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Altered Mental Status
Coma is the lack of any awareness of self and environment despite painful or other external stimulation ( Table 31.1 ). Delirium is an alternation in consciousness that falls along the spectrum from normal awareness to coma and is characterized by irritability, agitation, lack of contact with the environment, and confusion. Periods of lucidity may alternate with the delirious state, and patients may proceed rapidly from delirium to lethargy or coma. Any alteration in the level of consciousness whether delirium, lethargy, obtundation, stupor, or coma must be managed as a life-threatening emergency until proven otherwise.
TABLE 31.1
States of Altered Consciousness or Unresponsiveness
Coma: A state of unarousable unresponsiveness; even strong exteroceptive stimuli fail to elicit recognizable psychologic responses; unresponsive to pain
Stupor: Spontaneous unarousability interruptible only by vigorous, direct external stimulation; responsive only to pain
Hypersomnia, pathologic drowsiness, obtundation: Terms applied to an increase above the patient’s normal sleep/wake ratio, often accompanied during wakefulness by reduced attention and interest in the environment; responsive to pain and other stimuli
Delirium: An acute or subacute reduction in awareness, attention, orientation, and perception (“clouding of consciousness”), usually fluctuating and accompanied by abnormal sleep/wake patterns and often psychomotor disturbances
Syncope: Brief loss of consciousness caused by global failure of cerebrovascular perfusion
Dementia: A sustained or permanent multidimensional or global decline in cognitive functions
Vegetative state: A sustained, complete loss of cognition, with sleep/wake cycles and other autonomic functions remaining relatively intact; can either follow acute, severe bilateral cerebral damage or develop gradually as the end stage of a progressive dementia
Locked-in state: Preservation of intellectual activity accompanied by severe or total incapacity to express voluntary responses as a result of damage to or dysfunction of descending motor pathways in the brain or peripheral motor nerves; most, but not all, such patients can use vertical eye movements to signal by code
Modified from Plum F. Neurology/disturbances of consciousness and arousal. In: Wyngaarden JB, Smith LH, Bennett JC, eds. Cecil Textbook of Medicine . 19th ed. Philadelphia: WB Saunders; 1992:2049.
Background
Arousal and awareness form the foundation for normal cognitive function. Arousal is determined in the brainstem’s ascending reticular activating system, and awareness is generated in the cortex. The cortex is the central processing center that interprets neuronal input and generates awareness. Injury to these areas creates an alteration in consciousness. Standardized language is necessary to properly diagnose and treat alterations in consciousness since terms, such as lethargy, obtundation, stupor, and coma, are qualitative descriptions. Rating scales allow different observers to follow the progression of the patient’s mental status over time and facilitate effective communication of clinical information. The most widely used grading system is the Glasgow Coma Scale (GCS) ( Table 31.2 ), which has been modified for children less than 5 years of age based on their age-appropriate developmental abilities ( Table 31.3 ). The GCS was initially intended for use in traumatic injury but has been successfully applied in patients with nontraumatic altered mental status. This 15-point scale evaluates 3 areas of central nervous system (CNS) function: eye opening, verbal response, and motor response. A score of 15 indicates full function, whereas a score of 3 indicates no function. The 1st area of assessment is eye opening, in which the arousability and alertness of the patient are evaluated. Spontaneous eye opening indicates intact arousal mechanisms but does not imply awareness. The 2nd area, verbal response, requires a high degree of integration within the CNS. Oriented responses indicate awareness of person, place, and time. The 3rd area, motor functioning, reflects mentation as well as the integrity of the major CNS pathways. For purposes of gauging global brain function, the best motor response from any limb is taken as the score. Variation in response from one side of the body to the other is indicative of an asymmetric brain lesion. Spinal cord lesions resulting in paralysis or significant orthopedic injuries to the extremities prevent evaluation of the motor portion of the GCS.
TABLE 31.2
Glasgow Coma Scale Versus Full Outline of Unresponsiveness Score
Glasgow Coma Scale (GCS)
Full Outline of Unresponsiveness (FOUR)
Eye Opening:
Eye Response:
1
Does not open eyes
4
Eyelids open and comply with verbal stimuli
2
Opens eyes in response to noxious stimuli
3
Eyelids open but not tracking
3
Opens eyes in response to voice
2
Eyelids closed but open to loud noise
4
Opens eyes spontaneously
1
Eyelids closed but open to noxious stimuli
0
Eyelids remain closed
Verbal Response:
Motor Response:
1
No verbal response
4
Thumbs up, fist or peace sign
2
Incomprehensible sounds
3
Localize to pain
3
Inappropriate words
2
Flexion to pain
4
Confused and disoriented fluid speech
1
Extension to pain
5
Oriented with normal speech
0
No response to pain or myoclonus
Motor Response:
Brainstem Reflexes:
1
No movements
4
Pupil and corneal reflexes present
2
Extension to noxious stimuli
3
One pupil wide and fixed
3
Flexion to noxious stimuli
2
Pupil or corneal reflex absent
4
Withdrawal to pain
1
Pupil and corneal reflexes absent
5
Localizes to pain
0
Absent pupil, corneal, and cough reflex
6
Obeys commands
Respirations:
4
Regular breathing pattern
3
Cheyne–Stokes respirations
2
Irregular breathing
1
Intubated but breathing above the vent
0
Breathing at vent rate or apnea
TOTAL SCORE 3-15
TOTAL SCORE 0-16
(See Nelson Textbook of Pediatrics , Table 67-3.)
TABLE 31.3
Pediatric Glasgow Coma Scale
Activity
Best Response
Score
Eye opening
Spontaneously
4
To speech
3
To pain
2
None
1
Verbal
Oriented
5
Words
4
Vocal sounds
3
Cries
2
None
1
Motor
Obeys commands
5
Localizes pain
4
Flexion to pain
3
Extension to pain
2
None
1
Normal Total Score Based on Age
Birth–6 mo
9
7-12 mo
11
1-2 yr
12
2-5 yr
13
>5 yr
14
Modified from Simpson D, Reilly P. Pediatric coma scale. Lancet. 1982;2:450.
The GCS can provide a general assessment of consciousness but is not intended to take the place of a complete neurologic evaluation ( Table 31.4 ). The scale is an objective measure of the improvement or worsening of the patient’s level of consciousness over time, and interventions are often based on the score. Most patients with traumatic brain injury should undergo endotracheal intubation if their score is 8 or less. Deterioration of a patient’s score by 2 or more points indicates a need for quick re-evaluation of the patient and the possible need for interventions such as endotracheal intubation and diagnostic studies such as a brain computed tomography (CT) scan. The score has been used to assign a prognosis to patients with brain injury, particularly with traumatic brain injury. It may take days to weeks for patients with initial scores of 3-5 to become conscious as opposed to a few days in patients with scores of 6 or higher.
TABLE 31.4
The Neurologic Examination in Coma
1.
Guarantee vital functions.
2.
Feel the scalp for hematomas (overlying fracture lines); be sure the neck is not fractured; test gently for stiff neck.
3.
Test language. Test arousability by words, loud sounds, noxious stimuli. If vocalizations occur, check quickly for appropriate phrases, actual words, and presence or absence of aphasia.
4.
Perform a neuro-ophthalmologic examination.
Funduscopy (if difficult, can be deferred until patient is stabilized).
Papilledema (increased intracranial or venous sinus pressure)
Light reaction: Use bright flashlight and, if necessary, a magnifying glass to be certain of findings. Absence means potentially fatally deep sedative poisoning or acute or chronic structural brainstem damage.
Equality: 15% of normal patients have mild anisocoria, but new or >2-mm dilation means parasympathetic (3rd nerve) palsy.
Extraocular movements: Absence acutely means deep drug poisoning, severe brainstem damage, polyneuropathy, or botulism.
Dysconjugate deviation: At rest, this means an acute 3rd, 4th, or 6th nerve palsy or internuclear ophthalmoplegia. Tonic conjugate deviation toward a paralytic arm and leg means forebrain seizures or a contralateral pontine destructive lesion; such deviation away from the paralytic arm and leg means forebrain gaze paralysis.
Spontaneous eye movements: In comatose patients, nystagmus, bobbing, and independently moving eyes all mean brainstem damage.
Oculocephalic (away from direction of head turning) or oculovestibular (toward cold caloric irrigation) responses: Absence of responses means drug overdose or severe brainstem disease; dysconjugate responses with equal pupils mean internuclear ophthalmoplegia; responses with unequal pupils mean 3rd nerve disease.
5.
Examine the motor systems.
Strength
Unilateral weakness or motionlessness of arm and leg means contralateral supraspinal upper motor neuron lesion, most often cerebral; if of arm, leg, and face, contralateral cerebral lesion. Occasionally, arm and leg weakness reflects contralateral brainstem lesion.
Weakness or motionlessness of all 4 extremities implies metabolic disease; less likely is brainstem disease (tone and reflexes increased) or peripheral disease (tone and reflexes decreased).
Attempt to Elicit Reflex Posturing
Arm flexed, leg extended: contralateral deep cerebral-thalamic lesion
Arm and leg extended: thalamic or mesencephalic lesion
Arms extended and legs flexed or flaccid: pontine lesion
Legs flexed, arms flaccid: pontomedullary or spinal lesion
Compare side-to-side reflexes and examine plantar responses.
6.
Seek seizure activity or abnormal movements: (1) generalized, (2) focal, (3) multifocal, and (4) myoclonic.
