Uncovering the mystery of (un)consciousness:
A starting point for developing reliable prognosticators in patients who are in a vegetative state
The issue of patients left in a vegetative state after suffering devastating brain damage is currently in the focus of public and media attention due to such basic scientific and philosophical questions as “consciousness” and “self” from one side and such ethical and medical-legal questions such as “life or death” from the other. Collaboration between Finnish and Italian scientists produced knowledge about (un)consciousness which could have a direct clinical significance following further validation: it may establish a starting point in the development of reliable early markers for prognosis of patients in vegetative state. This could contribute to improving day-to-day management, access to early interventions, and quality of life in such patients.
The vegetative state (VS), or as it was recently suggested, the unresponsive wakefulness syndrome (UWS), is a complex neurological condition which occurs after severe brain injury (either traumatic, vascular or anoxic) and which is characterised by “unawareness of self and environment in which the patient breathes spontaneously, has a stable circulation, and shows cycles of eye closure and opening which may simulate sleep and waking” (Royal College of Physicians, 2003). From this perspective, VS/UWS is commonly agreed to be a state of “wakeful unconsciousness”.
VS/UWS remains among the least understood, treatable, and most ethically troublesome conditions of modern neurology. Prognostic accuracy for patients in persistent VS/UWS poses serious medical and ethical concerns because treatment decisions typically include the possibility of life-support being withdrawn. Currently, prognosis of the outcome is determined primarily through diagnosis and also by etiology of brain injury (traumatic, vascular, or anoxic) as well as the age of the patient. According to the Royal College of Physicians, a VS/UWS is classified as persistent when it lasts longer than a month with recovery rates approaching zero after 12 months for patients older than 40 years. Nontraumatic brain injuries are considered to have a poorer prognosis. However, misdiagnoses of VS/UWS are very common and have been shown to be as high as 45% if not using an appropriate behavioral scale. But even when behavioural scales are used some behavioural responses remain equivocal and difficult to interpret as evidence for the presence or absence of consciousness. Therefore, objective measurement tools through which an individual’s level of retained awareness can be assessed (without explicit report of a patient) are needed to achieve more accurate estimates of prognosis.
Current joint study by scientists from BM-Science – Brain & Mind Technologies Research Centre (Finland) and Rehabilitation Department at Fondazione Istituto “San Raffaele – G. Giglio” (Palermo, Italy) have shown that traditional electroencephalogram (EEG), which is routinely available in most clinics/laboratories, is affordable, and allows direct and objective recording of spontaneous brain activity without the need of any behavioral response from the patient, when analysed using advanced technologies, could provide reliable prognostic markers of consciousness recovery in patients in VS/UWS.
Researchers used Operational Architectonics analysis of EEG, which extracts from each local EEG signal (within multichannel EEG recording) the so-called quasi-stationary segments that relate to operations produced by neuronal assemblies and also estimates several characteristics of such operations and the level and strength of synchrony of operations among many neuronal assemblies located in different brain areas. The results of this study indicate that in contrast to the parameters of clinical history of patients and conventional EEG analysis, the parameters of resting-state EEG extracted with the help of Operational Architectonics analysis at three months post-injury (the time when patients meet all clinical criteria for the persistent VS/UWS) can reliably predict the recovery outcome of patients in persistent VS/UWS six months post-injury. In other words, the higher the number and the strength of synchrony of operations produced by multiple neuronal assemblies in patients in persistent VS/UWS, the higher their chance to recover some level of consciousness in the future.
The authors concluded that that Operational Architectonics strategy for resting-state EEG analysis is better suited for providing prognosis of consciousness recovery than existing methods of clinical assessment and of conventional EEG that relate to the physiological rather than conscious processes/states/contents.
Even though consciousness is a concept that remains in flux, and objective assessment of it is methodologically difficult due to its first-person nature, the Operational Architectonics framework of brain and mind functioning propose that consciousness is an emergent phenomenon of coherent dynamic binding of operations performed by multiple neuronal assemblies organized within a nested hierarchical brain architecture .
Co-authoring the paper with Andrew and Alexander Fingelkurts were Sergio Bagnato, Cristina Boccagni and Giuseppe Galardi.
A copy of the paper on prognostic value of resting-state EEG structure in disentangling vegetative and minimally conscious states may be viewed here (link: http://nnr.sagepub.com/content/early/2013/01/06/1545968312469836.abstract )
About Operational Architectonics theory of brain and mind functioning read here (link: http://www.bm-science.com/team/art61.pdf )
For more about the research of Andrew and Alexander Fingelkurts go here (link: http://www.bm-science.com/team/fingelkurts.html )