Sensorium in Children

Sensorium in Children

Assessment of Sensorium in Children

Infants and young children have a limited repertory (store house) of behavioural responses, making it difficult to detect and quantify the states of altered sensorium. A detailed, directed history and thorough physical examination is mandatory in arriving at the diagnosis and the underlying aetiology.

Since an accurate initial evaluation is critical to the management and the ultimate outcome in a child with coma, consistent and practical methods of describing various states of impaired consciousness in children are needed. The Glasgow Coma Scale (GCS), though effective and widely accepted, has its limitations in clinical practice because of the varied verbal and motor responses in children at different ages.

Several modifications of the Glasgow Coma Scale have come into existence, which are in use for gauging deterioration or improvement in acute stages of coma in children.

Introduction

Consciousness is a state of normal cerebral activity in which the patient is able to respond to internal changes and to changes in the external environment. Maintenance of consciousness requires an intact and functioning reticular activating system and an adequate volume of functional hemispheres. Alterations in consciousness are apparent as a decrease in spontaneous activity or in the response to environmental stimuli. The term ‚Äúaltered sensorium‚ÄĚ lacks precision and is applicable to all states where it is certain that normal sensorium is not present.

Definition of certain terms used in relation to altered sensorium

Sleep: Sleep is a normal variation in consciousness. The sleeping child is easily aroused and is then responsive to stimuli, questions and directions.

Drowsiness: the patient appears to be in normal sleep but can not be easily awakened. Once awake such patients tend to fall asleep despite attempts to continue conversation or clinical examination. There is disorientation and higher intellectual functions are impaired.

Stupor: defined as a state of impaired consciousness from which a child can be aroused only by vigorous and repeated stimuli. The child slips back into unresponsiveness after a few mumbled words. The superficial and deep tendon reflexes are preserved.

Confusional state: there is an inability to think with customary speed and clarity. Response to environmental stimuli is inappropriate and the patient is irritable, excitable and easily distracted.

Delirium: the American Psychiatric Association defines delirium as:

  1. A reduced ability to maintain attention to external stimuli, and to appropriately shift attention to new external stimuli.
  2. Disorganised thinking as evidenced by rambling, irrelevant and incoherent speech.
  3. At least two of the following:
    1. Reduced level of consciousness
    2. Disturbances of perception
    3. Disturbed sleep wake cycle
    4. Increased or decreased psychomotor activity
    5. Impaired memory.

Illusions: misinterpretations of actual sensory stimuli.

Hallucinations: perceptions of sensory stimuli that are not present e.g. hearing voices, music or sound, seeing objects, animals, people, insects etc. Delusions : incorrect beliefs that cannot be changed by evidence or reason. Coma : condition in which a patient is unreasonable and unresponsive to all external stimuli.

Akinetic mutism or Coma vigile: patient has a blank staring look and appears to be awake but is unresponsive by way of movement and speech. This state may precede coma or occur during the course of recovery.

Prolonged Coma: when a patient is in coma for longer than 2 weeks.

Persistent vegetative state: this is the end stage of severe and extensive brain damage and has the following features :

  1. Present for more than one month
  2. No evidence of awareness of self or environment.
  3. All responses are reflex.
  4. There is no meaningful or voluntary response to stimulation.
  5. No evidence of language comprehension.
  6. Preserved cranial nerve functions.
  7. Intact hypothalamic/autonomic functions.

Reflexes such as blinking, swallowing, chewing and gag are intact.

Brain death: this is a state of coma in which the brain has ceased to function completely, but pulmonary and cardiac functions can still be maintained by artificial means for hours to few days.

In children, systems for describing patients with impaired consciousness are not consistent. Moreover, infants and young children have a restricted repertoire of experience and behavioural responses. Therefore, the detection of and quantitation of alterations of consciousness are much more difficult.

Clinical Evaluation

A systematic approach to the initial evaluation of the child with altered sensorium may mean the difference between survival or death and permanent neurologic sequelae or full recovery.

A functional airway, adequate ventilation, effective cardiac output and perfusion pressure must be ensured before any attempt to reach at the diagnosis is made. A thorough, yet gentle examination for signs of internal or external haemorrhage must be performed.

Assessment consists of taking a directed history, general physical examination, neurological examination, neuro-imaging, EEG and determination of chemical, cytologic and microbiologic content of the various body fluids.

The specific objectives aimed for assessment of a patient with altered sensorium are:

  1. To determine the cause of coma.
  2. To delineate the area of the brain which is involved.
  3. To determine further course of management which will result in reversing the process and enhance the chances of recovery.

