Coma Recovery Scale-Revised Assessment Research Articles

Behavioral Assessment With the Coma Recovery Scale-Revised Is Safe and Feasible in Critically Ill Patients With Disorders of Consciousness.

Accurate classification of disorders of consciousness (DoC) is key in developing rehabilitation plans after brain injury. The Coma Recovery Scale-Revised (CRS-R) is a sensitive measure of consciousness validated in the rehabilitation phase of care. We tested the feasibility, safety, and impact of CRS-R-guided rehabilitation in the ICU for patients with DoC after acute hemorrhagic stroke. Retrospective cohort study. This single-center study was conducted in the neurocritical care unit at the University of Maryland Medical Center. We analyzed records from consecutive patients with subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH), who underwent serial CRS-R assessments during ICU admission from April 1, 2018, to December 31, 2021, where CRS-R less than 8 is vegetative state/unresponsive wakefulness syndrome (VS/UWS); CRS-R greater than or equal to 8 is a minimally conscious state (MCS). None. Outcomes included adverse events during CRS-R evaluations and associations between CRS-R and discharge disposition, therapy-based function, and mobility. We examined the utility of CRS-R compared with other therapist clinical assessment tools in predicting discharge disposition. Seventy-six patients (22 SAH, 54 ICH, median age = 59, 50% female) underwent 276 CRS-R sessions without adverse events. Discharge to acute rehabilitation occurred in 4.4% versus 41.9% of patients with a final CRS-R less than 8 and CRS-R greater than or equal to 8, respectively (odds ratio [OR] 13.4; 95% CI, 2.7-66.1; p < 0.001). Patients with MCS on final CRS-R completed more therapy sessions during hospitalization and had improved mobility and functional performance. Compared with other therapy assessment tools, the CRS-R had the best performance in predicting discharge disposition (area under the curve: 0.83; 95% CI, 0.72-0.94; p < 0.0001). Early neurorehabilitation guided by CRS-R appears to be feasible and safe in the ICU following hemorrhagic stroke complicated by DoC and may enhance access to inpatient rehabilitation, with the potential for lasting benefit on recovery. Further research is needed to assess generalizability and understand the impact on long-term outcomes.

388 Early Neurorehabilitation of Disorders of Consciousness after Acute Hemorrhagic Stroke

OBJECTIVES/GOALS: Accurate classification of disorders of consciousness (DoC) is key in developing rehabilitation plans following brain injury. The Coma Recovery Scale-Revised (CRS-R) is a sensitive measure of consciousness. We explore feasibility, safety and impact of CRS-R guided rehab in hemorrhagic stroke patients with DoC and evaluate predictors of recovery. METHODS/STUDY POPULATION: Consecutive patients with non-traumatic hemorrhagic stroke, defined as subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH), receiving serial CRS-R assessments during their ICU stay at University of Maryland Medical Center from 2017-2021 were retrospectively identified. Outcomes of interest included the association with CRS-R and discharge disposition, therapy-based function and mobility and occurrence of safety events during CRS assessment. We also examined the association between CRS-R and physiological and anatomical injury pattern on electroencephalography (EEG) and magnetic resonance imaging (MRI), respectively. CRS-R RESULTS/ANTICIPATED RESULTS: 76 patients with≥2 CRS-R assessments were identified (22 SAH, 54 ICH, median age = 59, 50% female). Median CRS-R completed was 3 with no SAEs identified during sessions. We identified 4 patterns: persistent VS/UWS (49%), persistent MCS or better (13%), emergence from VS/UWS to MCS or better (27%) and regression from MCS or better to VS/UWS (11%). Persistent low CRS-R correlated with older age in SAH (p=0.01), female gender in ICH (p=0.04), and history of diabetes (p=0.01). 2% of patients with final CRS-R DISCUSSION/SIGNIFICANCE: Early neurorehabilitation guided by CRS-R appears to be feasible and safe acutely following hemorrhagic stroke complicated by prolonged DoC and may enhance access to inpatient rehabilitation with a lasting benefit on recovery. Further characterization of DoC patterns and their correlation to clinical markers, including EEG and MRI is needed.

