Download Practice Guideline: Disorders of Consciousness

AAN Summary for Public Comment
Practice Guideline: Disorders of Consciousness
This document is a summary of the American Academy of Neurology (AAN), American Congress of Rehabilitation Medicine (ACRM) and National Institute
on Disability, Independent Living and Rehabilitation Research (NIDILRR) co-sponsored practice guideline “Disorders of Consciousness.” The guideline aimed
to update a 1995 AAN practice parameter on the persistent vegetative state and a 2002 case definition report on the minimally conscious state. The
guideline is in development and has not been published in final form. This summary was created as a tool for people without a medical background to better
understand the information in the full document. People can refer to this summary when they provide their feedback during the public comment period for
this practice guideline. The complete practice guideline is available at AAN.com/practice-guidelines/home/public-comments.
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This research was supported through a memorandum of understanding between the American Academy of Neurology, the American Congress of
Rehabilitation Medicine and the National Institute on Disability and Rehabilitation Research (NIDRR). In 2014 NIDRR was moved from the U.S. Department
of Education to the Administration for Community Living of the U.S. Department of Health and Human Services, and was renamed the National Institute on
Disability, Independent Living and Rehabilitation Research (NIDILRR). This article does not reflect the official policy or opinions NIDILRR or HHS and does not
constitute an endorsement by NIDILRR, HHS, or other components of the federal government.
What is a Practice Guideline?
A practice guideline is a document that makes recommendations (guidance statements) for clinicians (doctors and other health care professionals) regarding
use of tests to diagnose or therapies to treat a specific disease. Recommendations in practice guidelines are based on a thorough review of the medical
research. The complete practice guideline describes this review of the medical research and the background for each recommendation.
Terms Used in the Disorders of Consciousness Guideline
In simplest terms, “consciousness” can be defined as the state of awareness of the self and environment. Conscious behavior requires satisfactory arousal
(i.e., wakefulness) and awareness of themselves and what is around them (e.g., physical senses, thinking, and/or emotional experience). Severe acquired
brain injury (ABI) – brain injury that is not birth-related and not genetic (e.g., due to car accident, loss of oxygen to the brain due to heart attack, etc.) – is a
catastrophic event that disrupts these systems. The most severe injuries result in prolonged (i.e., lasting at least 4 weeks) disorders of consciousness (DoC),
including the vegetative state (VS) (also referred to as post-coma unawareness [PC-U] and unresponsive wakefulness syndrome [UWS]) and the minimally
conscious state (MCS). Accurate diagnosis is critically important to both clinicians and family members because patients diagnosed with MCS early in
during recovery (i.e., within 3-5 months) are more likely to recover more skills by 12 months after brain injury, as compared to those diagnosed with VS.
Detailed definitions of these terms can be found in the table below.
Table 1. Key Definitions
Term
Definition
Coma
A state of complete unconsciousness in which there is no evidence of wakefulness (for example, eyes remain
continuously closed) or awareness of one’s self or the environment.
Vegetative state (VS), unresponsive
wakefulness syndrome (UWS),
post-coma unawareness (PC-U)
A person has spontaneous eye-opening, but no evidence of purposeful behavior suggesting that he is aware of
himself or the environment
Persistent vegetative state (PVS)
Term that represents a VS/UWS lasting more than one month
Minimally conscious state (MCS)
When a person still has severely limited consciousness but there is evidence that the person is aware of
himself or the environment. This evidence can be subtle and inconsistent.
Emergence from MCS (EMCS)
EMCS is when a person recovers either reliable communication, which may occur through verbal means (e.g.,
spoken or written yes/no responses) or movement (e.g., yes–no head movements), or the ability to show how to
use at least two different familiar objects.
“Recovery of consciousness”
Someone is described as “recovering consciousness” when they are able to reliably show at least one behavior
suggesting awareness, suggesting that a person has moved from coma or VS/UWS to MCS.
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What are guideline recommendations and how are they determined?
Guideline recommendations are meant to guide clinicians when they are partnering with patients and/or families to make decisions about medical care.
