1) Disorders of consciousness range from mild impairment to coma and include conditions like confusion, delirium, vegetative state, and brain death. 2) The pathophysiology of consciousness involves the ascending reticular activating system and connections between the brainstem and cortex. Loss of consciousness can result from disruption of these systems. 3) Etiologies of impaired consciousness and coma include infectious or inflammatory causes, structural abnormalities, and metabolic/toxic derangements. Common causes in children are infections, trauma, seizures, and metabolic disorders.

1. DISORDER OF CONSCIOUSNESS
DR. SREEMAYEE KUNDU
MD Paediatrics

2. • Consciousness is the state of awareness of self
and environment.
• Dimensions:
a) Wakefulness
b) Awareness
• Clouding of consciousness: Minimal
reduction of wakefulness or awareness-main
difficulty attention.
• Confusion: State of impaired ability to think
and reason clearly at a developmentally and
intellectually appropriate level.

3. • Sleep: Biologically active state with
identifiable behavioral and EEG stages, with
appropriate stimulus intensity and duration
sleeping person can be aroused to a normal
state of consciousness.
• Coma and other states of consciousness
warrant medical emergency.

4. Pathophysiology

5. Pathophysiology
Integral Consciousness requires an intact -
1) Ascending reticular activating system,
2) Cerebral cortex,
3) Healthy projections between the two
systems.

6. Reticular Formation

7. Pathophysiology: afferent and efferent
connections of reticular formation

8. Pathophysiology: ARAS

9. Pathophysiology: ARAS
• Begins in the lower brainstem and extends
upward through pons, midbrain, thalamus
• Finally project throughout cerebral cortex-
into two pathways
a) through subthalamus
b) through thalamus

10. Pathophysiology
• The state of wakefulness is mediated by
neurons of the ascending reticular activating
system(ARAS).
• Neural pathways from these locations project
throughout the cortex , which is responsible
for awareness.

11. Loss of consciousness will result if
• The function of ARAS neurons compromised
or
• Both cerebral hemisphere are sufficiently
affected by disease.

12. Proper function of ARAS and both
cerebral hemisphere depends on:
• Presence of substrate for energy production
• Adequate blood flow
• Absence of abnormal metabolic wastes or
toxins
• Normal body temperature
• Absence of abnormal neuronal excitation or
irritation from seizure activity
• Absence of CNS infections
• Normal intracranial pressure

13. Etiology of impaired consciousness
and coma
• Infectious or inflammatory
• Structural
• Metabolic, Nutritional, Toxic

14. Etiologies of Impaired Consciousness
and Coma
1.Infectious or Inflammatory
A. Infectious
• Bacterial meningitis
• Viral encephalitis
• Rickettsial infection
• Protozoan infection
• Helminth infestation
B. Inflammatory
• Sepsis-associated encephalopathy
• Vasculitis, collagen vascular disorders
• Demyelination
• Acute disseminated encephalomyelitis
• Multiple sclerosis

15. Etiology –cont.
2. Structural
A. Traumatic
 Concussion
 Cerebral contusion
 Epidural hematoma or
effusion
 Intracerebral hematoma
 Diffuse axonal injury
 Abusive head trauma
B. Neoplasms
C. Focal Infection
• Abscess
• Cerebritis
D. Hydrocephalus
E.Vascular Disease
• Cerebral infarction
 Thrombosis
 Embolism
 Venous sinus thrombosis
• Cerebral hemorrhage
 Subarachnoid hemorrhage
 Arteriovenous malformation
 Aneurysm
• Congenital abnormality or
dysplasia of vascular supply
• Trauma to carotid or
vertebral arteries in the
neck

16. Etiology –cont.
3.Metabolic, Nutritional, or
Toxic
A. Hypoxic-Ischemic
Encephalopathy
 Shock
 Cardiac or pulmonary failure
 Near-drowning
 Carbon monoxide poisoning
 Cyanide poisoning
 Strangulation
B. Metabolic Disorders
 Sarcoidosis
 Hypoglycemia
 Fluid and electrolyte
imbalance
 Endocrine disorders
 With acidosis
 Diabetic ketoacidosis
 Aminoacidemias
 Organic acidemias
 With hyperammonemia
 Hepatic encephalopathy
 Urea cycle disorders
 Disorders of fatty acid
metabolism
 Reye’s syndrome
 Valproic acid encephalopathy
 Uremia
 Porphyria
 Mitochondrial disorders
 Leigh’s syndrome

