Disorder of consciousness: Structural integrity of brain networks for the clinical assessment.

AIM: When studying brain networks in patients with Disorders of Consciousness (DoC), it is important to evaluate the structural integrity of networks in addition to their functional activity. Here, we investigated whether structural MRI, together with clinical variables, can be useful for diagnostic purposes and whether a quantitative analysis is feasible in a group of chronic DoC patients. METHODS: We studied 109 chronic patients with DoC and emerged from DoC with structural MRI: 65 in vegetative state/unresponsive wakefulness state (VS/UWS), 34 in minimally conscious state (MCS), and 10 with severe disability. MRI data were analyzed through qualitative and quantitative approaches. RESULTS: The qualitative MRI analysis outperformed the quantitative one, which resulted to be hardly feasible in chronic DoC patients. The results of the qualitative approach showed that the structural integrity of HighOrder networks, altogether, had better diagnostic accuracy than LowOrder networks, particularly when the model included clinical variables (AUC = 0.83). Diagnostic differences between VS/UWS and MCS were stronger in anoxic etiology than vascular and traumatic etiology. MRI data of all LowOrder and HighOrder networks correlated with the clinical score. The integrity of the left hemisphere was associated with a better clinical status. CONCLUSIONS: Structural integrity of brain networks is sensitive to clinical severity. When patients are chronic, the qualitative analysis of MRI data is indicated.

Towards a New Assessment Tool for Caregivers of Patients with Disorders of Consciousness: The Social and Family Evaluation Scale (SAFE).

Monitoring the level of responsiveness of patients with Disorders of Consciousness (DoCs) represents an issue in all the settings where there is not the daily presence of clinicians, such as long-term and domestic settings. The involvement of patients' informal caregivers (i.e., patients' family) in such a monitoring process is thus fundamental. However, to date, no standardized tailored-made instruments exist that informal caregivers can use without the presence of clinicians, despite evidence illustrating the good accuracy of caregivers when expressing their opinions about the level of responsiveness of DoC patients. The present work aims to set the foundational knowledge, to create a standardized instrument that is able to assess the level of responsiveness of patients with DoCs by their informal caregivers. After selecting and modifying the items to be included in the new scale from the gold standard to diagnose DoCs (i.e., the Coma Recovery Scale-revised), and following a consensus process, we created the Social and Family Evaluation (SAFE) scale for caregivers of patients with DoCs. Although the SAFE needs a validation process, with the present work we provided its preliminary description along with insights into its clinical utility.

Resting-State fMRI in Chronic Patients with Disorders of Consciousness: The Role of Lower-Order Networks for Clinical Assessment.

Resting-state fMRI (rs-fMRI) is a widely used technique to investigate the residual brain functions of patients with Disorders of Consciousness (DoC). Nonetheless, it is unclear how the networks that are more associated with primary functions, such as the sensory-motor, medial/lateral visual and auditory networks, contribute to clinical assessment. In this study, we examined the rs-fMRI lower-order networks alongside their structural MRI data to clarify the corresponding association with clinical assessment. We studied 109 chronic patients with DoC and emerged from DoC with structural MRI and rs-fMRI: 65 in vegetative state/unresponsive wakefulness state (VS/UWS), 34 in minimally conscious state (MCS) and 10 with severe disability. rs-fMRI data were analyzed with independent component analyses and seed-based analyses, in relation to structural MRI and clinical data. The results showed that VS/UWS had fewer networks than MCS patients and the rs-fMRI activity in each network was decreased. Visual networks were correlated to the clinical status, and in cases where no clinical response occurred, rs-fMRI indicated distinctive networks conveying information in a similar way to other techniques. The information provided by single networks was limited, whereas the four networks together yielded better classification results, particularly when the model included rs-fMRI and structural MRI data (AUC = 0.80). Both quantitative and qualitative rs-fMRI analyses yielded converging results; vascular etiology might confound the results, and disease duration generally reduced the number of networks observed. The lower-order rs-fMRI networks could be used clinically to support and corroborate visual function assessments in DoC.

Incidence, prevalence and disability associated with neurological disorders in Italy between 1990 and 2019: an analysis based on the Global Burden of Disease Study 2019.

