Motor Attempt EEG Paradigm As a Diagnostic Tool for Disorders of Consciousness

To investigate whether a motor attempt EEG paradigm coupled with functional electrical stimulation can detect command following and, therefore, signs of conscious awareness in patients with disorders of consciousness, we recorded nine patients admitted to acute rehabilitation after a brain lesion. We extracted peak classification accuracy and peak session discriminant power (PSDP) and we assessed their correlation to the established coma recovery scale revised (CRS-R) and the agreement with diagnosis based on the novel motor behavior tool (MBT). Only PSDP correlated significantly with CRS-R and it also outperformed peak accuracy regarding the MBT. We conclude that PSDP might be more suitable than accuracy to complement CRS-R and MBT in evaluating ambiguous cases and in detecting cognitive motor dissociation

Effect of Long-Term Climbing Training on Cerebellar Ataxia: A Case Series

Background. Efficient therapy for both limb and gait ataxia is required. Climbing, a complex task for the whole motor system involving balance, body stabilization, and the simultaneous coordination of all 4 limbs, may have therapeutic potential. Objective. To investigate whether long-term climbing training improves motor function in patients with cerebellar ataxia. Methods. Four patients suffering from limb and gait ataxia underwent a 6-week climbing training. Its effect on ataxia was evaluated with validated clinical balance and manual dexterity tests and with a kinematic analysis of multijoint arm and leg pointing movements. Results. The patients increased their movement velocity and achieved a more symmetric movement speed profile in both arm and leg pointing movements. Furthermore, the 2 patients who suffered the most from gait ataxia improved their balance and 2 of the 4 patients improved manual dexterity. Conclusion. Climbing training has the potential to serve as a new rehabilitation method for patients with upper and lower limb ataxia

EEG paradigms as a supplemental tool to behavioral assessments of DOC

Introduction Diagnosis and prediction of recovery in the acute phase of disorders of consciousness (DOC) are critical for subsequent medical decisions. However, reliable assessment remains elusive due to the inability of current validated clinical scales to take into account motor and drive deficits. Recently, the Motor Behaviour Tool (MBT), a novel clinical scale, has been developed to address this caveat (1). In this context, neuroimaging and brain-computer interface (BCI) have also been proposed to improve the diagnosis and prognosis of these patients.(2). Objectives This pilot study aims to investigate the diagnostic and prognostic value of two electroencephalography (EEG)-based paradigms in patients with DOC, i.e., coma, Unresponsive Awareness Syndrome (UWS) or Minimally Conscious State (MCS). As a second step, we will employ them as evidence to further establish the added value of the MBT (i.e., assessment of minimal responses suggesting remaining conscious processing) combined with the Coma Recovery Scale-Revised (CRS-R), a standardized validated scale commonly used to assess consciousness in this population (3). Patients & Methods Acute DOC patients undergo CRS-R and MBT assessment prior to two EEG paradigms. Firstly, a motor attempt EEG-BCI coupled with Functional Electrical Stimulation (FES) is used (4). We hypothesize that replacing the need for overt movements with motor attempt can alleviate the tendency of CRS-R to underestimate the level of awareness in case of cognitive-motor dissociation (CMD) (5). In addition, a second EEG protocol presents patients with FES-tactile (T), auditory (A), and audio-tactile (AT) stimuli both in actionable and non-actionable space. EEG evoked potentials observed in the actionable space are expected to show a non-linear addition of sensory stimuli (i.e., A+T ≠ AT) indicating multisensory integration and the capacity of conscious processing (6). Results Pending elaborate analysis, preliminary findings show (Fig. 1) that BCI accuracy is significantly above chance only for a patient who was diagnosed as UWS by the CRS-R evaluation, but exhibited a motor behavior classified as CMD confirmed by the MBT tool, and not for one in real UWS (same diagnosis based on CRS-R and MBT), implying the presence of the hypothesized relation between motor EEG correlates and awareness (7). Average EEG evoked potentials of 8 patients during the second EEG paradigm highlight a difference between within (solid line) vs. outside (dashed line) the actionable space (Fig. 2), suggesting awareness-dependent modulation. Future analyses will explore correlations of such EEG descriptors with the clinical outcomes. Conclusion EEG correlates extracted from these EEG paradigms are promising tools for diagnosis of DOC and may supplement current clinical scales to help the validation of new tools like the MBT. References J. M. Pignat, E. Mauron, J. Jöhr, C. Gilart De Keranflec'h, D. Van De Ville, M. G. Preti, D. E. Meskaldji, V. Hörnberg, S. Laureys, B. Draganski, R. Frackowiak, K. Diserens, Outcome prediction of consciousness disorders in the acute stage based on a complementary motor behavioural tool, PLOS ONE 11(6), e0156882 (2016). A. M. Owen, M. R. Coleman, M. Boly, M. H. Davis, S. Laureys, J. D. Pickard, Detecting awareness in the vegetative state, Science, 313, 1402 (2006). J. T. Giacino, K. Kalmar, J. Whyte, The JFK Coma Recovery Scale-Revised: measurement characteristics and diagnostic utility, Arch. Phys. Med. Rehabil. 85(12), 2020-9 (2004). T. Corbet, R. Leeb, A. Biasiucci, S. Perdikis, J. del R. Millán et al. BCI-NMES therapy enhances effective connectivity in the damaged hemisphere in stroke patients. 6th International Brain-Computer Interface Meeting, Asilomar, California, USA (2016). N. D. Schiff, Cognitive motor dissociation following severe brain injuries, JAMA Neurol. 72(12), 1413–1415 (2015). J. P. Noel, C. Pfeiffer, O. Blanke, A. Serino, Full body peripersonal space as the space of the bodily self, Cognition 144, 49-57 (2015). A. M . Goldfine, J. D. Victor, M. M. Conte, J. C. Bardin, N. D. Schiff, Determination of awareness in patients with severe brain injury using EEG power spectral analysis, Clin. Neurophysiol. 122(11), 2157-68 (2011)