17. Etiology -cont
C. Nutritional
 Thiamine deficiency
 Niacin or nicotinic acid
deficiency
 Pyridoxine dependency
 Folate and B12 deficiency
D. Exogenous Toxins and
Poisons
 Alcohol intoxication
 Over-the-counter
medications
 Prescription medications
(oral and ophthalmic)
 Herbal treatments
 Heavy-metal poisoning
 Mushroom and plant
intoxication
 Illegal drugs
 Industrial agents
E. Hypertensive
Encephalopathy
F. Burn Encephalopathy

18. Impairment of consciousness
states
• Impairment of consciousness with activated
mental state
• Impairment of consciousness with reduced
mental state
• Impairment of consciousness along the
continuum of coma–vegetative state–
minimally conscious state and related
conditions.

19. 1) Impairment of consciousness with
activated mental state
• Hallucination : Perception of sensory input
that are not present.
• Illusion : Misinterpretation of actual sensory
stimuli.
• Delusion : Incorrect thoughts or beliefs that
do not change when challenged by
contradictory evidence or logical reason.
• Delirium : Activated mental state that may
include disorientation, irritability, fearful-
responses, and sensory misperception.

20. 2) Impairment of consciousness with
reduced mental state
• Drowsiness
• Obtundation arousal is present to stimuli
• Stupor
State Stimulus needed for arousal
Drowsiness Verbal and light touch
Obtundation Deep touch
Stupor Vigorous, painful, or noxious
stimulation

21. 3) Impairment of consciousness along
the continuum of coma–vegetative
state–minimally conscious state and
related conditions.

22. Coma
• State of deep, unarousable, sustained
pathologic unconsciousness with the eyes
closed that results from dysfunction of the
ascending reticular-activating system in the
brainstem or in both cerebral hemispheres.
• Patients in coma lack both wakefulness and
awareness.

23. Vegetative state
• Complete unawareness of self & environment
accompanied by sleep-wake cycles with
complete/partial preservation of
hypothalamic and brainstem autonomic
function.
• Demonstrate : variety of sounds, emotional
expressions, body movements, smile/shed
tears.
• Lack of sustained visual fixation or tracking.

25. Clinical course of evolution to vegetative state-
• Acute injury Coma several days-week
appearance of sleep-wake cycle.
• Decorticate & decerebrate posturing, roving
eye movements, eye blinking appeared earlier.
• Diagnosis – Clinically mainly.

26. Minimally conscious state
• Severely alterered consciousness,
demonstrates minimal evidence of self /
environmental awareness.
• Neurologic recovery-better.
• Life expectancy- longer than vegetative state.

28. Locked-In Syndrome
• Retain consciousness & cognition but unable
to move or communicate because of paralysis.
• Involvement – Descending corticospinal &
corticobulbar pathways at or below Pons/
Peripheral nervous system.
• Rare in children.
• Communication – using eye movements.

29. Akinetic Mutism
• Rare condition.
• Pathologically slowed or nearly absent bodily
movement accompanied by loss of speech.
• Wakefulness and Self awareness - Preserved.
• Mental function- Reduced.
• Area Involved – damage to paramedian
mesencephalon,basal diencephalon,inferior
frontal lobes.

30. Brain Death
• Irreversible cessation of all functions of entire
brain,including brainstem.
• Determination of death using neurologic
criteria.
• Legally accepted in US as equivalent of death.
• Universally not accepted.
• Clinical diagnosis- 3 key components-
Irreversible coma with a known cause,
Absence of brainstem reflexes and Apnea

31. Apnea
• Absence of respiratory effort in response to
an adequate stimulus.
• Apnea Clinically confirmed by apnea test.
• Test is performed if first two criteria of brain
death are met.

33. • Absence of respiratory effort with pCO2 > 60
mm Hg and > 20 mm Hg above baseline then,
Apnea has been demonstrated, supporting the
diagnosis of brain death criteria.

