Disorders of consciousness
Article first published online: 7 NOV 2012
© The Author. Developmental Medicine & Child Neurology © 2012 Mac Keith Press
Developmental Medicine & Child Neurology
Volume 55, Issue 1, pages 5–6, January 2013
How to Cite
ASHWAL, S. (2013), Disorders of consciousness. Developmental Medicine & Child Neurology, 55: 5–6. doi: 10.1111/dmcn.12031
- Issue published online: 13 DEC 2012
- Article first published online: 7 NOV 2012
‘Good facts make good ethics’ is a statement often quoted by medical ethicists and it certainly applies to children with disorders of consciousness. This article is a brief commentary on the three major disorders of consciousness (and related published guidelines or case definitions) that general/developmental pediatricians and child neurologists may see and should have familiarity in diagnosing and managing.
In 2011, a revision of the original 1987 brain death guidelines was published under the auspices of the Society of Critical Care Medicine, the American Academy of Pediatrics and the Child Neurology Society.1 These guidelines addressed some of the major limitations of the 1987 guidelines, reflecting the restricted clinical information available at the time. This included uncertainty concerning the sensitivity and specificity of ancillary testing; issues related to the biological rationale for the use of age-based criteria; and lack of recommendations as to whether, when, and how the diagnosis of brain death could be made in neonates. Improvements to the revised guidelines include:
- 1The recommendation for a waiting period before the initial examination was performed to reduce the possibility of a potentially reversible condition.
- 2Specific recommendations for components of the neurological examination/core body temperature so that these are universally standardized.
- 3The statement that there should be two examinations by two different examiners to standardize how and by whom the examinations are done, to avoid any conflict of interest and to ensure that all physicians caring for a particular pediatric patient agree.
- 4Use of only two age groups (term newborn infants [gestational age 37wks–30d; and infants and children [gestational age >30d–18y]) in contrast to the 1987 guidelines which have three age groups. Linked to these two age groups are specific observation times between the examinations (term newborn infants, 24h; infants and children, 12h) which were recommended by consensus and based on the available literature, as well as the experience of the twenty committee members who participated in preparing the document.
- 5Specific instructions on how to perform apnea testing including the appropriate partial pressure carbon dioxide (pCO2) thresholds. These were not stated in the 1987 guidelines.
- 6The recommendation that ancillary studies were not required but could be done under certain conditions. In the 1987 guidelines, ancillary studies were required in younger pediatric patients. Ancillary studies could be used (a) when components of the examination or apnea testing could not be completed safely because of the underlying medical condition of the patient; (b) if there was uncertainty about the examination results; (c) if a medication effect might be present; or (d) to reduce the inter-examination observation period.
- 7Finally, an algorithm and checklist were provided for clinicians to help certify that brain death had occurred.
These guidelines were published for US physicians and it is recognized that many countries have guidelines which are somewhat different. It is hoped that at some point there will be international consensus for diagnosing brain death in pediatric patients. It is also recognized that even the revised guidelines were based on limited information, so there is a clear need for further research to address some of the unanswered questions. For example, would one examination in children be specific and sensitive enough to diagnose brain death in children as is currently recommended for adults? Are the recommended pCO2 thresholds similar across the pediatric age spectrum? What are the outcomes of children whose clinical examination indicates brain death, but who have ancillary testing that is not confirmatory (i.e. electroencephalographic activity or presence of cerebral blood flow)?
Persistent vegetative state
In 1994, a Multi-Society Task Force described the medical aspects of the persistent vegetative state (PVS) in adults and children, and the following year the American Academy of Neurology and the Child Neurology Society published guidelines related to this condition.2–4 In large part the data and conclusions of the Task Force have been near universally accepted as have the guidelines. The American Academy of Neurology is planning on reviewing and updating these guidelines as the advent of functional magnetic resonance imaging studies have suggested in several case reports that some patients who clinically appear vegetative can task-activate brain regions. The major thrust of the Task Force was to state that the available literature indicated if the vegetative state persisted for longer than 12 months after traumatic brain injury or for longer than 3 months after non-traumatic injury, the vegetative state could be considered permanent. Since then, there has been little to refute these general contentions, although it is recognized that an extremely low percentage of patients may show late recoveries of consciousness but not with substantial neurocognitive improvement. The 1995 guidelines focused on physicians’ recommendations, including the responsibility of discussing with the family or surrogates the probabilities of the patient’s attaining the various stages of recovery or remaining in a PVS. It was also recommended that patients in a PVS should receive appropriate medical, nursing, or home care to maintain their personal dignity and hygiene. Physicians and the family should determine the appropriate levels of treatment relative to the administration or withdrawal of medications and other commonly ordered treatments, supplemental oxygen and use of antibiotics, complex organ-sustaining treatments such as dialysis, administration of blood products, and artificial hydration and nutrition. In addition, it was recommended that once the vegetative state was considered permanent, a ‘Do not resuscitate’ order was appropriate and that such an order could be made earlier in the course of the patient’s illness if there was an advance directive or agreement between the appropriate surrogate of the patient and the physician.
There is clearly a need for further research regarding many of the medical aspects of children in a vegetative state before it makes sense to try to update and revise the current guidelines. A major limiting problem is the cost and technical difficulties in doing sophisticated functional imaging in pediatric patients. It is likely that observational studies in relatively larger numbers of children could provide the data to address some of the concerns about how we diagnose the vegetative state, what the upper limits of being vegetative is, and when can we declare permanency of this devastating condition.
Minimally conscious state
In response to the publication of the Task Force report, the rehabilitation medicine community advocated for criteria to help clinicians distinguish patients who were vegetative from those who had emerged from the vegetative state showing some signs of consciousness. An operational consensus-based case definition of the ‘minimally conscious state’ was agreed by a committee of experts and subsequently published.5 The minimally conscious state was characterized by inconsistent but clearly discernible behavioral evidence of consciousness, and could be distinguished from coma and the vegetative state by the presence of specific behavioral features not found in either condition. It was recognized that patients could evolve to a minimally conscious state from coma or a vegetative state after an acute brain injury, or as the result of degenerative or congenital nervous system disorders. It was also recognized that the minimally conscious state could be a transient or permanent outcome and that it occurs in children as well as adults.
As with the vegetative state, there are little published data on this condition in children. For now, clinicians need to recognize that the minimally conscious state exists as a distinct clinical entity and probably carries a better prognosis than for children in a vegetative state. It is also well accepted that it is extremely difficult to differentiate these conditions in infants and very young children, and that there is essential no information as to whether the age of an affected child might affect potential recovery. Again, more clinical research is imperative.
There are many ethical issues involved in the care of catastrophically injured children who have a disorder of consciousness. Balancing the needs of the child and the family, and societal/religious/cultural concerns (as well as increasing issues related to providing ‘cost-effective’ care), places a tremendous burden on clinicians. An important starting point, as in any area of pediatric medicine, is to have the requisite knowledge to provide expert medical guidance.