Nociception Coma Scale-Revised Research Articles

Rasch Analysis of the Chinese Version of the Nociception Coma Scale-Revised in Patients with Prolonged Disorders of Consciousness.

The aim of this study was to analyze the Chinese version of the Nociception Coma Scale-Revised in patients with prolonged disorders of consciousness within the framework of Rasch modeling, including investigating the invariance of total scores across different etiologies of disorders of consciousness. Prospective psychometric study. Patients with prolonged disorders of consciousness from the Rehabilitation and Neurology units in hospital. None. The Nociception Coma Scale-Revised was undertaken by trained raters and the Coma Recovery Scale-Revised was used to assess patients' consciousness. The psychometric properties within the Rasch model including item-person targeting, reliability and separation, item fit, unidimensionality, and differential item functioning were assessed. 84 patients with prolonged disorders of consciousness (mean age 53 years; mean injury 5 months; 42 with Minimally Conscious State and 42 with Unresponsive Wakefulness Syndrome) of 252 observations were enrolled in the study. Through the procedure of repeated assessment and differential item function, a lower item bias Rasch set was purified. The Rasch model assumptions were examined and met, with item reliability and validity meeting the recommended threshold. The Chinese version of the Nociception Coma Scale-Revised demonstrated unidimensionality, good reliability and separation, and good item fit, but dissatisfied person fit and item-person targeting. The verbal subscale showed a notable discrepancy between person responses and the difficulty of the items, suggesting limited clinical significance.

Acupuncture-assisted therapy for prolonged disorders of consciousness: study protocol for a randomized, conventional-controlled, assessor-and-statistician-blinded trial.

Acupuncture is a promising non-pharmaceutical complementary therapy in treating prolonged Disorders of consciousness (pDOC), but solid evidence to support its effectiveness and safety is still lacking. Thus, the purpose of this study is to investigate the efficacy and safety of acupuncture-assisted therapy for pDOC patients. A single-center, prospective, randomized, conventional-controlled, assessor-and-statistician-blinded trial has been designed and is being conducted at West China Hospital of Sichuan University. A total of 110 participants will be randomly assigned to the experimental group and the control group in a 1:1 allocation ratio and evaluated using Coma Recovery Scale-Revised (CRS-R) at 8 a.m., 12 p.m., and 4 p.m. on 2 consecutive days before enrollment to determine the consciousness level. The experimental group will receive acupuncture combined with conventional treatment, while the control group will receive only conventional treatment during the trial observation period. The treatment duration of both groups will be 20 days. Among them, the frequency of acupuncture-assisted therapy is once a day, with 10 consecutive sessions followed by a day's rest for a total of 24 days. Data will be collected separately during baseline and after the final treatment. For data analysis, both Full Analysis Set (FAS) and Per Protocol Set (PPS) principles will be performed together by applying SPSS 27.0 software. The primary outcome measures are the changes of CRS-R before and after treatment, while the secondary outcome measures are the changes of Full Outline of Unresponsiveness Scale (FOUR), the changes of Nociception Coma Scale-Revised (NCS-R), the changes of Disability Rating Scale (DRS), the changes of Mismatch Negativity (MMN) and P300 before and after treatment, respectively. This trial aims to rationally assess the consciousness level from multiple 2 perspectives through subjective evaluation and objective detection by selecting several standardized clinical scales combined with Event-Related Potential (ERP) detection technology. In this way, we will be able to reduce the subjectivity of consciousness assessment and objectively evaluate the clinical efficacy of acupuncture-assisted therapy for pDOC. The study, if proven to be effective and safe enough, will provide a favorable evidence to guide medical decision-making choices and future researches. https://www.chictr.org.cn/, identifier ChiCTR2300076180.

Neck muscle spasticity in patients with disorder of consciousness: a pilot study.