34. Ancillary neurodiagnostic studies
• Electroencephalography- Absence cerebral
activity over 30 min recording.
• Radionuclide imaging – Absence of radionuclide
detection in brain parenchyma and large vessels.
• Cerebral angiography – Absence of intracranial
filling of large cerebral arteries & branches.
• Transcranial Doppler ultrasound- loss of diastolic
flow, systolic flow,flow reversal.

35. Observation period
Age 7 days to 2 months
Two examinations 48 hours apart and one EEG
Age 2 months-1 year
Two examinations 24 hours apart and one EEG
or perfusion scan
Age >1 year
Two examinations 12 to 24 hours apart.EEG and
isotope angiography optional

36. Severe Disorders of Consciousness
Condition Self-
Awareness
Pain and
Suffering
Sleep–
Wake
Cycles
Motor Function Respiratory
Function
Coma Absent No Absent No purposeful
movement
Variably
depressed
Vegetative
State
Absent No Intact No purposeful
movement
Normal
Minimally
conscious
State
Very
limited
Yes Intact Severe limitation
of movement
Variably
depressed
Locked-in-
syndrome
Present Yes Intact Quadriplegia,
Eye movements
+
Normal to
variably
depressed.
Brain
Death
Absent No Absent None Absent

37. Approach to a child with coma

38. • Incidence of non-traumatic coma is
30/100,000 children per yr & traumatic brain
injury is 670/100,000
• It is clinically useful to categorize the causes of
coma into:
1) Coma with focal signs
2) Coma without focal signs and with
meningeal irritation
3) Coma without focal signs and without
meningeal irritation

39. Etiology of coma
• Coma with focal signs
 Intracranial hemorrhage
 Stroke: Arterial ischemic or sinovenous
thrombosis
 Tumors
 Focal infections: Brain abscess
 Post seizure state: Todd’s paralysis
 Acute disseminated encephalomylelitis

40. Etiology: cont.
• Coma without focal signs and with meningeal
irritation:
 Meningitis
 Encephalitis
 Subarachnoid hemorrhage
• Coma without focal signs and without
meningial irritation:
• Hypoxic-ischemia: cardiac or pulmonary
failure,cardiac arrest, shock, near drowning

41. Etiology: cont.
• Metabolic disorders:
 Hypoglycemia
 Acidosis: DKA, organic acidemias
 Hyperammonemia: hepatic encephalopathy, urea
cycle disorders, valproic acid encephlopathy, Reye
syndrome.
 Uremia
 Fluid and electrolyte disturbance (dehydration,
hyponatremia, hypernatremia)
• Systemic infections :
 Gram negative sepsis, TSS, meningitis
shigella/enteric encephlopathy

42. Etiology: cont.
• Post infectious disorders:
 Acute Disseminated Encephalomyelitis
 Acute necrotising encephalopathy
 Hemorrhagic shock and encephalopathy syndrome
• Post immunisation encephalopathy
 Whole cell pertusis vaccine
• Drugs and toxins
• Cerebral malaria
• Rickettsial : lyme disease, rocky mountain spotted fever
• Hypertensive encephalopathy
• Post seizure states
• Non-convulsive status epilepticus

43. Rapid assessment and
stabilization

44. Rapid assessment and stabilization
• Establish and maintain airway: Intubate if
GCS<= 8 ,impaired airway reflexes, abnormal
breathing pattern, signs of raised ICT, oxygen
saturation<92% despite high flow oxygen,
fluid refractory shock
• Ventilation, Oxygenation
• Circulation: Establish IV access, take samples.
• Fluid bolus: In circulatory failure (20ml/kg NS),
inotropes if required
• Blood glucose : Strip testing , if <50mg/dl give
10% D , 2ml/kg.

45. • Identify signs of cerebral herniation or raised
ICP: ( if GCS<8,abnormal pupil size and reaction,
absent dolls eye movements, abnormal tone or
posturing, hypertension with bradycardia,
abnormal respiratory pattern)
Act immediately – Fluid restriction, Elevate the
Head end of bed at 30 degree, Intubate & short
term Hyperventilation,20% Mannitol (0.5-1g/kg)/
Furosemide /3% NS(if in shock), Sedation,
Barbiturate therapy, reduce fever, high dose of
corticosteroids, Decompressive craniectomy.

