scholarly journals Towards New Diagnostic Approaches in Disorders of Consciousness: A Proof of Concept Study on the Promising Use of Imagery Visuomotor Task

2020 ◽  
Vol 10 (10) ◽  
pp. 746
Author(s):  
Antonino Naro ◽  
Rocco Salvatore Calabrò

Background: advanced paraclinical approaches using functional neuroimaging and electroencephalography (EEG) allow identifying patients who are covertly aware despite being diagnosed as unresponsive wakefulness syndrome (UWS). Bedside detection of covert awareness employing motor imagery tasks (MI), which is a universally accepted clinical indicator of awareness in the absence of overt behavior, may miss some of these patients, as they could still have a certain level of awareness. We aimed at assessing covert awareness in patients with UWS using a visuomotor-guided motor imagery task (VMI) during EEG recording. Methods: nine patients in a minimally conscious state (MCS), 11 patients in a UWS, and 15 healthy individuals (control group—CG) were provided with an VMI (imagine dancing while watching a group dance video to command), a simple-MI (imagine squeezing their right hand to command), and an advanced-MI (imagine dancing without watching a group dance video to command) to detect command-following. We analyzed the command-specific EEG responses (event-related synchronization/desynchronization—ERS/ERD) of each patient, assessing whether these responses were appropriate, consistent, and statistically similar to those elicited in the CG, as reliable markers of motor imagery. Results: All patients in MCS, all healthy individuals and one patient in UWS repeatedly and reliably generated appropriate EEG responses to distinct commands of motor imagery with a classification accuracy of 60–80%. Conclusions: VMI outperformed significantly MI tasks. Therefore, patients in UWS may be still misdiagnosed despite a rigorous clinical assessment and an appropriate MI assessment. It is thus possible to suggest that motor imagery tasks should be delivered to patients with chronic disorders of consciousness in visuomotor-aided modality (also in the rehabilitation setting) to greatly entrain patient’s participation. In this regard, the EEG approach we described has the clear advantage of being cheap, portable, widely available, and objective. It may be thus considered as, at least, a screening tool to identify the patients who deserve further, advanced paraclinical approaches.

2020 ◽  
Vol 10 (12) ◽  
pp. 930
Author(s):  
Caroline Schnakers ◽  
Michaela Hirsch ◽  
Enrique Noé ◽  
Roberto Llorens ◽  
Nicolas Lejeune ◽  
...  

Covert cognition in patients with disorders of consciousness represents a real diagnostic conundrum for clinicians. In this meta-analysis, our main objective was to identify clinical and demographic variables that are more likely to be associated with responding to an active paradigm. Among 2018 citations found on PubMed, 60 observational studies were found relevant. Based on the QUADAS-2, 49 studies were considered. Data from 25 publications were extracted and included in the meta-analysis. Most of these studies used electrophysiology as well as counting tasks or mental imagery. According to our statistical analysis, patients clinically diagnosed as being in a vegetative state and in a minimally conscious state minus (MCS−) show similar likelihood in responding to active paradigm and responders are most likely suffering from a traumatic brain injury. In the future, multi-centric studies should be performed in order to increase sample size, with similar methodologies and include structural and functional neuroimaging in order to identify cerebral markers related to such a challenging diagnosis.


2020 ◽  
Vol 10 (10) ◽  
pp. 748
Author(s):  
Jitka Annen ◽  
Isabella Mertel ◽  
Ren Xu ◽  
Camille Chatelle ◽  
Damien Lesenfants ◽  
...  

