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.

Animal presence modulates frontal brain activity of patients in a minimally conscious state: A pilot study.

Integrating animals into therapy is applied increasingly in patients in a minimally conscious state (MCS). This pilot study investigates the effect of animal presence on frontal brain activity in MCS patients compared to healthy subjects. O2HB, HHb and tHb of two MCS patients and two healthy adults was measured in frontal cortex using functional near-infrared spectroscopy during three sessions with a live animal and three sessions with a mechanical toy animal present. Each session had five phases: (1) baseline, (2) watching animal, (3) passive contact, (4) active contact, (5) neutral. Data were descriptively analysed. All participants showed the largest hemodynamic response during direct contact with the live or toy animal compared to "baseline" and "watching." During active contact, three of the four participants showed a stronger response when stroking the live compared to the toy animal. All participants showed an inverted signal with higher HHb than O2Hb concentrations while stroking the live or toy animal. Animal contact leads to a neurovascular reaction in both MCS patients and healthy subjects, indicating elevated neural activity in the frontal cortex. We conclude that while a toy animal can elicit attention processes, active contact to a living animal is combined with emotional processes.

Development and reliability and validity testing of the assessment scale for patients with persistent vegetative state or minimally conscious state discharge from the anesthesia recovery room / 中国实用护理杂志

Objective:To develop and test the reliability and validity of the assessment scale for patients with persistent vegetative state (PVS) or minimally conscious state (MCS) discharge from the anesthesia recovery room after operation.Methods:From September 2018 to October 2020, three dimensions and 17 item pools were determined through literature review and discussion among the project members. Two rounds of expert consultation were conducted to determine the respiratory (R), circulatory (C), oxygenation (O), bispectral index (B) and neuromuscular monitoring (N) scale (RCOBN scale), the reliability and validity were tested. 87 patients with PVS or MCS after operation Affiliated Sichuan Bayi Rehabilitation Center of Chengdu University of Traditional Chinese Medicine were selected to verify the effectiveness.Results:In the first round, 23 questionnaires were distributed. The total score of experts was 50 ± 3, F=9.24, CV were 0.00-0.43. The Cronbach α coefficient of each dimension was 0.782-0.846, and the Cronbach α coefficient of the total scale was 0.813. In the second round, 10 questionnaires were distributed. The item-level content validity index was 0.7-1.0, the probability of random consistency ( Pc) was 0.001-0.117, the adjusted kappa value ( k*) was 0.567-1.000, and the sum of the index scores corresponding to k* > 0.74 was 8. The scale-level content validity index of the overall consistency was 0.87. The ratio of patients transferred out of PACU by two rounds of evaluation method was 100 : 96.55, and the difference was not statistically significant ( χ2=3.05, P>0.05). The time of the first round of assessment was significantly longer than that of the second round, which were (197 ± 52) s and (58 ± 14) s respectively. The difference was statistically significant ( t=26.52, P < 0.01). Conclusions:The RCOBN scale has high reliability and validity. It can be used as an assessment scale for patients with PVS or MCS to transfer out of PACU after surgery, and those with a total score of 8 can be transferred out of PACU.

An action-observation/motor-imagery based approach to differentiate disorders of consciousness: what is beneath the tip of the iceberg?

BACKGROUND: The evaluation of motor imagery in persons with prolonged Disorders of Consciousness (pDOC) is a practical approach to differentiate between patients with Minimally Conscious State (MCS) and Unresponsive Wakefulness Syndrome (UWS) and to identify residual awareness even in individuals with UWS. Investigating the influence of motor observation on motor imagery could be helpful in this regard. OBJECTIVE: In order to corroborate the clinical diagnosis and identify misdiagnosed individuals, we used EEG recordings, to assess the influence of the low-level perceptual and motoric mechanisms on motor observation on motor imagery, taking into account the role of the high-level cognitive mechanisms in patients with pDOC. METHODS: We assessed the influence of motor observation of walking in first-person or third-person view (by a video provision) on motor imagery of walking in the first-person view on the visual N190 (expression of motor observation processing), the readiness potential (RP) (expressing motor preparation), and the P3 component (high-level cognitive processes) in a sample of 10 persons with MCS, 10 with UWS, and 10 healthy controls (CG). Specifically, the video showed a first-view or third-view walk down the street while the participants were asked to imagine a first-view walking down the street. RESULTS: CG showed greater N190 response (low-level sensorimotor processing) in the non-matching than in the matching condition. Conversely, the P3 and RP responses (high-level sensorimotor processing) were greater in the matching than in the non-matching condition. Remarkably, 6 out of 10 patients with MCS showed the preservation of both high- and low-level sensorimotor processing. One UWS patient showed responses similar to those six patients, suggesting a preservation of cognitively-mediated sensorimotor processing despite a detrimental motor preparation process. The remaining patients with MCS did not show diversified EEG responses, suggesting limited cognitive functioning. CONCLUSIONS: Our study suggests that identifying the low-level visual and high-level motor preparation processes in response to a simple influence of motor observation of motor imagery tasks potentially supports the clinical differential diagnosis of with MCS and UWS. This might help identify UWS patients which were misdiagnosed and who deserve more sophisticated diagnoses.

Communication Abilities of Children with DoC after Severe Brain Injury in ICF Frames.

INTRODUCTION: The ability to communicate is one of the fundamental factors underlying human relationships. Severe brain damage and disorders of consciousness may indispose a person to participate in everyday social and family life. In spite of this fact, however, the issue of holistic approach to communication in the context of severe traumatic brain injury is still not well explained and described. The goal of this article is to introduce a profile of nonverbal behavior of children with disorders of consciousness. MATERIALS AND METHODS: The study included 30 children with minimal conscious state after severe brain trauma, aged between 7 and 16 years old. Research was conducted using the Coma Recovery Scale-Revised and the Bykova-Lukyanov Scale of Communication Activity. RESULTS: Significant differences in communication level between investigated groups were demonstrated, both in Body Function (F = 9.184; p < 0.001) and Activity and Participation (F = 13.100; p < 0.001). CONCLUSIONS: It is possible to map and classify communication ability of children with minimal conscious state by using International Classification of Functioning, Disability and Health (ICF) protocol and the Bykova-Lukyanov Scale of Communication Activity, with specific consideration of Activities and Participation factors. This approach reveals differences in communication and disability level between children with minimal conscious state plus (MSC+) and minimal conscious state minus (MSC-).

The treatment of integrated traditional Chinese and Western medicine to cure severe immune thrombocytopenia in a patient in a minimally conscious state: a case report.

Immune thrombocytopenia is a common complication in patients in a minimally conscious state (MCS). MCS patients are prone to pulmonary infection for the reasons of long-term bed rest and tracheotomy etc., which leads to frequent immune thrombocytopenia. At present, there is no specific treatment for immune thrombocytopenia. Moreover, the cost of routine treatment is high, and clinicians need to consider different drug combinations, side effects, and the risk of drug dependence when selecting treatments. Here, we report a case of a patient in a MCS who developed immune thrombocytopenia after tracheotomy and long-term bed laying in October 2015. The patient's platelet count declined continuously, and by December 2015, she was in a critical condition, with a platelet count of less than 20×109/L. The patient firstly received routine treatment, however, this could only temporarily prevent the drop in platelets. Following a series of explorations, the patient was treated with a combination of traditional Chinese and Western medicine, which included treatment and preventive measures. For treatment, the patient was given roxithromycin dispersible administration tablets and a self-made preparation of peanut red skin, which could quickly cure the immune thrombocytopenia. Preventive measures included the addition of ursodeoxycholic acid capsules, silybin capsules, and a traditional Chinese medicine preparation. As shown by laboratory examination results, the patient's platelet count has stayed around a normal level since March 2016, and she now has normal liver and kidney function. This outcome evidence that combined traditional Chinese and Western medicine could effectively cure immune thrombocytopenia and prevent its recurrence. Moreover, the cost of the treatment was lower and there were fewer side effects than routine treatment, and at the same time, the method of treatment was simple and convenient. Our practical experience may provide a valuable clue for the treatment of immune thrombocytopenia.

Covert Cognition in Disorders of Consciousness: A Meta-Analysis.

Covert cognition in patients with disorders of consciousness represents a real diagnostic conundrum for clinicians. In this meta-analysis, our main objective was to identify clinical and demographic variables that are more likely to be associated with responding to an active paradigm. Among 2018 citations found on PubMed, 60 observational studies were found relevant. Based on the QUADAS-2, 49 studies were considered. Data from 25 publications were extracted and included in the meta-analysis. Most of these studies used electrophysiology as well as counting tasks or mental imagery. According to our statistical analysis, patients clinically diagnosed as being in a vegetative state and in a minimally conscious state minus (MCS-) show similar likelihood in responding to active paradigm and responders are most likely suffering from a traumatic brain injury. In the future, multi-centric studies should be performed in order to increase sample size, with similar methodologies and include structural and functional neuroimaging in order to identify cerebral markers related to such a challenging diagnosis.

Towards New Diagnostic Approaches in Disorders of Consciousness: A Proof of Concept Study on the Promising Use of Imagery Visuomotor Task.

BACKGROUND: advanced paraclinical approaches using functional neuroimaging and electroencephalography (EEG) allow identifying patients who are covertly aware despite being diagnosed as unresponsive wakefulness syndrome (UWS). Bedside detection of covert awareness employing motor imagery tasks (MI), which is a universally accepted clinical indicator of awareness in the absence of overt behavior, may miss some of these patients, as they could still have a certain level of awareness. We aimed at assessing covert awareness in patients with UWS using a visuomotor-guided motor imagery task (VMI) during EEG recording. METHODS: nine patients in a minimally conscious state (MCS), 11 patients in a UWS, and 15 healthy individuals (control group-CG) were provided with an VMI (imagine dancing while watching a group dance video to command), a simple-MI (imagine squeezing their right hand to command), and an advanced-MI (imagine dancing without watching a group dance video to command) to detect command-following. We analyzed the command-specific EEG responses (event-related synchronization/desynchronization-ERS/ERD) of each patient, assessing whether these responses were appropriate, consistent, and statistically similar to those elicited in the CG, as reliable markers of motor imagery. RESULTS: All patients in MCS, all healthy individuals and one patient in UWS repeatedly and reliably generated appropriate EEG responses to distinct commands of motor imagery with a classification accuracy of 60-80%. CONCLUSIONS: VMI outperformed significantly MI tasks. Therefore, patients in UWS may be still misdiagnosed despite a rigorous clinical assessment and an appropriate MI assessment. It is thus possible to suggest that motor imagery tasks should be delivered to patients with chronic disorders of consciousness in visuomotor-aided modality (also in the rehabilitation setting) to greatly entrain patient's participation. In this regard, the EEG approach we described has the clear advantage of being cheap, portable, widely available, and objective. It may be thus considered as, at least, a screening tool to identify the patients who deserve further, advanced paraclinical approaches.

Is Animal-Assisted Therapy for Minimally Conscious State Beneficial? A Case Study.

OBJECTIVE: The goal of this single case study was to qualitatively investigate the effects of animal-assisted therapy in a patient in a minimally conscious state. METHOD: We present a 28-year-old female patient in a minimally conscious state following polytrauma after a sports accident leading to cerebral fat embolism causing multiple CNS ischemic lesions. She received eight animal-assisted therapy sessions and eight paralleled control therapy sessions over 4 weeks. We investigated the reactions of the patient during these sessions via qualitative behavior analysis. RESULTS: The patient showed a broader variability and higher quality of behavior during animal-assisted therapy compared to control therapy sessions. CONCLUSION: The observed behavioral changes showed higher arousal and increased awareness in the presence of an animal. The presented case supports the assumption that animal-assisted therapy can be a beneficial treatment approach for patients in a minimally conscious state.

Presynaptic dopamine deficit in minimally conscious state patients following traumatic brain injury.

