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Altered States of Consciousness

  • Maimonides Medical Center - Children's Hospital

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An altered level of consciousness is an important clinical entity in pediatrics and carries the potential for significant morbidity and mortality. The clinician must assess the level of consciousness rapidly as well as determine likely causes. Structural or medical causes usually can be differentiated through a focused history and physical examination. Asymmetric neurologic findings such as a dilated and fixed pupil, dyscongugate extraocular movements, and asymmetric motor findings suggest brainstem dysfunction as a result of a structural lesion; slowly progressive but symmetric neurologic findings usually result from a medical disorder. Specific neurologic findings associated with elevated intracranial pressure are seen in both central and uncal herniation. Disorders of metabolism, liver, kidneys, lungs, or heart as well as toxic exposure are common medical causes for alteration of consciousness. After initial assessment and stabilization, management centers on determining the specific diagnosis and continuing supportive care.
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Altered States of Consciousness
Jeffrey R. Avner, MD*
Author Disclosure
Dr Avner did not
disclose any financial
relationships relevant
to this article.
Objectives After completing this article, readers should be able to:
1. List the common causes of altered level of consciousness.
2. Discuss how to differentiate medical and structural causes of altered level of
3. Develop a plan for the initial phase of evaluation for an altered level of consciousness.
4. Recognize the importance of radiologic imaging in a child who has an altered level of
5. Know which ingestions are likely to cause neurologic adverse effects.
During the course of normal interaction with one another, we observe each other’s
mannerisms, responses, movements, and communications. In a sense, a person’s behavior
is determined by how he or she acts or reacts to internal and external stimuli. What is
considered normal behavior is often age-specific and person-specific. For example, the
response of a teenager to the early morning “buzz” of an alarm clock is usually a purposeful
attempt to shut the alarm off; an infant may cry as a response to the same stimulus.
Similarly, children who have certain chronic illnesses, such as static encephalopathy, may
have blunted responses as a baseline behavior. Although major changes in behavior are
readily apparent to any clinician, subtle changes often are appreciated best by parents and
Essential to the evaluation of abnormalities in a child’s behavior is an understanding of
levels of consciousness. Various terms that define specific conditions or alterations of
normal levels of consciousness often are used interchangeably and incorrectly by clinicians
and parents alike. Consciousness is a state of awareness of both one’s self and the
environment. A child who has a normal level of consciousness can be awakened and is
aware of what is happening to and around him- or herself. Alteration of the level of
consciousness usually begins with reduced awareness of one’s self, followed by reduced
awareness of the environment, and finally by an inability to be aroused. The opposite of
consciousness is coma, a state in which a person is unresponsive to all stimuli, including
Although consciousness and coma represent the extremes of mental status, there are
many abnormal states of consciousness along that spectrum that may, at times, blend
imperceptibly into one another. Appropriate use of terminology begins with a proper
understanding of the definition of such states of consciousness. Confusion occurs when
there is a loss of clear thinking, usually manifested by impairment of cognitive abilities and
decision-making. Disorientation often accompanies confusion. In general, disorientation
to time occurs first, followed by disorientation to place, and then by deficiency in
short-term memory. Loss of recognition of one’s self is a later finding. In delirium, there
is a succession of confused and unconnected ideas. Delirious children often have extreme
mental and motor excitement, so they become disoriented, fearful, irritable, offensive, or
agitated. Lethargy is a state resembling profound slumber, in which the child’s movement
or speech is limited. A lethargic child can be aroused with moderate external stimulation
but immediately relapses into a state of limited responsiveness. Stupor is a condition of
deep sleep or unresponsiveness from which the child can be aroused only with repeated
*Professor of Clinical Pediatrics, Albert Einstein College of Medicine; Chief, Division of Pediatric Emergency Medicine, Children’s
Hospital at Montefiore, Bronx, NY.
Article neurology
Pediatrics in Review Vol.27 No.9 September 2006 331
vigorous stimuli. Finally, in coma, the child is unrespon-
sive even to painful stimuli. A persistent vegetative state
and coma often are confusing. In both the vegetative
state and coma, there is no evidence of self-awareness (no
response to communication or purposeful movements)
or communication (either verbal or by gestures). How-
ever, in the vegetative state, the child’s eyes may open
spontaneously, giving the appearance of a state of arousal
(albeit poorly sustained and sluggish) as opposed to that
of coma, in which the eyes are always closed.
An altered level of consciousness in children has many
causes, with a fundamental differentiation being between
structural and nonstructural (referred to as “medical” in
this article) conditions. The mnemonic AEIOU TIPS
(tips on vowels) is helpful in listing the major categories
of illness or injury to be considered (Table 1). Although
these disorders can occur at any age, certain conditions
are more prevalent at specific ages. Nontraumatic coma
has a bimodal distribution, being most common in in-
fants and toddlers and having another smaller peak in
adolescence. Infection either of the brain (encephalitis),
meninges (meningitis), or both is the most common
cause of altered level of consciousness, accounting for
more than one third of nontraumatic cases. (Wong,
2001) Congenital malformations, especially those of the
central nervous system (CNS), typically present in the
first few postnatal months, but complications from sur-
gical correction of such problems (eg, ventriculoperito-
neal shunt obstruction) may occur at any age.
Diabetic ketoacidosis, the most common metabolic
disorder presenting with alteration of consciousness, can
occur at any age but is more common in adolescence.
