Coma Science (eBook)

Front cover 1
Coma Science: Clinical and Ethical Implications 4
Copyright page 5
List of Contributors 6
Foreword 10
References 11
Foreword 12
Preface 14
Contents 16
Chapter 1. The problem of unreportable awareness 20
Introduction 20
Consciousness, complexity, control 21
Consciousness, simplicity, helplessness 24
Which concept of consciousnessquest 25
Conclusion 27
Acknowledgement 28
References 28
Chapter 2. How can we know if patients in coma, vegetative state or minimally conscious state are consciousquest 30
Introduction 30
The patients 31
Signs of consciousnessquest 32
Conscious states and conscious levels 33
Reports and signals 35
Future directions 36
Acknowledgment 37
References 37
The definition and criterion of death 41
Alternative formulations of death 44
Determining death using circulatory-respiratory tests 46
Future directions 48
References 48
Chapter 4. Behavioral assessment in patients with disorders of consciousness: gold standard or fool’s goldquest 52
Diagnostic criteria 53
Behavioral assessment methods 55
Limitations of behavioral assessment 57
Functional neuroimaging 58
Case report (AZ) 59
Conclusion 64
Acknowledgments 65
References 65
Chapter 5. The problem of aphasia in the assessment of consciousness in brain-damaged patients 68
Introduction 68
A brief overview of the cognitive architecture of language processing and underlying neuroanatomical correlates 69
The likelihood of aphasia in altered states of consciousness 70
Detection of aphasia in altered states of consciousness 71
Implications for behavioral assessment of level of consciousness 75
Discussion 76
Conclusion and perspectives 77
Acknowledgments 78
References 78
Chapter 6. Predictors of short-term outcome in brain-injured patients with disorders of consciousness 82
Introduction 83
Methods 85
Results 88
Discussion 89
Conclusion 90
Abbreviations 91
Acknowledgments 91
References 91
Chapter 7. Natural history of recovery from brain injury after prolonged disorders of consciousness: outcome of patients admitted to inpatient rehabilitation with 1-4 year follow-up 92
Introduction 93
Materials and methods 96
Results 98
Discussion 103
Acknowledgement 105
References 105
Chapter 8. Cognitive deficits after traumatic coma 108
Introduction 108
Long-term memory 109
Working memory 112
Speed of processing and attention 115
Executive functions 119
Conclusion 122
Acknowledgments 122
References 124
Chapter 9. Long-term survival after severe TBI: clinical and forensic aspects 130
Introduction 130
Terminology 131
Life tables 132
Biostatistics and life expectancy determination 133
Methods for survival data analysis 133
Caveats on interpreting survival data studies 134
Clinical experience and prediction of survival time 134
Predictors of morbidity and mortality in STBI and DOC 135
Quality of care and impact on survival time 135
Life expectancy literature in STBI: Historical perspectives and criticisms 135
Recent literature on survival time and STBI 137
Conclusions 142
References 143
Chapter 10. Waking up the brain: a case study of stimulation-induced wakeful unawareness during anaesthesia 144
Introduction 145
Material and methods 146
Results 149
Discussion 156
Acknowledgments 160
References 160
Chapter 11. Consciousness and epilepsy: why are complex-partial seizures complexquest 166
Introduction 166
The network inhibition hypothesis in TLE 167
Behavioral semiology of temporal lobe seizures 168
EEG correlates of impaired consciousness in human TLE 170
Neuroimaging insights into impaired consciousness in human TLE 172
Network effects of temporal lobe seizures in animal models 175
The network inhibition hypothesis revisited 179
Future directions 182
Conclusions: the consciousness system and TLE 183
Acknowledgments 184
References 184
Chapter 12. You are only coming through in waves: wakefulness variability and assessment in patients with impaired consciousness 190
Wakefulness 191
Arousal and the intensity of responses 192
Sleep patterns (or how to assess brain network functions) 193
Circadian rhythms (or when is it best to test for consciousness) 199
Homeostasis (or the search for balance in severe brain injury) 201
Assessment of wakefulness 202
Conclusion 204
Acknowledgments 204
References 204
Chapter 13. Disorders of consciousness: further pathophysiological insights using motor cortex transcranial magnetic stimulation 210
Introduction 210
General principles of TMS 211
Single- and paired-pulse TMS 211
Repetitive and paired associative TMS 212
TMS in DOC 212
The prognostic utility of TMS in coma 212
The prognostic utility of TMS in VS and MCS 213
Possible confounding variables influencing TMS results in DOC 214
Directions for future research 215
Acknowledgments 216
References 216
Chapter 14. A perturbational approach for evaluating the brain’s capacity for consciousness 220
Evaluating a subject’s level of consciousness 220
Evaluating a brain’s capacity for consciousness 221
