SEIZURE DISORDERS IN CHILDREN

A seizure is defined as a paroxysmal involuntary disturbance of brain functio that may result in loss of consciousness and abnormalities in movement, behaviour, or sensation.

CAUSES

  • Organic lesions such as acute or chronic infections
  • Tumours and developmental defect,
  • More commonly the cause is unknown.

Epilepsy is defined as recurrent seizures.

Clinical Features

The clinical features depend on the type of seizure. The various forms of seizures are:

  • Partial seizures, which include:
    • Simple partial seizures – Can be motor, sensory and sensory-motor (consciousness not impaired).
    • Complex partial seizures – Starting with an aura (later impairment of consciousness) and often accompanied by automatic behaviour.
    • Partial seizures becoming progressive (jacksonian seizures) or generalized.
  • Generalized seizures, which include:
    • Absences, which are brief lapses of awareness that last for about 30 seconds and are uncommon below 5 years of age.
    • Tonic seizures, which manifest with sustained muscle contractions.
    • Myoclonic seizures, which are repetitive symmetrical muscle contractions whose distinctive forms are:
      • Benign myoclonus of infancy disappear by age 2 years.
      • Early childhood type, whose onset starts at about 2 years and has a relatively good prognosis.
      • