Comorbidities: a key issue in patients with disorders of consciousness

Assessment of Frequency and Predictive Value of Comorbidities in Patients With Disorders of Consciousness in the Acute Setting

Medical comorbidities are frequent in patients with disorders of consciousness (DoC) and their impact on outcomes is under investigation. The aim of this study was to investigate patients with DoC in the acute stage and the influence of comorbidities. Patients admitted to intensive care units and neurological units with a diagnosis of coma, vegetative state/unresponsive wakefulness syndrome (VS/UWS), and minimally conscious state (MCS) were investigated through the Glasgow Coma Scale (GCS), the Coma Recovery Scale - Revised (CRS-R) and the Comorbidities Coma Scale (CoCos). Forty-three patients (21 men and 22 women; mean age at admission: 60.4 ± 21.0) were included in the study. The most frequent diagnosis at admission was coma (72%) followed by VS/UWS (14%) and MCS (14%). The most frequent brain injury was subarachnoid hemorrhage (46%). At the 6-month follow-up, 19 patients had died (44%), 15 showed a full recovery of consciousness (35%), 7 were in a condition of emergence from MCS (16%), and 2 showed a persistent VS/UWS (5%). Forty-two (98%) patients showed at least one comorbidity: presence of life-support device (92.9%), anemia (76.2%), arterial hypertension (66,7%), hydrocephalus (45.3%), and respiratory infections (45.2%) were those most frequently reported. At the Multivariable Cox regression, the presence of renal disease (hazard ratio [HR] 33.37; p = 0.033) and malnutrition (HR 14.52; p = 0.001) were predictors of missed recovery of full consciousness. Although adverse outcomes are generally predicted by the severity of brain damage, the presence of medical comorbidities in an acute phase could influence outcomes and long-term prognosis.

Distinct Spectral Profiles of Awake Resting EEG in Disorders of Consciousness: The Role of Frequency and Topography of Oscillations

The prolonged disorders of consciousness (PDOC) pose a challenge for an accurate clinical diagnosis, mainly due to patients' scarce or ambiguous behavioral responsiveness. Measurement of brain activity can support better diagnosis, independent of motor restrictions. Methods based on spectral analysis of resting-state EEG appear as a promising path, revealing specific changes within the internal brain dynamics in PDOC patients. In this study we used a robust method of resting-state EEG power spectrum parameter extraction to identify distinct spectral properties for different types of PDOC. Sixty patients and 37 healthy volunteers participated in this study. Patient group consisted of 22 unresponsive wakefulness patients, 25 minimally conscious patients and 13 patients emerging from the minimally conscious state. Ten minutes of resting EEG was acquired during wakefulness and transformed into individual power spectra. For each patient, using the spectral decomposition algorithm, we extracted maximum peak frequency within 1-14 Hz range in the centro-parietal region, and the antero-posterior (AP) gradient of the maximal frequency peak. All patients were behaviorally diagnosed using coma recovery scale-revised (CRS-R). The maximal peak frequency in the 1-14 Hz range successfully predicted both neurobehavioral capacity of patients as indicated by CRS-R total score and PDOC diagnosis. Additionally, in patients in whom only one peak within the 1-14 Hz range was observed, the AP gradient significantly contributed to the accuracy of prediction. We have identified three distinct spectral profiles of patients, likely representing separate neurophysiological modes of thalamocortical functioning. Etiology did not have significant influence on the obtained results.

Medical comorbidities in patients with prolonged disorder of consciousness: A narrative review

BACKGROUND

A few studies specifically addressed medical comorbidities (MCs) in patients with severe acquired traumatic or non-traumatic brain injury and prolonged disorders of consciousness (pDoC; i.e., patients in vegetative state/unresponsive wakefulness syndrome, VS/UWS, or in minimally conscious state, MCS).

OBJECTIVE

To provide an overview on incidence of MCs in patients with pDoC.

METHODS

Narrative review on most impacting MCs in patients with pDoC, both those directly related to brain damage (epilepsy, neurosurgical complications, spasticity, paroxysmal sympathetic hyperactivity, PSH), and those related to severe disability and prolonged immobility (respiratory comorbidities, endocrine disorders, metabolic abnormalities, heterotopic ossifications).

RESULTS

Patients with pDoC are at high risk to develop at least one MC. Moderate or severe respiratory and musculoskeletal comorbidities are the most common MCs. Epilepsy and PSH seem to be more frequent in patients in VS/UWS compared to patients in MCS, likely because of higher severity in the brain damage in VS. Endocrine metabolic, PSH and respiratory complications are less frequent in traumatic etiology, whereas neurogenic heterotopic ossifications are more frequent in traumatic etiology. Spasticity did not significantly differ between VS/UWS and MCS and in the three etiologies. MCs are associated with higher mortality rates, worse clinical improvement and can impact accuracy in the clinical diagnosis.

