized controlled trial was performed at the China Rehabilitation Science Institute, China to test the hypothesis that musical auditory stimulation has positive effects on the autonomic nervous system of patients with disorder of consciousness. Although past studies have recommended that patients with disorder of consciousness listen to patient-preferred music, this practice is not universally accepted by researchers. Twenty patients with severe disorder of consciousness listened to either therapist-selected (n = 10, 6 males and 4 females; 43.33 ± 18.76 years old) or patient-preferred (n = 10, 5 males and 5 females, 48.83 ± 18.79 years old) musical therapy, 30 minutes/day, 5 times/week for 6 weeks. The results showed no obvious differences in heart rate variability-related parameters including heart rate, standard deviation of normal-to-normal R-R intervals, and the root-mean-square of successive heartbeat interval differences of successive heartbeat intervals between the two groups of patients. However, percentage of differences exceeding 50 ms between adjacent normal number of intervals, low-frequency power/high-frequency power, high-frequency power norm, low-frequency power norm, and total power were higher in patients receiving therapist-selected music than in patients receiving their own preferred music. In contrast, this relationship was reversed for the high-frequency power and very-low-frequency band. These results suggest that compared with preferred musical stimulation, therapist-selected musical stimulation resulted in higher interactive activity of the autonomic nervous system. Therefore, therapist-selected musical stimulation should be used to arouse the autonomic nervous system of patients with disorder of consciousness. This study was approved by the Institutional Ethics Committee of China Rehabilitation Research Center, China (approval No. 2018-022-1) on March 12, 2018 and registered with the Chinese Clinical Trial Registry (registration number ChiCTR1800017809) on August 15, 2018.

The effects of musical stimulation on the level of consciousness among patients with head trauma hospitalized in intensive care units: A randomized control trial

BACKGROUND

Improvement in the level of consciousness (LOC) is considered as an indicator of recovery among patients with head trauma (HT). musical stimulation is a simple noninvasive intervention with potential positive effects on LOC. This study evaluated the effects of musical stimulation on LOC among patients with HT hospitalized in intensive care unit.

METHODS

This clinical trial was conducted in 2018-2019. Fifty-four patients with HT were purposively and consecutively recruited from two trauma intensive care units in Qazvin, Iran, and randomly allocated to a control (n = 27) and an intervention (n = 27) group. Participants in the intervention group received fifteen-minute musical stimulation once daily for seven consecutive days using an MP3 player and a headphone for their counterparts, the headphones were silent for 15 min without receiving any musical stimulation once daily for seven consecutive days. A demographic questionnaire, the Glasgow Coma Scale, and the Richmond Agitation-Sedation Scale were used for data collection. LOC was daily assessed before and after each musical stimulation session. The SPSS program (v. 23.0) was used for data analysis at a significance level of less than 0.05.

FINDINGS

There were significant between-group differences respecting the posttest mean score of LOC in the third, fourth, fifth, sixth, and seventh days of the study intervention (P < 0.05)., the posttest mean score of LOC in the intervention group significantly increased in the intervention group (P < 0.0001), while it did not significantly change in the control group (P > 0.05).

CONCLUSION

musical stimulation is effective in significantly improving LOC among hospitalized patients with HT. Therefore, it can be used as a non-expensive noninvasive intervention to improve treatment outcomes among these patients.

Comparison of Single and Combined Effects of Nature Sounds and Foot Sole Reflexology Massage on the Level of Consciousness in Traumatic Comatose Patients: A Randomized Controlled Clinical Trial

Consciousness disturbances are the most common posttraumatic complications. The purpose of this study was to compare the single and combined effects of nature sounds and foot sole reflexology massage on level of consciousness in traumatic comatose patients. This randomized controlled clinical trial was conducted in 2 teaching hospitals in an urban area of Iran. Samples were 120 traumatic comatose patients who were randomly assigned into control, nature sounds, foot reflexology massage, and nature sounds plus foot sole reflexology massage groups. Patients in all groups received routine care. Interventions were performed twice a day for 2 weeks, each time for 30 minutes. The patients' level of consciousness was assessed using the Glasgow Coma Scale before, 1 week, and 2 weeks after the intervention. The groups had no significant differences in the mean scores of the consciousness level before, 1 week after, and the last day of the intervention. Also, there was a significant difference in the number of patients who regained full consciousness (P = .001) in the intervention groups compared with the control group. Significant differences in the number of days of consciousness were reported in at least one of the groups compared with other groups (P = .001). This difference was significant in the control group compared with the foot reflexology massage group (P = .032), as well as the nature sounds plus foot sole reflexology massage group (P = .001). Single or combined interventions can increase the level of consciousness in comatose patients and reduce the duration of coma.

Do Sensory Stimulation Programs Have an Impact on Consciousness Recovery?

