Detecting Awareness in the Vegetative State
ABSTRACT We used functional magnetic resonance imaging to demonstrate preserved conscious awareness in a patient fulfilling the criteria
for a diagnosis of vegetative state. When asked to imagine playing tennis or moving around her home, the patient activated
predicted cortical areas in a manner indistinguishable from that of healthy volunteers.
Full-textDOI: · Available from: Melanie Boly, Dec 28, 2013
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- "Patients diagnosed with Disorders of Consciousness (DOC), like patients with Unresponsive Wakefulness Syndrome (UWS, ) or in Minimally Conscious State (MCS), are characterized by the absence of non-reflexive responses or by intermittent behavioural responsiveness. However, initial functional magnetic resonance imaging (fMRI) studies ,  discovered that such patients, despite the inability to demonstrate voluntary behavioural responses to repeated clinical examinations, are able to wilfully modulate brain activity in response to auditory commands. These findings led to the conclusion that although some patients may meet the diagnostic criteria of the UWS, they may be consciously aware of their surroundings. "
ABSTRACT: A promising approach to establish basic communication for disorders of consciousness (DOC) patients, is the application of Brain-Computer Interface (BCI) systems, especially the use of single-switch BCIs (ssBCIs). Recently we proposed the concept of a novel auditory ssBCI paradigm and presented first classification results. In this study we report on the evaluation of four different modifications of the original paradigm with the intention to increase the suitability. Therefore we investigated different sound types and the inclusion of additional spatial information. Finally, the classification investigation with the most encouraging modifications shows an enhancement compared to our original paradigm, within healthy subjects, implicating better results for the future use in DOC patients.37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC’15), Milano, Italy; 08/2015
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- "While experimental research along the lines of Monti et al. (2010a) grapples with these questions, it seems equally urgent to gather statistical data by means of large-scale, multi-center, longitudinal studies, on the variables affecting the patients' likelihood of recovering consciousness and at least part of their motor functioning. Some such variables are already known, the patient's age, for example (Owen et al. 2006). Brain imaging may have a very important role to play in this kind of inquiry, leading to more information on the relations between the type and location of brain lesions, and long-term recovery outcome (Fins 2003; Coleman et al. 2009). "
DESCRIPTION: Recently, a number of neuroimaging studies have been conducted, aimed at detecting signs of consciousness in patients with a diagnosis of vegetative or minimally conscious state. The contributions appeared during an ongoing international ethical and socio-legal debate, on the admissibility of decisions to withdraw artificial nutrition from vegetative patients, thereby allowing them to die. We argue that neuroimaging is more likely to contribute to medical diagnosis and decision making if two requirements are met. First, those studies inferred awareness from the neural correlates of cognitive processes that are assumed to involve consciousness. However, neural correlates of consciousness proper, as defined by current philosophy and neuroscience, are the only admissible non-behavioral signs of awareness. Second, in those studies patients attempted to answer medically irrelevant questions by modulating their cortical activity in imagery tasks. We suggest patients should instead be queried on matters relevant to their clinical condition and quality of life.
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- "This finding suggests that MCS patients can direct active attention to an auditory target when asked to follow instructions. Finally, a neuroimaging study has also shown that a presumably VS patient was still able to understand and follow verbal instructions, such as " imagine you are walking around in your house " or " imagine you are playing tennis, " although clinical evaluation failed to detect her as conscious (Owen et al., 2006). However, the number of VS patients who could actually pass that test was extremely low: in a more recent study testing 54 DOC patients with this paradigm, only five patients were able to perform both mental activities on request and only one patient was able to associate these activities with a yes-or-no response and communicate with the researchers (Monti et al., 2010). "
ABSTRACT: Sensory stimuli are used to evaluate and to restore cognitive functions and consciousness in patients with a disorder of consciousness (DOC) following a severe brain injury. Although sophisticated protocols can help assessing higher order cognitive functions and awareness, one major drawback is their lack of sensitivity. The aim of the present review is to show that stimulus selection is crucial for an accurate evaluation of the state of patients with disorders of consciousness as it determines the levels of processing that the patient can have with stimulation from his/her environment. The probability to observe a behavioral response or a cerebral response is increased when her/his personal history and/or her/his personal preferences are taken into account. We show that personally relevant stimuli (i.e., with emotional, autobiographical, or self-related characteristics) are associated with clearer signs of perception than are irrelevant stimuli in patients with DOC. Among personally relevant stimuli, music appears to be a promising clinical tool as it boosts perception and cognition in patients with DOC and could also serve as a prognostic tool. We suggest that the effect of music on cerebral processes in patients might reflect the music's capacity to act both on the external and internal neural networks supporting consciousness.Frontiers in Psychology 08/2015; 6:1102. DOI:10.3389/fpsyg.2015.01102 · 2.80 Impact Factor