CONCLUSIONS

The frequent occurrence of several MCs requires a specialized rehabilitative setting with high level of multidisciplinary medical expertise to prevent, appropriately recognize and treat them. Comprehensive rehabilitation could avoid possible progression to more serious complications that can negatively impact clinical outcomes.

The neurobiology of functional neurological disorders characterised by impaired awareness

We review the neurobiology of Functional Neurological Disorders (FND), i.e., neurological disorders not explained by currently identifiable histopathological processes, in order to focus on those characterised by impaired awareness (functionally impaired awareness disorders, FIAD), and especially, on the paradigmatic case of Resignation Syndrome (RS). We thus provide an improved more integrated theory of FIAD, able to guide both research priorities and the diagnostic formulation of FIAD. We systematically address the diverse spectrum of clinical presentations of FND with impaired awareness, and offer a new framework for understanding FIAD. We find that unraveling the historical development of neurobiological theory of FIAD is of paramount importance for its current understanding. Then, we integrate contemporary clinical material in order to contextualise the neurobiology of FIAD within social, cultural, and psychological perspectives. We thus review neuro-computational insights in FND in general, to arrive at a more coherent account of FIAD. FIAD may be based on maladaptive predictive coding, shaped by stress, attention, uncertainty, and, ultimately, neurally encoded beliefs and their updates. We also critically appraise arguments in support of and against such Bayesian models. Finally, we discuss implications of our theoretical account and provide pointers towards an improved clinical diagnostic formulation of FIAD. We suggest directions for future research towards a more unified theory on which future interventions and management strategies could be based, as effective treatments and clinical trial evidence remain limited.

EEG-based Brain-Computer Interfaces for people with Disorders of Consciousness: Features and applications. A systematic review

Background

Disorders of Consciousness (DoC) are clinical conditions following a severe acquired brain injury (ABI) characterized by absent or reduced awareness, known as coma, Vegetative State (VS)/Unresponsive Wakefulness Syndrome (VS/UWS), and Minimally Conscious State (MCS). Misdiagnosis rate between VS/UWS and MCS is attested around 40% due to the clinical and behavioral fluctuations of the patients during bedside consciousness assessments. Given the large body of evidence that some patients with DoC possess "covert" awareness, revealed by neuroimaging and neurophysiological techniques, they are candidates for intervention with brain-computer interfaces (BCIs).

Objectives

The aims of the present work are (i) to describe the characteristics of BCI systems based on electroencephalography (EEG) performed on DoC patients, in terms of control signals adopted to control the system, characteristics of the paradigm implemented, classification algorithms and applications (ii) to evaluate the performance of DoC patients with BCI.

Methods

The search was conducted on Pubmed, Web of Science, Scopus and Google Scholar. The PRISMA guidelines were followed in order to collect papers published in english, testing a BCI and including at least one DoC patient.

Results

Among the 527 papers identified with the first run of the search, 27 papers were included in the systematic review. Characteristics of the sample of participants, behavioral assessment, control signals employed to control the BCI, the classification algorithms, the characteristics of the paradigm, the applications and performance of BCI were the data extracted from the study. Control signals employed to operate the BCI were: P300 (N = 19), P300 and Steady-State Visual Evoked Potentials (SSVEP; hybrid system, N = 4), sensorimotor rhythms (SMRs; N = 5) and brain rhythms elicited by an emotional task (N = 1), while assessment, communication, prognosis, and rehabilitation were the possible applications of BCI in DoC patients.

Conclusion

Despite the BCI is a promising tool in the management of DoC patients, supporting diagnosis and prognosis evaluation, results are still preliminary, and no definitive conclusions may be drawn; even though neurophysiological methods, such as BCI, are more sensitive to covert cognition, it is suggested to adopt a multimodal approach and a repeated assessment strategy.

