While the detection of voluntary signs at the patient’s bedside is considered sufficient to infer that the subject is conscious, their absence does not necessarily imply the absence of conscious perception. Recently, the development of new neuroimaging and electrophysiological active paradigms (where the patient has to mentally perform a task) allowed the detection of signs of consciousness in patients completely unable to move. However, in the case of a negative result, these two methods leave the question of the presence or absence of consciousness unanswered. In this chapter, we propose an additional level where consciousness can be studied using a combination of transcranial magnetic stimulation and EEG (TMS-EEG). This technique allows the direct stimulation of assemblies of cortical neurons and has been suggested as an efficient way to appreciate how the thalamocortical system can interact globally (integration) and produce specific responses (information).
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.
Giacino JT, Kalmar K, Whyte J. The JFK coma recovery scale-revised: measurement characteristics and diagnostic utility. Arch Phys Med Rehabil. 2004;85(12):2020–9.PubMedCrossRefGoogle Scholar
Gill-Thwaites H, Munday R. The sensory modality assessment and rehabilitation technique (SMART): a valid and reliable assessment for vegetative state and minimally conscious state patients. Brain Inj. 2004;18(12):1255–69.PubMedCrossRefGoogle Scholar
Shiel A, Horn SA, Wilson BA, et al. The wessex head injury matrix (WHIM) main scale: a preliminary report on a scale to assess and monitor patient recovery after severe head injury. Clin Rehabil. 2000;14(4):408–16.PubMedCrossRefGoogle Scholar
Laureys S, Owen AM, Schiff ND. Brain function in coma, vegetative state, and related disorders. Lancet Neurol. 2004;3(9):537–46.PubMedCrossRefGoogle Scholar
The Multi-Society Task Force on PVS. Medical aspects of the persistent vegetative state (1). N Engl J Med. 1994;330(21):1499–508.CrossRefGoogle Scholar
Giacino JT, Ashwal S, Childs N, et al. The minimally conscious state: definition and diagnostic criteria. Neurology. 2002;58(3):349–53.PubMedCrossRefGoogle Scholar
Schnakers C, Perrin F, Schabus M, et al. Detecting consciousness in a total locked-in syndrome: an active event-related paradigm. Neurocase. 2009;15(4):271–7.PubMedCrossRefGoogle Scholar
Boly M, Coleman MR, Davis MH, et al. When thoughts become action: an fMRI paradigm to study volitional brain activity in non-communicative brain injured patients. Neuroimage. 2007;36(3):979–92.PubMedCrossRefGoogle Scholar
Monti MM, Vanhaudenhuyse A, Coleman MR, et al. Willful modulation of brain activity in disorders of consciousness. N Engl J Med. 2010;362(7):579–89.PubMedCrossRefGoogle Scholar
Giacino JT, Hirsch J, Schiff N, Laureys S. Functional neuroimaging applications for assessment and rehabilitation planning in patients with disorders of consciousness. Arch Phys Med Rehabil. 2006;87(12):67–76.CrossRefGoogle Scholar
Massimini M, Boly M, Casali A, et al. A perturbational approach for evaluating the brain’s capacity for consciousness. Prog Brain Res. 2009;177:201–14.PubMedCrossRefGoogle Scholar
Massimini M, Ferrarelli F, Huber R, et al. Breakdown of cortical effective connectivity during sleep. Science. 2005;309(5744):2228–32.PubMedCrossRefGoogle Scholar
Massimini M, Ferrarelli F, Esser SK, et al. Triggering sleep slow waves by transcranial magnetic stimulation. Proc Natl Acad Sci USA. 2007;104(20):8496–501.PubMedCrossRefGoogle Scholar
Ferrarelli F, Massimini M, Sarasso S, et al. Breakdown in cortical effective connectivity during midazolam-induced loss of consciousness. Proc Natl Acad Sci USA. 2010;107(6):2681–6.PubMedCrossRefGoogle Scholar