Dopaminergic stimulation has been proposed as a treatment strategy for post-traumatic brain injured patients in minimally conscious state based on a clinical trial using amantadine, a weak dopamine transporter blocker. However, a specific contribution of dopaminergic neuromodulation in minimally conscious state is undemonstrated. In a phase 0 clinical trial, we evaluated 13 normal volunteers and seven post-traumatic minimally conscious state patients using 11C-raclopride PET to estimate dopamine 2-like receptors occupancy in the striatum and central thalamus before and after dopamine transporter blockade with dextroamphetamine. If a presynaptic deficit was observed, a third and a fourth 11C-raclopride PET were acquired to evaluate changes in dopamine release induced by l-DOPA and l-DOPA+dextroamphetamine. Permutation analysis showed a significant reduction of dopamine release in patients, demonstrating a presynaptic deficit in the striatum and central thalamus that could not be reversed by blocking the dopamine transporter. However, administration of the dopamine precursor l-DOPA reversed the presynaptic deficit by restoring the biosynthesis of dopamine from both ventral tegmentum and substantia nigra. The advantages of alternative pharmacodynamic approaches in post-traumatic minimally conscious state patients should be tested in clinical trials, as patients currently refractory to amantadine might benefit from them.

Event-related potentials in the odd-ball paradigm and behavioral scales for the assessment of children and adolescents with disorders of consciousness: A proof of concept study.

OBJECTIVE: Quantification of signatures of conscious processing in children with disorders of consciousness (DoC) using odd-ball paradigms in multiple modalities. METHOD: We review the diagnostic approaches available in the field, from clinical scales to neuroimaging methods, and concentrate upon measures derived from electroencephalographic event related potentials. RESULTS: Evoked potentials were recorded in five procedures, encompassing visual, auditory and tactile modalities, from ten pediatric DoC patients-six in a minimally conscious state (MCS), three in unresponsive wakefulness syndrome (UWS) and one who emerged from MCS (eMCS)-and the control group of 10 healthy children. In almost all the eMCS and MCS patients, higher amplitude of P300 was observed and the effect was statistically significant in at least one out of the five performed procedures. Additionally, signs of conscious information processing were detected in one UWS patient. CONCLUSION: The presented results provide a proof of concept for the possibility of applying ERP-derived electrophysiological measures as an aid in the assessment of children and adolescents in DoC.

Cortical Response to the Natural Speech Envelope Correlates with Neuroimaging Evidence of Cognition in Severe Brain Injury.

Recent studies identify severely brain-injured patients with limited or no behavioral responses who successfully perform functional magnetic resonance imaging (fMRI) or electroencephalogram (EEG) mental imagery tasks [1-5]. Such tasks are cognitively demanding [1]; accordingly, recent studies support that fMRI command following in brain-injured patients associates with preserved cerebral metabolism and preserved sleep-wake EEG [5, 6]. We investigated the use of an EEG response that tracks the natural speech envelope (NSE) of spoken language [7-22] in healthy controls and brain-injured patients (vegetative state to emergence from minimally conscious state). As audition is typically preserved after brain injury, auditory paradigms may be preferred in searching for covert cognitive function [23-25]. NSE measures are obtained by cross-correlating EEG with the NSE. We compared NSE latencies and amplitudes with and without consideration of fMRI assessments. NSE latencies showed significant and progressive delay across diagnostic categories. Patients who could carry out fMRI-based mental imagery tasks showed no statistically significant difference in NSE latencies relative to healthy controls; this subgroup included patients without behavioral command following. The NSE may stratify patients with severe brain injuries and identify those patients demonstrating "cognitive motor dissociation" (CMD) [26] who show only covert evidence of command following utilizing neuroimaging or electrophysiological methods that demand high levels of cognitive function. Thus, the NSE is a passive measure that may provide a useful screening tool to improve detection of covert cognition with fMRI or other methods and improve stratification of patients with disorders of consciousness in research studies.

Deep brain stimulation for the treatment of disorders of consciousness and cognition in traumatic brain injury patients: a review.

Traumatic brain injury (TBI) is a looming epidemic, growing most rapidly in the elderly population. Some of the most devastating sequelae of TBI are related to depressed levels of consciousness (e.g., coma, minimally conscious state) or deficits in executive function. To date, pharmacological and rehabilitative therapies to treat these sequelae are limited. Deep brain stimulation (DBS) has been used to treat a number of pathologies, including Parkinson disease, essential tremor, and epilepsy. Animal and clinical research shows that targets addressing depressed levels of consciousness include components of the ascending reticular activating system and areas of the thalamus. Targets for improving executive function are more varied and include areas that modulate attention and memory, such as the frontal and prefrontal cortex, fornix, nucleus accumbens, internal capsule, thalamus, and some brainstem nuclei. The authors review the literature addressing the use of DBS to treat higher-order cognitive dysfunction and disorders of consciousness in TBI patients, while also offering suggestions on directions for future research.