Inborn errors of metabolism, including those that
present with electrolyte and glucose abnormalities, typi-
cally present in infancy. Prolonged seizures, anticonvul-
sive therapy, and the postictal state also can alter the level
of consciousness.
In childhood and adolescence, toxic exposure or in-
gestion is most common. A toddler has the ability to
explore the environment but does not yet have the
cognitive ability to know that ingesting pills may be
harmful. Many medications (especially those targeted for
use in pediatrics) are brightly colored and taste like
candy, creating an inviting stimulus for accidental inges-
tion. Commonly ingested agents that cause an altered
level of consciousness are listed in Table 2. Ingestion by
adolescents usually is intentional and typically involves
over-the-counter medication (eg, acetaminophen, ibu-
profen) or psychotropic drugs such as antidepressants.
Although the overall incidence of traumatic and non-
traumatic coma is similar, the rate of traumatic injury
tends to increase throughout childhood. Trauma, espe-
cially head trauma, can cause intracerebral, epidural, or
subdural bleeding, leading to cerebral dysfunction either
by primary neuronal damage or the effects of cerebral
herniation or brainstem compression. Intentional trauma
(child abuse) always should be considered in any infant
presenting with an altered level of consciousness.
The clinician can determine the child’s state of awareness
by the child’s behavior. The content of a child’s behavior
can be inferred by his or her actions and appearance.
Normal behavior requires appropriate cognition and af-
fect, enabling children to perceive the relationship be-
Table 1. Mnemonic for Altered
Level of Consciousness
A Alcohol, Abuse of Substances
E Epilepsy, Encephalopathy, Electrolyte Abnormalities,
Endocrine Disorders
I Insulin, Intussusception
O Overdose, Oxygen Deficiency
U Uremia
T Trauma, Temperature Abnormality, Tumor
I Infection
P Poisoning, Psychiatric Conditions
S Shock, Stroke, Space-occupying Lesion (intracranial)
Table 2. Commonly Ingested
Agents that Cause an Altered
Level of Consciousness
Selective serotonin uptake inhibitors (SSRIs)
Tricyclic antidepressants
neurology altered states of consciousness
332 Pediatrics in Review Vol.27 No.9 September 2006
tween themselves and their environment. This component
of behavior is controlled by the cerebral hemispheres.
In a typical day, the body goes through a normal
cycling of alertness. From a state of wakefulness, it is
normal to become drowsy and, eventually, to fall asleep.
At some point during sleep (or even during drowsiness),
external stimuli are processed through sensory inputs to
increase awareness and cause one to be more awake. This
cycling of behavior is modulated predominately by the
ascending reticular activating system (ARAS), a core
brainstem structure that often is considered the “sleep
center.” Thus, normal behavior can be thought of as a
combination of appropriate “content” and arousal.
A useful method of approaching altered level of con-
sciousness is the bulb-switch analogy. Consider the con-
tent of behavior (controlled by the cerebral hemispheres)
to be a light bulb and the arousal component (controlled
by the ARAS) to be a light switch. For the bulb to be lit
(at a normal level of consciousness), the bulb has to be
functional and the switch on. There are three possibilities
if the bulb is not lit (altered level of consciousness): a
defect in the bulb itself (diffuse dysfunction of the cere-
bral hemispheres), a defect in the switch (a localized
abnormality of the ARAS), or defects in both the bulb
and the switch (global CNS dysfunction).
This model also helps differentiate the etiology of the
alteration in consciousness. The ARAS is located in the
vicinity of several brainstem reflexes, including those for
pupillary light reflexes (cranial nerves II and III) and
those for reflex eye movements (cranial nerves III, VI,
VIII, and the medial longitudinal fasciculus). Thus, pres-
ervation of these reflexes suggests that the ARAS is
functional. Under this condition, the altered level of
consciousness likely is due to a dysfunctional bulb (in-
volvement of both cerebral hemispheres).
On the other hand, impingement on the area of the
ARAS causes loss of the brainstem reflexes and an altered
level of consciousness, even though the cerebral hemi-
spheres are functioning normally. Diffuse cerebral dys-
function usually has a medical basis, such as toxic, meta-
bolic, or infectious causes; compression of the ARAS
usually is the result of structural causes (Table 3). About
90% of cases of nontraumatic coma in children are due to
medical causes. (Wong 2001)
It is important to note, however, that although focal
neurologic signs suggest a structural lesion and lack of
focality suggests a medical cause, there are many excep-
tions. For example, structural disorders that may present
without focality include acute hydrocephalus, bilateral
subdural hematomas, and acute bilateral cerebrovascular
disease. Medical encephalopathies that often present
with apparent focal neurologic signs include hypoglyce-
mia, hyperglycemia, hypercalcemia, hepatic encephalop-
athy, uremia, and the postictal state that includes Todd
The differentiation of structural and medical causes of
altered level of consciousness is assessed best by imaging
modalities such as computed tomography (CT) scan or
magnetic resonance imaging (MRI), which are readily
available in most acute-care settings. Although imaging
can pinpoint specific structural defects, the presence of
cerebral swelling, and focal neurologic abnormalities, it
also is important to have a clear understanding of the
underlying pathophysiology that accompanies both
structural and medical causes of altered level of con-
sciousness. Three major responses (ie, pupillary reflexes,
extraocular movements, and motor response to pain) are
helpful in evaluating both the level and progression of a
child’s state of consciousness. The pupillary reflex is a
balance between parasympathetic (pupillary constrictors)
and sympathetic (pupillary dilators) innervation. Because
the pathways that control this reflex lie adjacent to the
brainstem area that controls consciousness, lesions that
Table 3. Differential Diagnosis of
Altered Level of Consciousness
Structural Causes
Cerebral vascular accident
Cerebral vein thrombosis
Intracerebral tumor
Subdural empyema
Trauma (intracranial hemorrhage, diffuse cerebral
swelling, shaken baby syndrome)
Medical Causes (Toxic-Infectious-Metabolic)
Diabetic ketoacidosis
Electrolyte abnormality
Hypothermia or hyperthermia
Infection (sepsis)
Inborn errors of metabolism
Meningitis and encephalitis
Postictal state
Uremia (hemolytic-uremic syndrome)
neurology altered states of consciousness
Pediatrics in Review Vol.27 No.9 September 2006 333
impinge or affect the brainstem alter pupillary size or the
ability of the pupil to react to light. For example, a
midbrain lesion interrupts the parasympathetic and sym-
pathetic fibers equally, resulting in pupils that are in
midposition and fixed; a pontine lesion primarily inter-
rupts the descending sympathetic fibers, causing pin-
point pupils. Expanding lesions in the temporal area of
the brain may cause uncal herniation and compress cra-
nial nerve III, leading to a unilateral dilated and fixed
pupil on the side of the lesion.