Predicting outcome of patients with prolonged disorders of consciousness using machine learning models based on medical complexity

Patients with severe acquired brain injury and prolonged disorders of consciousness (pDoC) are characterized by high clinical complexity and high risk to develop medical complications. The present multi-center longitudinal study aimed at investigating the impact of medical complications on the prediction of clinical outcome by means of machine learning models. Patients with pDoC were consecutively enrolled at admission in 23 intensive neurorehabilitation units (IRU) and followed-up at 6 months from onset via the Glasgow Outcome Scale-Extended (GOSE). Demographic and clinical data at study entry and medical complications developed within 3 months from admission were collected. Machine learning models were developed, targeting neurological outcomes at 6 months from brain injury using data collected at admission. Then, after concatenating predictions of such models to the medical complications collected within 3 months, a cascade model was developed. One hundred seventy six patients with pDoC (M: 123, median age 60.2 years) were included in the analysis. At admission, the best performing solution (k-Nearest Neighbors regression, KNN) resulted in a median validation error of 0.59 points [IQR 0.14] and a classification accuracy of dichotomized GOS-E of 88.6%. Coherently, at 3 months, the best model resulted in a median validation error of 0.49 points [IQR 0.11] and a classification accuracy of 92.6%. Interpreting the admission KNN showed how the negative effect of older age is strengthened when patients' communication levels are high and ameliorated when no communication is present. The model trained at 3 months showed appropriate adaptation of the admission prediction according to the severity of the developed medical complexity in the first 3 months. In this work, we developed and cross-validated an interpretable decision support tool capable of distinguishing patients which will reach sufficient independence levels at 6 months (GOS-E > 4). Furthermore, we provide an updated prediction at 3 months, keeping in consideration the rehabilitative path and the risen medical complexity.

Neurogenic Dysphagia and Nutrition in Disorder of Consciousness: An Overview with Practical Advices on an “Old” but Still Actual Clinical Problem

Neurogenic dysphagia is a difficulty in swallowing food caused by disease or impairment of the nervous system, including stroke and traumatic brain injury. The most clinically apparent complication of neurogenic dysphagia is pulmonary aspiration, which may manifest itself acutely as choking or coughing, respiratory distress, wheezing, gasping or gurgling, and tachycardia. However, chronic symptoms, including weight loss, production of excessive oral secretions and aspiration pneumonia, may be also present, especially in patients with a disorder of consciousness (DOC). Usually, patients with dysphagia after the acute phase need to be treated with enteral nutrition using a feeding tube. This avoids patient malnutrition and supports the rehabilitation program. This narrative review aims to investigate dysphagia and its complications and management in patients with DOC. Clinical indications and practical advice on how to assess and treat this complex problem are also provided.

Epilepsy in prolonged disorders of consciousness: a systematic review

To date, no guideline exists for the management of epilepsy in patients with prolonged Disorders of Consciousness (DoC). This review aimed to assess the occurrence of epilepsy and epileptic abnormalities (EA) in these patients, to determine their impact on recovery; and to review the effect of antiepileptic drugs (AED) and therapeutic interventions on seizure occurrence and consciousness recovery. A structured search for studies on prolonged DoC and epilepsy was undertaken following PRISMA guidelines. From an initial search resulting in 5,775 titles, twelve studies met inclusion criteria. The occurrence of epilepsy and EA in DoC was poorly and inconsistently reported across studies. The results estimated a seizure prevalence of 27% in DoC. No conclusive data were found for the effects of AED on recovery nor on the influence of any therapeutic interventions on seizure occurrence. Given the scarcity of data, it is premature to make evidence-based recommendations on epilepsy in prolonged DoC. Based on this review and current clinical practices the following are recommended: (1) repeated standard EEG for detecting seizures and EA; (2) treating epilepsy while avoiding AEDs with sedating or cognitive side-effects. Future research should use standardized classification systems for seizures and EA.

Translation and Transcultural Adaptation of the Wessex Head Injury Matrix, Italian Version: A Preliminary Report

Background: Patients who are in a coma, a vegetative state or a minimally conscious state present a clinical challenge for neurological assessment, which is a prerequisite for establishing a prognosis and planning management. Several scales have been developed to evaluate these patients. The Wessex Head Injury Matrix is a comprehensive tool but is currently available only in the French and English languages. The aim of this study was to translate and evaluate the reliability of the Italian version of the scale. Methods: The original scale was translated according to a standard protocol: three separate translations were made, and a selected version was back-translated to check for any errors in order to obtain the most accurate Italian translation. A final back translation of the agreed version was made as a further check. The final version was then administered blind to a consecutive series of patients with severe acquired brain injury by two examiners. Inter-rater and test-retest reliability were assessed using a weighted Cohen’s kappa (Kw). Concurrent validity of the WHIM was evaluated by ρ Spearman’s correlation coefficient using the Glasgow Coma Scale (GCS) and the Coma Recovery Scale Revised (CRS-R) as the available gold standard. Results: Twenty-four patients (12 males and 12 females; mean age 59.9 ± 20.1; mean duration from index event 17.7 ± 20.0 days) with stroke (n = 15), traumatic brain injury (n = 7) and anoxic encephalopathy (n = 2) were included. Inter-rater [Kw 0.80 (95% CI 0.75–0.84)] and test-retest reliability [Kw 0.77 (95% CI 0.72–0.81)] showed good values. WHIM total scores correlated significantly with total scores on the GCS (ρ = 0.776; p < 0.001) and the CRS-R (ρ = 0.881; p < 0.001) demonstrating concurrent validity; Conclusion: The Italian version of the scale is now available for clinical practice and research.

