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Shows the transcranial Doppler waveforms (on the right) from left middle (MCA), anterior (ACA), and posterior (PCA) cerebral arteries at rest in a representative subject for each group (HC, MCS, and UWS). Flow velocity (in centimeter per second, right vertical bar) are provided.
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The assessment of behavioral responsiveness in patients suffering from chronic disorders of consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. Even if a patient is unresponsive, he/she may be covertly aware in reason of a cognitive-motor dissociation, i.e., a preservation of c...
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Objective: To explore the ways in which health care professionals and families understand terms and concepts associated with disorders of consciousness.
Methods: Open-ended, semi-structured interviews were conducted with 20 health care professionals and 18 family caregivers affiliated with a disorders of consciousness program within a nationally ra...
Citations
... However, in our analysis, neither power spectra in band-specific analysis nor ACNS parameters were capable to precisely distinguish MCS − and MCS + groups. As underlined in recent systematic reviews [51][52][53], some studies based on brain imaging techniques investigated the instrumental stratification of consciousness states exploring the differentiation between MCS − and MCS +. [54][55][56][57][58] Such differential assessment is crucial for medical decision-making, communication with relatives, and rehabilitation pathway planning, given the better prognosis in recovering full consciousness for MCS + patients [6,57]. Nevertheless, despite such encouraging results, these sophisticated techniques are often limited in feasibility and translatability in every-day clinical practice. ...
Detecting signs of residual neural activity in patients with altered states of consciousness is a crucial issue for the customization of neurorehabilitation treatments and clinical decision-making. With this large observational prospective study, we propose an innovative approach to detect residual signs of consciousness via the assessment of the amount of autonomic information coded within the brain. The latter was estimated by computing the mutual information (MI) between preprocessed EEG and ECG signals, to be then compared across consciousness groups, together with the absolute power and an international qualitative labeling. One-hundred seventy-four patients (73 females, 42%) were included in the study (median age of 65 years [IQR = 20], MCS +: 29, MCS -: 23, UWS: 29). Electroencephalography (EEG) information content was found to be mostly related to the coding of electrocardiography (ECG) activity, i.e., with higher MI (p < 0.05), in Unresponsive Wakefulness Syndrome and Minimally Consciousness State minus (MCS -). EEG-ECG MI, besides clearly discriminating patients in an MCS - and +, significantly differed between lesioned areas (sides) in a subgroup of unilateral hemorrhagic patients. Crucially, such an accessible and non-invasive measure of residual consciousness signs was robust across electrodes and patient groups. Consequently, exiting from a strictly neuro-centric consciousness detection approach may be the key to provide complementary insights for the objective assessment of patients' consciousness levels and for the patient-specific planning of rehabilitative interventions.
... Indeed, different neurophysiological approaches, including EEG and event-related potentials (ERPs), have been used to evaluate patients' outcomes or diagnosis. Specifically, (i) two studies used ERP to monitor residual cognitive functions [42,43]; (ii) eight studies used EEG/ERP to evaluate residual brain activity of DoC patients potentially suggesting cognition [44][45][46][47][48][49]55,56]; (iii) two studies used the enrichment environment or VR to stimulate cognitive function and awareness recovery in DoC patients, without EEG monitoring [13,14]; (iv) seven studies used other neurophysiological tools in DoCs, without EEG or VR, to evaluate residual brain activity of DoC patients [50][51][52][53][54]57]. These studies suggest that VR and several types of neurophysiological assessment, both individually and in combination, are potentially effective in corroborating DoC differential diagnosis and prognosis. ...
... This data was consistent with the literature evidence on the suitability of EEG-based approaches in understanding the processes subtending awareness and their pathophysiology [30,36,39,44,[71][72][73]. In fact, some studies indicate that EEG, as well as other advanced neurophysiological approaches, could be useful to differentiate patients with DoC, with regard to those in a functional locked-in syndrome to reduce the still high misdiagnosis rate [46,47,49,56]. In particular, various types of neurophysiological data in a pre-and post-intervention design demonstrated that clinical neurophysiology could help in both assessing the clinical severity and measuring the brain activity related to the patient's recovery [45,[50][51][52][53][54][55]57]. Particularly, these studies employed neurofeedback techniques evaluated with EEG, EEG recording during motor imagery or cognitive tasks, neural network reconstruction and evaluation of cerebral blood flow during passive and active paradigms and in resting state modality, sleep parameter variability, cardiovascular and EEG responsiveness to nociceptive stimulation, and a bulk of biological responses (ERPs, EEG oscillatory activity, neural networks, autonomic responses) to visual and auditory stimuli (either artificial-using, e.g., transcranial currents-or ecological-using, e.g., BTS-NIRVANA), delivered individually or in combination [13,14,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. ...