Spatial Properties of Mismatch Negativity in Patients with Disorders of Consciousness.

In recent decades, event-related potentials have been used for the clinical electrophysiological assessment of patients with disorders of consciousness (DOCs). In this paper, an oddball paradigm with two types of frequency-deviant stimulus (standard stimuli were pure tones of 1000 Hz; small deviant stimuli were pure tones of 1050 Hz; large deviant stimuli were pure tones of 1200 Hz) was applied to elicit mismatch negativity (MMN) in 30 patients with DOCs diagnosed using the JFK Coma Recovery Scale-Revised (CRS-R). The results showed that the peak amplitudes of MMN elicited by both large and small deviant stimuli were significantly different from baseline. In terms of the spatial properties of MMN, a significant interaction effect between conditions (small and large deviant stimuli) and electrode nodes was centered at the frontocentral area. Furthermore, correlation coefficients were calculated between MMN amplitudes and CRS-R scores for each electrode among all participants to generate topographic maps. Meanwhile, a significant negative correlation between the MMN amplitudes elicited by large deviant stimuli and the CRS-R scores was also found at the frontocentral area. In consequence, our results combine the above spatial properties of MMN in patients with DOCs, and provide a more precise location (frontocentral area) at which to evaluate the correlation between clinical electrophysiological assessment and the level of consciousness.

Music interventions in disorders of consciousness (DOC) - a systematic review.

OBJECTIVES: The effects of music interventions including active and receptive music therapy for people living with neurogenic disorders of consciousness (DOC) have been subject to empirical studies in the past. The aim of this systematic review was to find and analyse the current research about the effects of musical interventions on people with DOC. METHODS: For this purpose, studies with music interventions and patients with DOC from the year 1900 to 2017 were searched in English, German, and French in different databases. Risk-of-bias-analyses were conducted for each study that fulfilled the inclusion criteria. RESULTS: Twenty-two quantitative studies (three randomised controlled trials with more than 10 participants) were found eligible for review. They include a total of 329 participants living with either coma, unresponsive wakefulness syndrome, or minimally conscious state. Music interventions were associated with favourable behavioural and physiological responses in several studies, but methodological quality and outcomes were heterogeneous. CONCLUSIONS: More studies with a larger number of participants are needed as well as a consensus on key characteristics of effective short-term and long-term music interventions for DOC.

Spatial Properties of Mismatch Negativity in Patients with Disorders of Consciousness / 神经科学通报·英文版

In recent decades, event-related potentials have been used for the clinical electrophysiological assessment of patients with disorders of consciousness (DOCs). In this paper, an oddball paradigm with two types of frequency-deviant stimulus (standard stimuli were pure tones of 1000 Hz; small deviant stimuli were pure tones of 1050 Hz; large deviant stimuli were pure tones of 1200 Hz) was applied to elicit mismatch negativity (MMN) in 30 patients with DOCs diagnosed using the JFK Coma Recovery Scale-Revised (CRS-R). The results showed that the peak amplitudes of MMN elicited by both large and small deviant stimuli were significantly different from baseline. In terms of the spatial properties of MMN, a significant interaction effect between conditions (small and large deviant stimuli) and electrode nodes was centered at the frontocentral area. Furthermore, correlation coefficients were calculated between MMN amplitudes and CRS-R scores for each electrode among all participants to generate topographic maps. Meanwhile, a significant negative correlation between the MMN amplitudes elicited by large deviant stimuli and the CRS-R scores was also found at the frontocentral area. In consequence, our results combine the above spatial properties of MMN in patients with DOCs, and provide a more precise location (frontocentral area) at which to evaluate the correlation between clinical electrophysiological assessment and the level of consciousness.

