Case report: Tongdu Xingshen acupuncture for a patient with persistent vegetative state after herpes simplex virus encephalitis.

Introduction: A persistent vegetative state (PVS) can be caused by traumatic or non-traumatic brain injury. PVS is a complex clinical condition with numerous complications. Nursing care, medical treatment, and comprehensive rehabilitation are necessary to improve the outcomes of PVS. However, the prognosis remains unsatisfactory. Acupuncture therapy has been used as a rehabilitation strategy to treat patients with PVS in China, showing better results in the recovery of consciousness, intellectual capability, and motor function. Case description: We present the case of a 4-month-long PVS after herpes simplex virus encephalitis (HSVE) in a 3.5-year-old boy who underwent Tongdu Xingshen acupuncture integrated with Western medicine and rehabilitation. The patient regained consciousness post-treatment. His intelligence and motor function gradually recovered after seven treatment sessions. Conclusion: Tongdu Xingshen acupuncture is a potential complementary therapy to optimize clinical outcomes in PVS.

Effects of acupuncture on nutritional status in patients in a persistent vegetative state: a prospective randomized controlled study / 针灸推拿医学（英文版）

Objective: To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state. Methods: A prospective randomized controlled trial was designed. A total of 66 patients in a persistent vegetative state were randomized into a control group and an observation group, with 33 cases in each group. The control group was given conventional treatment plus enteral nutrition support. The observation group was treated with additional Tiao Shen Jian Pi acupuncture therapy (acupuncture for spirit-regulating and spleen-invigorating) based on the same interventions in the control group. Both groups were treated for 8 weeks. The levels of total protein (TP), prealbumin (PA), albumin (Alb), and hemoglobin (Hb) were measured before and after treatment. The upper arm circumference and skinfold thickness of triceps brachii were measured. And the intestinal flora and fecal short-chain fatty acids contents were determined.Results: After treatment, the levels of TP, PA, Alb, and Hb in the control group were decreased (P<0.05), while in the observation group, compared with those before treatment, the levels of TP, PA, Alb, and Hb had no statistical differences (P>0.05), and the levels were all higher than those in the control group (P<0.05). The upper arm circumference and skinfold thickness of triceps brachii in both groups decreased (P<0.05), and the values of these two items in the observation group were higher than those in the control group (P<0.05). In the control group, the contents of Bifidobacterium and Lactobacillus in feces decreased (P<0.05), and the content of Enterococcus increased (P<0.05). In the observation group, the contents of Bifidobacterium and Lactobacillus in feces increased (P<0.05), and the content of Enterococcus decreased (P<0.05). The differences between the two groups were statistically significant (P<0.05). In the control group, the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces decreased (P<0.05). In the observation group, the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces increased (P<0.05) and were all higher than those in the control group (P<0.05). Conclusion: Acupuncture can improve nutrition-related blood indicators in patients in a persistent vegetative state and delay the decrease of upper arm circumference and skinfold thickness of triceps brachii, which may be related to the regulation of intestinal flora and fecal short-chain fatty acids contents.

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.

[Xingnao Kaiqiao acupuncture on promoting wake-up of vegetative state after brain injury].

OBJECTIVE: To observe the clinical effect of Xingnao Kaiqiao acupuncture on promoting wake-up of vegetative state after brain injury on the basis of comprehensive rehabilitation training. METHODS: A total of 100 patients with vegetative state after brain injury were randomly divided into an observation group (50 cases, 2 cases dropped off) and a control group (50 cases). Both groups were treated with routine clinical treatment. The patients in the control group were treated with rehabilitation and hyperbaric oxygen; on the basis of the control group treatment, the patients in the observation group were treated with Xingnao Kaiqiao acupuncture at Neiguan (PC 6), Shuigou (GV 26), Sanyinjiao (SP 6), Chize (LU 5), Weizhong (BL 40), Hegu (LI 4) and Taichong (LR 3). The acupuncture was given once a day, 5 days per week, for continuous 30 days. The Glasgow coma scale (GCS) and coma recovery scale-revised (CRS-R) scores were observed before treatment and 10, 20 and 30 days into treatment. The wake-up rate of the two groups was compared after treatment. RESULTS: On 10, 20 and 30 days into treatment, the GCS and CRS-R scores in the two groups were higher than those before treatment (P<0.01), and the scores in the observation group were higher than those in the control group (P<0.01). After treatment, the wake-up rate was 16.7% (8/48) in the observation group, which was higher than 12.0% (6/50) in the control group (P<0.01). CONCLUSION: On the basis of comprehensive rehabilitation and wake-up promotion therapy, the Xingnao Kaiqiao acupuncture could promote the recovery of consciousness level in patients with vegetative state after brain injury.