History

The history must be directed at the following:

  1. Mode of onset of illness.
  2. Presence or absence of preceding warning symptoms.
  3. Temporal course of illness.
  4. Treatment given and the response to the treatment.

In addition, factors like age of the child may have a bearing on the cause of altered sensorium e.g. inborn-errors of metabolism present during neonatal period or early infancy. Pyogenic meningitis is more common below 3 years of age, whereas, viral encephalitis usually occurs after the age of 6 years. Cardio-vascular accidents take place more commonly in older children as compared to infants.

The clinician must be aware of the racial, geographic and seasonal variations in causes of coma e.g. polio encephalitis is more common during the monsoons whereas, ARBO viral encephalitides and cerebral malaria epidemics fall usually in summers. Mode of onset : The onset of illness may be acute, subacute or insidious depending on the cause.

Table No. 1 ‚Äď Mode of onset

Acute

  • Trauma
  • Cerebro-vascular accidents
  • Seizures

Subacute

  • Infections,
  • Metabolic derangements
  • Poisonings
  • Physical agents,
  • Heat stroke,
  • Hypothermia

Insidious

  • Neoplasms
  • Degenerative diseases
  • Slow virus diseases

Preceding warning symptoms: Altered sensorium may or may not be preceded by warning symptoms like fever, headache, jaundice, seizures, vomiting, anuria, polyuria/polydipsia, diarrhoea and exposure to heat/cold depending upon the cause.

Table No. 2 ‚Äď Preceding Warning symptoms

Present

  • Infections
  • Neoplasms
  • Degenerative diseases
  • Metabolic derangements
  • Hepatic, renal encephalopathy
  • Epilepsy

Absent

  • Trauma
  • Accidental poisoning
  • Cerebro-vasular accident
  • Rapidly expanding mass lesions

General Physical Examination

A general physical examination, systematically conducted gives vital clues that might finally lead to the diagnosis.

Characteristic facies: if any, point to the following conditions:

  • Hypothyroidism
  • Hypopituitarism
  • Congenital errors of metabolism

Pallor is seen in

  • Acute blood loss; trauma, intra-cranial haemorrhage
  • Shock (septicemic or hypovolaemic)

Chronic renal failure

Jaundice¬†‚Äď Hepatic encephalopathy

Cyanosis

  • Cyanotic congenital heart disease
  • Brain abscess, Infarct, Cyanotic spell
  • Hypoxia
  • Shock

Edema

  • Chronic renal failure
  • Chronic liver disease
  • Congestive heart failure

Nutritional status: Patient may be poorly nourished in:

  • Insulin dependent diabetes mellitus
  • Inborn errors of metabolism
  • Renal failure

Breath odour: Certain distinct odours may be discernable in the following conditions :

  • Diabetic ketoacidosis: fruity smell
  • Hepatc encephalopathy : mousy odour
  • Uremic encephalopathy : mousy odour
  • Aluminum phosphide poisoning: Garlic odour
  • Kerosene poisoning: Smell of hydrocarbon

Heart rate

  • Tachycardia: along with decreased blood pressure may suggest hypovolemic shock.
  • Bradycardia: increased intracranial tension.

Pattern of breathing

a)¬†Cheyne ‚Äď Stokes breathing¬†(also called periodic breathing ): Term used for a pattern of breathing in which there is a phase of gradual deepening of respiration followed by a phase of slowly decreasing respiratory rate. Respiration gradually becomes quieter and may cease for a few seconds. The cycle is then repeated. This is a sign of raised intracranial tension and can occur in coma due to any cause.

b) Kussmaul breathing: manifests as a deep, sighing and rapid breathing at a regular rate and is suggestive of metabolic acidosis.

c) Central pontine hyperventilation: Term used for the deep and regular breathing that occurs in rostral brainstem damage due to reticular pontine infarction or in central brainstem dysfunction secondary to herniation. Interspersed deep sighs or yawns may precede the development of this respiratory pattern.

Hyperventilation: comatose conditions associated with hyperventilation are:

  • Metabolic acidosis
  • Diabetic ketoacidosis
  • Raised intracranial tension
  • Bacterial meningitis Renal failure Pneumonia Liver failure Brainstem lesions

Head, Neck and Spine

Should be thoroughly examined for any evidence of head injury and for any abnormality of the following:

  • Head circumference
  • Anterior fontanelle
  • Sutures

Look for bruits or dysraphisms, transillumination of the skull must be done in young infants in coma.