Disorder of consciousness (DOC) is a state of prolonged altered consciousness due to severe acquired brain injury (ABI). DOC can be differentiated into coma, unresponsive wakefulness syndrome (UWS), or minimally conscious state (MCS) depending on the behavioral features observed and their relationship to the level of consciousness. Spasticity is one of the most frequently reported medical comorbidities in DOC patients. Since there is a critical lack of spasticity-focused studies and, in turn, of target treatment, we designed this pilot prospective study to evaluate cervical spine muscle spasticity and its effect on rehabilitation outcome in a large cohort of patients followed from the post-acute phase to 6 months after severe ABI. To evaluate neck muscle spasticity and investigate its impact on neurological and functional outcome in a large cohort of adult patients with DOC followed from post-acute to 6 months after severe ABI. Single-center prospective pilot study. Highly specialized inpatient neurorehabilitation clinic. Patients with severe ABI admitted within 3 months after the acute event to our Neurorehabilitation Unit between May 21st, 2019 and April 23rd, 2020 for treatment of DOC as a part of their rehabilitation program. In this single-center prospective pilot study demographic data, etiology of ABI (traumatic versus non-traumatic), DOC evaluated with the revised Coma Recovery Scale (CRS-R), and neurological and functional outcome assessed respectively with the Glasgow Coma Scale (GCS) and Functional Independence Measure (FIM) were considered. During cervical examination, we assessed spasticity with the Modified Ashworth Scale (MAS), deviation of head alignment with a goniometer, and pain with the Nociception Coma Scale-Revised (NCS-R). Of the 48 patients, 41.7% were diagnosed with UWS and 58.3% were in a minimally conscious state (MCS). We found spasticity of neck muscles in 91.7% of patients, with no difference in severity (assessed with MAS) between UWV and MCS. The NCS-R score at cervical spine examination was lower in UWS than MCS. Spasticity was severer in patients with traumatic brain injury (TBI) compared to non-traumatic. At multiple linear regression analysis, younger age, hemisyndrome, and tetraparesis were independent predictors of severity of neck muscle spasticity in MCS. More severe spasticity was a predictor of worse neurological and functional outcome at discharge in UWS patients, independently of the other confounding variables at admission (e.g., age, severity of brain injury, functional assessment, and pain). Spasticity of neck muscles frequently develops in patients with DOC and is more severe in those after TBI. UWV and MCS have different spasticity profiles as regards risk factors and neurological and functional outcome. Severity of neck muscle spasticity in UWV patients may represent an early indicator of worse neurological and functional outcome after inpatient rehabilitation. Our findings could prompt clinicians to redefine the rehabilitation aims regarding spasticity and to estimate the functional outcome in patients undergoing intensive rehabilitation after severe ABI.

Effects of simultaneous transcutaneous auricular vagus nerve stimulation and high-definition transcranial direct current stimulation on disorders of consciousness: a study protocol.

Non-invasive brain stimulation (NIBS) techniques are now widely used in patients with disorders of consciousness (DOC) for accelerating their recovery of consciousness, especially minimally conscious state (MCS). However, the effectiveness of single NIBS techniques for consciousness rehabilitation needs further improvement. In this regard, we propose to enhance from bottom to top the thalamic-cortical connection by using transcutaneous auricular vagus nerve stimulation (taVNS) and increase from top to bottom cortical-cortical connections using simultaneous high-definition transcranial direct current stimulation (HD-tDCS) to reproduce the network of consciousness. The study will investigate the effect and safety of simultaneous joint stimulation (SJS) of taVNS and HD-tDCS for the recovery of consciousness. We will enroll 84 MCS patients and randomize them into two groups: a single stimulation group (taVNS and HD-tDCS) and a combined stimulation group (SJS and sham stimulation). All patients will undergo a 4-week treatment. The primary outcome will be assessed using the coma recovery scale-revised (CRS-R) at four time points to quantify the effect of treatment: before treatment (T0), after 1 week of treatment (T1), after 2 weeks of treatment (T2), and after 4 weeks of treatment (T3). At the same time, nociception coma scale-revised (NCS-R) and adverse effects (AEs) will be collected to verify the safety of the treatment. The secondary outcome will involve an analysis of electroencephalogram (EEG) microstates to assess the response mechanisms of dynamic brain networks to SJS. Additionally, CRS-R and AEs will continue to be obtained for a 3-month follow-up (T4) after the end of the treatment. This study protocol aims to innovatively develop a full-time and multi-brain region combined neuromodulation paradigm based on the mesocircuit model to steadily promote consciousness recovery by restoring thalamocortical and cortical-cortical interconnections.

