Coma Recovery Scale-Revised Score Research Articles

EEG and Coma Recovery Scale-Revised prediction of neurological outcome in Disorder of Consciousness patients.

According to electroencephalogram (EEG) descriptors included in the American Clinical Neurophysiology Society (ACNS) terminology, we generated a score, and we compared it to the EEG scores previously proposed in order to identify the one with the best prognostic power for neurological outcome at post-acute stages in patients with severe disorders of consciousness (DoC). Patients included in the analysis were clinically evaluated with the Coma Recovery Scale-Revised (CRS-R). An EEG was performed within the first week after admission to Intensive Rehabilitation Unit (IRU). EEGs were classified according to the ACNS terminology and to the scores of Bagnato and Estraneo. A total of 260 patients admitted to the IRU were analysed. A total of 160 patients (61%) improved their consciousness level during IRU stay. EEG score based on the ANCS terminology showed higher overall performance (receiver-operating area under the curve=0.79) and greater sensitivity (65%), at comparable specificities (80%), for clinical improvement as compared to both CRS-R admission score and other EEG scores. Combining our EEG score with CRS-R score at admission, the cumulative sensitivity increased to 76% when at least one good prognostic index test was present in the same patient, whereas specificity increased up to 93% if both the good prognostic patterns of clinical and instrumental parameters were simultaneously present. The EEG scored according to the ACNS terminology is the best among those looked at for the prediction of short-term clinical improvement in patients with DoC and represents a useful instrumental test, complementary to clinical evaluation at admission, to be added in post-acute neurological prognostication methods.

Effects of a Vibro-Tactile P300 Based Brain-Computer Interface on the Coma Recovery Scale-Revised in Patients With Disorders of Consciousness.

Persons diagnosed with disorders of consciousness (DOC) typically suffer from motor and cognitive disabilities. Recent research has shown that non-invasive brain-computer interface (BCI) technology could help assess these patients’ cognitive functions and command following abilities. 20 DOC patients participated in the study and performed 10 vibro-tactile P300 BCI sessions over 10 days with 8–12 runs each day. Vibrotactile tactors were placed on the each patient’s left and right wrists and one foot. Patients were instructed, via earbuds, to concentrate and silently count vibrotactile pulses on either their left or right wrist that presented a target stimulus and to ignore the others. Changes of the BCI classification accuracy were investigated over the 10 days. In addition, the Coma Recovery Scale-Revised (CRS-R) score was measured before and after the 10 vibro-tactile P300 sessions. In the first run, 10 patients had a classification accuracy above chance level (>12.5%). In the best run, every patient reached an accuracy ≥60%. The grand average accuracy in the first session for all patients was 40%. In the best session, the grand average accuracy was 88% and the median accuracy across all sessions was 21%. The CRS-R scores compared before and after 10 VT3 sessions for all 20 patients, are showing significant improvement (p = 0.024). Twelve of the twenty patients showed an improvement of 1 to 7 points in the CRS-R score after the VT3 BCI sessions (mean: 2.6). Six patients did not show a change of the CRS-R and two patients showed a decline in the score by 1 point. Every patient achieved at least 60% accuracy at least once, which indicates successful command following. This shows the importance of repeated measures when DOC patients are assessed. The improvement of the CRS-R score after the 10 VT3 sessions is an important issue for future experiments to test the possible therapeutic applications of vibro-tactile and related BCIs with a larger patient group.

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

To observe the influence of Xiao's "xingnaofusu" needling (the technique for resuscitation) on regaining consciousness in the patients with persistent vegetative state (PVS). 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. 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). 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.

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

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. 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. 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). 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.

Prognosis for patients with cognitive motor dissociation identified by brain-computer interface.