Ear

  • Blue discoloration of the ear drum: basilar skull fracture
  • Ecchymosis over the mastoid process: fracture base of skull. (Battle sign)
  • Head circumference
  • Anterior fontanelle
  • Sutures

Nose

  • Epistaxis: head injury, deranged coagulation with intracranial haemorrhage

Tongue

  • Laceration of tongue: tonic/clonic seizures
  • Coated furry tongue: chronic renal failure

Signs of Trauma

  • Ecchymosis over long bones: fracture
  • Disolouration of flanks and periumbilical region: blunt trauma abdomen
  • Severity of injury more than degree of trauma reported; child abuse

Skin

Some dermatological findings may help in clinching the diagnosis.

  • Flushing: hypercarbia, atropine poisoning
  • Rash: measles, other viral exanthemata, bacterial endocarditis
  • Pigmentation: pellagra
  • Changes in turgor: dehydration
  • Uremic frost: chronic renal failure
  • Petechiae: meningococcal septicemia
  • General erythema: atropine poisoning

Examination of the Central Nervous System

Signs of Meningeal Irritation

  • Meningitis (a) Bacterial (b) Aseptic (viral)
  • Sub-arachnoid haemorrhage
  • Cerebral Malaria
  • Intra ‚Äď cranial haemorrhage

Pupils

Look for size, shape, reaction to light and accommodation.

  • Pontine lesions: pinpoint pupils
  • Thalamic lesions: anisocoria
  • Transtentorial herniation: Hutchison‚Äôs pupil (ipsilateral constriction followed by dilatation and subsequently contralateral constriction and dilatation)
  • Poisoning:
    1. Fixed and dilated pupils: Sympathomimetic drugs, deep ether anaesthesia
    2. Constricted pupils: Narcotics, anticholinergics, phenothiazines, sodium valproate.

      Ocular Movements

      Doll’s eye movements: presence of doll’s eye movements (occulocephalic reflex) in coma denotes that the brain stem is intact.

      Cold caloric test: the fast component of nystagmus occurs towards the side which is being tested in an unconscious patient.

      Conjugate lateral deviation of eyes:¬†In cerebral lesion ‚Äď towards the side of lesion.

      In brain stem lesion: opposite to side of lesion.

      Fundus Examination

      • Retinal haemorrhage: head injury
      • Papilloedema: raised intracranial tension
      • Diabetic retinopathy: diabetes mellitus
      • Hypertensive retinopaty: hypertension
      • Choroid tubercles: tubercular meningitis
      • Cherry red spot: Tay Sach‚Äôs disease

      Tone/Posture

      Decerebrate rigidity: results from brain stem lesion anywhere between the inter-collicular level and vestibular nucleus and is characterized by extensor hypertonia and internal rotation of limbs with opisthotonus.

      Decorticate rigidity: site of lesion is more cephalad at the interface of cerebral hemispheres and diencephalon. There is flexor hypertonia in upper limbs. No specificity regarding nature of lesion, these can occur transiently. Decerebrate rigidity has a grave prognosis.

      Focal Neurological Signs

      These may be demonstrated in cases of:

      • Stroke
      • Cerebral abscess
      • Cerebral venous sinus thrombosis
      • Bacterial meningitis (cortical infarcts)
      • Sub-arachnoid haemorrhage/intra-cranial haemorrhage
      • Extra-dural haemorrhage/sub-dural haemorrhage following trauma.

      Unusual Clinical Presentations

      Blunt head injury may present with hyperglycemia or renal glycosuria, subdural haematoma may present with signs of dehydration, intussusception may present as altered sensorium, in subclinical status epilepticus, patient is unresponsive, but the EEG shows discharges.

      In assessing deterioration or improvement in the acute stage of coma as well as in predicting the ultimate outcome, the degree and duration of altered consciousness usually overshadow all other clinical features. It is therefore, vital to be able to assess and to record changing status of altered consciousness reliably.

      Measurement of Impaired Consciousness

      Glasgow Coma Scale

      The Glasgow Coma Scale is an effective method of describing the various states of impaired consciousness encountered in clinical practice. It is a practical system, can be used in a wide range of hospitals and by staff without special training. Three different aspects of behavioural responses examined are motor response, verbal response and eye opening, each being evaluated independently of the other. The responses are clearly defined and accurately graded according to a rank order that indicates the degree of dysfunction.