... In particular, various types of neurophysiological data in a pre-and post-intervention design demonstrated that clinical neurophysiology could help in both assessing the clinical severity and measuring the brain activity related to the patient's recovery [45,[50][51][52][53][54][55]57]. Particularly, these studies employed neurofeedback techniques evaluated with EEG, EEG recording during motor imagery or cognitive tasks, neural network reconstruction and evaluation of cerebral blood flow during passive and active paradigms and in resting state modality, sleep parameter variability, cardiovascular and EEG responsiveness to nociceptive stimulation, and a bulk of biological responses (ERPs, EEG oscillatory activity, neural networks, autonomic responses) to visual and auditory stimuli (either artificial-using, e.g., transcranial currents-or ecological-using, e.g., BTS-NIRVANA), delivered individually or in combination [13,14,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. All such approaches permit identifying even covert biological responses suggesting volitional cognitive activity and, thus, awareness as well as the potential to recover awareness. ...
Chronic disorders of consciousness cause a total or partial and fluctuating unawareness of the surrounding environment. Virtual reality (VR) can be useful as a diagnostic and/or a neurorehabilitation tool, and its effects can be monitored by means of both clinical and electroencephalography (EEG) data recording of brain activity. We reported on the case of a 17-year-old patient with a disorder of consciousness (DoC) who was provided with VR training to improve her cognitive-behavioral outcomes, which were assessed using clinical scales (the Coma Recovery Scale-Revised, the Disability Rating Scale, and the Rancho Los Amigos Levels of Cognitive Functioning), as well as EEG recording, during VR training sessions. At the end of the training, significant improvements in both clinical and neurophysiological outcomes were achieved. Then, we carried out a systematic review of the literature to investigate the role of EEG and VR in the management of patients with DoC. A search on PubMed, Web of Science, Scopus, and Google Scholar databases was performed, using the keywords: “disorders of consciousness” and “virtual reality”, or “EEG”. The results of the literature review suggest that neurophysiological data in combination with VR could be useful in evaluating the reactions induced by different paradigms in DoC patients, helping in the differential diagnosis. In conclusion, the EEG plus VR approach used with our patient could be promising to define the most appropriate stimulation protocol, so as to promote a better personalization of the rehabilitation program. However, further clinical trials, as well as meta-analysis of the literature, are needed to be affirmative on the role of VR in patients with DoC.
... A still debated issue is the degree of awareness related to PPS processing [44]. The knowledge of PPS related-awareness may be important to better understand the neurophysiological basis of neurological or neuropsychiatric disorders involving the PPS, including neuropsychiatric disorders [45], cognitive decline [46], and chronic Disorders of Consciousness [47]. ...
... However, partial knowledge is available on the changes of sensory-motor rhythms during PPS-related motor tasks. Studying these rhythms and, in particular, their top-down modulation may offer useful information concerning PPS-related movement planning and execution and their level of awareness, as specific modulation of brain responses evoked by PPS perturbation would suggest awareness of the PPS [46][47][57][58][59]. To this end, we investigated the spatial rules of a visuo-tactile interaction task targeting the PPS of the face. ...
The subcortical mechanisms subtending the sensorimotor processes related to the peripersonal space (PPS) have been well characterized, whereas less evidence is available concerning the cortical mechanisms. We investigated the theta, alpha and beta event-related spectral perturbations (ERSP) while holding the forearm in different positions into the PPS of the face. Fifty healthy individuals were subjected to EEG recording while being provided with median nerve electric stimulation at the wrist of the right hand held at different hand-to-face distances. Theta and beta rhythms were significantly perturbed depending on the hand-to-face distance, whereas alpha oscillations reflected a more general, non-specific oscillatory response to the motor task. The perturbation of theta and beta frequency bands may reflect the processes of top-down modulation overseeing the conscious spatiotemporal encoding of sensory-motor information within the PPS. In other words, such perturbation reflects the continuous update of the conscious internal representations of the PPS to build up a purposeful and reflexive motor response.