When guideline authors write recommendations, they consider:
• The best medical research evidence available
• The balance of potential benefit and potential harm of following the recommendation
• The anticipated result of following the recommendation (how important is the outcome that will result from following the recommendation)
• The cost and availability of the test, therapy, or other subject of the recommendation
• Patients’ values and preferences
The strength of the recommendation is based on these factors (see table 2 at end of document).
Disorders of Consciousness Guideline Recommendations
These guidelines were developed to help clinicians, patients, and families in the situation where a patient has a prolonged DoC, defined as being in a DoC for
at least 4 weeks. Unless otherwise noted, this guideline does not apply to patients whose brain injury occurred within the last 4 weeks. Important: this is a
draft document; these recommendations are not yet finalized and have not been approved by the AAN Institute Board of Directors.
Recommendation
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1. C linicians may refer medically stable patients with DoC to specialty rehabilitation centers to help diagnose different DoC states,
predict if and how patients might improve, and manage treatment (where available).
Strength
Weak
2a. Clinicians should use standardized behavioral assessments (published tools that have been tested and are accurate and reliable) to
improve diagnosis of the different types of DoC.
Moderate
2b. To decrease the chance of mistakes when diagnosing prolonged DoC after brain injury, clinicians should test patients multiple
times before making a diagnosis.
Moderate
2c. B efore testing a patient with a DoC in order to make a diagnosis, clinicians should use different strategies to make sure the person
is as awake as possible for the examination.
Moderate
2d. Medical complications such as infections can make diagnosing a DoC more difficult. Clinicians should identify and treat conditions
(like infections) that may make it harder to accurately diagnose the type of DoC (e.g. VS/UWS versus MCS).
Moderate
2e. Sometimes when patients are in VS/UWS, clinicians aren’t sure if patients are showing subtle signs of awareness, even with
repeated assessments over time. Some complications, such as severe body stiffness, can also make it hard for clinicians to know
if a person is trying to move or communicate. In situations where clinicians cannot be sure if there are subtle signs of awareness,
clinicians may order special brain scans or electrophysiological studies looking at brain activity (where available) to look for signs
of awareness.
Weak
2f. W
hen the specialized testing mentioned in Recommendation 2e suggests that a patient with VS/UWS has awareness, clinicians
should reassess those patients more frequently to look for signs that the patient is recovering consciousness. If the patient is still
receiving active rehabilitation treatments at the time of the specialized testing, decisions to decrease the intensity of rehabilitation
treatment should be delayed.
Moderate
2g. In situations where MCS is suspected but severe problems with speech and/or movement limit assessment, or when testing isn’t
clear about whether or not consciousness is present, clinicians may order special brain scans, electrophysiological studies looking
at brain activity, or other tests designed to meaure command-following to try to find evidence of command-following that would
support a diagnosis of MCS.
Weak
If these tests are used to look for command following, they should not be used to exclude the possibility of MCS because they
are not perfectly accurate and could miss the ability of some patients to follow commands.
Moderate
3. C linicians caring for patients with a DoC should perform repeated evaluations in order to see if there are changes over time (e.g.
gradual improvements) that could be helpful in predicting whether the patient is expected to improve further in the future.
Moderate
4. R esearch suggests that for some patients with a DoC, early after the brain injury it can be hard to predict whether someone will
recover in the long term. In the first four weeks after brain injury, clinicians should avoid statements that suggest that patients with
a DoC have universally poor prognosis when discussing this with families.
Strong
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5. C linicians should counsel families that MCS, when diagnosed within five months of injury, and when caused by trauma, is
associated with better outcomes (for example, patients may eventually become more independent). The diagnosis of VS/UWS and
non-traumatic causes of DoC are associated with poorer outcomes, although individual outcomes vary.
Moderate
Recommendations under 6a apply to a person in VS/UWS due to a traumatic injury
6a. Clinicians should perform the Disability Rating Scale (DRS) at 2-3 months post-injury to assist in predicting 12-month recovery of
consciousness for patients in VS/UWS after a traumatic injury.