Objectives: Considering sensory stimulation programs (SSP) as a treatment for disorders of consciousness is still debated today. Previous studies investigating its efficacy were affected by various biases among which small sample size and spontaneous recovery. In this study, treatment-related changes were assessed using time-series design in patients with disorders of consciousness (i.e., vegetative state-VS and minimally conscious state-MCS). Methods: A withdrawal design (ABAB) was used. During B phases, patients underwent a SSP (3 days a week, including auditory, visual, tactile, olfactory, and gustatory stimulation). The program was not applied during A phases. To assess behavioral changes, the Coma Recovery Scale-Revised (CRS-R) was administered by an independent rater on a weekly basis, across all phases. Each phase lasted 4 weeks. In a subset of patients, resting state functional magnetic resonance imaging (fMRI) data were collected at the end of each phase. Results: Twenty nine patients (48 ± 19 years old; 15 traumatic; 21 > a year post-injury; 11 VS and 18 MCS) were included in our study. Higher CRS-R total scores (medium effect size) as well as higher arousal and oromotor subscores were observed in the B phases (treatment) as compared to A phases (no treatment), in the MCS group but not in the VS group. In the three patients who underwent fMRI analyses, a modulation of metabolic activity related to treatment was observed in middle frontal gyrus, superior temporal gyrus as well as ventro-anterior thalamic nucleus. Conclusion: Our results suggest that SSP may not be sufficient to restore consciousness. SSP might nevertheless lead to improved behavioral responsiveness in MCS patients. Our results show higher CRS-R total scores when treatment is applied, and more exactly, increased arousal and oromotor functions.

Consciousness and Personhood in Medical Care

Current paradigms in Western medicine often fail to differentiate clearly between consciousness, responsiveness and personhood. The growing number of individuals who exist with sustainable cardiopulmonary systems but who are behaviorally unresponsive has prompted a cultural reconsideration of the relationship between the presence of consciousness and what it means to be a person. This article presents relevant clinical situations that exemplify the different modes in which personhood and consciousness can be associated and dissociated: disorders of consciousness, emergence from anesthesia, and neocortical death. We draw from these examples to call for a reflection on and possible revision of the dominant approach towards unresponsive persons to one in which care providers may work from the default assumption of the existence of an individual’s personhood as part of their therapeutic intervention. Behavior consistent with this assumption aligns with the principle of respect for persons in the face of the uncertainty created by the high rate of misdiagnosis of unconsciousness in unresponsive patients and is most consistent with a therapeutic approach to care considering evidence suggesting that attributing personhood may in fact evoke consciousness in these patients.

Disorders of consciousness after severe brain injury: therapeutic options

PURPOSE OF REVIEW

Very few options exist for patients who survive severe traumatic brain injury but fail to fully recover and develop a disorder of consciousness (e.g. vegetative state, minimally conscious state).

RECENT FINDINGS

Among pharmacological approaches, Amantadine has shown the ability to accelerate functional recovery. Although with very low frequency, Zolpidem has shown the ability to improve the level of consciousness transiently and, possibly, also in a sustained fashion. Among neuromodulatory approaches, transcranial direct current stimulation has been shown to transiently improve behavioral responsiveness, but mostly in minimally conscious patients. New evidence for thalamic deep brain stimulation calls into question its cost/benefit trade-off.

SUMMARY

The growing understanding of the biology of disorders of consciousness has led to a renaissance in the development of therapeutic interventions for patients with disorders of consciousness. High-quality evidence is emerging for pharmacological (i.e. Amantadine) and neurostimulatory (i.e. transcranial direct current stimulation) interventions, although further studies are needed to delineate preconditions, optimal dosages, and timing of administration. Other exciting new approaches (e.g. low intensity focused ultrasound) still await systematic assessment. A crucial future direction should be the use of neuroimaging measures of functional and structural impairment as a means of tailoring patient-specific interventions.

Effect of acoustic stimuli in patients with disorders of consciousness: a quantitative electroencephalography study

Auditory stimuli are proposed as beneficial neurorehabilitation methods in patients with disorders of consciousness. However, precise and accurate quantitative indices to estimate their potential effect remain scarce. Fourteen patients were recruited from the Neuro-Rehabilitation Unit of Hangzhou Hospital of Zhejiang Armed Police Corps of China. Altogether, there were seven cases of unresponsive wakefulness syndrome (five males and two females, aged 45.7 ± 16.8 years) and seven cases of minimally conscious state (six males and one female, aged 42.3 ± 20.8 years). Simultaneously, fourteen healthy controls (10 males and 4 females, aged 51.7 ± 9.7 years) also participated in this case-control experiment. Brain response to music, subjects’ own name, and noise was monitored by quantitative electroencephalography (QEEG) in the resting state and with acoustic stimulation. Predictive QEEG values in various brain regions were investigated. Our results show that cerebral activation was high in subjects stimulated by their own name, especially in the temporal lobe in patients with disorders of consciousness, and the frontal lobe in the control group. Further, during resting and stimulation, QEEG index (δ + θ/α + β ratio) negatively correlated with the Coma Recovery Scale-Revised score in traumatic disorders of consciousness patients. Hence, we speculate that a subject's own name might be an effective awakening therapy for patients with disorders of consciousness. Moreover, QEEG index in specific stimulation states may be used as a prognostic indicator for disorders of consciousness patients (sensitivity, 75%; specificity, 50%). This clinical study has been registered at ClinicalTrials.gov (identifier: NCT03385291).