46. • Temperature : Treat fever and Hypothermia
• Acid-base and electrolyte imbalance: to be
corrected.
• Specific Antidotes: Naloxone - opiate
overdose, Flumazenil – benzodiazepine
overdose.
• Stop seizures: Specific treatment for status
epilecticus & other seizure emergencies. Give
IV lorazepam 0.1-0.2mg/kg , then phenytoin
20mg/kg loading.

47. • Treat infection: Appropriate
antibiotic/antiviral therapy to be started
• Manage agitation : May increase ICP, difficult
to control respiration under MV – Sedate.

48. History: Age
Infant Child Adolescent
CNS infection
(meningitis,encephalitis)
Ingestion Drug/Alcohol overdose
Systemic infection with shock CNS infection Intentional poisoning
Metabolic disorders Seizure Trauma, seizures
Abuse / Trauma, Abuse / Trauma CNS infection,
Inborn errors of
metabolism,seizures
DKA, Reye
syndrome
DKA, , Reye syndrome
Post immunisation
encephalopathy, hemorrhagic
shock and encephalopathy
syndrome

49. History: Onset, episode
• Sudden onset: Intracranial haemorrage or a
convulsion
• Acute onset in normal child: Ingestion of drug,
toxin, poison.
• Gradual onset : Infectious process, metabolic
derangement.
• Intermittent episode : Ingestion, Drug
overdose, IEM.
• Recurrent episode : use of ophthalmic drops
Brimonidine-can cause coma in 1month
child,epilepsy,IEM.

50. History: Associated symptoms
• Fever – Infections
• Headache, Vomiting, Diplopia – Increased
ICP
• Neck stiffness – Meningitis, SAH
• Rash - Meningococcemia
• H/o excess cry, irritability, enlarging head in
infants – Meningitis, Hydrocephalus
• Retinal hemorarhage,metaphyseal #, rib #,
subdural hge, Bleeding from ear/nose –
Traumatic brain injury
• Seizures – ICH, ICSOL, Epilepsy, Post-ictal

51. History
• H/o of infectious disease – Mumps (Parotid
swelling), measles (rash), TB, Malaria, Dengue.
• Failure to thrive, vomiting, peculiar skin & urine
odour – Metabolic cause
• Jaundice, abdominal distension, hematemesis,
melena, bleeding - Hepatic encephalopathy
• ↓ Urine output, swelling, periorbital puffiness,
Nausea, vomiting, loss of appetite – Uremic
encephalopathy
• H/o use of stove/ heater – CO poisoning.

52. History
• H/o loose stools- HUS, Hypovolemia,
Ingestion of toxins/poisons, medications
• H/o Diabetes – hypoglycemia / ketoacidosis
• H/o Congenital heart disease – brain Abcess/
infarction
• H/o Immunocompromised state, malignancy
• Family h/o TB, migraine, epilepsy
• Birth H/o: Birth asphyxia
• H/o envenomation

53. Clues to etiology of coma in general examination
Look for if present ,think of
Pallor Cerebral malaria, intracranial bleed, hemolytic uremic
syndrome
Icterus Hepatic encephalopathy, leptospirosis, complicated malaria
Rashes Meningococcemia, dengue , measles, rickettsial diseases,
arboviral diseases
Petechiae Dengue, meningococcemia , hemorrhagic fevers
Head and scalp
hematomas
Traumatic/ non accidental injury
Dysmorphism,
neurocutaneusmarkers
Possibility of seizures
Abnormal odour DKA, hepatic coma
Cyanosis Cyanotic congenital heart disease, Hypoxia
Oedema CHF, Renal failure
Dehydration Hypovolemic shock, HUS

54. Vital Signs
• Temp:
 Fever – Sepsis, pneumonia, meningitis, encephalitis,
intracranial abscess,empyema.
 Hypothermia - Sepsis, shock, alcohol, barbiturate
poisoning, hypoglycemia.
 Very high fever and dry skin – Heat stroke.
• HR:
 Bradycardia - ↑ ICT, myocardial injury due to
hypoxia, sepsis
 Tachycardia - Shock, Infections, Fever, Heart failure
 Irregular - Arrhythmia.