On the other hand, the pupillary reflex is relatively
resistant to metabolic insult; although the pupils may be
small, they maintain the ability to react to light. There-
fore, a child who has unequal, sluggishly reactive, or
unreactive pupils should be presumed to have brainstem
dysfunction in the area of the ARAS and likely a struc-
tural cause for the abnormal level of consciousness, as
opposed to a medical cause, which would spare the
pupillary reflex. For that reason, the presence or absence
of the pupillary reflex is one of the most important
findings for differentiating structural and medical causes
of altered consciousness.
Dysfunction of certain extraocular movements also
may accompany structural causes of altered conscious-
ness. In particular, the oculocephalic reflexes are helpful
in assessing low brainstem function. For example, when
the head is turned to one side in a child who has a
functioning brainstem, the eyes move in conjugate fash-
ion, regardless of the level of consciousness. Stimuli from
the cervical muscles in the neck, the semicircular canals in
the ear, and the cerebellum synapse with the vestibular
nucleus in the brainstem. The impulse, then, is transmit-
ted caudally through the medial longitudinal fasciculus
(MLF) to the ipsilateral abducens nucleus (cranial nerve
VI) that contracts the lateral rectus muscle and abducts
the ipsilateral eye. The impulse also continues caudally
but crosses the brainstem to synapse with the contralat-
eral oculomotor nucleus (cranial nerve III), which con-
tracts the medial rectus muscle and adducts the contralat-
eral eye. Thus, the eyes move in conjugate fashion (one
eye adducts and the other abducts). If there is a brain-
stem lesion at the level of the MLF, the eyes move
dysconjugately when the head is turned. If there is a low
brainstem lesion, the eyes do not move at all relative to
the head; in this “doll eyes” phenomenon, the eyes
appear as if they were painted on the head.
Finally, motor response to a painful stimulus can help
localize the level of brainstem dysfunction. Lesions at or
above the diencephalic level are associated with decorti-
cate posturing, so the legs stiffen and the arms are rigidly
flexed at the elbow and wrist. As the lesion moves ros-
trally to the level of the midbrain or upper pons, the arms
and legs extend and pronate in response to pain, in what
is called decerbrate posturing. If the lesion extends to the
medulla, the child’s muscles are flaccid, and there is no
response to painful stimuli.
Clinical Aspects
The history and physical examination should focus on
identifying both the cause and progression of the altered
level of consciousness. Information
about the onset of the neurologic symp-
toms is particularly important. Time of
day, location, and duration of initial
symptoms may offer clues to the under-
lying cause. Clearly, a history of trauma
directs the differential diagnosis toward
traumatic causes. However, especially in
the young child, a history of minor
trauma may be overlooked. Early morn-
ing headaches, dizziness, and somno-
lence often are seen with increased intracranial pressure.
Proximity to a poorly ventilated combustible gas source
(home heating system, car exhaust) can cause carbon
monoxide poisoning. Dizziness and lethargy following a
party or school event should raise suspicion for a toxic
ingestion. An abrupt change in the child’s mental status
often results from an acute event such as a CNS hemor-
rhage or obstructive hydrocephalus.
A gradual onset of symptoms over hours or days
suggests a metabolic, infectious, or toxic cause. Contin-
ued clinical deterioration may signal increasing intracra-
nial pressure, systemic infection, or progressive meta-
bolic derangement (acidosis, electrolyte abnormality).
A past history of medical conditions associated with
altered level of consciousness may be seen in diabetes
mellitus, hypoglycemia, hypertension, or uremia.
Evidence of drug or alcohol use or availability of
prescription or nonprescription drugs should be ascer-
tained. In both intentional and accidental ingestions,
there may be no specific history of ingestion. Therefore,
Evidenceof drug or alcohol use or
availability of prescription or nonprescription
drugs should be ascertained.
neurology altered states of consciousness
334 Pediatrics in Review Vol.27 No.9 September 2006
the clinician must determine the availability and type of
medication in the home. Because ingestions are a com-
mon cause of altered mental status in children, a list of
important historical questions is shown in Table 4.