Features of postoperative pain relief in patients with a low level of consciousness: a prospective randomised study

AIM: To determine the possibility of using analgonociception monitoring (analgesia nociception index, ANI) to assess the need for postoperative analgesia in patients with prolonged impairment of consciousness.
 MATERIAL AND METHODS: This pilot prospective randomized study enrolled 34 consecutive patients with chronic impairment of consciousness (vegetative state/minimal state of consciousness) who underwent neurosurgical interventions. Randomization was made by the envelope method for the grouping of the patients: study group (SG, n=17), received anesthesia with intravenous paracetamol 1000 mg according to ANI in the postoperative period; control group (CG, n=17), without additional anesthesia in the postoperative period. Patients with arrhythmias were excluded. The groups are comparable in terms of the main clinical parameters (all parameters p 0.05). The ANI (MetroDoloris device, France) was recorded at 1, 4, 8, 12, and 24 h after surgery. The valuation was based on the revised scale for assessing pain in a coma, i.e., Nociception Coma ScaleRevised (NCS-R) [7], after 4, 12, and 24 h.
 RESULTS: An intragroup comparison of the changes in ANI during postoperative day 1 showed an adequate level of pain relief (60.1 [55.362.5]), whereas in the group without postoperative analgesia with paracetamol, by 4 h after the operation, ANI dropped to the lower limit (46.3 [40.251.9]). In an intergroup comparison in the first 8 h after surgery, ANI was significantly higher than in the group without anesthesia (p=0.04) and had values of 55, which indicates the absence of pronounced vegetative reactions indicating the presence of pain. From 12 oclock, the values are leveled out, not going beyond the limits of indicators of inadequate anesthesia (p=0.69). When assessing nociception on the NCR-R scale during the postoperative day in both groups, a tendency to the appearance of weak autonomic responses was observed (6 [5; 8] in SG and 6 [5; 7] in CS, respectively), which did not differ significantly. The presence of pain 4 h after surgery was confirmed by increased levels of cortisol and salivary alpha-amylase in patients without postoperative analgesia (p=0.03).
 CONCLUSION: No generally recognized and available evidence-based instrumental methods are available for the assessment of pain intensity in patients with chronic impairment of consciousness. There is no single position of the professional community on the need for postoperative analgesia in such patients. Further studies to evaluate the effectiveness of using the ANI Metro Doloris monitoring system with a significant number of observations will lead to the determination of adequate perioperative analgesia regimens in patients with various forms of prolonged impairment of consciousness.

Pain assessment during physiotherapy and noxious stimuli in patients with disorders of consciousness: A preliminary study.

ObjectivesThe primary purpose of this study is to determine whether patients with disorders of consciousness (DOC) (unresponsive wakefulness syndrome, UWS; minimally conscious state, MCS) experience pain during physiotherapy and noxious stimuli in a larger patient population.Materials and methodsThe patients’ level of consciousness was measured with the Coma Recovery Scale-Revised (CRS-R). Additionally, the Nociception Coma Scale-revised (NCS-R) was used to assess their pain response. The NCS-R total scores between UWS and MCS at baseline, physiotherapy and noxious stimulus were compared using the Mann-Whitney U test (Wilcoxon rank-sum test) and the Kruskal-Wallis H test with Bonferroni correction.ResultsThe study enrolled 93 participants. There was a statistically significant difference in NCS-R total scores between the three conditions (H = 215.25, p < 0.001). At baseline, there was no statistically significant difference between MCS and UWS (U = 378, z = –1.35, p = 0.178). While there was a statistically significant difference between MCS and UWS during physiotherapy (U = 1,362, z = –3.06, p < 0.01) and under noxious stimuli (U = 5142.5, z = –11.22, p < 0.001).ConclusionPhysiotherapy improved the activity responsiveness of DOC patients, and patients experienced less potential pain. However, some DOC patients, especially MCS patients, perceived pain under the noxious stimuli.

Nociception coma scale-revised (NCS-R) with personalized painful stimulation versus standard stimulus in non-communicative patients with disorders of consciousness

Covert cognition may be present in around 15% of patients with Disorder of Consciousness (DoC). The lack of overt behavioural responsiveness may be due to many confounding factors, including diffuse pain. Aim of the present study was to compare, in non-communicative DoC patients, NCS-R scores obtained with the pressure on fingernail bed (standard stimulus, SS) versus other personalized painful stimuli (PS), shared with the rehabilitation staff and to verify possible correlations between NCS-R and Coma Recovery Scale-Revised (CRS-R).