Toward Assessment of Sound Localization in Disorders of Consciousness Using a Hybrid Audiovisual Brain-Computer Interface.

Behavioral assessment of sound localization in the Coma Recovery Scale-Revised (CRS-R) poses a significant challenge due to motor disability in patients with disorders of consciousness (DOC). Brain-computer interfaces (BCIs), which can directly detect brain activities related to external stimuli, may thus provide an approach to assess DOC patients without the need for any physical behavior. In this study, a novel audiovisual BCI system was developed to simulate sound localization evaluation in CRS-R. Specifically, there were two alternatively flashed buttons on the left and right sides of the graphical user interface, one of which was randomly chosen as the target. The auditory stimuli of bell sounds were simultaneously presented by the ipsilateral loudspeaker during the flashing of the target button, which prompted patients to selectively attend to the target button. The recorded electroencephalography data were analyzed in real time to detect event-related potentials evoked by the target and further to determine whether the target was attended to or not. A significant BCI accuracy for a patient implied that he/she had sound localization. Among eighteen patients, eleven and four showed sound localization in the BCI and CRS-R, respectively. Furthermore, all patients showing sound localization in the CRS-R were among those detected by our BCI. The other seven patients who had no sound localization behavior in CRS-R were identified by the BCI assessment, and three of them showed improvements in the second CRS-R assessment after the BCI experiment. Thus, the proposed BCI system is promising for assisting the assessment of sound localization and improving the clinical diagnosis of DOC patients.

Early Neurorehabilitation and Recovery from Disorders of Consciousness After Severe COVID-19.

BackgroundEarly neurorehabilitation improves outcomes in patients with disorders of consciousness (DoC) after brain injury, but its applicability in COVID-19 is unknown. We describe our experience implementing an early neurorehabilitation protocol for patients with COVID-19-associated DoC in the intensive care unit (ICU) and evaluate factors associated with recovery.MethodsDuring the initial COVID-19 surge in New York City between March 10 and May 20, 2020, faced with a disproportionately high number of ICU patients with prolonged unresponsiveness, we developed and implemented an early neurorehabilitation protocol, applying standard practices from brain injury rehabilitation care to the ICU setting. Twenty-one patients with delayed recovery of consciousness after severe COVID-19 participated in a pilot early neurorehabilitation program that included serial Coma Recovery Scale-Revised (CRS-R) assessments, multimodal treatment, and access to clinicians specializing in brain injury medicine. We retrospectively compared clinical features of patients who did and did not recover to the minimally conscious state (MCS) or better, defined as a CRS-R total score (TS) ≥ 8, before discharge. We additionally examined factors associated with best CRS-R TS, last CRS-R TS, hospital length of stay, and time on mechanical ventilation.ResultsPatients underwent CRS-R assessments a median of six (interquartile range [IQR] 3–10) times before discharge, beginning a median of 48 days (IQR 40–55) from admission. Twelve (57%) patients recovered to MCS after a median of 8 days (IQR 2–14) off continuous sedation; they had lower body mass index (p = 0.009), lower peak serum C-reactive protein levels (p = 0.023), higher minimum arterial partial pressure of oxygen (p = 0.028), and earlier fentanyl discontinuation (p = 0.018). CRS-R scores fluctuated over time, and the best CRS-R TS was significantly higher than the last CRS-R TS (median 8 [IQR 5–23] vs. 5 [IQR 3–18], p = 0.002). Earlier fentanyl (p = 0.001) and neuromuscular blockade (p = 0.015) discontinuation correlated with a higher last CRS-R TS.ConclusionsMore than half of our cohort of patients with prolonged unresponsiveness following severe COVID-19 recovered to MCS or better before hospital discharge, achieving a clinical benchmark known to have relatively favorable long-term prognostic implications in DoC of other etiologies. Hypoxia, systemic inflammation, sedation, and neuromuscular blockade may impact diagnostic assessment and prognosis, and fluctuations in level of consciousness make serial assessments essential. Early neurorehabilitation of these patients in the ICU can be accomplished but is associated with unique challenges. Further research should evaluate factors associated with longer-term neurologic recovery and benefits of early rehabilitation in patients with severe COVID-19.