Key findings on the physical examination can help
differentiate structural from medical causes of altered
consciousness. Accurate assessment of the child’s vital
signs is of paramount importance. If the child is febrile,
an infectious cause is likely, although some toxic inges-
tions (eg, anticholingerics) also can cause fever. The
respiratory rate and pattern may be helpful in localizing
the level of a brainstem lesion. Because the respiratory
center is located in the pons and medulla, compression
on this area of the brainstem changes the pattern of
respiration. If there is primary cerebral dysfunction, there
may be posthyperventilation apnea. As the level of the
brain dysfunction progresses from caudal to rostral
through the brainstem, the respiratory pattern progresses
from Cheyne-Stokes respiration (crescendo-decrescendo
pattern followed by intervals of apnea) to central neuro-
genic hyperventilation (sustained, rapid, deep respira-
tion). In low brainstem lesions, respiratory effort is gasp-
ing, irregular, or sporadic.
The pulse or blood pressure often is abnormal in cases
of impending cerebral herniation. The cranial vault can
accommodate a modest increase in intracranial contents
caused by brain swelling, cerebral mass, or hemorrhage.
The anterior fontanelle and the flexible skull of the infant
allow the intracranial cavity to expand. In the older child
and adult, an intracranial buffering system (displacement
of cerebrospinal fluid and venous blood) maintains the
intracranial pressure despite increasing intracranial con-
tents. However, once the capabilities of these protective
mechanisms are exceeded, intracranial pressure rises pre-
cipitously. The resulting intracranial hypertension causes
brain injury by a variety of mechanisms.
Cerebral perfusion pressure is estimated by subtract-
ing the intracranial pressure from the mean arterial pres-
sure. As the intracranial pressure rises, the cerebral per-
fusion pressure falls, thus compromising the delivery of
oxygen and nutrients to the brain and causing cerebral
ischemia. Systemic hypertension is the body’s attempt to
maintain mean arterial pressure and preserve cerebral
perfusion. In particular, the Cushing triad (systemic hy-
pertension, bradycardia, abnormal respiration) is a late
sign of increased intracranial pressure.
Differences in pressure between cerebral compart-
ments may lead to herniation of cerebral contents and
compression of the brainstem. The tentorium cerebelli,
which divides the anterior and posterior fossa, is the usual
opening through which the midbrain passes. If the tem-
poral fossa has an expanding lesion (such as an epidural
hematoma), the medial temporal lobe (uncus) on the
Table 4. Important Questions in
the History of Ingestion
To what potential poisons was the child exposed?
What medications (prescription and nonprescription)
are in the home?
Where did the poisoning take place?
When (or over what potential time period) did the
poisoning occur?
How much poison was involved?
By what route did the poisoning occur?
Was the poisoning accidental or intentional?
Table 5. Progression of Herniation Syndromes*
Status Pupils
Movements Motor Response
Central Herniation
Diencephalic (early) Normal or
Small, reactive Normal Appropriate
Diencephalic (late) Decreased Small, reactive Normal Decorticate
Midbrain, upper pons Decreased Midpoint, fixed Asymmetric Decerebrate
Lower pons, medulla Decreased Pinpoint, fixed Absent Flaccid
Uncal Herniation
Third nerve (early) Usually normal Unilateral, dilated,
Normal or asymmetric Appropriate or asymmetric
Third nerve (late) Decreased Unilateral, dilated, fixed Asymmetric or absent Decorticate or decerebrate
Midbrain, upper pons Decreased Midpoint, fixed Asymmetric or absent Decerebrate
*Adapted from Plum F, Posner J, 1980.
neurology altered states of consciousness
Pediatrics in Review Vol.27 No.9 September 2006 335
side of the lesion can herniate through the tentorium, in
what is known as uncal herniation (Table 5). Because the
oculomotor nerve (cranial nerve III) passes alongside the
midbrain, it usually becomes compressed along with the
brainstem. Thus, uncal herniation is associated with a
unilateral, dilated pupil on the side of the lesion. In the
early stages of herniation, the pupil is sluggishly reactive;
as the symptoms progress, however, the pupil becomes
fixed and dilated. In addition, there is dysconjugate gaze
due to asymmetric extraocular movements.
Motor findings progress from asymmetric to decorti-
cate posturing and, in the late stages, to decerebrate
posturing. In central herniation, parenchymal lesions of
frontal, parietal, or occipital lobes cause cerebral swelling
and downward displacement of both temporal lobes
through the tentorium (Table 5). The herniation syn-
drome progresses rostral to caudal, affecting first the
diencephalic brain (small reactive pupils, normal extraoc-
ular movements, appropriate or decorticate posturing),
then the midbrain/lower pons (midpoint and fixed pu-
pils, dysconjugate gaze, decerebrate posturing), and fi-
nally the lower pons/medulla (pinpoint and fixed pupils,
absent extraocular movements, flaccid paralysis). There-
fore, it is important to note the level of consciousness,
pupillary size and reactivity, extraocular movements, and
motor response when examining a child whose level of
consciousness is altered.
It should be emphasized that early imaging of the
brain with a CT scan or MRI remains the cornerstone of
rapid and accurate diagnosis. Because the MRI does not
use ionizing radiation and displays greater anatomic de-
tail, it often is the preferred imaging modality. However,
CT scanning typically is used in the acute setting because
of availability and logistic considerations.