... The mortality after coma has decreased because of improvements in the management of emergency medicine, as a result, the number of patients diagnosed with unresponsive wakefulness syndrome/vegetative state (UWS/VS) (1) and minimally conscious state (MCS) (2) is rapidly increasing. Compared with some studies on the differential diagnosis of UWS/VS and MCS (3,4), in our opinion, prognosis evaluation and therapeutic approaches of patients with disorders of consciousness (DOC) may be more relevant. Recently, functional neuroimaging studies have markedly contributed to the understanding of DOC, mainly showing that the default mode network (DMN) is closely related to the differential diagnosis and occurrence of DOC (5)(6)(7). ...
Background: We hypothesize that the anterior insula is important for maintenance of awareness. Here, we explored the functional connectivity alterations of the anterior insula with changes in the consciousness level or over time in patients with disorders of consciousness (DOC) and determined potential correlation with clinical outcomes.
Methods: We examined 20 participants (9 patients with DOC and 11 healthy controls). Each patient underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a standardized Coma Recovery Scale-Revised (CRS-R) assessment on the same day. We categorized the patients according to the prognosis: those who emerged from a minimally conscious state (recovery group, n = 4) and those who remained in the unconscious state (unrecovery group, n = 5). Two rs-fMRI scans were obtained from all patients, and the second scan of patients in the recovery group was obtained after they regained consciousness. We performed seed-based fMRI analysis and selected the left ventral agranular insula (vAI) and dorsal agranular insula (dAI) as the regions of interest. Correlations with CRS-R were determined with the Spearman's correlation coefficient.
Results: Compared with healthy controls, the functional connectivity between dAI and gyrus rectus of patients who recovered was significantly increased (p < 0.001, cluster-wise family-wise error rate [FWER] < 0.05). The second rs-fMRI scan of patients who remained with DOC showed a significant decreased functional connectivity between the dAI to contralateral insula, pallidum, bilateral inferior parietal lobule (IPL), precentral gyrus, and middle cingulate cortex (p < 0.001, cluster-wise FWER < 0.05) as well as the functional connectivity between vAI to caudate and cingulum contrast to controls (p < 0.001, cluster-wise FWER < 0.05). Finally, the functional connectivity strength of dAI-temporal pole (Spearman r = 0.491, p < 0.05) and dAI-IPL (Spearman r = 0.579, p < 0.05) were positively correlated with CRS-R scores in all DOC patients. The connectivity of dAI-IPL was also positively correlated with clinical scores in the recovery group (Spearman r = 0.807, p < 0.05).
Conclusions: Our findings indicate that the recovery of consciousness is associated with an increased connectivity of the dAI to IPL and temporal pole. This possibly highlights the role of the insula in human consciousness. Moreover, longitudinal variations in dAI-IPL and dAI-temporal pole connectivity may be potential hallmarks in the outcome prediction of DOC patients.
... The sample size estimate was based on extrapolations from previous studies examining the effects of motor tasks targeting the PPS (Marra et al., 2018;Naro et al., 2018). Accordingly, we used the effect size (0.9) of the endpoint (PI change) for calculations. ...
Introduction
The approach of an external stimulus to the peripersonal space (PPS) modifies some physiological measures, including the cerebral blood flow (CBF) in the supplementary motor area and premotor cortex. CBF measurement may be useful to assess brain activations when producing specific motor responses, likely mediated by cortical and subcortical neural circuits.
Methods
This study investigated PPS in 15 healthy humans by characterizing the hemodynamic responses (pulsatility index, PI; and heart rate, HR) related to different directions of movements of individual's hand toward and backward his/her own face, so to perturb PPS).
Results
We observed that the CBF and HR were enhanced more when the stimulated hand was inside the PPS of the face in the passive and active condition than when the hand was outside the PPS and during motor imagery task.
Conclusions
These results suggest that the modulation of PPS‐related brain responses depends on specific sensory‐motor integration processes related to the location and the final position of a target in the PPS. We may thus propose TCD as a rapid and easy approach to get information concerning brain responses related to stimuli approaching the PPS. Understanding the modulations of brain activations during tasks targeting PPS can help to understand the results of psychophysical and behavioral trials and to plan patient‐tailored cognitive rehabilitative training.
