When you encounter "disorders of consciousness" in the emergency department, you can handle it like this

Impairment of consciousness is a symbol of "critical illness" in various clinical disciplines, and it is a common topic in neurology and emergency departments
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For novices, it is especially important to correctly identify the disorder of consciousness and understand its potential dangers.
Correct evaluation is particularly important
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This article mainly takes everyone to review the classification and assessment of disorders of consciousness
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This article is published by Yimaitong authorized by the author, please do not reprint without authorization
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Delineation of "contour" disorders of consciousness (DoC) refers to a state of consciousness in which consciousness disorder exceeds 28 days after various brain injuries (2018 American Practice Guidelines for Disorders of Consciousness), which is mainly determined by the level and content of consciousness, that is, the degree of awareness ( It consists of two aspects: wakefulness and awareness
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Awareness refers to the perception of oneself and the surrounding environment.
It is related to the frontal and parietal cortex and can be assessed by responding to verbal commands (such as visual tracking)
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Arousal is related to the arousal state or underlying cognitive experience, is related to the brainstem and thalamus network, and can be expressed as an eye-opening response
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Arousal is often the precipitation of cognition.
Increasing arousal can promote the enhancement of both, and at the same time promote the experience of consciousness (Figure 1)
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Figure 1 The two dimensions of consciousness and related states (conscious content and consciousness level) [Source: Laureys S.
Trends Cogn Sci.
2005;9(12):556-9.
] The concept of DoC changes over time
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In 1972, the term vegetable state (VS) was first proposed; in 1994, the American Multidisciplinary Working Group and the Royal College of Medicine in 1996 further clarified that it was defined as the lack of cognitive self and the ability of the surrounding environment, the inability to communicate with other people, and the inability to communicate with others.
Produce reproducible or purposeful spontaneous behaviors to audiovisual touch or painful stimuli, inability to understand language, existence of sleep-wake cycles, autonomic and hypothalamic function retention, urinary and fecal incontinence, and divide them into persistent plants according to the time of onset State (persistent vegetable state) (traumatic or non-traumatic 1 month) and permanent vegetable state (non-traumatic 3 months, traumatic 1 year)
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In 2002, the United States Multidisciplinary Working Group proposed the concept of minimally conscious state (MCS), which refers to the ability to complete command actions in short answers, whether to respond to gestures or language, language can be understood, and movement and relief related to stimuli.
Emotional behaviors, not reflex activities; the concept of functional locked-in syndrome was proposed in 2009.
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At present, according to the behavioral response of DoC patients, it can be divided into coma and vegetable states according to different states.
state, VS)/unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), see Table 1 for details
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Table 1 Clinical characteristics of different types of consciousness disorders [Source: Nat Rev Neurol.
2014;10:99–114.
swiss aechives of neurology and psychiatry, 2015;166(5):163-169.
] Coma is a kind of inability to wake up Unconscious state, usually several days or weeks after acute brain injury; VS/UWS refers to patients who are awake but unconscious and can show unconscious reflexes; MCS shows non-reflective cortex-mediated behavior, and some MCS patients can be to a certain extent Obey commands, but cannot communicate with functions, and can change continuously with VS/UWS
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MCS has obvious heterogeneity.
It can be divided into MCS + and MCS + according to its behavioral response.
The former refers to the patient's ability to follow instructions, speak understood vocabulary and complete purposeful communication, and the latter refers to the autonomy that can only complete consciousness.
Signs, such as pain localization and visual tracking, but lack behaviors that suggest language processing
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 The awareness of anatomical traces is related to a variety of structures in the brain, including reticular structures and complex cortical networks.
Injuries to different parts of the brain can cause different degrees of DoC (Figure 2, Table 2)
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In addition, the Ascending Reticular Activating System (RRAS) is very important in maintaining awareness and awareness.
Animal experiments have found that when the RRAS structure is destroyed, the animal will enter a continuous sleep state.
After waking up, the stimulus disappears and the animal will return to sleep; when the RRAS is continuously stimulated, the animal will continue to stay awake, and the normal sleep-wake cycle can be restored after the stimulation is stopped
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In addition, there are other reticular activation systems in the brain, including parabrachial nucleus (PBN (maintain sleep-wake cycle) and periaqueductal gray matter (pain and emotional experience)
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Figure 2 The anatomical location of different components of consciousness in the brain [Source: M.
Gavriliuc.
coma and related disorders of consciousness.
Health & Medicine, Spiritual.
2013.
11] Table 2 The anatomical location of different components of consciousness It is very critical in terms of prognosis, but unlike other neurological diseases, the classification of DoC has no specific pathophysiological basis
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Recent studies on neuroimaging and electrophysiology have promoted the research of DoC neuromarkers, but there is still no objective diagnostic gold standard, and medical history and behavioral responses are still the most important basis for DoC assessment
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In addition, the scale is also an important means of assessment, and it is very important for the assessment of the emergency state of consciousness
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Summary table 3 of DoC scales commonly used in clinical practice
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Table 3 Common Consciousness Disorder Assessment Scale (click to view larger image) Note: * J Neurol.
2011;258:1373–84.
# Including diagnostic criteria [Source: Arch Phys Med Rehabil.
2010;91(12):1795– 813.
] The GCS scale has become the most commonly used clinical DoC prognostic assessment scale due to its small number of items, less time-consuming, and easy operation.
However, its applicability to patients with intubation and complicated communication difficulties has decreased; the GLS scale makes up for it This defect adds to the items of the brainstem reflex
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The FOUR scale can be used for the evaluation of intubated patients, and includes visual tracking items (the primary sign of intention recovery, but its predictive value has not been verified), but it is not included in the language function items
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The CRS scale is the tool with the highest content validity and specificity so far.
It comprehensively evaluates the level of consciousness through exercise, language behavior, and arousal (6 subscales).
In each subscale, the score of reflex activity is the lowest.
The recognition activity has the highest score, and both have diagnostic criteria for UWS and MCS and predictive value for MCS
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The SMART scale evaluates the response to multiple sensory stimuli to guide rehabilitation exercises, but it takes a long time, requires higher professionalism, and has less clinical application
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The WHIM scale evaluates various subtle changes in the process of cognitive function recovery.
Its assessment content covers daily life functions.
It is mainly used to assess the improvement of consciousness recovery.
In a strict sense, it is not used to diagnose DoC
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The content validity of SMART and WHIM scales is very high, and they are of great value for evaluating UWS or MCS and the patient's state of recovery from both
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DoC must identify other simulated diseases that are unresponsive but intact
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For example, patients with lock-in syndrome (LIS), although their limbs are paralyzed, are fully conscious and can communicate through reserved eye movements
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Those who cannot execute commands at the bedside, but the active conscious activity in their brains can be found in functional magnetic resonance (fMRI) and electroencephalogram (EEG), that is, cognitive-motor separation state, this situation is called non- Behavioral MCS, MCS*, functional locked-in syndrome, or hidden state of consciousness
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 Challenges and Progress The accurate diagnosis of DoC is still challenging.
fMRI and electrophysiological examinations help to further determine the structural and functional positioning
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FDG-PET brain metabolic activity contributes to the display, the EEG binding transcranial magnetic stimulation (TMS-EEG) contribute to the complex interaction between the micro discrimination cortex, including quantitative other metabolic labeling, and the like fMRI resting state
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In 2014, Lancet pointed out that repeated measurements of CRS-R combined with FDG-PET can provide a simple and reliable diagnosis with high sensitivity to unresponsive but conscious patients
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In 2017, Olivier and other studies found that the simultaneous use of FDG-PET and TMS-EEG can improve the accuracy of clinical diagnosis (Figure 3)
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Figure 3 The difference between true and false DoC (UWS=vegetative state/anergy awakening state syndrome, MCS*=non-behavioral minimum state of consciousness, MCS=minimal state of consciousness, LIS=locked-in syndrome, A=front, P= Back) The CRS-R scale shows the scores of each sub-item, and the black line represents the MCS threshold; FDG-PET shows and shows the area where the metabolism of the patient’s left cerebral hemisphere is significantly reduced (blue) or retained (red); after PCI computer processing The TMS-EEG data shows the potential traces evoked by TMS at the cortical level
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UWS and MCS* are similar in CRS-R scale scores, but the TMS evoked potential and FDG-PET pattern of MCS* are similar to those of MCS and LIS
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The 2020 EAN Guidelines for the Diagnosis of Coma and Other Consciousness Disorders also supplemented the examination methods
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The CRS-R scale is more accurate for patient assessment and is freely available.
It is recommended to use CRS-R to classify the level of consciousness (medium level of evidence, strong recommendation); the recommendations for fMRI should be based on actual conditions and hospital conditions; TMS-EEG performs a general analysis of clinical standard EEG, and may detect patients with residual consciousness, with high specificity but poor sensitivity (low level of evidence, strong recommendation)
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Click to review more content ☟☟☟2020EAN: Guide to coma and other disorders of consciousness, a list of recommendations! Summary The diagnosis of DoC is still a clinical problem that needs to be further resolved, especially in the evaluation of the value of patients in the acute phase
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GCS scale, fMRI and electrophysiological examination are still important methods of DoC diagnostic evaluation
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