In addition to signs noted on a complete neurologic
examination, other findings on physical examination may
suggest certain conditions. Papilledema on funduscopic
examination is a late finding of increased intracranial
pressure because it usually requires more than 12 hours
to develop. Therefore, normal fundi do not rule out the
presence of increased intracranial pressure. In an infant or
young child, the presence of retinal hemorrhages should
raise the concern for child abuse. Meningismus on the
neck examination results from meningeal irritation, usu-
ally from meningitis or a focal neurologic lesion. A child
in heart failure may present with a tachydysrhythmia,
hepatomegaly, or a gallop on cardiac examination. The
presence of hepatomegaly may represent an acute infec-
tious hepatitis or a metabolic disorder causing hepatic
encephalopathy. In a febrile child, petechiae, especially if
present below the nipple line, are a hallmark of menin-
gococcemia. In an afebrile child, petechiae may be a sign
of thrombocytopenia that places the child at risk for
cerebral hemorrhage.
A child who has any acute alteration in level of conscious-
ness should be transported immediately to an acute care
facility for additional evaluation and management. How-
ever, if hypoglycemia is suspected, intramuscular gluca-
gon should be administered. Once in
the emergency department, manage-
ment begins with assessment of airway,
breathing, and cardiovascular status (the
ABCs of resuscitation). Often, a child
whose level of consciousness is altered
has recognizable stridor caused by
downward displacement of the mandib-
ular block of tissue and tongue into the
upper airway. This obstruction usually is
relieved by a chin-lift or jaw thrust, but if
such maneuvers fail, an oral airway or endotracheal intu-
bation may be needed. All children initially should be
given 100% oxygen by nonrebreather facemask until
adequate oxygenation is assured.
Because many of the causes of an altered level of
consciousness require immediate intravenous (IV) fluid
or medication, most children should have an IV line
placed. Rapid infusion of IV normal saline solution often
is needed to restore and maintain adequate perfusion of
the vital organs. Blood tests to help determine the cause
should be obtained and a bedside glucose concentration
determined immediately. Hypoglycemia is a common
direct cause as well as associated symptom of an altered
level of consciousness and is immediately correctable
with the administration of IV glucose. Therefore, the
blood glucose concentration never should be over-
looked. If the child has a history of possible ingestion or
shows signs of opiate toxicity (pinpoint pupils, coma,
respiratory depression), the opiate antagonist nalaxone
can be given IV.
...earlyimaging of the brain with a
CT scan or MRI remains the cornerstone of
rapid and accurate diagnosis.
neurology altered states of consciousness
336 Pediatrics in Review Vol.27 No.9 September 2006
Once life-saving management is performed and the
child has stabilized, results of the history and physical
examination should point to either a structural lesion or
a medical disorder. If a structural lesion is suspected,
immediate intervention to control an increase in intracra-
nial pressure is warranted. The head should be elevated
to 30 degrees and kept in a midline position to facilitate
venous drainage from the intracranial vault. An emergent
CT scan should be obtained, although the child may
require endotracheal intubation to be sedated properly
for the procedure. Because many structural causes in-
volve surgical management, a neurosurgeon should be
If a medical cause is suspected, additional laboratory
and radiologic testing may help determine whether the
cause is infectious, metabolic, or toxicologic. Serum elec-
trolyte concentrations may be abnormal, and any acid-
base alteration should be corrected. A febrile child is
likely to have an infectious etiology and should be given
empiric antibiotics IV after a blood culture is obtained.
Because meningitis is a common infectious cause of
altered consciousness, a lumbar puncture can help con-
firm that diagnosis. However, if the child is clinically
unstable or has focal neurologic signs, the lumbar punc-
ture should be deferred and antibiotics administered
immediately. Empiric acyclovir is recommended if herpes
encephalitis is a concern. Serum ammonia and liver func-
tion tests may diagnose an inborn error of metabolism,
other metabolic disorder, or hepatic encephalopathy.
A positive stool guaiac test raises the concern of intussus-
ception, which can be diagnosed with ultrasonography
or air-contrast enema. Cardiac dysrhythmias or conduc-
tion abnormalities often can be identified with electro-
cardiography. After immediate treatment and stabilization,
additional testing may include electroencephalography and
an MRI.
In the absence of a clear cause, especially in an afebrile
toddler or adolescent, a toxic ingestion should be sus-
pected. Family members should be questioned about the
availability of any medication, whether prescription or
over-the-counter. Cough medication, antipyretics, and
iron pills often are ingested by toddlers. If possible, the
bottle of the medication should be checked for remain-
ing pills to estimate the maximum amount ingested. If
the ingested agent is determined, the appropriate anti-
dote can be given. Specialists at the local poison control
center can assist in additional management of a suspected
overdose. Many children require a dose of activated
charcoal, which binds the toxin, thereby limiting intesti-
nal absorption.
After stabilization and initial management, the child
should be observed in a monitored setting until his or her
mental status improves. The specific disorder and the
severity of the child’s clinical state determine whether
management can be accomplished on the inpatient unit
or in an intensive care unit.