The evaluation of the level of consciousness in patients with disorders of consciousness (DOC) is primarily based on behavioural assessments. Patients with unresponsive wakefulness syndrome (UWS) do not show any sign of awareness of their environment, while minimally conscious state (MCS) patients show reproducible but fluctuating signs of awareness. Some patients, although with remaining cognitive abilities, are not able to exhibit overt voluntary responses at the bedside and may be misdiagnosed as UWS. Several studies investigated functional neuroimaging and neurophysiology as an additional tool to evaluate the level of consciousness and to detect covert command following in DOC. Most of these studies are based on auditory stimulation, neglecting patients suffering from decreased or absent hearing abilities. In the present study, we aim to assess the response to a P3-based paradigm in 40 patients with DOC and 12 healthy participants using auditory (AEP) and vibrotactile (VTP) stimulation. To this end, an EEG-based brain-computer interface was used at DOC patient’s bedside. We compared the significance of the P3 performance (i.e., the interpretation of significance of the evoked P3 response) as obtained by ‘direct processing’ (i.e., theoretical-based significance threshold) and ‘offline processing’ (i.e., permutation-based single subject level threshold). We evaluated whether the P3 performances were dependent on clinical variables such as diagnosis (UWS and MCS), aetiology and time since injury. Last we tested the dependency of AEP and VTP performances at the single subject level. Direct processing tends to overestimate P3 performance. We did not find any difference in the presence of a P3 performance according to the level of consciousness (UWS vs. MCS) or the aetiology (traumatic vs. non-traumatic brain injury). The performance achieved at the AEP paradigm was independent from what was achieved at the VTP paradigm, indicating that some patients performed better on the AEP task while others performed better on the VTP task. Our results support the importance of using multimodal approaches in the assessment of DOC patients in order to optimise the evaluation of patient’s abilities.


2021 ◽  
Vol 70 (5) ◽  
pp. 23-36
Author(s):  
Ekaterina A. Kondratyeva ◽  
Alina O. Ivanova ◽  
Maria I. Yarmolinskaya ◽  
Elena G. Potyomkina ◽  
Natalya V. Dryagina ◽  
...  

BACKGROUND: Consciousness is the state of being awake and aware of oneself and the environment. The disorders of consciousness result from pathologies that impair awareness. The development of effective comprehensive personalized interventions contributing to the recovery of consciousness in patients with chronic disorders of consciousness is one of the most pressing and challenging tasks in modern rehabilitation. AIM: The aim of this study was to understand structural problems of the pituitary gland, blood levels of gonadotropins and melatonin as well as brain damage markers in the blood and cerebrospinal fluid in patients with chronic disorders of consciousness and to analyze the levels of the above markers among different groups of patients depending on the level of impaired consciousness. MATERIALS AND METHODS: We examined 61 chronic disorders of consciousness patients and identified three groups depending on the level of consciousness including 24 patients with unresponsive wakefulness syndrome, 24 patients with a minus minimally conscious state, and 13 patients with minimally conscious state plus. We performed magnetic resonance imaging of chiasmatic-sellar region and determined blood serum levels of follicle-stimulating and luteinizing hormones and melatonin, as well as urinary level of 6-sulfatoxymelatonin and the content of brain derived neurotrophic factor (BDNF), apoptosis antigen (APO-1), FasL, glutamate, and S100 protein in the blood serum and cerebrospinal fluid. RESULTS: The patients were examined in the age ranging from 15 to 61 years old. Patient groups were homogeneous by the level of consciousness in terms of age and duration of chronic disorders of consciousness by the time of examination. The patients did not differ in the pituitary volume regardless of the level of consciousness. No significant differences were found between the groups with different levels of consciousness when studying the levels of melatonin in the blood serum and its metabolite in the urine. A peak in melatonin secretion was detected at 3 a.m. in 54.5 % of the patients, which can be considered as a favorable prognostic marker for further recovery of consciousness. Hypogonadotropic ovarian failure was found in 34 % of the patients, with normogonadotropic ovarian failure in the remaining patients. Serum APO-1 and BDNF levels were significantly higher in patients with minimally conscious state relative to those with unresponsive wakefulness syndrome. Significantly lower levels of glutamate in the cerebrospinal fluid were detected in women with unresponsive wakefulness syndrome compared to patients with minimally conscious state. CONCLUSIONS: Further in-depth examination and accumulation of data on patients with chronic disorders of consciousness may provide an opportunity to identify highly informative markers for predicting outcomes and to develop new effective approaches to rehabilitation of consciousness in this category of patients.