Outcome registry of early intensive neurorehabilitation in patients with disorders of consciousness: study protocol of a prospective cohort study

BACKGROUND

Prolonged disorders of consciousness (PDOC) may occur after severe brain injury. Two diagnostic entities are distinguished within PDOC: unresponsive wakefulness syndrome (UWS, previously known as vegetative state) and minimally conscious state (MCS). Patients with PDOC may benefit from early intensive neurorehabilitation (EIN). In the Netherlands, the EIN programme is provided by one designated expert rehabilitation centre and forms the starting point of a dedicated chain of specialised rehabilitation and care for this group. This study project, called DOCTOR: Disorders of Consciousness; Treatment and Outcomes Registry, sets up a registry and systematically investigates multiple short- and long-term outcomes of patients with PDOC who receive EIN.

METHODS

Single-centre prospective cohort study with a 2-year follow-up period. Patients with PDOC due to acute brain injury who receive EIN, aged 16 years and older are included. Measurements will take place at start EIN, in week 5, 10, and at discharge from the EIN programme (duration = max 14 weeks) and at week 28, 40, 52, and 104 after admission to the EIN programme, following patients through the health-care chain. Outcome measures are the changes over time in level of consciousness, using the Coma Recovery Scale-Revised; the frequency and type of medical complications; the mortality rate; level of disability, including the level of motor, cognitive, behavioural and emotional functioning; participation; and quality of life. Secondary outcomes include self-efficacy of caregivers, caregivers' strain and cost-effectiveness of the programme.

DISCUSSION

The DOCTOR study will provide insight in the recovery patterns and predictors of recovery for multiple outcomes in PDOC patients after following EIN. The results of the study will enable us to benchmark and improve EIN and the organisation of the health-care chain, both for patients with PDOC and for their families.

TRIAL REGISTRATION

Netherlands Trial Register, NL 8138 . Retrospectively registered 6 November 2019.

Multi-center study on overall clinical complexity of patients with prolonged disorders of consciousness of different etiologies

Aim: to assess overall clinical complexity of patients with acquired disorders of consciousness (DoC) in vegetative state/unresponsive wakefulness syndrome (VS/UWS) vs. minimally conscious state- MCS) and in different etiologies..Design: Multi-center cross-sectional observational study.Setting: 23 intensive neurorehabilitation units.Subjects: 264 patients with DoC in the post-acute phase: VS/UWS = 141, and MCS = 123 due to vascular (n = 125), traumatic (n = 83) or anoxic (n = 56) brain injury.Main Measures: Coma Recovery Scale-Revised, and Disability Rating Scale (DRS); presence of medical devices (e.g., for eating or breathing); occurrence and severity of medical complications.Results: patients in DoC, and particularly those in VS/UWS, showed severe overall clinical complexity. Anoxic patients had higher overall clinical complexity, lower level of responsiveness/consciousness, higher functional disability, and higher needs of medical devices. Vascular patients had worse premorbid clinical comorbidities. The two etiologies showed a comparable rate of MC, higher than that observed in traumatic etiology.Conclusion: overall clinical complexity is significantly higher in VS/UWS than in MCS, and in non-traumatic vs. traumatic etiology. These findings could explain the worse clinical evolution reported in anoxic and vascular etiologies and in VS/UWS patients and contribute to plan patient-tailored care and rehabilitation programmes.

The Impact of Medical Complications in Predicting the Rehabilitation Outcome of Patients With Disorders of Consciousness After Severe Traumatic Brain Injury

In this study, we sought to assess the predictors of outcome in patients with disorders of consciousness (DOC) after severe traumatic brain injury (TBI) during neurorehabilitation stay. In total, 96 patients with DOC (vegetative state, minimally conscious state, or emergence from minimally conscious state) were enrolled (69 males; mean age 43.6 ± 20.8 years) and the improvement of the degree of disability, as assessed by the Disability Rating Scale, was considered the main outcome measure. To define the best predictor, a series of demographical and clinical factors were modeled using a twofold approach: (1) logistic regression to evaluate a possible causal effect among variables; and (2) machine learning algorithms (ML), to define the best predictive model. Univariate analysis demonstrated that disability in DOC patients statistically decreased at the discharge with respect to admission. Genitourinary was the most frequent medical complication (MC) emerging during the neurorehabilitation period. The logistic model revealed that the total amount of MCs is a risk factor for lack of functional improvement. ML discloses that the most important prognostic factors are the respiratory and hepatic complications together with the presence of the upper gastrointestinal comorbidities. Our study provides new evidence on the most adverse short-term factors predicting a functional recovery in DOC patients after severe TBI. The occurrence of medical complications during neurorehabilitation stay should be considered to avoid poor outcomes.

