Recovery from prolonged disorders of consciousness:A dual-center prospective cohort study in China

BACKGROUND Recent innovations in intensive care have improved the prognosis of patients with severe brain injuries and brought more patients with disorders of consciousness(DoC).Data are lacking regarding the long-term outcomes of those patients in China.It is necessary to study the long-term outcomes of patients with prolonged DoC in light of many factors likely to influence crucial decisions about their care and their life.AIM To present the preliminary results of a DoC cohort.METHODS This was a two-center prospective cohort study of inpatients with vegetative state(VS)/unresponsive wakefulness syndrome(UWS).The study outcomes were the recovery from VS/UWS to minimally conscious state(MCS)and the long-term status of patients with prolonged DoC considered in VS/UWS or MCS for up to 6 years.The patients were evaluated using the Glasgow coma scale,coma recovery scale-revised,and Glasgow outcome scale.The endpoint of follow-up was recovery of full consciousness or death.The changes in the primary clinical outcome improvement in clinical diagnosis were evaluated at 12 mo compared with baseline.RESULTS The study population included 93 patients(62 VS/UWS and 31 MCS).The postinjury interval range was 28-634 d.Median follow-up was 20 mo(interquartile range,12-37 mo).At the endpoint,33 transitioned to an emergence from MCS or full consciousness,eight had a locked-in syndrome,and there were 35 patients remaining in a VS/UWS and 11 in an MCS.Seven(including one locked-in syndrome)patients(7.5%)died within 12 mo of injury.Compared with the unresponsive group(n=52)at 12 mo,the responsive group(n=41)had a higher proportion of males(87.8%vs 63.5%,P=0.008),shorter time from injury(median,40.0 d vs 65.5 d,P=0.006),higher frequency of vascular etiology(68.3%vs 38.5%,P=0.007),higher Glasgow coma scale score at admission(median,9 vs 6,P<0.001),higher coma recovery scale-revised score at admission(median,9 vs 2.5,P<0.001),at 1 mo(median,14 vs 5,P<0.001),and at 3 mo(median,20 vs 6,P<0.001),lower frequency of VS/UWS(36.6%vs 90.0%,P<0.001),and more favorable Glasgow outcome scale outcome(P<0.001).CONCLUSION Patients with severe DoC,despite having strong predictors of poor prognosis,might recover consciousness after a prolonged time of rehabilitation.An accurate initial diagnosis of patients with DoC is critical for predicting outcome and a long-term regular follow-up is also important.

Finger or Light:Stimulation Sensitivity of Visual Startle in the Coma Recovery Scale-Revised for Disorders of Consciousness

Dear Editor,Coma, the vegetative state （VS）, and the minimally- conscious state （MCS）, often collectively referred to as disorders of consciousness （DOCs）, typically occur after severe traumatic or non-traumatic brain injury [1]. The boundary between awareness and unawareness remains elusive, making it difficult to correctly distinguish MCS from VS patients. It is possible to employ noninvasive neuroimaging techniques, such as functional MRI （fMRI） [2] to assess residual cognitive processing as well as consciousness. However, the causal link between neural activity in specific brain areas and specific behavioral tasks is hard to dissect using fMRI [3]. Therefore, detecting residual cognitive function and consciousness in patients surviving severe brain injury remains extremely challenging.

视觉威胁反应在判断严重意识障碍程度的应用

目的用强弱光源作为视觉威胁刺激物,与CRS-R量表中以手指为刺激物的视觉威胁反应进行对比,比较严重意识障碍患者对不同视觉威胁刺激物的敏感性差异;在此基础上研究视觉威胁反应能否作为意识的指标。方法随机选择89例严重意识障碍(DOC)患者,采用The JFK Coma Recovery Scale-Revise(JFK改进的昏迷恢复量表,以下简称CRS-R)对其进行床边测量。对于视觉威胁反应项,分别对患者采取手指、弱光、强光刺激物进行刺激,比较反应的差异。结果植物状态(VS)和最小意识状态(MCS)患者对手指视觉威胁刺激的反应具有显著的差异(P<0.001),植物状态和最小意识状态患者对强光视觉威胁刺激的反应具有显著的差异(P<0.001)。最小意识障碍患者对手指、强光两种视觉威胁刺激的反应没有显著性的差异(P>0.05),植物状态患者对手指、强光两种视觉威胁刺激的反应没有显著性的差异(P>0.05)。结论严重意识障碍患者(n=89)对不同刺激物(手指、弱光、强光)的反应无显著性差异;视觉威胁反应(手指和光)能反映意识。

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

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

Visual Fixation Assessment in Patients with Disorders of Consciousness Based on Brain-Computer Interface

Visual fixation is an item in the visual function subscale of the Coma Recovery Scale-Revised （CRS-R）. Sometimes clinicians using the behavioral scales find it difficult to detect because of the motor impairment in patients with disorders of consciousness （DOCs）. Brain- computer interface （BCI） can be used to improve clinical assessment because it directly detects the brain response to an external stimulus in the absence of behavioral expres- sion. In this study, we designed a BCI system to assist the visual fixation assessment of DOC patients. The results from 15 patients indicated that three showed visual fixation in both CRS-R and BCI assessments and one did not show such behavior in the CRS-R assessment but achieved significant online accuracy in the BCI assessment. The results revealed that electroencephalography-based BCI can detect the brain response for visual fixation. Therefore, the proposed BCI may provide a promising method for assisting behavioral assessment using the CRS-R.

Clinical application of Chinese Nanjing persistent vegetative state scale

Background:It is a challenge to characterize the consciousness level of patients with severe disturbance of consciousness and predict their prognosis effectively for Chinese doctors.We aimed to investigate the psychometric property and the diagnostic practicality of severe disturbance of consciousness by Chinese Nanjing persistent vegetative state scale(CNPVSS)which was first set up in 1996 and modified in 2001 and 2011.Methods:The concurrent validity,inter-rater consistency and diagnostic accuracy of CNPVSS and Chinese version of coma recovery scale-revised(CRS-R)were investigated by assessment of 380 patients with severe disorders of consciousness.Results:Total scores of the CNPVSS were correlated significantly with that of the CRS-R,indicating acceptable concurrent validity.Sub-scale analysis showed moderate to high inter-rater reliability and test-retest reliability.CNPVSS was superior to CRS-R on the diagnosis sensitivity.The CNPVSS was able to distinguish 65 patients in emergence from minimal consciousness state who were misclassified as in minimal consciousness state(MCS)by the CRS-R,and it could also distinguish two patients in MCS who were misclassified as in vegetative state by the CRS-R.Conclusion:The CNPVSS is an appropriate measurement and is sensitive to distinguish the MCS patients from the VS patients.