Cognitive motor dissociation describes a subset of patients with disorders of consciousness who show neuroimaging evidence of consciousness but no detectable command-following behaviours. Although essential for family counselling, decision-making, and the design of rehabilitation programmes, the prognosis for patients with cognitive motor dissociation remains under-investigated. The current study included 78 patients with disorders of consciousness who showed no detectable command-following behaviours. These patients included 45 patients with unresponsive wakefulness syndrome and 33 patients in a minimally conscious state, as diagnosed using the Coma Recovery Scale-Revised. Each patient underwent an EEG-based brain-computer interface experiment, in which he or she was instructed to perform an item-selection task (i.e. select a photograph or a number from two candidates). Patients who achieved statistically significant brain-computer interface accuracies were identified as cognitive motor dissociation. Two evaluations using the Coma Recovery Scale-Revised, one before the experiment and the other 3 months later, were carried out to measure the patients' behavioural improvements. Among the 78 patients with disorders of consciousness, our results showed that within the unresponsive wakefulness syndrome patient group, 15 of 18 patients with cognitive motor dissociation (83.33%) regained consciousness, while only five of the other 27 unresponsive wakefulness syndrome patients without significant brain-computer interface accuracies (18.52%) regained consciousness. Furthermore, within the minimally conscious state patient group, 14 of 16 patients with cognitive motor dissociation (87.5%) showed improvements in their Coma Recovery Scale-Revised scores, whereas only four of the other 17 minimally conscious state patients without significant brain-computer interface accuracies (23.53%) had improved Coma Recovery Scale-Revised scores. Our results suggest that patients with cognitive motor dissociation have a better outcome than other patients. Our findings extend current knowledge of the prognosis for patients with cognitive motor dissociation and have important implications for brain-computer interface-based clinical diagnosis and prognosis for patients with disorders of consciousness.

Effect of repetitive transcranial magnetic stimulation on the ascending reticular activating system in a patient with disorder of consciousness: a case report

BackgroundWe report on a stroke patient with disorder of consciousness (DOC) who underwent repetitive transcranial magnetic stimulation (rTMS) and showed recovery of an injured upper ascending reticular activating system (ARAS) injury, which was demonstrated by using serial diffusion tensor tractography (DTT).Case presentationA 45-year-old male patient was diagnosed as subarachnoid and intracerebral hemorrhages in the left fronto-parieto-temporal lobes. At 5 months after onset, the patient exhibited a persistent vegetative state, with a Coma Recovery Scale-Revised (CRS-R) score of 4. He underwent comprehensive rehabilitative therapy that included drugs for recovery of impaired consciousness and rTMS of the right dorsolateral prefrontal lobe. He recovered to a minimally conscious state (CRS-R: 13) at 7 months after onset and was transferred to a local rehabilitation hospital where he underwent similar rehabilitation but without rTMS. At 9 months after onset, his CRS-R score remained at 13. He was then readmitted to our hospital and underwent rehabilitation with rTMS until 10 months after onset. His CRS-R remained at 13, but his higher cognition had improved. The tract volume (TV) of the neural tract in the right prefrontal lobe in the upper ARAS on the 7-month DTT was higher than that on the 5-month DTT. However, compared to the 7-month DTT, the right prefrontal lobe TV was lower on the 9-month DTT. On the 10-month DTT, the TV of that neural tract had again increased.ConclusionsIncreases in neural TV in the right prefrontal lobe of the upper ARAS that were associated with the periods of rTMS application were demonstrated in a stroke patient with DOC.

Bedside EEG predicts longitudinal behavioural changes in disorders of consciousness