A multi-domain prognostic model of disorder of consciousness using resting-state fMRI and laboratory parameters

OBJECTIVES

Although laboratory parameters have long been recognized as indicators of outcome of traumatic brain injury (TBI), it remains a challenge to predict the recovery of disorder of consciousness (DOC) in severe brain injury including TBI. Recent advances have shown an association between alterations in brain connectivity and recovery from DOC. In the present study, we developed a prognostic model of DOC recovery via a combination of laboratory parameters and resting-state functional magnetic resonance imaging (fMRI).

METHODS

Fifty-one patients with DOC (age = 52.3 ± 15.2 y, male/female = 31/20) were recruited from Hangzhou Hospital of Zhejiang CAPR and were sub-grouped into conscious (n = 34) and unconscious (n = 17) groups based upon their Glasgow Outcome Scale-Extended (GOS-E) scores at 12-month follow-ups after injury. Resting-state functional connectivity, network nodal measures (centrality), and laboratory parameters were obtained from each patient and served as features for support vector machine (SVM) classifications.

RESULTS

We found that functional connectivity was the most accurate single-domain model (ACC: 70.1% ± 4.5%, P = 0.038, 1000 permutations), followed by degree centrality, betweenness centrality, and laboratory parameters. The stacked multi-domain prognostic model (ACC: 73.4% ± 3.1%, P = 0.005, 1000 permutations) combining all single-domain models yielded a significantly higher accuracy compared to that of the best-performing single-domain model (P = 0.002).

CONCLUSION

Our results suggest that laboratory parameters only contribute to the outcome prediction of DOC patients, whereas combining information from neuroimaging and clinical parameters may represent a strategy to achieve a more accurate prognostic model, which may further provide better guidance for clinical management of DOC patients.

Concordance between current American Academy of Sleep Medicine and Centers for Medicare and Medicare scoring criteria for obstructive sleep apnea in hospitalized persons with traumatic brain injury: a VA TBI Model System study

STUDY OBJECTIVES

The objective of this study was to compare obstructive sleep apnea (OSA), demographic, and traumatic brain injury (TBI) characteristics across the American Academy of Sleep Medicine (AASM) and Centers for Medicare and Medicare (CMS) scoring rules in moderate to severe TBI undergoing inpatient neurorehabilitation.

METHODS

This is a secondary analysis from a prospective clinical trial of sleep apnea at 6 TBI Model System study sites (n = 248). Scoring was completed by a centralized center using both the AASM and CMS criteria for OSA. Hospitalization and injury characteristics were abstracted from the medical record, and demographics were obtained by interview by trained research assistants using TBI Model System standard procedures.

RESULTS

OSA was prevalent using the AASM (66%) and CMS (41.5%) criteria with moderate to strong agreement (weighted κ = 0.64; 95% confidence interval = 0.58-0.70). Significant differences were observed for participants meeting AASM and CMS criteria (concordant group) compared with those meeting criteria for AASM but not CMS (discordant group). At an apnea-hypopnea index ≥ 5 events/h, the discordant group (n = 61) had lower Emergency Department Glasgow Coma Scale Scores consistent with greater injury severity (median, 5 vs 13; P = .0050), younger age (median, 38 vs 58; P < .0001), and lower body mass index (median, 22.1 vs 24.8; P = .0007) compared with the concordant group (n = 103). At an apnea-hypopnea index ≥ 15 events/h, female sex but no other differences were noted, possibly because of the smaller sample size.

CONCLUSIONS

The underestimation of sleep apnea using CMS criteria is consistent with prior literature; however, this is the first study to report the impact of the criteria in persons with moderate to severe TBI during a critical stage of neural recovery. Management of comorbidities in TBI has become an increasing focus for optimizing TBI outcomes. Given the chronic morbidity after moderate to severe TBI, the impact of CMS policy for OSA diagnosis for persons with chronic disability and young age are considerable.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Comparison of Sleep Apnea Assessment Strategies to Maximize TBI Rehabilitation Participation and Outcome; Identifier: NCT03033901.