Most of Clinically Unresponsive Patients Present Richer Brain Activity than Expected: Lessons from a Multimodal Neuroimaging Study

Background: A significant proportion of brain-injured patients who are unresponsive at the bedside (i.e., unresponsive wakefulness syndrome – UWS) may present brain activity similar to patients in minimally conscious state (MCS). This peculiar condition has been termed “non-behavioural MCS” or “MCS*”. Methods: Brain 18 F-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was acquired on 135 brain-injured patients diagnosed in prolonged UWS (n=48) or MCS (n=87). Clinical diagnosis was based on repeated Coma Recovery Scale-Revised assessments. Relative metabolic preservation in the fronto-parietal network (measured with standardized uptake value) was evaluated by 3 experts blinded to the clinical diagnosis. Patients with hypometabolism of the fronto-parietal network were labelled UWS, while preservation either confirmed the behavioural diagnosis of MCS or, in absence of behavioural signs of consciousness, suggested a diagnosis of MCS*. The clinical outcome at 1-year follow-up, the functional connectivity (measured with electroencephalography), the grey matter atrophy (assessed with magnetic resonance imaging), and the regional brain metabolic patterns were investigated in the three groups (UWS, MCS* and MCS). Findings: Out of the 48 behavioural UWS patients, 32 (67%) presented a partial preservation of brain metabolism (i.e., MCS*). Compared to the hypometabolic UWS patients, MCS* patients demonstrated a better outcome, higher global functional connectivity in the alpha and theta bands, as well as greater grey matter preservation in the frontal and temporal regions, the fusiform gyrus, and the insula. MCS* patients presented lower brain metabolism mostly in the posterior regions compared to MCS patients. Interpretation: MCS* is a frequent phenomenon that is also associated with a better outcome than the diagnosis of UWS. Complementary exams should be provided to all unresponsive patients before taking medical decisions. Funding Statement: Belgian National Funds for Scientific Research, Human Brain Project SGA3 (No. 945539), DOCMA project (EU-H2020-MSCA–RISE–778234), Belgian Federal Science Policy Office (PRODEX), Bial Foundation, fund Generet, King Baudouin Foundation, AstraZeneca Foundation. Declaration of Interests: The authors declare that there is no conflict of interest regarding the publication of this paper. Ethics Approval Statement: The study was approved by the Ethics Committee of the Faculty of Medicine of the University of Liege. Written informed consent was obtained from healthy controls and patients' legal representatives.

The misdiagnosis of prolonged disorders of consciousness by a clinical consensus compared with repeated coma-recovery scale-revised assessment

BackgroundPrevious studies have shown that a single Coma-Recovery Scale-Revision (CRS-R) assessment can identify high rates of misdiagnosis by clinical consensus. The aim of this study was to investigate the proportion of misdiagnosis by clinical consensus compared to repeated behavior-scale assessments in patients with prolonged disorders of consciousness (DOC).MethodsPatients with prolonged DOC during hospitalization were screened by clinicians, and the clinicians formed a clinical-consensus diagnosis. Trained professionals used the CRS-R to evaluate the consciousness levels of the enrolled patients repeatedly (≥5 times) within a week. Based on the repeated evaluation results, the enrolled patients with prolonged DOC were divided into unresponsive wakefulness syndrome (UWS), minimally conscious state (MCS), and emergence from MCS (EMCS). Finally, the relationship between the results of the CRS-R and the clinical consensus were analyzed.ResultsIn this study, 137 patients with a clinical-consensus diagnosis of prolonged DOC were enrolled. It was found that 24.7% of patients with clinical UWS were actually in MCS after a single CRS-R behavior evaluation, while the repeated CRS-R evaluation results showed that the proportion of misdiagnosis of MCS was 38.2%. A total of 16.7% of EMCS patients were misdiagnosed with clinical MCS, and 1.1% of EMCS patients were misdiagnosed with clinical UWS.ConclusionsThe rate of the misdiagnosis by clinical consensus is still relatively high. Therefore, clinicians should be aware of the importance of the bedside CRS-R behavior assessment and should apply the CRS-R tool in daily procedures.Trial registrationClinicalTrials.gov ID: NCT04139239; Registered 24 October 2019 - Retrospectively registered.