An altered level of consciousness is an important clinical
entity in pediatrics and carries the potential for significant
morbidity and mortality. The clinician must assess the
level of consciousness rapidly as well as determine likely
causes. Structural or medical causes usually can be differ-
entiated through a focused history and physical examina-
tion. Asymmetric neurologic findings such as a dilated
and fixed pupil, dyscongugate extraocular movements,
and asymmetric motor findings suggest brainstem dys-
function as a result of a structural lesion; slowly progres-
sive but symmetric neurologic findings usually result
from a medical disorder. Specific neurologic findings
associated with elevated intracranial pressure are seen in
both central and uncal herniation. Disorders of metabo-
lism, liver, kidneys, lungs, or heart as well as toxic expo-
sure are common medical causes for alteration of con-
sciousness. After initial assessment and stabilization,
management centers on determining the specific diagno-
sis and continuing supportive care.
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King D, Avner JR. Altered mental status. Clin Pediatr Emerg Med.
Kirkham FJ. Non-traumatic coma in children. Arch Dis Child.
Meyer PG, Ducrocq S, Carli P. Pediatric neurologic emergencies.
Curr Opin Crit Care. 2001;7:81– 87
Pattisapu JV. Etiology and clinical course of hydrocephalus. Neu-
rosurg Clin North Am. 2001;36:651– 659
Plum F, Posner J. The Diagnosis of Stupor and Coma. Philadelphia,
Pa: FA Davis; 1980
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altered states of consciousness
Pediatrics in Review Vol.27 No.9 September 2006 337
PIR Quiz
Quiz also available online at
5. A 2-year-old boy is found unresponsive in his bedroom by his mother. He had eaten his breakfast 2 hours
earlier, and he seemed normal at the time. On physical examination, the child is obtunded and responds to
only deep, persistent stimuli by moaning and brief opening of his eyes. He is afebrile and has a heart rate
of 60 beats/min, respiratory rate of 16 breaths/min, and blood pressure of 88/56 mm Hg. Pupils are 2 mm,
and they react briskly to light. Extraocular movements and the oculocephalic reflex are intact. No dystonic
movement is noted. Dysfunction of which of the following
explains these clinical findings?
A. Ascending reticular activating system.
B. Cerebral hemispheres.
C. Limbic system.
D. Medulla oblongata.
E. Pons.
6. A 12-year-old boy is brought to the emergency department after being struck by a baseball while batting
during his Little League game. He lost consciousness immediately after being hit and has remained
unresponsive to his environment. On arrival at the hospital, his heart rate is 60 beats/min, respiratory rate
is 16 breaths/min, and blood pressure is 180/120 mm Hg. A large hematoma is noted on his right temporal
region. His right pupil is 8 mm and reacts very sluggishly to light. The left pupil is 3 mm and reacts briskly
to light. Dysconjugate gaze is noted because of limitation of the movement of the right eye. Both the
upper and lower extremities are extended and pronated with increased tone. Which of the following is the
likely explanation for these findings?
A. Cerebral infarction with right middle cerebral artery pattern.
B. Cervical spine injury.
C. Diffuse axonal injury.
D. Subarachnoid hemorrhage.
E. Uncal herniation.
7. A 6-year-old girl has been complaining of fever and headaches for the last 2 weeks. She has been treated
with amoxicillin for sinusitis for the last week without improvement. She is now brought to the emergency
department for decreasing responsiveness. Examination reveals an axillary temperature of 102.9°F (39.4°C),
respiratory rate of 24 breaths/min, heart rate of 90 beats/min, and blood pressure of 138/95 mm Hg. She is
somnolent and can be aroused only with persistent external stimulation. She opens her eyes to painful
stimuli and appears disoriented and confused, using inappropriate words. She does not obey verbal
commands but localizes the site of a painful stimulus. Her pupils are 3 mm and react briskly to light.
Lateral deviation of the left eye and drooping of the right angle of the mouth are noted. Her neck is stiff,
with positive Kernig and Brudzinski signs. After ensuring adequacy of airway, drawing blood for culture,
and administering antibiotics, the next
appropriate step in management is:
A. Antihypertensive medication.
B. Computed tomography scan of the head with contrast.
C. Lumbar puncture.
D. Neurology consultation.
E. Toxicology screen.
8. A 3-year-old boy is brought to the emergency department after falling from monkey bars 6 hours ago. He
has been vomiting for the last hour and now has become increasingly unresponsive. A diffuse swelling with
bluish discoloration is noted over his left temporal-parietal region. Which of the following pupillary
abnormalities is
consistent with expanding left temporal-parietal epidural hematoma?
A. Bilateral constricted, unreactive pupils.
B. Unilateral constricted, unreactive left pupil.
C. Unilateral constricted, unreactive right pupil.
D. Unilateral dilated, unreactive left pupil.
E. Unilateral dilated, unreactive right pupil.
neurology altered states of consciousness
338 Pediatrics in Review Vol.27 No.9 September 2006
... According to Avner, consciousness is a state of being aware of yourself and the environment. Consciousness has two aspects, namely wakefulness and awareness [3]. A compatible complementary therapy with spiritual support often used is Murattal therapy. ...
... The study of consciousness emphasizes certain areas like dreams, creativity, and supernormal experiences. Altered states of consciousness can be induced by overstimulation, sensory deprivation, or by altering body chemistry including waking and sleeping, dreaming, hypnosis, hysteric trance and schizoid, orgiastic trances, aesthetic, drug-induced and mystic states (Avner, 2006). ...