Cost-Benefit Analysis From the Payor's Perspective for Screening and Diagnosing Obstructive Sleep Apnea During Inpatient Rehabilitation for Moderate to Severe TBI

OBJECTIVE

To describe the cost benefit of 4 different approaches to screening for sleep apnea in a cohort of participants with moderate to severe traumatic brain injury (TBI) receiving inpatient rehabilitation from the payor's perspective.

DESIGN

A cost-benefit analysis of phased approaches to sleep apnea diagnosis.

SETTING

Six TBI Model System Inpatient Rehabilitation Centers.

PARTICIPANTS

Trial data from participants (N=214) were used in analyses (mean age 44±18y, 82% male, 75% white, with primarily motor vehicle-related injury [44%] and falls [33%] with a sample mean emergency department Glasgow Coma Scale of 8±5).

INTERVENTION

Not applicable.

MAIN OUTCOME

Cost benefit.

RESULTS

At apnea-hypopnea index (AHI) ≥15 (34%), phased modeling approaches using screening measures (Snoring, Tired, Observed, Blood Pressure, Body Mass Index, Age, Neck Circumference, and Gender [STOPBANG] [-$5291], Multivariable Apnea Prediction Index MAPI [-$5262]) resulted in greater cost savings and benefit relative to the portable diagnostic approach (-$5210) and initial use of laboratory-quality polysomnography (-$5,011). Analyses at AHI≥5 (70%) revealed the initial use of portable testing (-$6323) relative to the screening models (MAPI [-$6250], STOPBANG [-$6237) and initial assessment with polysomnography (-$5977) resulted in greater savings and cost-effectiveness.

CONCLUSIONS

The high rates of sleep apnea after TBI highlight the importance of accurate diagnosis and treatment of this comorbid disorder. However, financial and practical barriers exist to obtaining an earlier diagnosis during inpatient rehabilitation hospitalization. Diagnostic cost savings are demonstrated across all phased approaches and OSA severity levels with the most cost-beneficial approach varying by incidence of OSA.

Minimum Competency Recommendations for Programs That Provide Rehabilitation Services for Persons With Disorders of Consciousness: A Position Statement of the American Congress of Rehabilitation Medicine and the National Institute on Disability, Independent Living and Rehabilitation Research Traumatic Brain Injury Model Systems

Persons who have disorders of consciousness (DoC) require care from multidisciplinary teams with specialized training and expertise in management of the complex needs of this clinical population. The recent promulgation of practice guidelines for patients with prolonged DoC by the American Academy of Neurology, American Congress of Rehabilitation Medicine (ACRM), and National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) represents a major advance in the development of care standards in this area of brain injury rehabilitation. Implementation of these practice guidelines requires explication of the minimum competencies of clinical programs providing services to persons who have DoC. The Brain Injury Interdisciplinary Special Interest Group of the ACRM, in collaboration with the Disorders of Consciousness Special Interest Group of the NIDILRR-Traumatic Brain Injury Model Systems convened a multidisciplinary panel of experts to address this need through the present position statement. Content area-specific workgroups reviewed relevant peer-reviewed literature and drafted recommendations which were then evaluated by the expert panel using a modified Delphi voting process. The process yielded 21 recommendations on the structure and process of essential services required for effective DoC-focused rehabilitation, organized into 4 categories: diagnostic and prognostic assessment (4 recommendations), treatment (11 recommendations), transitioning care/long-term care needs (5 recommendations), and management of ethical issues (1 recommendation). With few exceptions, these recommendations focus on infrastructure requirements and operating procedures for the provision of DoC-focused neurorehabilitation services across subacute and postacute settings.

The Comorbidities Coma Scale (CoCoS): Psychometric Properties and Clinical Usefulness in Patients With Disorders of Consciousness

Although comorbidities have a well-known impact on the functional recovery of patients with disorders of consciousness, including coma, vegetative state (VS), and minimally conscious state (MCS), a specific tool for their assessment in this challenging group of patients is lacking. For this aim, a multistep process was used to develop and validate the Comorbidities Coma Scale (CoCoS) in a sample of 162 patients with a diagnosis of coma, VS or MCS admitted to four Acute Inpatient Rehabilitation Units. To establish the psychometric properties of the scale, content validity, and internal consistency were investigated through Exploratory Factor Analysis in the whole sample (n = 162). Interrater reliability, assessed by the weighted Cohen's kappa (Kw), and concurrent validity of the scale as compared to the Greenfield Scale, assessed by ρ Spearman's correlation coefficient, were investigated in a subsample of patients (n = 52) within two of the above units. Our findings provided evidence of a good content validity of the scale, with the identification of a 12-factor structure representing the different comorbid dimensions of the target population. Inter-rater reliability was excellent in both the rehabilitation units where the assessment was made [Kw 0.98 (95% CI 0.96–0.99)]. CoCoS total scores correlated significantly with total scores of the Greenfield Scale (ρ = 0.932, 95% CI 0.89–0.96; P < 0.0001) indicating that CoCoS has concurrent validity while being more informative about the specific pattern of comorbidities of these challenging patients. The CoCos is a new tool which standardizes the approach to assessment of comorbid conditions and reliably identifies the category and severity of each comorbidity detected. It may be used for both clinical and research applications.