55. Vital Signs
• RR:
 Bradypnea/ Apnea - Drug intoxication, septicemia
 Tachypnea - Metabolic Acidosis, Pneumonia, Asthma,
Pulmonary embolism, Brainstem lesion.
 Cheyne-Stoke breathing - B/L cortical damage with
intact brainstem
 Irregular - medulla involved
 Slow periodic – raised ICP
• BP:
 HTN - ↑ICP or stroke, HTN encephalopathy
 Hypotension - Shock, sepsis, myocardial injury /
failure, drug ingestion , adrenal insufficiency.
• SPO2 monitoring:

56. Respiratory pattern
• Patient breathing pattern is also helpful in
localising area of CNS dysfunction. They are :
Cheyne-Stokes respiration
Biot’s breathing / Cluster breathing
Kussmaul’s breathing
Apneustic breathing
Ataxic breathing
Central neurogenic hyperventilation

59. Neurogical Assesment
 Level of consciousness
 Pupillary responses
Brainstem function
 Motor response
 Other neurological findings
Herniation syndrome

60. A. Level of conciousness
• The level of conciousness must be recorded
in the form of an objective scale.
• The Glasgow coma scale is a useful tool for the
grading of the degree of altered consciousness
and the severity of CNS insult.
• Glasgow coma scale is used for adults and older
children and its modification is used in infants
and young children.

61. Glasgow coma scale
ACTIVITY
BEST RESPONSE
Adults/Older Children Infants ( modified GCS ) Score
Eye Opening
( E )
1. Spontaneous
2. To speech
3. To pain
4. None
1. Spontaneous
2. To speech
3. To pain
4. None
4
3
2
1
Verbal
( V )
1. Appropriate speech
2. Confused speech
3. Inappropriate words
4. Incomprehensible or
none specific sounds
5. None
1. Coos, babbles
2. Irritable, cries but
consolable
3. Cries, inconsolable
4. Moans to pain
5. None
5
4
3
2
1
Motor
( M )
1.Obeys commands
2.Localizes pain
3.Withdraws to pain
4.Decorticate to pain
5.Decerebrate to pain
6.None
1. Spontaneous
movement
2. Withdraws to touch
3. Withdraws to pain
4. Decorticate to pain
5. Decerebrate to pain
6. None
6
5
4
3
2
1

63. B. Size and reactivity of pupils
Pupils Lesion/Dysfunction
Pinpoint Pons, opiates, cholinergic intoxication
Mid position –
fixed or irregular
Midbrain lesion
Unilateral , dilated
and fixed
Uncal herniation
Bilateral , dilated
and fixed
Diffuse damage, central herniation, global
hypoxia ischemia, barbiturates, atropine

64. C. Brainstem function
1)Pupillary light reflex
2)Oculocephalic reflex (doll’s eye reflex)
3)Corneal reflex
4)Oculovestibular reflex (caloric reflex)
5)Gag and Cough reflex

65. Pupillary light reflex
• Area tested – CN II ,III,
midbrain.
• Midposition (4-6mm) or
fully dilated pupils,not
reactive to light –
consistent with brain
death.

66. Oculocephalic reflex
• Area tested – CN III, VI and VIII, midbrain ,
pons.
• Should not be performed patient with
cervical injury.
• Intact patient – eyes remain fixed on a distant
spot as if maintaining eye contact.
• Brain death- eyes move with patient head
movement.

68. Corneal reflex
• Area tested – CN III,V and
VII, pons.
• Intact patient – touch
result in eyelid closure
and eye may rotate
upward.
• Brain death– no response.

69. Oculovestibular reflex
• Area tested – CN III, IV,
VI and VIII, pons,
midbrain.
• Brain death – Absent of
eye movement.

70. Gag and Cough reflex
• Area tested – CN IX and
X , medulla.
• Brain death – absence
of both cough and gag
reflex.

71. D. Motor response
• Single best indicator of the depth and severity
of coma
1. Spontaneous movements.
2. Tone and reflexes
3. Induced movements.

72. • Decorticate posturing with flexion of the
upper extremities and extension of the lower
extremities suggests involvement of the
cerebral cortex and preservation of brainstem
function.
• Decerebrate posturing with rigid extension of
the arms and legs is indicative of cortical and
brainstem damage.
• The flaccid patient with no response to
painful stimuli has the gravest prognosis with
injury sustained to deep brainstem lesions.