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.

[From Vegetative State to Participation: Amantadine As a Trigger of the Rehabilitation Program]. / Do Estado Vegetativo à Participação: A Amantadina Como Potenciadora do Programa de Reabilitação.

The use of amantadine in clinical practice still seems limited, despite its increasing evidence in the emergence of vegetative state after traumatic brain injury. We describe the case of an adolescent with severe traumatic brain injury after being run over by a car. After four months of hospitalization in a Central Hospital where he remained in a vegetative state, he was transferred to a Rehabilitation Center. He underwent a comprehensive rehabilitation program with physiotherapy, occupational therapy and speech therapy, including multisensory stimulation and intervention in the surrounding environment. He started amantadine, 50 mg/day, titrated up to 200 mg/day, with significant clinical and functional improvements, and emerged from vegetative state to minimally conscious state at week three and recovered consciousness at the sixth week of amantadine, maintaining progressive improvement, even after drug suspension. The case described underlines the importance of a holistic intervention and corroborates the literature in demonstrating the efficacy and safety of amantadine in the emergence from vegetative state.

A utilização da amantadina na prática clínica ainda parece pouco difundida, apesar da evidência crescente na emergência de alterações do estado de consciência após traumatismo cranioencefálico. Descrevemos o caso de um adolescente com traumatismo cranioencefálico grave por atropelamento. Após quatro meses de internamento num hospital central onde se manteve em estado vegetativo foi transferido para um centro de reabilitação. Iniciou um programa de reabilitação integral liderado por equipa médica, incluindo estimulação multissensorial e intervenção no meio envolvente. Iniciou amantadina, 50 mg/dia, titulada até 200 mg/dia, verificando-se melhoria clínica e funcional significativas, com emergência para estado de consciência mínima à terceira semana e recuperação da consciência à sexta semana de amantadina. Manteve melhoria progressiva mesmo após suspensão do fármaco. O caso descrito salienta a importância da intervenção holística e corrobora a literatura ao demonstrar a eficácia e segurança da amantadina na emergência do estado vegetativo.

[Midnight-noon ebb-flow acupuncture combined with rehabilitation therapy for severe craniocerebral trauma patients with vegetative state: a randomized controlled trial].

OBJECTIVE: To compare the clinical therapeutic effect of midnight-noon ebb-flow acupuncture combined with rehabilitation therapy and simple rehabilitation therapy in severe craniocerebral trauma patients with vegetative state. METHODS: A total of 100 patients were randomized into an observation group and a control group, 50 cases in each one. Basic treatment of medication, hyperbaric oxygen therapy and specialized nursing were given in both groups. In the control group, rehabilitation therapy was adopted for 30 min each time, once a day. On the basis of the control group, midnight-noon ebb-flow acupuncture was applied in the observation group, the needles were sustained for 30 min, once a day, 5 times a week. The treatment was for 30 days in both groups. Before treatment and after 10, 20, 30 days of treatment, scores of Glasgow coma scale (GCS) and coma recovery scale-revised (CRS-R) were observed, and the conscious rate after treatment was calculated in both groups. RESULTS: Compared before treatment, the GCS and CRS-R scores after 10, 20, 30 days of treatment were increased in both groups (P<0.01), and the scores in the observation group were superior to those in the control group (P<0.01). After treatment, the conscious rate was 20.0% (10/50) in the observation group, which was superior to 12.0% (6/50) in the control group (P<0.01). CONCLUSION: Midnight-noon ebb-flow acupuncture combined with rehabilitation therapy can effectively treat the severe craniocerebral trauma patients with vegetative state, improve the consciousness level, and have superior therapeutic effect compared with simple rehabilitation therapy.

[Xiao's "xingnaofusu" needling for regaining consciousness and the influence on width of the third ventricle in patients with persistent vegetative state].