Multicentre registry of brain-injured patients with disorder of consciousness: rationale and preliminary data

Diagnostic accuracy and reliable estimation of clinical evolution are challenging issues in the management of patients with disorders of consciousness (DoC). Longitudinal systematic investigations conducted in large cohorts of patients with DoC could make it possible to identify reliable diagnostic and prognostic markers. On the basis of this consideration, we devised a multicentre prospective registry for patients with DoC admitted to ten intensive rehabilitation units. The registry collects homogeneous and detailed data on patients' demographic and clinical features, neurophysiological and neuroimaging findings, and medical and surgical complications. Here we present the rationale and the design of the registry and the preliminary results obtained in 53 patients with DoC (vegetative state or minimally conscious state) enrolled during the first seven months of the study. Data at 6-month post-injury follow-up were available for 46 of them. This registry could be an important tool for collecting high-quality data through the application of rigorous methods, and it could be used in the routine management of patients with DoC admitted to rehabilitation settings.

Early rehabilitation of Disorders of Consciousness (DOC): management, neuropsychological evaluation and treatment

In order to ensure the best possible rehabilitation plan and best outcome for patients with Disorders of Consciousness (DOC), optimal management of the early phase of rehabilitation is fundamental. This includes a correct diagnosis, accurate assessment of the patient's state of alertness and the main comorbidities, appropriate neurophysiological and neuroradiology examinations, and education of the caregiver and family so that they can provide the best assistance. Thirty years ago, specialists first began applying a systematic approach to the rehabilitation of patients with DOC, but still today many problems remain unsolved: the rate of misdiagnosis is still high, and recommendations about the most appropriate mode of rehabilitation are lacking, both as regards the timing of interventions and what the best techniques to use are. In a medical sector where nosography has changed over the last decade and where the documented evidence, though increasing, still remains insufficient, we discuss in this brief review the main assessment tools and disability scales to use and the key issues that need to be considered when a patient with DOC is admitted to the rehabilitation unit and decisions about the early rehabilitation plan are made.

Do Medical Complications Impact Long-Term Outcomes in Prolonged Disorders of Consciousness?

OBJECTIVE

To investigate medical complications (MCs) occurring within 6 months postinjury in brain-injured patients with prolonged disorders of consciousness (DoC) and to evaluate impact of MC on mortality and long-term clinical outcomes.

DESIGN

Prospective observational cohort study.

SETTING

Rehabilitation unit for acquired DoC.

PARTICIPANTS

Patients (N=194) with DoC (142 in vegetative state [VS], 52 in minimally conscious state; traumatic etiology 43, anoxic 69, vascular 82) consecutively admitted to a neurorehabilitation unit within 1-3 months postonset.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Mortality and improvements in clinical diagnosis and functional disability level (assessed by Coma Recovery Scale-Revised [CRS-R] and Disability Rating Scale) at 12, 24, and 36 months postonset.

RESULTS

Within 6 months postinjury, 188 of 194 patients (>95%) developed at least 1 MC and 142 of them (73%) showed at least 1 severe MC. Respiratory and musculoskeletal-cutaneous MCs were the most frequent, followed by endocrino-metabolic abnormalities. Follow-up, complete in 189 of 194 patients, showed that male sex and endocrine-metabolic MCs were associated with higher risk of mortality at all timepoints. Old age, anoxic etiology, lower CRS-R total scores, and diagnosis of VS at study entry predicted no clinical and functional improvements at most timepoints; however, epilepsy predicted no improvement in diagnosis at 24 months postonset only.

CONCLUSIONS

MCs are very frequent in patients with DoC within at least 6 months after brain injury, regardless of clinical diagnosis, etiology, and age. Endocrino-metabolic MCs are independent predictors of mortality at all timepoints; however,epilepsy predicted poor long-term outcome. Occurrence and severity of MCs in patients with DoC call for long-term appropriate levels of care after the postacute phase.

Incidence, Characterization, and Predictors of Sleep Apnea in Consecutive Brain Injury Rehabilitation Admissions

OBJECTIVE

To prospectively examine the incidence and risk factors for sleep apnea in consecutive brain injury rehabilitation admissions.

SETTING

Inpatient neurorehabilitation hospital.