Evaluation of the effect of analgesic treatment on signs of nociception-related behaviors during physiotherapy in patients with disorders of consciousness: a pilot crossover randomized controlled trial.

Neuro-orthopedic disorders are common in patients with disorders of consciousness (DOC) and can lead to potential pain. However, the patients' inability to communicate makes pain detection and management very challenging for clinicians. In this crossover randomized double-blind placebo-controlled study, we investigated the effects of an analgesic treatment on the presence of nociception-related behaviors. At baseline, the Nociception Coma Scale-Revised (NCS-R) was performed in 3 conditions: a non-noxious stimulation, a noxious stimulation, and during a physiotherapy session. Patients with a NCS-R total score during physiotherapy equal or above the score observed after the noxious stimulation could participate to the clinical trial, as well as patients with a score above 5. They received an analgesic treatment and a placebo on 2 consecutive days in a randomized order followed by an assessment with the NCS-R. Of the 18 patients, 15 displayed signs of potential pain during physiotherapy. Patients showed higher NCS-R scores during physiotherapy compared with the other conditions, suggesting that mobilizations were potentially painful. Of these 15 patients, 10 met the criteria to participate in the placebo-controlled trial. We did not find any effect of analgesic treatment on the NCS-R scores. This study highlights that physiotherapy may be potentially painful for patients with DOC, while analgesic treatments did not reduced NCS-R scores. Therefore, careful monitoring with appropriate assessment and treatment before and during mobilization should become a priority in clinical settings. Future studies should focus on the development of assessment tools sensitive to analgesic dosage to manage pain in DOC.

Cross-cultural adaptation and content validity evidence of the Brazilian version of the Nociception Coma Scale-revised

Cross-cultural adaptation and content validity evidence of the Brazilian version of the Nociception Coma Scale-revised

Can the Nociception Coma Scale-Revised Be Used in Patients With a Tracheostomy?

ObjectiveTo investigate the influence of the presence of a tracheostomy tube to assess pain with the Nociception Coma Scale-Revised (NCS-R) in patients with disorders of consciousness (DOC). DesignA cohort study in which patients were evaluated at a single time point. SettingPatients were evaluated in a tertiary care hospital. ParticipantsPatients (N=125) (unresponsive wakefulness syndrome [UWS]: 46 patients, minimally conscious state [MCS]: 74 patients, emerging from MCS [eMCS]: 5 patients, mean age: 46±16y, time since injury: 817±1280d) in a convenience sample were evaluated with the NCS-R after noxious stimulation. InterventionsNot applicable. Main Outcome MeasuresWe compared the NCS-R scores of patients with and without tracheostomy with a Mann-Whitney U test. A secondary outcome was to evaluate the influence of the presence of a tracheostomy on the previously described cutoff score of 2. ResultsThe presence of a tracheostomy was associated with lower verbal subscores (P=.002) as well as total scores (P=.039). The cutoff score of 2 remained valid for the group of patients with tracheostomy with a high sensitivity (71.43%) and specificity (89.29%), as well as when we excluded the verbal subscore of the NCS-R (sensitivity=83.2% and specificity=92.4%). ConclusionOur study confirms the validity of the NCS-R in DOC patients with a tracheostomy. However, the presence of a nonspeaking tracheostomy should be clearly mentioned when applying the NCS-R, because it significantly lowers the verbal subscore.

Nociception Coma Scale-Revised Allows to Identify Patients With Preserved Neural Basis for Pain Experience

The Nociception Coma Scale-Revised (NCS-R) was developed to help assess pain in patients with disorders of consciousness (DOC). Several studies have shown its sensitivity in assessing response to acute noxious stimuli. However, they failed to determine a reliable cut-off score that could be used to infer pain processing in these patients. This retrospective cross-sectional study aimed to determine a NCS-R cut-off score supporting preserved neural basis for pain experience, based on brain metabolism preservation as measured by fluorodeoxyglucose positron emission tomography (FDG-PET). We included patients in unresponsive wakefulness syndrome (UWS) confirmed by the FDG-PET and examined the NCS-R total scores. As the highest score was 4, we defined the cut-off to be 5 and compared the brain metabolism of these patients to matched patients with DOC and a NCS-R cut-off score ≥5 (ie, potential pain), as well as healthy subjects. We found a higher global cerebral metabolism in healthy subjects compared to both patient groups and also in patients with potential pain compared with FDG-PET confirmed UWS. We observed a preserved metabolism in the left insula in patients with potential pain compared with FDG-PET confirmed UWS. PerspectivesOur data suggest that using the cut-off score of 5 could be helpful to improve pain management in patients with DOC. Future studies should focus on patients showing scores below this cut-off to better characterize their profile and improve care.