Providing an accurate prognosis for prolonged disorder of consciousness (pDOC) patients remains a clinical challenge. Large cross-sectional studies have demonstrated the diagnostic and prognostic value of functional brain networks measured using high-density electroencephalography (hdEEG). Nonetheless, the prognostic value of these neural measures has yet to be assessed by longitudinal follow-up. We address this gap by assessing the utility of hdEEG to prognosticate long-term behavioural outcome, employing longitudinal data collected from a cohort of patients assessed systematically with resting hdEEG and the Coma Recovery Scale-Revised (CRS-R) at the bedside over a period of two years. We used canonical correlation analysis to relate clinical (including CRS-R scores combined with demographic variables) and hdEEG variables to each other. This analysis revealed that the patient’s age, and the hdEEG theta band power and alpha band connectivity, contributed most significantly to the relationship between hdEEG and clinical variables. Further, we found that hdEEG measures recorded at the time of assessment augmented clinical measures in predicting CRS-R scores at the next assessment. Moreover, the rate of hdEEG change not only predicted later changes in CRS-R scores, but also outperformed clinical measures in terms of prognostic power. Together, these findings suggest that improvements in functional brain networks precede changes in behavioural awareness in pDOC. We demonstrate here that bedside hdEEG assessments conducted at specialist nursing homes are feasible, have clinical utility, and can complement clinical knowledge and systematic behavioural assessments to inform prognosis and care.

Auditory steady-state response to chirp-modulated tones: A pilot study in patients with disorders of consciousness.

Due to the problems with behavioral diagnosis of patients with prolonged DOC (disorders of consciousness), complementary approaches based on objective measurement of neural function are necessary. In this pilot study, we assessed the sensitivity of auditory chirp-evoked responses to the state of patients with severe brain injury as measured with CRS-R (Coma Recovery Scale - Revised). A convenience sample of fifteen DOC patients was included in the study. Auditory stimuli, chirp-modulated at 1-120 Hz were used to evoke auditory steady-state response (ASSR). Phase-locking index (PLI) estimates within low gamma and high gamma windows were evaluated. The PLI estimates within a narrow low gamma 38-42 Hz window positively correlated with the CRS-R total score and with the scores of the Auditory and Visual Function subscales. In the same low gamma window, significant difference in the PLIs was found between minimally conscious (MCS) and vegetative state (VS) patients. We did not observe any between-group differences nor any significant correlations with CRS-R scores in the high gamma window (80-110 Hz). Our results support the notion that the activity around 40 Hz may serve as a possible marker of the integrity of thalamocortical networks in prolonged DOC patients. Auditory steady-state responses at gamma-band frequencies highlight the role of upper parts of auditory system in evaluation of the level of consciousness in DOC patients.

Additive effect of cerebrolysin and amantadine on disorders of consciousness secondary to acquired brain injury: A retrospective case-control study.

Acquired brain injury can cause disorders of consciousness. An additive effect of cerebrolysin and amantadine has been postulated, but not systematically studied. The present study aimed to investigate this additive effect in patients with disorders of consciousness secondary to acquired brain injury. The medical records of patients diagnosed with disorders of consciousness after acquired brain injury were reviewed. The patients were categorized into 2 groups: single regimen (amantadine only) and dual regimen (amantadine plus cerebrolysin). The patients' conscious states were assessed using the Coma Recovery Scale-Revised (CRS-R) before, and after 4 weeks of drug administration. Data for a total of 84 patients were analysed. The degree of change in CRS-R and the proportion of patients in the disorders of consciousness category showing a change was higher in the dual regimen group than in the single regimen group. Analysis of patients who had initially been in a prolonged vegetative state or minimally conscious state minus before administration showed that the patients in the dual regimen group had greater increases in CRS-R scores than those in the single regimen group. This study identified that an amantadine-plus-cerebrolysin regimen additively affects patients with prolonged disorders of consciousness. A future controlled trial is needed to investigate the efficacy of each regimen in patients with prolonged disorders of consciousness secondary to acquired brain injury, particularly for patients who have remained in a prolonged vegetative state after acquired brain injury.

Transcranial magnetic stimulation-evoked connectivity reveals modulation effects of repetitive transcranial magnetic stimulation on patients with disorders of consciousness.