The clinical effect of vagus nerve stimulation in the treatment of patients with a minimally conscious state

Objective:Vagus nerve stimulation (VNS) has recently been used in neurorehabilitation and the recovery of consciousness based on its effects on cortical plasticity. The aim of this study was to examine the therapeutic effects of VNS on patients with a minimally conscious state (MCS).Methods:All patients included in the study were assessed more than 5 months after injury and were receiving regular rehabilitation at our hospital from August 2018 to October 2019. Ten patients diagnosed with MCS by Coma Recovery Scale-Revised (CRS-R) test who underwent VNS surgery were enrolled. The scores on CRS-R evaluation at baseline (before VNS implantation) and 1, 3, and 6 months after VNS treatment were recorded. The stimulation parameters were chosen according to a previous study. All clinical rehabilitation protocols remained unchanged during the study. Furthermore, safety was assessed by analyzing treatment-emergent adverse events (TEAEs).Results:No significant improvement in the total CRS-R scores at the end of the 1-month follow-up was observed (p &gt; 0.05). After 3 months of stimulation, a significant difference (p = 0.0078) was observed in the total CRS-R scores compared with the baseline. After 6 months of VNS treatment, CRS-R assessments showed a continuous significant improvement (p = 0.0039); one patient emerged from the MCS and recovered functional communication and object use. Interestingly, one item of CRS-R scores on visual domain was sensitive to VNS treatment (p = 0.0039). Furthermore, no serious adverse event occurred throughout the study.Conclusion:This exploratory study provides preliminary evidence suggesting that VNS is a safe and effective tool for consciousness recovery in patients with MCS.

Unresponsive wakefulness syndrome: Outcomes from a vicious circle.

Unresponsive wakefulness syndrome: Outcomes from a vicious circle.

Coma Recovery Scale-Revised With and Without the Emotional Stimulation of Caregivers.

The Coma Recovery Scale-Revised (CRS-R) is the gold standard of responsiveness assessment in patients with disorder of consciousness. The purpose of this study is to search for the efficacy of the caregivers' involvement in the evaluation of responsiveness in these patients. Responsiveness assessment was performed in 15 patients with CRS-R. The CRS-R was administered with and without the emotional stimulation of the primary caregiver at different times. Our preliminary findings seem to suggest that, including also the caregivers during CRS-R assessment, may obtain better responsiveness scoring than that obtained by professionals and might reduce the misdiagnosis rate.

A Brain-Computer Interface Based on Three-Dimensional Stereo Stimuli for Assisting Clinical Object Recognition Assessment in Patients With Disorders of Consciousness.

The coma recovery scale-revised (CRS-R) behavioral scale is commonly used for the clinical evaluation of patients with disorders of consciousness (DOC). However, since DOC patients generally cannot supply stable and efficient behavioral responses to external stimulation, evaluation results based on behavioral scales are not sufficiently accurate. In this paper, we proposed a novel brain-computer interface (BCI) based on 3D stereo audiovisual stimuli to supplement object recognition evaluation in the CRS-R. During the experiment, subjects needed to follow the instructions and to focus on the target object on the screen, whereas EEG data were recorded and analyzed in real time to determine the object of focus, and the detection result was output as feedback. Thirteen DOC patients participated in the object recognition assessments using the 3D audiovisual BCI and CRS-R. None of the patients showed object recognition function in the CRS-R assessment before the BCI experiment. However, six of these DOC patients achieved accuracies that were significantly higher than the chance level in the BCI-based assessment, indicating the successful detection of object recognition function in these six patients using our 3D audiovisual BCI system. These results suggest that the BCI method may provide a more sensitive object recognition evaluation compared with CRS-R and may be used to assist clinical CRS-R for DOC patients.