Nociception Coma Scale–Revised: Nurses’ Experience in Clinical Practice

BackgroundThe Nociception Coma Scale–Revised (NCS-R) is a rating scale developed and validated for measurement of nociception and pain among patients with brain injuries in unresponsive wakefulness syndrome or minimally conscious state. However, little is known about its use in daily clinical practice. AimsThe aim of this study was to explore clinical experience with the NCS-R by means of focus group interviews with nurses and nurse assistants in a subacute rehabilitation ward for patients with severe brain injuries. DesignQualitative focus group interview study. SettingsDepartment for highly specialized neurorehabilitation for patients with severe brain injuries. Participants/SubjectsNurses and nurse assistants. MethodsIn total, 12 experienced registered nurses and nurse assistants participated in two recorded focus group interviews. The participants were selected from the subacute neurorehabilitation ward on the following criteria: Employed at the ward for at least 11 months and being introduced to and having experience with using the NCS-R in own patients for a minimum period of 6 months. An inductive qualitative analysis was conducted by reading the interview text through several times, and meaning units were defined first separately and later jointly between the authors. Then meaning units were coded and categorized into subthemes and themes. ResultsWe found three themes, general relevance of the NCS-R, NCS-R versus level of consciousness, and overall assessment of pain in patients with disorders of consciousness, with a total of eight subthemes. ConclusionsThe content and subscales of the NCS-R are relevant for pain assessment in patients with severe brain injury in subacute rehabilitation. However, with the present cutoff value at 4 points, challenges are associated with using NCS-R, especially in patients with unresponsive wakefulness syndrome because they are at risk of not being assessed with respect to pain.

Reliability and validity of nociception coma scale-revised (NCS-R) in patients with disorders of consciousness

Objective To assess the pain of patients with disorders of consciousness(DOC) and evaluate the reliability and validity of Chinese version of Nociception Coma Scale- revised (NCS-R). Methods Sixty-two patients with disorders of consciousness were assessed by NCS-R and the internal reliability, inter-rater reliability, test-retest reliability and concurrent validity was analyzed. Results Cronbach's alpha (α) of internal reliability was 0.611, test-retest reliability for the NCS-R total scores by spearman was 0.884.For the subscales, the reliability for the motor, verbal and facial subscale scores by Cronbach's kappa were 0.856, 0.870 and 0.856 respectively.Inter-rater reliability for the NCS-R total scores by spearman was 0.662.For the subscales, the reliability for the motor, verbal and facial subscale scores by Cronbach's kappa were 0.962, 0.867 and 0.671 respectively.The spearman coefficient of concurrent validity was 0.560 (all P<0.01). Conclusion The NCS-R is a good valid scale and available for Chinese clinician and researchers to assess the pain of DOC patients. Key words: Nocieption coma scale-revised; Pain assessment; Disorders of consciousness; Reliability and validity

Assessing pain in patients with chronic disorders of consciousness: Are we heading in the right direction?

The deterioration of sensory-motor integration within the pain matrix in patients with chronic Disorders of Consciousness (DoC) is one of the principal mechanisms responsible for non-conscious pain perception. The present study aimed to assess whether the variability in the inter-peak interval (IPI) between the N2 and P2 components of laser evoked potentials (LEP) could represent an objective marker of the behavioral responsiveness to nociceptive stimulation, as measured by the Nociception Coma Scale-Revised (NCS-R), and regardless of the sensory part of pain processing. We found that only IPI variability showed a significant correlation with NCS-R score, independently of the stimulation intensity (that influences the sensory part of pain processing). It was thus concluded that IPI variability might represent an objective measure of pain processing, which may help clinicians in the development of effective pain management strategies.