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Ancient knowledge and mythological studies have shown a tri-unity in the human body which comprises three integrated parts i.e. body, mind, and soul. Although the previous work supports the action of the body takes place in association with mind and soul, inter and intra-interaction/working principle are not well understood. In the present work, an attempt has been made to develop an electrical circuit model to connect each other and to purpose a communication network among body mind and soul. It is also proposed in an electrical model that the body as resistive, mind as capacitance and soul as the power of energy and find themselves as engine, controller/regulator, and source of energy respectively. The soul is connected as the power to deliver energy to the circuit through body and mind as messenger and information are processed during life state of body while it stops its activity of physiological function of body and mind lead to death. The energy of the soul reverses its path and merges to GOD for further reincarnation. We hope that the present work has extended a circuit theory to explain the functional control of embedded human body systems and the conservation of the creative energy of the soul.
... Altered consciousness is variously caused by (a) accidental events or organic pathologies that manifest themselves through a symptomatology that goes from a slight reduction to a serious impairment of self-awareness; (b) traumatic experiences (car accident, blunt force or other) [43] that may have a high impact on the brain with severe changes in brain functioning, especially when these injuries concern the prefrontal cortex [44], with effects ranging from impaired logical-analytical thinking, behavioural changes, reduced self-awareness and others [45]; (c) neurological syndromes, such as epilepsy, which in some of their specific critical clinical features cause hallucinations, loss of control over one's body and/or dissociation from reality [46]; (d) infections from bacterial or viral agents, such as meningitis (inflammation of the meninges which not infrequently extends to the cerebral parenchyma in forms of meningoencephalitis) which, together with the classical triad (fever, headache and nuchal rigidity) and other symptoms, cause altered states of conscience; (e) disorders of the sleep-wake cycle, in particular sleep deprivation which may even cause epileptic seizures, hallucinations and inability to control sensory-motor functions, with an accompanying impairment of the patient's self-awareness; (f) metabolic alterations consequent to fasting-secondary to religious purposes or eating disorders such as anorexia-which can lead to forms of malnutrition that may even generate epileptic seizures that generate altered states of consciousness [47]; (g) psychotic or manic episodes that also involve reduced self-awareness and severe alterations of the reality test. ...
Although it is a familiar experience for everyone, in the vast majority of cases we discover the importance of consciousness only when in front of someone who no longer appears to possess it: someone ‘absent’, with their eyes fixed in the void, while the heart beats vigorously and their muscle tone is intact; or a patient with a psycho-organic syndrome or brain trauma, who is awake, even alert, but no longer in contact with the surrounding environment. Despite the fact that millions of people around the world enter and leave the state of consciousness every day, neurophysiological and clinical knowledge about consciousness is still far from forming a coherent scientific corpus. In fact, nowadays, there is no general shared definition of an altered state of consciousness. In this paper we propose a structured model of the phenomenon of consciousness, viewed as a multivariate combination of independent factors, which includes the variations and transitions of consciousness from a normal state of wakefulness to a psychopathological condition (with discrete deviations in subjective experience), and to severe clinical-neurological pictures.
... Algunos planteamientos filosóficos afirman que el rasgo de la conciencia es la intencionalidad, es decir, la cualidad de estar referida a algo (Searle, 1992). Sin embargo, en las experiencias Unitivas, la barrera yo/otro sujeto/ objeto está ausente. ...
We report a 5 months old boy who was admitted to the PICU because of fluctuating level of consciousness. An extensive workup in search for infectious, neurologic, toxicologic and metabolic etiologies was done. Although abdominal symptoms were absent, he eventually was diagnosed with intussusception which needed surgery to recover. Intussusception should be included in the differential diagnosis of infants presenting with unexplained neurologic symptoms, ensuring timely diagnosis, treatment, and improved outcome.
A child presenting with decreased level of conscious (dLOC) is of great concern due to the wide range of possible causes, and potential for death or serious long-term sequelae. It is therefore vital that health professionals can recognise a child with dLOC quickly, intervene appropriately and escalate for senior review as a matter of urgency. This article provides an explanation for the mechanisms of decreased consciousness, outlines the different causative pathologies, and provides a simple and logical approach to the first-line recognition and management that a health professional may apply when faced with such a patient. Illustrative case studies have been included, to demonstrate how children with dLOC may present in clinical practice
Pediatric in-flight emergencies comprise a small, but not insignificant, number of medical events that occur on board commercial airlines. Pediatric patients require special considerations for care due to differences in anatomy and pathophysiology. However, in many instances, adaptations can be made to adult treatments to aid in pediatric care. This chapter reviews a variety of illnesses with specific pediatric considerations for management.
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AIM To determine the incidence, presentation, aetiology, and outcome of non-traumatic coma in children aged between 1 month and 16 years. METHODS In this prospective, population based, epidemiological study in the former Northern NHS region of the UK, cases were notified following any hospital admission or community death associated with non-traumatic coma. Coma was defined as a Glasgow Coma Score below 12 for more than six hours. RESULTS The incidence of non-traumatic coma was 30.8 per 100 000 children under 16 per year (6.0 per 100 000 general population per year). The age specific incidence was notably higher in the first year of life (160 per 100 000 children per year). CNS specific presentations became commoner with increasing age. In infants, nearly two thirds of presentations were with non-specific, systemic signs. Infection was the commonest overall aetiology. Aetiology remained unknown in 14% despite extensive investigation and/or autopsy. Mortality was highly dependent on aetiology, with aetiology specific mortality rates varying from 3% to 84%. With follow up to approximately 12 months, overall series mortality was 46%.