Control (1) immediately, (2) and (3) deliberately; if (4) is present, treat underlying disease.
Regular hyperpnea: metabolic acidosis; pulmonary infarction; congestive failure or alveolar infiltration; sepsis; salicylism; hepatic coma
Cyclically irregular (Cheyne–Stokes): low cardiac output plus bilateral cerebral or upper brainstem dysfunction
Irregularly irregular gasping, slow or weak: lower, brainstem dysfunction (including hypoglycemia, drug effects); less often, peripheral ventilatory paralysis
8.
Proceed with laboratory tests and emergency management as described in text.
Modified from Plum F. Neurology/sustained impairments of consciousness. In: Wyngaarden JB, Smith LH, Bennett JC, eds. Cecil Textbook of Medicine. 19th ed. Philadelphia: WB Saunders; 1992:2057.
The GCS score has also been used as a prognostic indicator in nontraumatic coma. Children presenting after near-drowning with an initial score of 6 or higher have a good outcome. Patients presenting with a score of 5 or less have a high probability of mortality or profound neurologic sequelae, although a patient with a score of 4 or 5 may survive with minimal impairment. A score of 3 on transfer to an intensive care unit after near-drowning has been associated with a nearly 100% rate of poor outcome.
Although the GCS is a widely applied tool for assessment, it does not assess brainstem function and fails to discriminate between low scores and intubated patients. The Full Outline of Unresponsiveness (FOUR) scale is another tool to assess consciousness that has been validated in several different settings with high inter-rater consistency. The FOUR score evaluates eye response, motor response, brainstem reflexes, and respiratory effort on a 4-point scale. The FOUR score eye and motor responses are defined very similar to the GCS (see Table 31.2 ). The assessment of brainstem response focuses on the pupillary and corneal reflexes. The respiratory assessment includes the intubated patient along with respiratory effort. Because the FOUR score includes brainstem responses and not only recognizes but differentiates intubated patients, this scale is better able to discriminate an unresponsive patient with a GCS of 3. In children with nontraumatic impairment of consciousness, using endpoints of mortality and functional outcome, both scales have similar predictive value. Regardless of the scoring system used, reporting the score for each element can increase the precise description of alteration in consciousness in order to make management decisions.
Other scales have been developed to measure the level of consciousness in specific disease states, such as poisonings, and hepatic failure. The Reed classification of coma has been used in the setting of poisoning or intoxication ( Table 31.5 ) and is used to evaluate increasing depths of coma encountered with CNS-depressant drugs. The cardiovascular system is included in this classification because toxic ingestions may depress myocardial contractility or cause vasodilation. Neurologic function in a patient with hepatic encephalopathy is graded according to the scoring system in Table 31.6 .
Comatose Reflexes absent Respiratory or circulatory problems
Modified from Ellenhorn MJ, Barceloux DE. Medical Toxicology: Diagnosis and Treatment of Human Poisoning . New York: Elsevier Science; 1988:17.
* Good prognosis.
† Very serious, may need measures to enhance elimination.
TABLE 31.6
Classification of Hepatic Encephalopathy
Grade 0
Normal
Grade I
Altered spatial orientation, sleep patterns, and affect
Grade II
Drowsy but arousable, slurred speech, confusion, and asterixis
Grade III
Stuporous but responsive to painful stimuli
Grade IV
Unresponsive, with decorticate or decerebrate posturing possible
From Rogers EL, Perman JA. Gastrointestinal and hepatic failure. In: Rogers MC, ed. Textbook of Pediatric Intensive Care . 2nd ed. Baltimore: Williams & Wilkins; 1992:1151.
Differential Diagnosis
Coma is caused by 1 of 3 etiologies: structural brain disease, diffuse neuronal injury, or to a lesser degree, psychogenic causes. Within these 3 categories, the differential diagnosis of coma in the child is extensive. Excluding traumatic head injuries, broad category causes of altered mental status in children include intracranial infections, hypoxic-ischemic, epilepsy, metabolic encephalopathies, abusive head trauma, toxic ingestion, anatomic abnormalities, and cerebral vascular abnormalities such as emboli or vasculitis ( Table 31.7 ). Some diagnoses (subdural hematoma, hydrocephalus, cerebral edema) may apply to more than 1 category. The age of the patient can help the clinician differentiate the likely causes of coma, although there is considerable overlap ( Table 31.8 ). Patients with delirium must be differentiated from an acute psychotic event ( Table 31.9 ). In addition, in patients who are awake but presenting with an altered mental status, performing an appropriate mental status exam may help evaluate the degree of impairment and potential etiology ( Table 31.10 ). The mental status exam is most abnormal with organic (encephalopathy, encephalitis) causes of altered behavior and mental status.
TABLE 31.7
Etiologic Classification of Altered Mental Status in Children
Differential Diagnosis 