OBJECTIVE: To observe the influence of Xiao's "xingnaofusu" needling (the technique for resuscitation) on regaining consciousness in the patients with persistent vegetative state (PVS). METHODS: A total of 50 patients of PVS were randomized into an observation group and a control group, 25 cases in each. The patients in the control group were treated by the routine western medicine, and those in the observation group treated by Xiao's "xingnaofusu" needling and routine western medicine. Baihui (GV20), Dingshen (Extra) to Shangen (Extra) (penetrating technique), Fengchi (GB20) to GB20 (penetrating technique), Neiguan (PC6) to Waiguan (TE5) (penetrating technique), Hegu (LI4) to Laogong (HT8) (penetrating technique) and Taichong (LR3) to Yongquan (KI1) (penetrating technique) were selected. The treatment was given once a day, 10 days as one treatment course, 3 courses in total. The coma recovery scale-revised (CRS-R) score, the modified Ashworth scale (MAS) score and the Glasgow coma scale (GCS) were separately compared before and after the treatment. Additionally, CT scanning was adopted to measure the width of the third ventricle before and after treatment so as to evaluate the clinical therapeutic effect. RESULTS: After the treatment, the CRS-R and GCS scores in the two groups increased remarkably, and MAS score reduced obviously as compared with that before the treatment(P<0.05); and the CRS-R and GCS scores were higher, and MAS score lower in the observation group than those in the control group(P<0.05). Compared with the control group, the width of the third ventricle reduced obviously in the observation group after the treatment(P<0.05). At the end of the treatment courses, the effective rate was 79.2%(19/24)in the observation group and was 47.8%(11/23) in the control group. The effective rate of the observation group was obviously higher than that of the control group (P<0.05). CONCLUSION: Xiao's "xingnaofusu" needling can remarkably improve the central nerve function, promote the recovery of brain function and the motor function of limbs, reduce the width of the third ventricle and improve the clinical therapeutic effect of regaining consciousness in the patients with PVS.

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.

The influence of moxibustion on the bone metabolism of persistent vegetative state patients / 国际中医中药杂志

Abjective To observe the influence of moxibustion on the bone metabolism of persistent vegetative state patients. Methods A total of 60 patients with persistent vegetative state were divided randomly into the treatment group and control group, 30 in each. Both groups were treated with routine therapy, and the patients used moxibustion on the acupoints of zhongwan, xiawan , qihai and guanyuan. The treatment lasted 12 weeks. The changes of T-lymphoctyte subgroups, serum immunoglobulin were tested and compared before and 12th week after treatment. Result After 12th week treatment, the BMD of distal radius (0.563 ± 0.205 g/cm2 vs. 0.451 ± 0.114 g/cm2, t=2.615), the second lumbar vertebra (0.596 ± 0.108 g/cm2 vs. 0.533 ± 0.127 g/cm2, t=2.069) and the femoral neck (0.567 ± 0.214g/cm2 to 0.463 ± 0.163g/cm2, t=2.117) in the treatment group were significantly higher than those in the control group (Ps＜0.05). The PTH (6.41 ± 0.56 pmol/L vs. 6.72 ± 0.42 pmol/L, t=0.018), CT (217.48 ± 57.35 ng/L vs. 228.46 ± 52.44ng/L, t=0.012) and BGP (9.16 ± 1.57 g/L vs. 10.37 ± 2.37 g/L, t=0.023) in the treatment group were significantly higher than those in the control group (Ps＜0.05). Conclusions Moxibustion can help to treat the bone metabolism of persistent vegetative state patients and prevent the osteoporosis.

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.

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.

Familiar auditory sensory training in chronic traumatic brain injury: a case study.

PURPOSE: The evaluation and treatment for patients with prolonged periods of seriously impaired consciousness following traumatic brain injury (TBI), such as a vegetative or minimally conscious state, poses considerable challenges, particularly in the chronic phases of recovery. METHOD: This blinded crossover study explored the effects of familiar auditory sensory training (FAST) compared with a sham stimulation in a patient seven years post severe TBI. Baseline data were collected over 4 weeks to account for variability in status with neurobehavioral measures, including the Disorders of Consciousness scale (DOCS), Coma Near Coma scale (CNC), and Consciousness Screening Algorithm. Pre-stimulation neurophysiological assessments were completed as well, namely Brainstem Auditory Evoked Potentials (BAEP) and Somatosensory Evoked Potentials (SSEP). RESULTS: Results revealed that a significant improvement in the DOCS neurobehavioral findings after FAST, which was not maintained during the sham. BAEP findings also improved with maintenance of these improvements following sham stimulation as evidenced by repeat testing. CONCLUSIONS: The results emphasize the importance for continued evaluation and treatment of individuals in chronic states of seriously impaired consciousness with a variety of tools. Further study of auditory stimulation as a passive treatment paradigm for this population is warranted. Implications for Rehabilitation Clinicians should be equipped with treatment options to enhance neurobehavioral improvements when traditional treatment methods fail to deliver or maintain functional behavioral changes. Routine assessment is crucial to detect subtle changes in neurobehavioral function even in chronic states of disordered consciousness and determine potential preserved cognitive abilities that may not be evident due to unreliable motor responses given motoric impairments. Familiar Auditory Stimulation Training (FAST) is an ideal passive stimulation that can be supplied by families, allied health clinicians and nursing staff of all levels.