Moderate
Moderate
Clinicians should perform a special brain scan called a SPECT scan (single-photon emission computerized tomography) to assist in
predicting 12-month recovery of consciousness and degree of disability/recovery for patients in VS/UWS after a traumatic injury.
Moderate
Clinicians may assess for the presence of P300 (brain waves triggered by decision making) at 2-3 months post-injury to assist in
predicting 12-month recovery of consciousness for patients in VS/UWS after a traumatic injury.
Weak
Clinicians may assess EEG reactivity (a measurement of electrical activity in the brain) at 2-3 months post-injury to assist in
predicting 12-month recovery of consciousness for patients in VS/UWS after a traumatic injury.
Weak
Clinicians may order a special brain scan called BOLD fMRI (where available) assessing brain changes in response to a familiar
voice speaking the patient’s name to assist in predicting 12-month (post-scan) recovery of consciousness for patients in posttraumatic VS/UWS.
Weak
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Clinicians should perform MRI imaging 6-8 weeks post-injury to assess for injury to specific areas of the brain associated with
consciousness in order to assist in predicting whether patients will be in persistent vegetative state at 12 months for patients in
VS/UWS after a traumatic injury.
Recommendations under 6b apply to a person in VS/UWS due to a loss of oxygen to the brain
6b. Clinicians should perform the Coma Recovery Scale-Revised (CRS-R) to assist in predicting recovery of consciousness at 24 months
for patients in VS/UWS due to loss of oxygen to the brain.
Clinicians may assess somatosensory evoked potential (SEPs) (an examining testing if the brain receives/detects body sensations)
to assist in predicting recovery of consciousness at 24 months for patients in VS/UWS due to loss of oxygen to the brain.
Moderate
Weak
7. In patients with a prolonged DoC, when it seems very likely that the patient will have severe long-term disability, clinicians should
counsel family members to seek assistance in completing an advance directive for the patient (if not available), applying for
disability benefits, and starting estate, caregiver, and long-term care planning.
Strong
8. E arly in caring for a patient with a prolonged DoC, clinicians should understand patient and family preferences to help guide
decision-making.
Strong
9. C linicians caring for patients in VS/UWS or MCS due to a traumatic injury who are between 4 and 16 weeks after the injury should
prescribe amantadine 100-200 mg twice daily to speed recovery (unless there is a reason that the patient should not take the
amantadine).
Moderate
10. Clinicians should carefully watch for medical complications that commonly occur during the first few months after injury in patients
with a DoC by using an organized assessment approach to help with prevention, early diagnosis and treatment.
Moderate
11. Patients with a prolonged DoC are at risk for particular complications. Because of this, clinicians should refer patients with a
prolonged DoC who are in the early stages of recovery to a rehabilitation setting staffed by clinicians from different specialties that
are familiar with these risks and can monitor for them and treat them while providing rehabilitation.
Moderate
12a. Because there are not good treatments for patients with DoC, sometimes families request to try unapproved treatments (e.g.,
hyperbaric oxygen, natural supplements, stem cell therapies, primrose oil, etc.), but these treatments have either little or no
evidence to suggest they will help or to show that they are safe. Clinicians should counsel families about that there is not good
evidence to suggest that these treatments will help and that we don’t have reliable information about the potential risks and
harms.
Moderate
12b. When discussing treatments that have not been well studied, clinicians should provide the available evidence-based information
regarding the projected benefits and risks of a particular treatment, and the level of uncertainty associated with trying the
requested treatment.
12c. P atients with a DoC can show gradual improvement due to natural recovery over time and/or rehabilitation, even if specific
additional treatments are not tried. Clinicians should counsel families that, in many cases, it is impossible to know whether
improvements observed early during recovery are caused by a specific treatment or spontaneous recovery.
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13a. Families are often concerned about whether a person with a DoC is experiencing pain and suffering. The medical research about
this is mixed. The use of pain medication can make it more difficult to test how awake a person is, but clinicians and families
want to make sure that a person with a DoC does not suffer.
Moderate
Clinicians should assess individuals with a DoC for evidence of pain or suffering and should treat when there is reasonable cause
to suspect that the patient is experiencing pain, regardless of how conscious or unconscious a person is.