Pain assessment tools in critical patients with oral communication difficulties: a scope review

ABSTRACT BACKGROUND AND OBJECTIVES: Pain is a frequent experience in intensive care units and its assessment and handling are challenging to healthcare professionals. The objective of this study was to identify and analyze the available tools to assess pain in patients with oral communication difficulties in intensive care units. CONTENTS: Scope review of the literature in six databases that identified four observational tools to assess pain in critical patients: Behavioral Pain Scale, Critical-Care Pain Observation Tool, Nociception Coma Scale and Nociception Coma Scale-Revised. All tools use behavior indicators of pain and only one is adapted to the Portuguese language. CONCLUSION: The use of a valid, easy to apply instrument, with clear and straightforward descriptions is essential to assess pain in patients with oral communication difficulties in intensive care units. There are good quality tools to assess pain in intensive care units. Most tools, however, are not yet validated to the Portuguese language. Translation and validation studies are necessary so that tools with well-established psychometric properties can be available in our practice.

Is the Nociception Coma Scale-Revised a Useful Clinical Tool for Managing Pain in Patients With Disorders of Consciousness?

Our objective was to assess the clinical usefulness of the Nociception Coma Scale-revised (NCS-R) in pain management of patients with disorders of consciousness. Thirty-nine patients with potential painful conditions (eg, due to fractures, decubitus ulcers, or spasticity) were assessed during nursing cares before and after the administration of an analgesic treatment tailored to each patient's clinical status. In addition to the NCS-R, the Glasgow Coma Scale (GCS) was used before and during treatment to observe fluctuations in consciousness. Twenty-three of them had no analgesic treatment before the assessment, whereas the analgesic treatment has been adapted in the other 16 patients. We performed nonparametric Wilcoxon tests to investigate the difference in the NCS-R and GCS total scores but also in the NCS-R subscores before versus during treatment. The effect of the level of consciousness and the etiology were assessed using a Mann-Whitney U test. NCS-R total scores were statistically lower during treatment when compared with the scores obtained before treatment. We also found that the motor, verbal, and facial expression subscores were lower during treatment than before treatment. In contrast, we found no difference between the GCS total scores obtained before versus during treatment. Our results suggest that the NCS-R is an interesting clinical tool for pain management. Besides, this tool seems useful when a balance is needed between reduced pain and preserved level of consciousness in patients with disorders of consciousness.

Do unresponsive wakefulness syndrome patients feel pain? Role of laser-evoked potential-induced gamma-band oscillations in detecting cortical pain processing

It has been proposed that a neural signature of aware pain perception could be represented by the modulation of gamma-band oscillation (GBO) power induced by nociceptive repetitive laser stimulation (RLS). The aim of our study was to correlate the RLS-induced GBO modulation with the Nociception Coma Scale-Revised (NCS-R) scores (a validated scale assessing possible aware pain perception in patients with chronic disorders of consciousness), in an attempt to differentiate unresponsive wakefulness syndrome (UWS) patients from minimally conscious state (MCS) ones (both of them are awake but exhibit no or limited and fluctuant behavioral signs of awareness and mentation, and low and high NCS-R scores, respectively). In addition, we attempted to identify those among UWS patients who probably experienced pain at covert level (i.e. being aware but unable to show pain-related purposeful behaviors, which are those sustained, reproducible, and voluntary behavioral responses to nociceptive stimuli). Notably, the possibility of clearly differentiating UWS from MCS patients has outmost consequences concerning prognosis (worse in UWS) and adequate pain treatment. RLS consisted in 80 trains of three laser stimuli (delivered at 1Hz), at four different energies, able to evoke Aδ-fiber related laser evoked potentials. After each train, we assessed the NCS-R score. EEG was divided into epochs according to the laser trains, and the obtained epochs were classified in four categories according to the NCS-R score magnitude. We quantified the GBO absolute power for each category. RLS protocol induced a strongly correlated increase in GBO power and NCS-R score (the higher the laser stimulation intensity, the higher the NCS-R, independently of stimulus repetition) in all the MCS patients, thus confirming the presence of aware pain processing. Nonetheless, such findings were present even in five UWS individuals. This could suggest the presence of covert pain processing in such subjects, despite the low NCS-R scores. In conclusion, RSL-induced GBO power evaluation could be helpful in the differential diagnosis between MCS and UWS patients, besides the clinical assessment, and in identifying covert pain perception in some UWS individuals.

Commentary: Cortical responses to salient nociceptive and not nociceptive stimuli in vegetative and minimal conscious state.