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 expression. 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.

Assessment of Visual Pursuit in Patients With Disorders of Consciousness Based on a Brain-Computer Interface.

Visual pursuit assessment is extensively applied in the behavioral scale-based clinical examination of patients with disorders of consciousness (DOC). However, this assessment is challenging because it relies on behavioral markers, and these patients severely lack behavioral responses. Brain-computer interfaces (BCIs) may provide a potential solution to detect brain responses to external stimuli without requiring behavioral expressions. A BCI system was designed to simulate visual pursuit detection in the coma recovery scale-revised (CRS-R). The graphical user interface included four buttons, one that moved on the screen and three that did not. These buttons flashed in a random order. The patients were prompted to follow the moving button. Based on the collected electroencephalography data, the algorithm determined whether the patient focused on the moving target. Among the 14 DOC patients who participated in the assessments based on the BCI system and the CRS-R, four patients exhibited visual pursuit, and three were nonresponsive in both assessments. More importantly, seven patients who did not exhibit visual pursuit in CRS-R were detected to be responsive to the moving target stimuli in the BCI assessment. Furthermore, five out of seven recovered consciousness to some degree and showed visual pursuit in the second CRS-R assessment. The proposed BCI system is better able to detect visual pursuit than the behavioral scale-based assessment and thus can assist in clinically evaluating the challenging population of DOC patients.

White matter integrity correlates with residual consciousness in patients with severe brain injury.

Previous studies have suggested that white matter disruption plays an important role in disorders of consciousness (DOC) after severe brain injury. Nevertheless, the integrity of white matter architecture supporting consciousness and its relations with clinical severity in patients with DOC remain to be established. In this study, diffusion tensor imaging (DTI) data was collected from 14 DOC patients and 15 healthy control subjects. We combined tract-based spatial statistics (TBSS) with region of interest (ROI) analysis to examine differences of DTI metrics on white matter skeletons between DOC patients and healthy controls, and the association between white matter integrity and patients' residual consciousness assessed by Coma Recovery Scale-Revised (CRS-R). We found that: (1) patients with DOC had widespread white matter integrity disruptions, especially in the fornix; (2) the alteration of white matter microstructure was mainly attributed to the increase in radial diffusivity, possibly reflecting demyelination; (3) the behavioral CRS-R assessment score was positively correlated with white matter integrity in the fornix, uncinate fasciculus, pontine crossing tract, and posterior limb of internal capsule. Our results suggest that despite the widespread abnormalities of white matter following severe brain injury, the impairment of consciousness is likely to result from disruptions of key pathways that link brain regions in distributed networks.

The repetition of behavioral assessments in diagnosis of disorders of consciousness.

To determine whether repeated examinations using the Coma Recovery Scale-Revised (CRS-R) have an impact on diagnostic accuracy of patients with disorders of consciousness and to provide guidelines regarding the number of assessments required for obtaining a reliable diagnosis. One hundred twenty-three adult patients with chronic disorders of consciousness were referred to our tertiary center. They were assessed at least six times with the CRS-R within a 10-day period. Clinical diagnoses based on one, two, three, four, and five Coma Recovery Scale-Revised assessments were compared with a reference diagnosis (ie, the highest behavioral diagnosis obtained after six evaluations) using nonparametric statistics. Results were considered significant at p < 0.05 corrected for multiple comparisons. The number of assessments had a significant effect on the clinical diagnosis. Up to the fourth examination, the diagnosis was still statistically different from the reference diagnosis based on six CRS-R assessments. Compared to this reference diagnosis, the first evaluation led to 36% of misdiagnoses. The number of CRS-R assessments has an impact on the clinical diagnosis of patients with chronic disorders of consciousness. Up to the fourth examinations, behavioral fluctuations may still impact the diagnostic accuracy. We here suggest performing at least five assessments in each patient with disorders of consciousness within a short time interval (eg, 2 weeks) to reduce misdiagnosis. Ann Neurol 2017;81:883-889 Ann Neurol 2017;81:883-889.