Neurology ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 450-460 ◽  
Author(s):  
Joseph T. Giacino ◽  
Douglas I. Katz ◽  
Nicholas D. Schiff ◽  
John Whyte ◽  
Eric J. Ashman ◽  
...  

ObjectiveTo update the 1995 American Academy of Neurology (AAN) practice parameter on persistent vegetative state and the 2002 case definition on minimally conscious state (MCS) and provide care recommendations for patients with prolonged disorders of consciousness (DoC).MethodsRecommendations were based on systematic review evidence, related evidence, care principles, and inferences using a modified Delphi consensus process according to the AAN 2011 process manual, as amended.RecommendationsClinicians should identify and treat confounding conditions, optimize arousal, and perform serial standardized assessments to improve diagnostic accuracy in adults and children with prolonged DoC (Level B). Clinicians should counsel families that for adults, MCS (vs vegetative state [VS]/unresponsive wakefulness syndrome [UWS]) and traumatic (vs nontraumatic) etiology are associated with more favorable outcomes (Level B). When prognosis is poor, long-term care must be discussed (Level A), acknowledging that prognosis is not universally poor (Level B). Structural MRI, SPECT, and the Coma Recovery Scale–Revised can assist prognostication in adults (Level B); no tests are shown to improve prognostic accuracy in children. Pain always should be assessed and treated (Level B) and evidence supporting treatment approaches discussed (Level B). Clinicians should prescribe amantadine (100–200 mg bid) for adults with traumatic VS/UWS or MCS (4–16 weeks post injury) to hasten functional recovery and reduce disability early in recovery (Level B). Family counseling concerning children should acknowledge that natural history of recovery, prognosis, and treatment are not established (Level B). Recent evidence indicates that the term chronic VS/UWS should replace permanent VS, with duration specified (Level B). Additional recommendations are included.


2021 ◽  
Author(s):  
Min Wu ◽  
Benyan Luo ◽  
Yamei Yu ◽  
Xiaoxia Li ◽  
Jian Gao ◽  
...  

Abstract Disorders of consciousness (DOC) are often accompanied by aberrant oscillatory neural activity in the thalamus and cerebral cortex. Patient-friendly non-invasive treatments targeting this functional anomaly are still missing. We propose and validate a novel approach that aims to restore DOC patients’ thalamocortical oscillations by combining rhythmic trigeminal-nerve stimulation (TNS) with comodulated musical stimulation. In a cluster-randomized, placebo-controlled, double-blinded, pretest-posttest clinical study, we show that application of this multisensory approach for 40 min on five consecutive days reliably leads to long-lasting improvements in DOC patients’ consciousness (assessed with Coma Recovery Scale-Revised) and oscillatory brain activity at the musical-electric TNS frequency (assessed with electroencephalography and a novel rhythmic auditory-speech paradigm). We found diagnostic improvement in 47% of patients in minimally conscious state and a positive relationship between patients’ behavioral and neural improvements. Based on this evidence we argue that non-invasive musical-electric TNS may serve as an effective patient-friendly DOC treatment and suggest frequency-specific oscillatory neural enhancement as its mode of action.


Author(s):  
Joseph J. Fins ◽  
Maria Masters

This chapter explains how neuro-palliative care can be provided to patients with severe brain injury. Before arguing that the right to die must be preserved and that the right to care for patients who are minimally conscious must be supported, it defines and reviews brain states that constitute disorders of consciousness along with their differential biology. It then gives an overview of palliative care for patients with severe brain injury and the challenges involved in diagnosing the minimally conscious state. It proceeds by discussing advances in technology, particularly neuroimaging, that may help meet the needs of such patients. It also considers the neuroethics of diagnosis and concludes by suggesting ways to integrate the needs of individuals suffering from disorders of consciousness in both the local and national palliative care infrastructure.