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To determine the incidence, presentation, aetiology, and outcome of non-traumatic coma in children aged between 1 month and 16 years. In this prospective, population based, epidemiological study in the former Northern NHS region of the UK, cases were notified following any hospital admission or community death associated with non-traumatic coma. Coma was defined as a Glasgow Coma Score below 12 for more than six hours. The incidence of non-traumatic coma was 30.8 per 100 000 children under 16 per year (6.0 per 100 000 general population per year). The age specific incidence was notably higher in the first year of life (160 per 100 000 children per year). CNS specific presentations became commoner with increasing age. In infants, nearly two thirds of presentations were with non-specific, systemic signs. Infection was the commonest overall aetiology. Aetiology remained unknown in 14% despite extensive investigation and/or autopsy. Mortality was highly dependent on aetiology, with aetiology specific mortality rates varying from 3% to 84%. With follow up to approximately 12 months, overall series mortality was 46%.
Altered mental status is a sign of serious neurologic or systemic disease. The physician must rapidly assess the depth of coma and risk of intracranial hypertension, then determine the etiology and prescribe appropriate management. This is no small task, considering the variety and multitude of illnesses that may present with altered mental status. The etiologies can be broken down into structural and medical causes. The structural causes more frequently affect the brainstem centers adjacent to the ascending reticular activating system that are responsible for pupillary response and oculocephalic reflexes. Medical causes generally spare these structures. Management of structural lesions requires prompt diagnosis and neurosurgical input. Medical etiologies are protean and treatment is often supportive.
SUMMARY We have tested and developed protocols for both sequence-independent and hybridization probe real-time PCR for the detection of Polymyxa betae glutathione-S-transferase transcripts in infected sugar beet roots. When using the test on P. betae-free plants, no signal above the level of the non-template control was observed. Real-time PCR analysis of both serially diluted zoospore suspensions and infected root material demonstrated a close relationship between the threshold cycle and the amount of P. betae. Hybridization probe real-time analysis of infected plants sampled sequentially over 20 days from sowing showed that the levels of the transcript rose steadily after initial infection to a peak and then declined. Comparative time-course analyses of infection in susceptible plants and a resistant wild Beta species indicated that, whilst transcript levels in susceptible plants showed a continuing upward trend, in the resistant species they were detectable only at an extremely low level.
Neuroemergencies are life-threatening situations in which, whatever the cause, common pathologic phenomena result in secondary brain lesions. The goal of critical care management is to stop these self-aggravating processes as soon as possible. Initial resuscitation is devoted to control of the airway and hemodynamic and hydroelectrolytic stabilization. With mass lesions, minimal computed tomographic exploration immediately precedes surgical decompression. Further critical care adapted to the child's needs requires multimodal monitoring. Normoventilation, deep sedation, osmotherapy with mannitol or hypertonic saline solutions, and optimization of mean arterial pressure are the basis of management. A purely pressure-driven approach aimed at controlling cerebral perfusion pressure could be potentially harmful, and associated measurement of blood flow velocity with transcranial Doppler and jugular bulb oxygen saturation monitoring allows an approach to cerebral blood flow and metabolism. Outcome can be improved in dangerous situations such as severe brain injuries, cerebral arteriovenous malformation rupture, status epilepticus, and acute hydrocephalus, provided that emergency management could be applied efficiently.
Hydrocephalus results from an imbalance of CSF formation and absorption, with dilatation of the ventricles and displacement of the cerebral cortex. Although the pathophysiologic findings are incompletely understood, recent advances have offered some insight into the molecular basis of the hydrocephalic condition. Patients are benefiting from improved neurodiagnostic evaluations and shunt technology, resulting in better neurologic and developmental outcomes. The goal of permanently improving brain CSF absorption remains elusive; however, through diligent effort, it should be realized in the near future.
The purpose of this study was to determine the etiologies responsible for altered mental status (AMS) in an emergency department (ED) population, to gauge the diagnostic (DX) value of the various features of the clinical evaluation, and to examine patient outcomes. Prospective identification of patients with AMS followed by a retrospective review of the medical record was performed in a university hospital E among ED patients with AMS. Three hundred seventeen patients (5% of the ED patient volume) were identified with a mean age of 49 years (57% men). Descriptions of the AMS included 24% unresponsive, 46% lethargic/difficult to arouse, 12% agitated, and 18% unusual behavior. The most common discharge diagnoses accounting for AMS were neurologic (28%) and toxicologic (21%) followed by trauma (14%), psychiatric (14%), infectious (10%), endocrine/metabolic (5%), pulmonary (3%), oncologic (3%), cardiovascular (1%), gastrointestinal (1%), and renal (1%). The specific features of the clinical evaluation of greatest DX value followed by rates of positive DX finding included history of present event (51%), past medical history (43%), and physical examination (41%); features of little DX value included radiographs (16%), 12-lead electrocardiogram (7%), and various laboratory studies (chemistry panel [5%], complete blood count [1%], coagulation panel [0], urinalysis [11%]). Sixty-four percent of the patients were admitted with a mean hospital stay of 7.6 days and 9% deaths. Common causes of AMS included neurologic, toxicologic, traumatic, and psychiatric syndromes. The patient history and physical examination were most useful in DX terms; ancillary investigations were less often DX. This group represented a minority of the ED population yet rates of ED resource use, hospital admission, and death were high.