Several studies have investigated possible role of repetitive transcranial magnetic stimulation (rTMS) in patients with disorder of consciousness (DOC). But the details of patients' brain responses to the rTMS are yet to be disclosed. The aim of the study is to explore the neural electrical responses of DOC patients to rTMS modulation. DOC Patients [14 vegetative state, seven minimally conscious state (MCS)] and healthy subjects were enrolled and received one session of rTMS. The TMS-electroencephalogram was recorded at before and immediately after rTMS stimulation. TMS-evoked potentials as well as TMS-evoked connectivity were proposed to capture the effective connectivity alteration induced by rTMS. Significant changes of TMS-evoked potential were found in the healthy group but not in DOC patients. TMS-evoked connectivity was significantly enhanced by the rTMS in healthy and MCS groups. In addition, the enhancement was positively correlated with patients' Coma Recovery Scale-Revised scores. Global synchrony of the TMS-evoked connectivity matrix significantly enhanced by rTMS in the control and MCS groups but not in vegetative state patients. Furthermore, after rTMS stimulation, the similarity of TMS-evoked connectivity patterns between pairwise patients was significantly raised in MCS patients. But no significant changes were found in vegetative state patients. TMS-evoked connectivity reveals that rTMS can effectively modulate effective connectivity of MCS patients, but no evidence of changes in vegetative state patients.

Therapeutic effect of spinal cord stimulation on chronic disorders of consciousness after brain injury: A report of 110 cases

Objective To investigate the efficacy and influencing factors of spinal cord stimulation (SCS) in the treatment of patients with chronic disorders of consciousness (DOC) after brain injury. Methods The clinical data of 110 patients with chronic DOC after brain injury were analyzed retrospectively who were admitted to Department of Neurosurgery, the Seventh Medical Center of Chinese PLA General Hospital from August 2011 to December 2017. CT scan of the cervical spine was performed to show the location of the electrode implanted. All patients underwent clinical follow-up at 3 and 6 months after surgery. The follow-up included neurological physical examination and assessment based on modified coma recovery scale-revised (CRS-R). According to the patient's clinical symptom outcome and CRS-R scores, the surgical outcomes were evaluated and divided into effective and ineffective. Univariate and multivariate logistic regression analysis were used to explore risk factors affecting the patient′s outcomes. Results Cervical CT was performed after operation. The electrodes of 110 patients were implanted at cervical spinal epidural C2-C4 level. Stimulation parameters in 110 patients included the frequency of 5 Hz or 70 Hz, pulse width of 210 μs, voltage of 1-5 V, daily device-on time of 8-12 h, stimulation mode of 15-min stimulation with 15-min interval. At 6 months post surgery in this series of 110 patients, 38 cases were effective (good in 24 and improved in 14), 72 were ineffective (ineffective in 67 and death in 5), and the overall effective rate was 34.5% (38/110). Univariate analysis showed that age, duration of disease, CRS-R score, and preoperative surgical recommendation criterion were clinical factors affecting the patient′s outcome (all P < 0.05). Further multivariate logistic regression analysis showed that preoperative evaluation recommendation criterion was an independent risk factor affecting the patient′s outcome (OR=8.179, 95% CI: 2.171-30.816, P=0.002). CRS high score was an independent protective factor affecting the patient’s outcome (OR=0.304, 95% CI: 0.095-0.978, P=0.046). Conclusion SCS is effective in the treatment of DOC and can be used as one of the feasible treatments for DOC. The preoperative evaluation recommendation criterion is an independent risk factor for the efficacy of patients with DOC. Key words: Consciousness disorders; Treatment outcome; Factor analysis, statistical; Spinal cord stimulation

Unresponsive wakefulness syndrome: Outcomes from a vicious circle.

Unresponsive wakefulness syndrome: Outcomes from a vicious circle.

Effects of Cerebrolysin® in Patients With Minimally Conscious State After Stroke: An Observational Retrospective Clinical Study.