BACKGROUND: Neurological conditions are highly prevalent and disabling, in particular in the elderly. The Italian population has witnessed sharp ageing and we can thus expect a rising trend in the incidence, prevalence and disability of these conditions. METHODS: We relied on the Global Burden of Disease 2019 study to extract Italian data on incidence, prevalence and years lived with a disability (YLDs) referred to a broad set of neurological disorders including, brain and nervous system cancers, stroke, encephalitis, meningitis, tetanus, traumatic brain injury, and spinal cord injury. We assessed changes between 1990 and 2019 in counts and age-standardized rates. RESULTS: The most prevalent conditions were tension-type headache, migraine, and dementias, whereas the most disabling were migraine, dementias and traumatic brain injury. YLDs associated with neurological conditions increased by 22.5%, but decreased by 2.3% in age-standardized rates. The overall increase in prevalence and YLDs counts was stronger for non-communicable diseases with onset in old age compared to young to adult-age onset ones. The same trends were in the opposite direction when age-standardized rates were taken into account. CONCLUSIONS: The increase in YLDs associated with neurological conditions is mostly due to population ageing and growth: nevertheless, lived disability and, as a consequence, impact on health systems has increased. Actions are needed to improve outcome and mitigate disability associated with neurological conditions, spanning among diagnosis, treatment, care pathways and workplace interventions.

EEG Assessment in Patients With Disorders of Consciousness: Aims, Advantages, Limits, and Pitfalls.

This study presents a brief review of literature exploring simple EEG-polygraphic examinations and procedures that can be carried out at a patient's bedside. These include EEG with a common electrode array and sleep evaluation. The review briefly discusses more complex analytical techniques, such as the application of advanced EEG signal processing methods developed by our research group, to define what type of consistent markers are suitable for clinical use or to better understand complex patient conditions. These advanced analytical techniques aim to detect relevant EEG-based markers that could be useful in evaluating patients and predicting outcomes. These data could contribute to future developments in research.

Corrigendum: Preservation of Language Processing and Auditory Performance in Patients With Disorders of Consciousness: A Multimodal Assessment.

[This corrects the article DOI: 10.3389/fneur.2020.526465.].

Outcome prediction in brain tumor surgery: a literature review on the influence of nonmedical factors.

The purpose of the present study was to review the existing data on preoperative nonmedical factors that are predictive of outcome in brain tumor surgery. Our hypothesis was that also the individual characteristics (e.g., emotional state, cognitive status, social relationships) could influence the postoperative course in addition to clinical factors usually investigated in brain tumor surgery. PubMed, Embase, and Scopus were searched from 2008 to 2018 using terms relating to brain tumors, craniotomy, and predictors. All types of outcome were considered: clinical, cognitive, and psychological. Out of 6.288 records identified, 16 articles were selected for analysis and a qualitative synthesis of the prognostic factors was performed. The following nonmedical factors were found to be predictive of surgical outcomes: socio-demographic (age, marital status, type of insurance, gender, socio-economic status, type of hospital), cognitive (preoperative language and cognitive deficits, performance at TMT-B test), and psychological (preoperative depressive symptoms, personality traits, autonomy for daily activities, altered mental status). This review showed that nonmedical predictors of outcome exist in brain tumor surgery. Consequently, individual characteristics (e.g., emotional state, cognitive status, social relationships) can influence the postoperative course in addition to clinical factors.

Preservation of Language Processing and Auditory Performance in Patients With Disorders of Consciousness: A Multimodal Assessment.

The impact of language impairment on the clinical assessment of patients suffering from disorders of consciousness (DOC) is unknown or underestimated and may mask the presence of conscious behavior. In a group of DOC patients (n = 11; time post-injury range: 5-252 months), we investigated the main neural functional and structural underpinnings of linguistic processing, and their relationship with the behavioral measures of the auditory function using the Coma Recovery Scale-Revised (CRS-R). We assessed the integrity of the brainstem auditory pathways, of the left superior temporal gyrus and arcuate fasciculus, the neural activity elicited by passive listening of an auditory language task, and the mean hemispheric glucose metabolism. Our results support the hypothesis of a relationship between the level of preservation of the investigated structures/functions and the CRS-R auditory subscale scores. Moreover, our findings indicate that patients in minimally conscious state minus (MCS-): (1) when presenting the auditory startle (at the CRS-R auditory subscale) might be aphasic in the receptive domain, being severely impaired in the core language structures/functions; (2) when presenting the localization to sound might retain language processing, being almost intact or intact in the core language structures/functions. Despite the small group of investigated patients, our findings provide a grounding of the clinical measures of the CRS-R auditory subscale in the integrity of the underlying auditory structures/functions. Future studies are needed to confirm our results that might have important consequences for the clinical practice.