2019 ◽  
Vol 8 (4) ◽  
pp. 516 ◽  
Author(s):  
Manuela Berlingeri ◽  
Francesca Giulia Magnani ◽  
Gerardo Salvato ◽  
Mario Rosanova ◽  
Gabriella Bottini

Neuroimaging tools could open a window on residual neurofunctional activity in the absence of detectable behavioural responses in patients with disorders of consciousness (DOC). Nevertheless, the literature on this topic is characterised by a large heterogeneity of paradigms and methodological approaches that can undermine the reproducibility of the results. To explicitly test whether task-related functional magnetic resonance imaging (fMRI) can be used to systematically detect neurofunctional differences between different classes of DOC, and whether these differences are related with a specific category of cognitive tasks (either active or passive), we meta-analyzed 22 neuroimaging studies published between 2005 and 2017 using the Activation Likelihood Estimate method. The results showed that: (1) active and passive tasks rely on well-segregated patterns of activations; (2) both unresponsive wakeful syndrome and patients in minimally conscious state activated a large portion of the dorsal-attentional network; (3) shared activations between patients fell mainly in the passive activation map (7492 voxels), while only 48 voxels fell in a subcortical region of the active-map. Our results suggest that DOCs can be described along a continuum—rather than as separated clinical categories—and characterised by a widespread dysfunction of brain networks rather than by the impairment of a well functionally anatomically defined one.


2020 ◽  
Vol 15 (3) ◽  
pp. 111-119
Author(s):  
L Syd M Johnson ◽  
Kathy L Cerminara

The minimally conscious state presents unique ethical, legal, and decision-making challenges because of the combination of diminished awareness, phenomenal experience, and diminished or absent communication. As medical expertise develops and technology advances, it is likely that more and more patients with disorders of consciousness will be recognized as being in the minimally conscious state, with minimal to no ability to participate in medical decision-making. Here we provide guidance useful for surrogates and medical professionals at any medical decision point, not merely for end-of-life decision-making. We first consider the legal landscape: precedent abounds regarding unconscious patients in coma or the vegetative state/Unresponsive Wakefulness Syndrome (VS/UWS), but there is little legal precedent involving patients in the minimally conscious state. Next we consider surrogates’ ethical authority to make medical decisions on behalf of patients with disorders of consciousness. In everyday medical decision-making, surrogates generally encounter few, if any, restrictions so long as they adhere to an idealized hierarchy of decision-making standards designed to honor patient autonomy as much as possible while ceding to the reality of what may or may not be known about a patient’s wishes. We conclude by proposing an ethically informed, practical guide for surrogate decision-making on behalf of patients in the minimally conscious state.


2016 ◽  
Vol 6 (2) ◽  
pp. 21-28
Author(s):  
T. Komendziński ◽  
E. Mikołajewska ◽  
D. Mikołajewski ◽  
J. Dreszer ◽  
B. Bałaj

Neurological early and long-term rehabilitation plays a crucial role in the therapy of patients with disorders of consciousness (DOC) such as unresponsive wakefulness syndrome or minimally conscious state. Neuroscience tries to explain the effect of music therapy on all levels of the nervous system = activity in patients with DOC, but full understanding is still incomplete. This paper attempts to answer how current clinical outcomes may reflect the influence of various factors including music's capacity. Based on their interdisciplinary perspective and previous experiences, the authors try to investigate the extent to which current occupations have been explored. The authors analyzed the literature data concerning the results of the studies published until the first half of 2016, to sum up the current state of research. Research in the main databases: PubMed, PEDro, Health Source: Nursing/Academic Edition was made using specified keywords and inclusion and exclusion criteria. Next, the authors sorted them all out into a coherent view of the current state. Music listening may constitute a part of an enriched environment setting. However, due to weak evidence, the therapeutic value of music-based interventions in patients with DOC is uneven or limited. The role of music therapy is thus complementary. Standardized clinical settings, protocols, and behavioral measures should be developed to increase its clinical validity, reliability, sensitivity, and objectivity. There is a reasonable hypothesis that music may produce a high level of diagnostic and therapeutic outcomes as stimuli usually reflecting strong personal meaning in patients with DOC.


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