Research Progress of Music Therapy for Patients with Disorders of Consciousness after Brain Injury (review) / 中国康复理论与实践

@#The recovery of disorders of consciousness after brain injury is very difficult, music therapy is one of the important ways to promote the awakening. The effects of music therapy are various among individuals, the vegetative state and the minimally conscious state, and the pieces of music. The default mode network is one of the most important networks to maintain awareness, which many other networks participate in. The brain regions affected by music involve in many networks, including hearing, cognition, emotion, and so on.

Reducing the rate of misdiagnosis in patients with chronic disorders of consciousness: Is there a place for audiovisual stimulation?

BACKGROUND: The patients with chronic Disorders of Consciousness (DoC) mostly present with extremely challenging differential diagnosis. The advanced analysis of electroencephalographic (EEG) signals induced by brain stimulation paradigms may provide an appropriate approach to differentiate patients with DoC, besides the clinical assessment. OBJECTIVE: This study was performed with an objective of identifying residual brain network perturbations following an innovative, non-invasive audiovisual stimulation protocol, which could be related to behavioral responsiveness in patients with DoC. METHODS: The study comprised of ten healthy controls (HC), seven patients with Minimally Conscious State (MCS), and nine patients with Unresponsive Wakefulness Syndrome (UWS). Both synchronous as well as asynchronous transorbital and transauricolar alternating current were employed as stimuli and their effects were measured in terms of functional and effective connectivity. RESULTS: A more noticeable deterioration of long range connectivity patterns were found in patients with UWS than in those with MCS, with an exception of two patients with UWS, who showed connectivity values similar to those of MCS patients. CONCLUSION: The audiovisual stimulation paradigm used in the present study may be employed as a supportive bedside tool for improving the differential diagnosis in patients with DoC.

The historical origins of the vegetative state: Received wisdom and the utility of the text.

The persistent vegetative state (PVS) is one of the most iconic and misunderstood phrases in clinical neuroscience. Coined as a diagnostic category by Scottish neurosurgeon Bryan Jennett and American neurologist Fred Plum in 1972, the phrase "vegetative" first appeared in Aristotle's treatise On the Soul (circa mid-fourth century BCE). Aristotle influenced neuroscientists of the nineteenth and early-twentieth centuries, Xavier Bichat and Walter Timme, and informed their conceptions of the vegetative nervous system. Plum credits Bichat and Timme in his use of the phrase, thus putting the ancient and modern in dialogue. In addition to exploring Aristotle's definition of the "vegetative" in the original Greek, we put Aristotle in conversation with his contemporaries-Plato and the Hippocratics-to better apprehend theories of mind and consciousness in antiquity. Utilizing the discipline of reception studies in classics scholarship, we demonstrate the importance of etymology and historical origin when considering modern medical nosology.

Behavioural improvement in a minimally conscious state after caloric vestibular stimulation: evidence from two single case studies.

OBJECTIVE: To investigate whether caloric vestibular stimulation, a non-invasive form of neuro-modulation, alters the level of awareness in people residing in a minimally conscious state. DESIGN: Single-case ( n = 2), prospective, controlled (ABAB) efficacy study. SETTING: Tertiary, neuro-rehabilitation inpatient ward within a university hospital. PARTICIPANTS: Two individuals in a minimally conscious state. INTERVENTION: Left ear caloric vestibular stimulation was performed in two four/five-week blocks interleaved with two four/five-week blocks of sham stimulation. Session duration and frequency gradually increased within each block from once per day for 10 minutes (Week 1) to once per day for 20 minutes (Week 2) to 20 minutes twice per day in the remaining weeks. MEASURES: Wessex Head Injury Matrix, JFK Coma Recovery Scale - Revised. RESULTS: Both participants' Wessex Head Injury Matrix scores indicated a transition from involuntary (i.e. mechanical vocalization) to voluntary (i.e. gesture making, selective responses to family members) behaviour that was time-locked to the onset of active stimulation. In one participant, this improvement persisted for at least four weeks after active stimulation, while in the other it diminished two weeks after stimulation. Allied, although less dramatic, changes were seen on the arousal and auditory subscales of the JFK Coma Recovery Scale - Revised. CONCLUSION: The data provide the first evidence that vestibular stimulation may help improve outcome in a low awareness state, although further studies are needed to replicate effect and determine longer-term benefit.