13b. Clinicians should counsel families that there is uncertainty about how much pain and suffering that may be experienced by
patients with DoC.
14a. A 1994 task force defined VS as “permanent” 3 months after a non-traumatic injury leading to VS (e.g. due to loss of oxygen
to the brain) and 12 months after a traumatic injury. Research since that time, however, shows that some patients recover
consciousness (though often with ongoing severe disability) even after those times. Given that some patients can recover after
these times, the guideline authors recommend that the use of the term “permanent VS” should be stopped. After these time
points (3 months for DoC due to loss of oxygen to the brain or other non-traumatic injury and 12 months for DoC due to traumatic
injury), the term “chronic VS” (UWS) should be applied, accompanied by the duration of the VS/UWS.
Moderate
14b. When patients enter the chronic phase of VS/UWS, clinicians should emphasize to families that ongoing permanent severe
disability is still likely with a need for long-term assistive care.
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The recommendations above were developed based on research looking at disorders of consciousness in adults. Much less is known about what to expect
when children have disorders of consciousness. The guideline authors made the following recommendations for clinicians when caring for children with a
disorder of consciousness (e.g. due to trauma, loss of oxygen to the brain due to drowning injuries, etc.).
Recommendations 15, 16, and 17 apply to children
15. Clinicians should treat medical complications, maximize wakefulness prior to testing, use reliable tools for assessing how awake
someone is (particularly those designed to use with children), and do repeated examinations to improve diagnosis in children with
a DoC.
Moderate
16. Clinicians should counsel families that the natural history (what to expect over time) and prognosis of children with a DoC is not
well-defined and that there are no current tests or examinations that help to predict whether (or how much) children will recover
from a DoC.
Moderate
17. Clinicians should counsel families that there are no established treatments for children with a prolonged DoC.
Moderate
In addition to making recommendations about how to care for adults and children with prolonged DoC, the complete guideline makes suggestions for future
research. There is a lot that remains unknown about caring for both adults and children with DoC. For example, clinicians and researchers need to learn more
about what to expect (over months and years) when patients are in a DoC, how to best diagnose the different kinds of DoC, what medical findings and tests
will better predict what to expect for patients with a DoC, and how best to treat patients with a DoC to improve recovery. The guideline describes where the
research is most needed and how to better design research that will give patients, families, and clinicians the information that they need.
Table 2. Definitions for Recommendation Levels
Recommendation Level
Definition
A (Strong)
There are very strong and compelling reasons to follow this recommendation, it possible to follow this recommendation
in almost all circumstances, and in almost all circumstances, patients would want the course of action described in the
recommendation to be followed.
B (Moderate)
There are good and compelling reasons to follow this recommendation, it is generally possible to follow this
recommendation, and in most circumstances, patients would want the course of action described in the recommendation
to be followed.
C (Weak)
There are reasons to follow this recommendation, but the research supporting this recommendation is weak, the benefits
relative to the risks is less certain, the test or treatment is costly, or only some patients would want the course of action
described in the recommendation to be followed. Recommendations can be “weak” for a variety of different reasons and
these reasons are described in the complete guideline.
U (None Made)
There is not enough research to make a recommendation and/or the balance of the benefits, harms, and costs is unknown.
R (Research Setting Only)
There is not enough research to make a recommendation and/or the balance of the benefits, harms, and costs is unknown,
but there is a good reason to think that more research should be done. Only patients in a research study would receive the
course of action.
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This statement is provided as an educational service of the American Academy of Neurology. It is based on an assessment of current scientific and clinical information. It is not intended to include all possible proper
methods of care for a particular neurologic problem or all legitimate criteria for choosing to use a specific procedure. Neither is it intended to exclude any reasonable alternative methodologies. The AAN recognizes that
specific patient care decisions are the prerogative of the patient and the physician caring for the patient, based on all of the circumstances involved.
The AAN develops these summaries as educational tools for neurologists, patients, family members, caregivers, and the public. You may download and retain a single copy for your personal use. Please contact
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Copies of this summary and additional companion tools are available at AAN.com or through AAN Member Services at (800) 879-1960.
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