74. E. Other neurological findings
• Fundus examination : Papilloedema
Retinal hemorrhages
• Signs of meningeal irritation
• Cranial nerve Examination

75. E. Herniation syndromes
• Brain tissue deforms intracranially and moves from
higher to low pressure when there is asymmetric,
unilateral or generalised increase in intracranial
pressure.
• Signs of cerebral herniation
1. Glasgow coma score <8
2. Abnormal pupil size and reaction (unilateral or bilateral)
3. Absent doll’s eye movements
4. Abnormal tone (decerebrate/decorticate posturing,
flaccidity)
5. Hypertension with bradycardia
6. Respiratory abnormalities (hyperventilation, Cheyne-
Stokes breathing, apnea, respiratory arrest)
7. Papilledema

77. Clinical features of herniation
syndrome
Types Clinical manifestation
Central herniation Impaired consciousness, abnormal respiration,
small reactive / midposition fixed pupil
decorticatea evolving to decerebrate posture
Uncal Herniation Impaired consciousness, abnormal
respirations,unilateral dilated pupil, ptosis,
unilateral hemiparesis
Foramen magnum or
Tonsillar herniation
Impaired consciousness, neck rigidity,
opisthotonus, decerebrate rigidity,
vomiting, irregular respirations, apnea,
bradycardia

78. Other Systemic Examination
• CVS : Arrhythmias, Murmurs (Congenital heart
disease, Infective endocarditis)
• RS : Signs of lung disease
• P/A : Tender hepatomegaly (Hepatitis, Sepsis),
Hepatosplenomegaly (malaria), palpable
abdominal mass (intussuception
encephalopathy)

79. Investigations
Neuroimaging:
• CT scan: Any comatose child or infant in whom
the neurological findings suggest a structural
lesion or in whom the clinical diagnosis is evasive,
done after stabilistion of a patient.
• Magnetic Resonance Imaging (MRI) of brain is
valuable in identifying evidence of herpes simplex
encephalitis or an acute demyelinating process,
such as acute disseminated encephalomyelitis.

80. Biochemical investigations

81. Other Investigations

82. Electroencephalography
EEG findings Interpretation
•High voltage slow waves
•Slowing of background
activity
•Triphasic waves
•PLEDS Periodic Lateralised
Epileptiform Discharges
•Underlying supratentorial
lesion
•Metabolic coma
•Hepatic coma
•Herpes encephalitis
EEG findings in coma

83. Rapid assessment and stabilization
Evaluate:
Establish & maintain airway
Ventilation, Oxygenation
Circulation
Fluid bolus
Blood glucose
Identify cerebral herniation/^ICP
Temperature

84. History
Examination
Neurological assessment
Investigate:
CT
CSF (suspected meningitis/ encephalitis)
Investigation as presentation

85. Manage:
Shock
Sepsis
Hypoglycemia
Seizures
Raised ICP
Treat dyselectrolytemia
Treat Acid-base imbalance

86. Specific management:
Acute febrile encephalopathy
(antibiotic,steroids)
Antimalarials
DKA
Hypertensive encephalopathy
Toxidrome
Envenomation

87. Second line investigation:
MRI
EEG
Drug levels
Metabolic work-up
Urine toxicology screen
ESR and autoimmune screen
Thyroid profile

89. Prognosis
• The prognosis for recovery from coma depends
primarily on the cause, rather than on the depth
of coma.
• Coma from drug intoxication and metabolic
causes carry the best prognosis.
• Prolonged coma after a global hypoxic ischemic
insult carries a poor prognosis.
• Infectious encephalopathies have a good
outcome with mild or moderate difficulties only.
• Children who survive traumatic injury have a
better prognosis than children who suffer a global
hypoxic-ischemic injury

90. List of references
• Pediatric Neurology , fourth edition; Swaiman,
• Nelson Textbook of Pediatrics 20th Edition,
• Indian Journal of Pediatrics,
• Human Physiology C.C.Chatterjee,
• Ganong’s Review Of Medical Physiology

91. THANK
YOU