Introduction: The neurotrophic drug Cerebrolysin is composed of low-molecular-weight peptides and amino acids and has been shown to have neuroprotective and neuroplastic properties. Cerebrolysin has been reported to promote the recovery of motor functions in central nervous system disorders; however, the effects on the consciousness improvements in post-stroke patients have not yet been studied extensively. Therefore, we aimed to examine the effectiveness of Cerebrolysin on improving the consciousness level of stroke patients with minimally conscious state (MCS).Materials and Methods: In this retrospective study we included ischemic and/or hemorrhagic stroke patients with MCS according to the Coma Recovery Scale-Revised (CRS-R), who were admitted to our hospital between 2014 and 2017. All patients received comprehensive rehabilitation therapy including physical and occupational therapy. We compared patients treated with Cerebrolysin against patients who did not receive Cerebrolysin. Patients were included in the verum group if they received 10 mL of Cerebrolysin IV for at least 20 days. CRS-R scores were assessed at admission and discharge.Results: Of 1,531 patients screened, 75 were included in the study (Cerebrolysin, n = 43; control, n = 32). Baseline characteristics were similar between groups. At discharge, ~2 months after onset of stroke, Cerebrolysin-treated patients improved significantly in the CRS-R (p = 0.010) after adjustment for confounders using linear mixed model (LMM), especially in the Oromotor (p = 0.003) and Arousal subscales (p = 0.038). No safety issues were observed.Conclusion: This retrospective study suggests that Cerebrolysin may improve the level of consciousness in stroke patients with MCS, which should be further investigated in a well-designed, double-blind, placebo-controlled, randomized trial.

Low- and medium-rate auditory steady-state responses in patients with prolonged disorders of consciousness correlate with Coma Recovery Scale - Revised score

Diagnosis of consciousness in patients with prolonged disorders of consciousness (PDOC) remains challenging since their responsiveness is often very impaired, while their assessment depends on observable behavior. The aim of this proof-of-concept study was to evaluate whether low- and medium-rate amplitude-modulated (AM) auditory steady-state responses (ASSRs) can be sensitive to the state of PDOC patients and may thus serve as a diagnostic tool which does not explicitly depend on a patient's cooperation.EEG was recorded from nine unresponsive wakefulness syndrome/vegetative state (UWS/VS) and eight minimally conscious state (MCS)/emergence from MCS patients during stimulation with two-minute trains of simple tones, amplitude modulated (AM) by 4 Hz, 6 Hz, 8 Hz, 12 Hz, 20 Hz, 40 Hz. The obtained ASSRs were then related to the Coma Recovery Scale – Revised (CRS-R) diagnosis and its total score.We observed significant correlations between mean inter-trial phase coherence (PC) (averaged across all stimulation frequencies) and total CRS-R score, as well as between 40 Hz relative power (RP) and total CRS-R score. Moreover, both parameters significantly differed between the patient groups.Our preliminary results suggest that a passive auditory stimulation protocol consisting of low- and medium-rate ASSRs might be used as an objective estimate of the level of neural dysfunction in PDOC patients. Consequently, the integrity of the auditory system appears to be an important predictor of the actual state of consciousness in PDOC patients.

Prognostic value of post-acute EEG in severe disorders of consciousness, using American Clinical Neurophysiology Society terminology

To evaluate whether electroencephalographic (EEG) features recorded during the post-acute stage in patients with severe disorders of consciousness (DoC) after acute brain injury (ABI), contribute to neurological outcome prediction of these patients at discharge from the intensive rehabilitation unit (IRU). We retrospectively evaluated all patients consecutively admitted to the IRU from August 2012 to December 2016. Inclusion criteria were: 1) age >18years, 2) patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS), and 3) EEG and a coma recovery scale-revised (CRS-R) score available within the first week after admission. Clinical evaluation was performed using the Italian version of the CRS-R score. EEGs were classified according to American Clinical Neurophysiology Society (ACNS) terminology. Clinical state at final discharge was evaluated using the CRS-R score. In total, 102 patients were included in the analysis. After a mean of five months of IRU stay, among the 61 UWS subjects, 19 transitioned to MCS and 11 recovered to exit-MCS (E-MCS); twenty-three of the 41 subjects in MCS progressed to E-MCS. Using logistic regression, consciousness level (UWS/MCS-OR=13.4), CRS-R score at admission (OR=1.33) and use of activating drugs (OR=4.7) were significant predictors of clinical improvement. Multivariable analysis showed that specific EEG patterns were independent predictors of improved consciousness at discharge in UWS patients. EEG performed within the first week after IRU admission, classified according to ACNS-terminology in patients with UWS at admission, can provide useful prognostic contribution.