Peri-personal space encoding in patients with disorders of consciousness and cognitive-motor dissociation

Behavioral assessments of consciousness based on overt command following cannot differentiate patients with disorders of consciousness (DOC) from those who demonstrate a dissociation between intent/awareness and motor capacity: cognitive motor dissociation (CMD). We argue that delineation of peri-personal space (PPS) – the multisensory-motor space immediately surrounding the body – may differentiate these patients due to its central role in mediating human-environment interactions, and putatively in scaffolding a minimal form of selfhood. In Experiment 1, we determined a normative physiological index of PPS by recording electrophysiological (EEG) responses to tactile, auditory, or audio-tactile stimulation at different distances (5 vs. 75 cm) in healthy volunteers (N = 19). Contrasts between paired (AT) and summed (A + T) responses demonstrated multisensory supra-additivity when AT stimuli were presented near, i.e., within the PPS, and highlighted somatosensory-motor sensors as electrodes of interest. In Experiment 2, we recorded EEG in patients behaviorally diagnosed as DOC or putative CMD (N = 17, 30 sessions). The PPS-measure developed in Experiment 1 was analyzed in relation with both standard clinical diagnosis (i.e., Coma Recovery Scale; CRS-R) and a measure of neural complexity associated with consciousness. Results demonstrated a significant correlation between the PPS measure and neural complexity, but not with the CRS-R, highlighting the added value of the physiological recordings. Further, multisensory processing in PPS was preserved in putative CMD but not in DOC patients. Together, the findings suggest that indexing PPS allows differentiating between groups of patients whom both show overt motor impairments (DOC and CMD) but putatively distinct levels of awareness or motor intent

Processus d’implantation d’une échelle d’évaluation de la douleur pour les patients cérébrolésés ::description d’un projet de changement de pratique clinique basé sur le Modèle Intégré de la Consultation

Contexte : dans un service de neurochirurgie, des infirmières ont sélectionné l’échelle Critical Pain Observation Tool (CPOT) pour évaluer la douleur des patients cérébrolésés. Quelques mois après l’implantation, les cadres infirmiers constataient une sous-utilisation de l’échelle. But : soutenir l’équipe de soins pour surmonter les écueils rencontrés lors de l’implantation de l’échelle CPOT. Méthode : le Modèle de Lescarbeau, Payette et St-Arnaud a été sélectionné. En plus d’une recherche documentaire, un questionnaire auto-administré et trois guides-entretien ont permis de recueillir la perspective des soignants. Résultats : les écueils rencontrés se situaient au niveau de la collaboration interprofessionnelle, de l’échelle CPOT et du processus initial d’implantation. L’amélioration de la collaboration interprofessionnelle et l’adaptation de l’échelle CPOT pour des patients cérébrolésés ont été les priorités d’actions retenues. Discussion : une méthodologie rigoureuse, la reconnaissance mutuelle des compétences cliniques et l’établissement d’une relation de confiance sont des conditions sine qua non de la réussite de tout changement de pratique clinique. Conclusion : le modèle utilisé est une méthodologie de choix pour l’intégration des données probantes et les préférences de tous les acteurs à chaque étape du processus, conduisant à des choix éclairés et à l’établissement de priorités d’action pour une implantation réussie du CPOT