Theoretical guidelines: the integrated information theory of consciousness 222
Employing TMSsolhd-EEG to evaluate thalamocortical integration and information capacity 223
TMSsolhd-EEG detects changes in the brain’s capacity for integrated information during sleep 225
TMSsolEEG in DOC patients: some predictions 230
Future perspectives 231
Acknowledgements 231
References 231
Chapter 15. Magnetic resonance spectroscopy and diffusion tensor imaging in coma survivors: promises and pitfalls 234
Introduction 235
Imaging protocols 235
Comatose patients assessment 241
Prediction of outcome with MRI 242
Conclusion 245
Acknowledgments 245
References 245
Chapter 16. A multimodal approach to the assessment of patients with disorders of consciousness 250
Introduction 251
Existing criteria 252
The creation of a multimodal approach to the assessment of patients with impaired consciousness 255
Application of the multimodal assessment approach to a single patient 259
Implications for the diagnostic decision-making process 262
Adoption of a standard assessment protocol 262
Information and support for families 264
Conclusion 265
Information for families 265
Acknowledgments 265
References 265
Chapter 17. Executive functions in the absence of behavior: functional imaging of the minimally conscious state 268
Methods and materials 270
Results 272
Discussion 274
Conclusions 276
References 277
Chapter 18. Reaching across the abyss: recent advances in functional magnetic resonance imaging and their potential relevance to disorders of consciousness 280
Introduction 281
High extrinsic and intrinsic functionality: the ‘‘locked-in’’ syndrome 282
‘‘Losing the self’’: hypoactivity of the intrinsic system 285
‘‘Self-centered absorption’’ 286
Spontaneous fMRI activity patterns as a diagnostic tool in DOCs 287
Acknowledgments 290
References 290
Chapter 19. Another kind of ’BOLD Response’: answering multiple-choice questions via online decoded single-trial brain signals 294
Introduction 295
Brain-computer interfaces for severely motor-disabled patients 296
Answering multiple-choice questions based on single-trial BOLD responses 298
Potential clinical applications for patients with severe motor disabilities 307
Promising paths for future hemodynamically based BCI developments 307
Abbreviations 309
Acknowledgements 309
References 309
Chapter 20. Pharmacotherapy to enhance arousal: what is known and what is not 312
Introduction 312
Neuroanatomy of arousal 313
Neuroanatomic and neurotransmitter function following brain injury 316
Pharmacotherapy that may impair arousal 321
Pharmacotherapy of arousal 321
Nonpharmacologic 325
Conclusion 329
References 329
Chapter 21. Intrathecal administration of GABA agonists in the vegetative state 336
Introduction 337
Intrathecal baclofen therapy 337
Recovery from unconscious state after ITB 338
Case reports 339
Discussion 342
References 343
Chapter 22. Different beliefs about pain perception in the vegetative and minimally conscious states: a European survey of medical and paramedical professionals 348
Introduction 349
Neuroimaging of pain 350
Attitudes toward pain perception 351
Acknowledgments 355
References 355
Chapter 23. Life can be worth living in locked-in syndrome 358
Introduction 359
Quality of life 360
Psychological adaptation in LIS 362
Depression rate 363
Social participation 364
Alternative communication devices 365
Wish to die 365
Conclusion 366
Acknowledgments 367
References 367
Chapter 24. Defining personal loss after severe brain damage 372
Introduction 372
Conclusion 377
References 377
Chapter 25. Moral significance of phenomenal consciousness 380
Concepts of consciousness 381
Consciousness: new evidence 383
The moral significance of consciousness 385
Conclusion and future directions 387
References 388
Chapter 26. The ethics of measuring and modulating consciousness: the imperative of minding time 390
A time of discovery 390
Cultural and historical perceptions 392
Clinical assessment 396
Systems of care 398
Acknowledgments 400
References 400
Chapter 27. Theoretical approaches to the diagnosis of altered states of consciousness 402
The need for a scientific theory of consciousness 403
Introduction to information integration theory of consciousness 405
Conditions where IITC predicts markedly reduced levels of consciousness 411
Location of the main complex - an informed guess 412
Available in vivo brain imaging techniques and potential applications 413
Conclusion 415
Acknowledgments 415
References 416
Chapter 28. A new era of coma and consciousness science 418
Introduction 418
fMRI: from passive paradigms to the assessment of awareness 419
fMRI as a form of communicationquest 421
Resting state fMRI 422
Diffusion tensor imaging 423
The impact on diagnosis and prognosis 424
Therapeutic advances 425
Neuroimaging and ethics 426
Conclusions 427
Acknowledgments 427
References 427
Subject Index 432