Current validity of diagnosis of permanent vegetative state: a longitudinal study in a sample of patients with altered states of consciousness

IntroductionAltered states of consciousness have traditionally been associated with poor prognosis. At present, clinical differences between these entities are beginning to be established. MethodOur study included 37 patients diagnosed with vegetative state/unresponsive wakefulness syndrome (UWS) and 43 in a minimally conscious state (MCS) according to the Coma Recovery Scale–Revised (CRS-R). All patients were followed up each month for at least 6 months using the CRS-R. We recorded the time points when vegetative state progressed from ‘persistent’ to ‘permanent’ based on the cut-off points established by the Multi-Society-Task-Force: 12 months in patients with traumatic injury and 3 months in those with non-traumatic injury. A logistic regression model was used to determine the factors potentially predicting which patients will emerge from MCS. ResultsIn the UWS group, 23 patients emerged from UWS but only 9 emerged from MCS. Of the 43 patients in the MCS group, 26 patients emerged from that state during follow-up. Eight of the 23 patients (34.7%) who emerged from UWS and 17 of the 35 (48.6%) who emerged from MCS recovered after the time points proposed by the Multi-Society-Task-Force. According to the multivariate regression analysis, aetiology (P<.01), chronicity (P=.01), and CRS-R scores at admission (P<.001) correctly predicted emergence from MCS in 77.5% of the cases. ConclusionsUWS and MCS are different clinical entities in terms of diagnosis and outcomes. Some of the factors traditionally associated with poor prognosis, such as time from injury and likelihood of recovery, should be revaluated.

Electroencephalography quadratic phase self-coupling correlates with consciousness states and restoration in patients with disorders of consciousness

ObjectiveThe objective of this study was to explore the role for quadratic phase coupling within electroencephalography (EEG) oscillations in the diagnosis of consciousness and consciousness restoration for disorders of consciousness (DOC). MethodsFifty-one DOC patients were enrolled in this study. For each patient, a Coma Recovery Scale-Revised (CRS-R) score and 20-min resting-state EEG were recorded. Consciousness recovery was assessed with a CRS-R score at a three-month follow-up. Twenty healthy subjects were included as controls. General harmonic wavelet transform-based bicoherence was used to quantify the quadratic phase coupling characteristics of the EEG oscillations. ResultsQuadratic phase self-coupling (QPSC) at the delta (QPSC_delta), theta (QPSC_theta) and alpha (QPSC_alpha) bands were closely correlated with patient CRS-R scores. Particularly, the QPSC_theta value could significantly differentiate between vegetative state (VS) patients, minimally conscious state (MCS) patients and healthy control subjects. As compared to VS patients, patients with MCS had a lower QPSC_theta value on the left as well as a higher QPSC_alpha value in right frontal regions. The frontal QPSC_theta value showed significant differences between recovered and unrecovered patients. ConclusionQPSC characteristics could differentiate between consciousness states and show a predictive ability for the recovery of consciousness in DOC patients. SignificanceChanges in QPSC accompany consciousness injury and restoration in DOC patients. A QPSC assessment is helpful in the diagnosis and prognosis of DOC patients.

Effects of Long-Lasting High-Definition Transcranial Direct Current Stimulation in Chronic Disorders of Consciousness: A Pilot Study.