Prevalence of coma-recovery scale-revised signs of consciousness in patients in minimally conscious state

ABSTRACTDifferent behavioural signs of consciousness can distinguish patients with an unresponsive wakefulness syndrome from patients in minimally conscious state (MCS). The Coma Recovery Scale-Revised (CRS-R) is the most sensitive scale to differentiate the different altered states of consciousness and eleven items detect the MCS. The aim of this study is to document the prevalence of these items. We analysed behavioural assessments of 282 patients diagnosed in MCS based on the CRS-R. Results showed that some items are particularly frequent among patients in MCS, namely fixation, visual pursuit, and reproducible movement to command, which were observed in more than 50% of patients. These responses were also the most probably observed items when the patients only showed one sign of consciousness. On the other hand, some items were rarely or never observed alone, e.g., object localisation (reaching), object manipulation, intelligible verbalisation, and object recognition. The results also showed that limiting the CRS-R assessment to the five most frequently observed items (i.e., fixation, visual pursuit, reproducible movement to command, automatic motor response and localisation to noxious stimulation) detected 99% of the patients in MCS. If clinicians have only limited time to assess patients with disorders of consciousness, we suggest to evaluate at least these five items of the CRS-R.

An Auditory BCI System for Assisting CRS-R Behavioral Assessment in Patients with Disorders of Consciousness.

The Coma Recovery Scale-Revised (CRS-R) is a consistent and sensitive behavioral assessment standard for disorders of consciousness (DOC) patients. However, the CRS-R has limitations due to its dependence on behavioral markers, which has led to a high rate of misdiagnosis. Brain-computer interfaces (BCIs), which directly detect brain activities without any behavioral expression, can be used to evaluate a patient’s state. In this study, we explored the application of BCIs in assisting CRS-R assessments of DOC patients. Specifically, an auditory passive EEG-based BCI system with an oddball paradigm was proposed to facilitate the evaluation of one item of the auditory function scale in the CRS-R – the auditory startle. The results obtained from five healthy subjects validated the efficacy of the BCI system. Nineteen DOC patients participated in the CRS-R and BCI assessments, of which three patients exhibited no responses in the CRS-R assessment but were responsive to auditory startle in the BCI assessment. These results revealed that a proportion of DOC patients who have no behavioral responses in the CRS-R assessment can generate neural responses, which can be detected by our BCI system. Therefore, the proposed BCI may provide more sensitive results than the CRS-R and thus assist CRS-R behavioral assessments.

TDCS in patients with disorders of consciousness

We assessed the effects of left dorsolateral prefrontal cortex transcranial direct current stimulation (DLPF-tDCS) on Coma Recovery Scale-Revised (CRS-R) scores in severely brain-damaged patients with disorders of consciousness. In a double-blind sham-controlled crossover design, anodal and sham tDCS were delivered in randomized order over the left DLPF cortex for 20 minutes in patients in a vegetative state/unresponsive wakefulness syndrome (VS/UWS) or in a minimally conscious state (MCS) assessed at least 1 week after acute traumatic or nontraumatic insult. Clinical assessments were performed using the CRS-R directly before and after anodal and sham tDCS stimulation. Follow-up outcome data were acquired 12 months after inclusion using the Glasgow Outcome Scale-Extended. Patients in MCS (n = 30; interval 43 ± 63 mo; 19 traumatic, 11 nontraumatic) showed a significant treatment effect (p = 0.003) as measured by CRS-R total scores. In patients with VS/UWS (n = 25; interval 24 ± 48 mo; 6 traumatic, 19 nontraumatic), no treatment effect was observed (p = 0.952). Thirteen (43%) patients in MCS and 2 (8%) patients in VS/UWS further showed postanodal tDCS-related signs of consciousness, which were observed neither during the pre-tDCS evaluation nor during the pre- or post-sham evaluation (i.e., tDCS responders). Outcome did not differ between tDCS responders and nonresponders. tDCS over left DLPF cortex may transiently improve signs of consciousness in MCS following severe brain damage as measured by changes in CRS-R total scores. This study provides Class II evidence that short-duration tDCS of the left DLPF cortex transiently improves consciousness as measured by CRS-R assessment in patients with MCS.