PARTICIPANTS

Participants (n = 86) were consecutive neurorehabilitation admissions.

DESIGN

Retrospective analysis of prospectively collected data.

MAIN MEASURES

Polysomnography.

RESULTS

Half (49%) of the sample was diagnosed with sleep apnea. For the full sample, univariate logistic regression revealed age (odds ratio: 1.08; 95% confidence interval: 1.04-1.11) and hypertension (odds ratio: 7.77; 95% confidence interval: 2.81-21.47) as significant predictors of sleep apnea diagnosis. Results of logistic regression conducted within the traumatic brain injury group revealed age (odds ratio: 1.07; 95% confidence interval: 1.02-1.13) as the only significant predictor of apnea diagnosis after adjustment for other variables. Hierarchical generalized linear regression models for the prediction of apnea severity (ie, apnea-hypopnea index found that Functional Independence Measure Cognition Score (P = .01) and age (P < .01) were significant predictors. Following adjustment for all other terms, only age (P < .01) remained significant.

CONCLUSION

Sleep apnea is prevalent in acute neurorehabilitation admissions and traditional risk profiles for sleep apnea may not effectively screen for the disorder. Given the progressive nature of obstructive sleep apnea and morbidity associated with even mild obstructive sleep apnea, early identification and intervention may address comorbidities influencing acute and long-term outcome.

Disorders of Consciousness: Painless or Painful Conditions?-Evidence from Neuroimaging Studies

The experience of pain in disorders of consciousness is still debated. Neuroimaging studies, using functional Magnetic Resonance Imaging (fMRI), Positron Emission Tomography (PET), multichannel electroencephalography (EEG) and laser-evoked potentials, suggest that the perception of pain increases with the level of consciousness. Brain activation in response to noxious stimuli has been observed in patients with unresponsive wakefulness syndrome (UWS), which is also referred to as a vegetative state (VS), as well as those in a minimally conscious state (MCS). However, all of these techniques suggest that pain-related brain activation patterns of patients in MCS more closely resemble those of healthy subjects. This is further supported by fMRI findings showing a much greater functional connectivity within the structures of the so-called pain matrix in MCS as compared to UWS/VS patients. Nonetheless, when interpreting the results, a distinction is necessary between autonomic responses to potentially harmful stimuli and conscious experience of the unpleasantness of pain. Even more so if we consider that the degree of residual functioning and cortical connectivity necessary for the somatosensory, affective and cognitive-evaluative components of pain processing are not yet clear. Although procedurally challenging, the particular value of the aforementioned techniques in the assessment of pain in disorders of consciousness has been clearly demonstrated. The study of pain-related brain activation and functioning can contribute to a better understanding of the networks underlying pain perception while addressing clinical and ethical questions concerning patient care. Further development of technology and methods should aim to increase the availability of neuroimaging, objective assessment of functional connectivity and analysis at the level of individual cases as well as group comparisons. This will enable neuroimaging to truly become a clinical tool to reliably investigate pain in severely brain-injured patients as well as an asset for research.

Morfeo Study II: Clinical Course and Complications in Patients With Long-Term Disorders of Consciousness

BACKGROUND

The life expectancy of patients with disorders of consciousness (DOCs) is ever-increasing, but little is known about their clinical course over late stages. Several issues (premorbid conditions, complications and pressure sores) are to be considered for their effect on clinical outcome, risk of death and recovery of functional performance. Unfortunately, in late stages of long-term rehabilitation, these aspects are still more neglected than in acute and postacute stages. The aim of this study was to investigate the clinical course and the complications of patients in the late stages of DOCs and to explore the relationship between mortality and specific biomarkers.

MATERIALS AND METHODS

A total of 112 patients, admitted over 10 years in a dedicated ward, were retrospectively studied. Sociodemographic data, preadmission and inpatient clinical features were collected. Disability Rating Scale scores, complications including pressure sores and blood markers were assessed monthly. Data were analyzed through descriptive statistics and correlations using SPSS.

RESULTS

Most patients were men older than 50 years with a nontraumatic etiology and a history of hypertension (42.86%). The most common complication was pneumonia (76.79%). No association was found between sex and mortality or between etiology and mortality (P > 0.05). Mortality correlated significantly with sepsis (ρ = 0.253), albumin (ρ = -0.558), hemoglobin (ρ = -0.354) and white blood cells (ρ = 0.243). Only 42% of patients remained unchanged at Disability Rating Scale evaluation.

CONCLUSIONS

These data confirmed that DOCs are not static conditions and they require ongoing monitoring and assessment of clinical status, level of consciousness and laboratory biomarkers.

The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness

Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population.