      The Glasgow Coma Scale was earlier used only for head injury, but it is now used for all types of altered sensorium. The Glasgow Coma Scale has several limitations and in the following circumstances, its

      Eye Opening Response (E)

      • Spontaneous: 4
      • Response to speech: 3
      • Response to pain: 2
      • none: 1

      Best verbal Response (V)

      • oriented: 5
      • confused: 4
      • inappropriate word: 3
      • incomprehensible sounds: 2
      • none: 1

      Best Motor Response (M)

      • obeys commands: 6
      • localizes pain: 5
      • withdraws: 4
      • flexion to pain: 3
      • extension to pain: 2
      • none: 1

      Best score is E4 V5 M6 = 15
      Worst score is E1 V1 M1 = 3

      Interpretation may become erroneous:

      1. Limbs may be paralysed or immobilized
      2. Tracheostomy or endotracheal intubation would preclude speech
      3. Swelling of eyelids or bilateral 3rd nerve palsy may make eye opening impossible.Glasgow Coma Scale depends upon higher integrative functions which are not present in the infant or very young child. In children the verbal and motor response are not readily graded and depend on the child’s age and development. Hence, in children several modifications of the Glasgow Coma Scale have become necessary.In Pediatric practice, the scales used for clinical assessment of impaired conciousness are the Adelaide Paediatric Coma Scale, the Children’s Coma Scale and the Modified Children’s Coma Scale.

        Adelaide Paediatric Coma Scale

        Simpson and Reilly proposed that the best motor response of a child depends on his age and development status so the score of motor response should be adjusted according to age. And the verbal response be graded as follows:

        • oriented: 5
        • words: 4
        • vocal sounds: 3
        • cries: 2
        • no sounds: 1

        The response to eye opening remaining the same as for Glasgow Coma Scale which is up to a maximum of 4.

        Age Related Motor and Verbal Scores

        0-6 Months

        Motor response / Verbal response

        • flexes to pain: 3 / cries : 2
        • extends to pain:2 / no sound: 1
        • no movements: 1
        • Best score: 9

        6 Months to 12 Months

        Motor response / Verbal response

        • withdraws: 4 / vocal sounds : 3
        • flexes: 3 / cries: 2
        • extends: 2 / no sound: 1
        • no movements: 1
        • Best score: 11

        1-2 Years

        Motor response / Verbal response

        • localizes pain: 5 / words: 4
        • withdraws: 4 / vocal sounds: 3
        • flexes: 3 / cries: 2
        • extends: 2 / no sound: 1
        • none: 1
        • Best score: 13

        2-5 Years
        Best score 14

        > 5 years
        Best score : 15

        Children’s Coma Scale (Raimondi and Hirschauer 1984)

        Response Form of Occurrence Score

        A. Ocular

        • pursuit: 4,
        • extra ocular muscles intact/pupil reacting: 3,
        • fixed pupils or extra-ocular muscles impaired: 2,
        • fixed pupils and extra-ocular muscles impaired: 1

        B. Verbal

        • cries: 3,
        • spontaneous respiration: 3,
        • apnoeic: 1

        C. Motor

        • flexes and extends: 4,
        • withdraws from painful stimuli: 3,
        • hypertonic: 2,
        • flaccid: 1

        Modified Children’s Coma Scale
        (James and Trauner, 1985

        Response Form of Occurrence Score

        A. Eye Opening

        • Spontaneous: 4
        • response to speech: 3
        • response to pain: 2
        • none: 1

        B. Verbal

        • coos/babbles: 5
        • irritable, cries: 4
        • cries to pain: 3
        • moans to pain: 2
        • none : 1

        C. Motor

        • normal spontaneous : 6
        • withdraws to touch : 5
        • withdraws to pain : 4
        • abnormal flexion : 3
        • abnormal extension : 2
        • none : 1

        Clinical Focus

        • A rapid and accurate evaluation of a child with altered sensorium is necessary for appropriate management.
        • A detailed history and general physical examination provides vital pointers towards the underlying diagnosis.
        • The Glasgow Coma Scale (GCS) is an effective method of describing various states of impaired consciousness in a wide range of clinical settings.
        • In paediatric practice, the Adelaide Paediatric Coma Scale, the Children‚Äôs Coma Scale and the Modified Children‚Äôs Coma Scale offer clearly defined and accurately graded assessment of the degree of dysfunction of the central nervous system in children of various ages.

        Conclusion

        Impairment of consciousness in children may result from a wide range of aetiological conditions. History taking and a meticulous physical examination provide important clues to the underlying diagnosis. An accurate assessment of the cause and extent of altered sensorium not only helps in the management of coma, but also helps in focusing attention to a limited number of diagnostic possibilities, making expensive and exhaustive investigations unnecessary.

        The Glasgow Coma Scale, earlier used for assessment of head injuries is considered to be an effective method of describing and grading of coma in children. However, since the motor and verbal responses in children depend upon their age and degree of development, several modifications of the GCS have come into existence which provide easy assessment of accurate grading of central nervous system dysfunction.

        Dr. Gurdev Chowdhary,
        Dr. Praveen C. Sobti,
        Prof. Daljit Singh,

        Dept. of Pediatrics, DMC and Hospital, Ludhiana

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