We read with great interest the work by de Tommaso et al. (2015) assessing cortical responsiveness to nociceptive and multimodal sensory stimuli in patients affected by chronic disorders of consciousness (DOC). In their valuable work, the authors attempted to assign each patient to the most appropriate DOC category by using auditory, visual, somatosensory, and nociceptive laser stimuli. Interestingly, the motor responsiveness to nociceptive stimuli assessed through the Coma Recovery Scale-Revised and the Nociception Coma Scale-Revised correlated with each evoked response, but Laser Evoked Potentials (LEPs). The latter were recognizable in all of the patients, independently from the preservation of other sensory modalities and the motor responsiveness to nociceptive stimuli. Hence, LEP absence should not be considered as a demonstration of the inability to experience pain, since the preservation does not per se indicate a conscious pain perception in DOC (de Tommaso et al., 2015). However, it is to note that we should be aware in interpreting authors' findings since these are based on a very limited number of patients (i.e., only 4 MCS and 5 VS). Moreover, since the presence vs. absence of LEPs was based on a subjective visual identification of the event-related potential waveforms, the possibility of misinterpretations (mainly due to very low signal-to-noise ratio) should be taken into account.

Cortical responses to salient nociceptive and not nociceptive stimuli in vegetative and minimal conscious state.

Aims: Questions regarding perception of pain in non-communicating patients and the management of pain continue to raise controversy both at a clinical and ethical level. The aim of this study was to examine the cortical response to salient visual, acoustic, somatosensory electric non-nociceptive and nociceptive laser stimuli and their correlation with the clinical evaluation.Methods: Five Vegetative State (VS), 4 Minimally Conscious State (MCS) patients and 11 age- and sex-matched controls were examined. Evoked responses were obtained by 64 scalp electrodes, while delivering auditory, visual, non-noxious electrical and noxious laser stimulation, which were randomly presented every 10 s. Laser, somatosensory, auditory and visual evoked responses were identified as a negative-positive (N2-P2) vertex complex in the 500 ms post-stimulus time. We used Nociception Coma Scale-Revised (NCS-R) and Coma Recovery Scale (CRS-R) for clinical evaluation of pain perception and consciousness impairment.Results: The laser evoked potentials (LEPs) were recognizable in all cases. Only one MCS patient showed a reliable cortical response to all the employed stimulus modalities. One VS patient did not present cortical responses to any other stimulus modality. In the remaining participants, auditory, visual and electrical related potentials were inconstantly present. Significant N2 and P2 latency prolongation occurred in both VS and MCS patients. The presence of a reliable cortical response to auditory, visual and electric stimuli was able to correctly classify VS and MCS patients with 90% accuracy. Laser P2 and N2 amplitudes were not correlated with the CRS-R and NCS-R scores, while auditory and electric related potentials amplitude were associated with the motor response to pain and consciousness recovery.Discussion: pain arousal may be a primary function also in vegetative state patients while the relevance of other stimulus modalities may indicate the degree of cognitive and motor behavior recovery. This underlines the importance of considering the potential experience of pain also in patients in vegetative state and to appropriately assess a possible treatment also in those patients.

Clinical monitoring scales in acute brain injury: assessment of coma, pain, agitation, and delirium.

Serial clinical examination represents the most fundamental and basic form of neurological monitoring, and is often the first and only form of such monitoring in patients. Even in patients subjected to physiological monitoring using a range of technologies, the clinical examination remains an essential tool to follow neurological progress. Key aspects of the clinical examination have now been systematized into scoring schemes, and address consciousness, pain, agitation, and delirium (PAD). The Glasgow Coma Scale has been the traditional tool to measure consciousness, but the full outline of unresponsiveness (FOUR) score has recently been validated in a variety of settings, and at present, both represent clinically useful tools. Assessment of PAD in neurologically compromised patients present special challenges. For pain, the Numeric Rating Scale is the preferred initial approach, with either the Behavioral Pain Scale or the Critical Care Pain Observation Tool in subjects who are not able to respond. The Nociception Coma Scale-Revised may be useful in patients with severe disorders of consciousness. Conventional sedation scoring tools for critical care, such as the Richmond Area Sedation Scale (RASS) and Sedation-Agitation Scale (SAS) may provide reasonable tools in some neurocritical care patients. The use of sedative drugs and neuromuscular blockers may invalidate the use of some clinical examination tools in others. The use of sedation interruption to assess neurological status can result in physiological derangement in unstable patients (such as those with uncontrolled intracranial hypertension), and is not recommended.