Metabolic activity in external and internal awareness networks in severely brain-damaged patients

An extrinsic cerebral network (encompassing lateral frontoparietal cortices) related to external/sensory awareness and an intrinsic midline network related to internal/self-awareness have been identified recently. This study measured brain metabolism in both networks in patients with severe brain damage. Prospective [18F]-fluorodeoxyglucose-positron emission tomography and Coma Recovery Scale-Revised assessments in a university hospital setting. Healthy volunteers and patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), emergence from MCS (EMCS), and locked-in syndrome (LIS). A total of 70 patients were included in the study: 24 VS/UWS, 28 MCS, 10 EMCS, 8 LIS and 39 age-matched controls. VS/UWS showed metabolic dysfunction in extrinsic and intrinsic networks and thalami. MCS showed dysfunction mostly in intrinsic network and thalami. EMCS showed impairment in posterior cingulate/retrosplenial cortices. LIS showed dysfunction only in infratentorial regions. Coma Recovery Scale-Revised total scores correlated with metabolic activity in both extrinsic and part of the intrinsic network and thalami. Progressive recovery of extrinsic and intrinsic awareness network activity was observed in severely brain-damaged patients, ranging from VS/UWS, MCS, EMCS to LIS. The predominance of intrinsic network impairment in MCS could reflect altered internal/self-awareness in these patients, which is difficult to quantify at the bedside.

Diagnostic accuracy of the vegetative and minimally conscious state: Clinical consensus versus standardized neurobehavioral assessment

BackgroundPreviously published studies have reported that up to 43% of patients with disorders of consciousness are erroneously assigned a diagnosis of vegetative state (VS). However, no recent studies have investigated the accuracy of this grave clinical diagnosis. In this study, we compared consensus-based diagnoses of VS and MCS to those based on a well-established standardized neurobehavioral rating scale, the JFK Coma Recovery Scale-Revised (CRS-R).MethodsWe prospectively followed 103 patients (55 ± 19 years) with mixed etiologies and compared the clinical consensus diagnosis provided by the physician on the basis of the medical staff's daily observations to diagnoses derived from CRS-R assessments performed by research staff. All patients were assigned a diagnosis of 'VS', 'MCS' or 'uncertain diagnosis.'ResultsOf the 44 patients diagnosed with VS based on the clinical consensus of the medical team, 18 (41%) were found to be in MCS following standardized assessment with the CRS-R. In the 41 patients with a consensus diagnosis of MCS, 4 (10%) had emerged from MCS, according to the CRS-R. We also found that the majority of patients assigned an uncertain diagnosis by clinical consensus (89%) were in MCS based on CRS-R findings.ConclusionDespite the importance of diagnostic accuracy, the rate of misdiagnosis of VS has not substantially changed in the past 15 years. Standardized neurobehavioral assessment is a more sensitive means of establishing differential diagnosis in patients with disorders of consciousness when compared to diagnoses determined by clinical consensus.

Measuring the effect of amantadine in chronic anoxic minimally conscious state

The effect of pharmacological agents on recovery in chronic disorders of consciousness remains unsatisfactory.1 Amantadine, a dopaminergic agonist, has been suggested to behaviourally improve recovery from both a vegetative state...