Transcranial direct current stimulation (tDCS) recently was shown to benefit rehabilitation of patients with disorders of consciousness (DOC). However, high-Definition tDCS (HD-tDCS) has not been applied in DOC. In this study, we tried to use HD-tDCS protocol (2 mA, 20 min, the precuneus, and sustaining 14 days) to rehabilitate 11 patients with DOC. Electroencephalography (EEG) and Coma Recovery Scale–Revised (CRS-R) scores were recorded at before (T0), after a single session (T1), after 7 days’ (T2), and 14 days’ HD-tDCS (T3) to assess the modulation effects. EEG coherence was measured to evaluate functional connectivity during the experiment. It showed that 9 patients’ scores increased compared with the baseline. The central-parietal coherence significantly decreased in the delta band in patients with DOC. EEG coherence might be useful for assessing the effect of HD-tDCS in patients with DOC. Long-lasting HD-tDCS over the precuneus is promising for the treatment of patients with DOC.

Cervical Spinal Cord Stimulation for the Vegetative State: A Preliminary Result of 12 Cases

Data on the treatment of the vegetative state (VS) with cervical spinal cord stimulation (cSCS) are limited and prognostic factors are inconclusive. In this study, we present our experience of treating 12 VS patients with cSCS and discuss the prognostic factors. Twelve VS patients were enrolled. Preoperative assessments included CT/MRI, PET, brainstem auditory evoked potentials (BAEPs), somatosensory evoked potentials (SEPs), and electroencephalogram (EEG). cSCS surgeries were performed at West China Hospital. The electrode was implanted in the epidural space of the C2-4 vertebrae. Levels of consciousness were evaluated based on the Coma Recovery Scale-Revised (CRS-R) at baseline and during follow-up. The average follow-up was 11.1 months. The average CRS-R score at the last evaluation was 10.8, which was significantly improved compared with the baseline score (6.25). Five patients achieved responsive outcomes (three recovered and two evolved to a minimally conscious state) and seven achieved unresponsive outcomes (six remained in VS and one died). Age, preoperative CRS-R score, the interval between acute comatose injury and cSCS, and the Vth wave of BAEPs did not differ significantly between the responsive group and the unresponsive group. Appearance of the N20 of SEPs and multifocal abnormalities on CT/MRI and PET were significantly associated with a better outcome, while the etiology of ischemia and anoxia (IAA) was significantly associated with a poor outcome. cSCS should be a glimmer of hope for VS patients. Patients whose N20 is elicited or whose CT/MRI or PET demonstrates multifocal abnormalities are more likely to benefit from cSCS, whereas those with an IAA etiology have a lower likelihood of recovery after cSCS.

Healthier rhythm, healthier brain? Integrity of circadian melatonin and temperature rhythms relates to the clinical state of brain-injured patients.

BackgroundHealthy circadian rhythmicity has been suggested to relate to a better state of brain‐injured patients and to support the emergence of consciousness in patient groups characterized by a relative instability thereof such as patients with disorders of consciousness (DOC).MethodsGoing beyond earlier studies, a systems‐level perspective was adopted and, using multilevel modelling, the joint predictive value of three indices of circadian rhythm integrity derived from skin temperature variations, melatoninsulfate secretion, and physical activity (wrist actigraphy) patterns was evaluated for the behaviourally assessed state [Coma Recovery Scale ‐ Revised (CRS‐R) score] of DOC patients [13 unresponsive wakefulness syndrome; seven minimally conscious (exit) state]. Additionally, it was assessed in a subset of 16 patients whether patients’ behavioural repertoire (CRS‐R score) varied (i) with time of day or (ii) offset from the body temperature maximum (BT max), i.e. when cognitive performance is expected to peak.ResultsThe results reveal that better integrity of circadian melatoninsulfate and temperature rhythms relate to a richer behavioural repertoire. Moreover, higher CRS‐R scores are, by trend, related to assessments taking place at a later daytime or deviating less from the pre‐specified time of occurrence of BT max.ConclusionsIn conclusion, the results suggest that therapeutic approaches aimed at improving circadian rhythms in brain‐injured patients are promising and should be implemented in hospitals or nursing homes. Beyond this, it might be helpful to schedule diagnostic procedures and therapies around the (pre‐assessed) BT max (≈4 pm in healthy individuals) as this is when patients should be most responsive.