A comparative study on assessment procedures and metric properties of two scoring systems of the Coma Recovery Scale-Revised items: standard and modified scores.

OBJECTIVE: The study compared the metric characteristics (discriminant capacity and factorial structure) of two different methods for scoring the items of the Coma Recovery Scale-Revised and it analysed scale scores collected using the standard assessment procedure and a new proposed method. DESIGN: Cross sectional design/methodological study. SETTING: Inpatient, neurological unit. PARTICIPANTS: A total of 153 patients with disorders of consciousness were consecutively enrolled between 2011 and 2013. INTERVENTION: All patients were assessed with the Coma Recovery Scale-Revised using standard (rater 1) and inverted (rater 2) procedures. MAIN OUTCOME MEASURES: Coma Recovery Scale-Revised score, number of cognitive and reflex behaviours and diagnosis. RESULTS: Regarding patient assessment, rater 1 using standard and rater 2 using inverted procedures obtained the same best scores for each subscale of the Coma Recovery Scale-Revised for all patients, so no clinical (and statistical) difference was found between the two procedures. In 11 patients (7.7%), rater 2 noted that some Coma Recovery Scale-Revised codified behavioural responses were not found during assessment, although higher response categories were present. A total of 51 (36%) patients presented the same Coma Recovery Scale-Revised scores of 7 or 8 using a standard score, whereas no overlap was found using the modified score. Unidimensionality was confirmed for both score systems. CONCLUSION: The Coma Recovery Scale Modified Score showed a higher discriminant capacity than the standard score and a monofactorial structure was also supported. The inverted assessment procedure could be a useful evaluation method for the assessment of patients with disorder of consciousness diagnosis.

The Coma Recovery Scale Modified Score: a new scoring system for the Coma Recovery Scale-revised for assessment of patients with disorders of consciousness.

The differential diagnosis between vegetative state and minimally conscious state is still complex and the development of an evaluation systems is one of the challenging tasks for researchers and professionals. The Coma Recovery Scale-revised is considered the gold standard for clinical/behavioral assessment and for the differential diagnosis of patients with disorder of consciousness. However, the scale presents some limitations in that (i) scores may partially overlap between different diagnoses and (ii) there is an underlying assumption that if a patient is able to show higher-level behaviors, he/she is also able to show lower-level responses. In the present study, a procedure to calculate a modified Coma Recovery Scale-revised score is presented that attempts to avoid these problems. To exemplify this new scoring approach, 60 patients with disorder of consciousness were studied and the results showed the usefulness of the Modified Score.

Assessment of patients with disorder of consciousness: do different Coma Recovery Scale scoring correlate with different settings?

Differential diagnosis between Vegetative State and Minimally Conscious State is a challenging task that requires specific assessment scales, involvement of expert neuropsychologists or physicians and use of tailored stimuli for eliciting behavioural responses. Although misdiagnosis rate as high as 40% has been reported, no clear guidelines are available in literature on the optimal setting for assessment. The present study aims to analyse score differences in behavioural assessments of persons with disorders of consciousness (DOC) with or without family members and to determine whether the presence of caregivers could improve clinical accuracy in diagnostic evaluation. The research was conducted on 92 adults with DOC among 153 consecutive patients enrolled in the Coma Research Centre of the Neurological Institute C. Besta of Milan between January 2011 and May 2013. The results indicate that in almost half of the sample the scoring, thus the performance, observed with caregivers was better than without them. Furthermore, in 16% of the sample, when assessment was performed with caregivers there was a change in diagnosis, from Vegetative to Minimally Conscious State or from that to Severe Disability. Finally, statistical differences were found in relation to diagnosis between mean scores in the "visual function" Coma Recovery Scale revised's subscale obtained by raters plus caregiver and rates only assessment. This study demonstrates how the presence of caregivers can positively affect behavioural assessments of persons with DOC, thus contributing to the definition of the optimal setting for behavioural evaluation of patients, to decrease misdiagnosis rates.