Disentangling disorders of consciousness: Insights from diffusion tensor imaging and machine learning.

Previous studies have suggested that disorders of consciousness (DOC) after severe brain injury may result from disconnections of the thalamo-cortical system. However, thalamo-cortical connectivity differences between vegetative state (VS), minimally conscious state minus (MCS-, i.e., low-level behavior such as visual pursuit), and minimally conscious state plus (MCS+, i.e., high-level behavior such as language processing) remain unclear. Probabilistic tractography in a sample of 25 DOC patients was employed to assess whether structural connectivity in various thalamo-cortical circuits could differentiate between VS, MCS-, and MCS+ patients. First, the thalamus was individually segmented into seven clusters based on patterns of cortical connectivity and tested for univariate differences across groups. Second, reconstructed whole-brain thalamic tracks were used as features in a multivariate searchlight analysis to identify regions along the tracks that were most informative in distinguishing among groups. At the univariate level, it was found that VS patients displayed reduced connectivity in most thalamo-cortical circuits of interest, including frontal, temporal, and sensorimotor connections, as compared with MCS+, but showed more pulvinar-occipital connections when compared with MCS-. Moreover, MCS- exhibited significantly less thalamo-premotor and thalamo-temporal connectivity than MCS+. At the multivariate level, it was found that thalamic tracks reaching frontal, parietal, and sensorimotor regions, could discriminate, up to 100% accuracy, across each pairwise group comparison. Together, these findings highlight the role of thalamo-cortical connections in patients' behavioral profile and level of consciousness. Diffusion tensor imaging combined with machine learning algorithms could thus potentially facilitate diagnostic distinctions in DOC and shed light on the neural correlates of consciousness. Hum Brain Mapp 38:431-443, 2017. © 2016 Wiley Periodicals, Inc.

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.

The neural correlates of lexical processing in disorders of consciousness.

There is a growing interest in the use of functional imaging to assess brain activity in the absence of behavioural responses in patients with disorders of consciousness (DOC). In the present study, we applied a hierarchical auditory stimulation paradigm to functional magnetic resonance (fMRI) in a group of long-term DOC adult patients. Brain response to pairs of pseudowords, of unrelated words and of semantically related words, i.e. stimuli differing in lexical status (words vs. pseudowords) and semantic relatedness (related vs. unrelated) was assessed. The former contrast was considered to reflect the automatic brain response to the passive presentation of meaningful real words, while the latter aimed to assess the response to meaning relationships. The results of the study indicate that automatic lexical processing can be observed in minimally conscious state (MCS), but also in vegetative state/unresponsive wakefulness syndrome (VS/UWS) patients, as indicated by increase in blood oxygenation level dependent (BOLD) activity in the linguistic networks. DOC patients, for some task conditions, recruited additional areas in comparison to healthy participants. Furthermore this study provides additional evidence of the potential role of fMRI in the assessment of residual cognitive processing in some of these patients, which may not be evident at the clinical level.

A hierarchy of event-related potential markers of auditory processing in disorders of consciousness.

Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS). Here we report an event-related potential (ERP) paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44%) patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect). In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness.

Brain-computer interfaces for patients with disorders of consciousness.

The disorders of consciousness refer to clinical conditions that follow a severe head injury. Patients diagnosed as in a vegetative state lack awareness, while patients diagnosed as in a minimally conscious state retain fluctuating awareness. However, it is a challenge to accurately diagnose these disorders with clinical assessments of behavior. To improve diagnostic accuracy, neuroimaging-based approaches have been developed to detect the presence or absence of awareness in patients who lack overt responsiveness. For the small subset of patients who retain awareness, brain-computer interfaces could serve as tools for communication and environmental control. Here we review the existing literature concerning the sensory and cognitive abilities of patients with disorders of consciousness with respect to existing brain-computer interface designs. We highlight the challenges of device development for this special population and address some of the most promising approaches for future investigations.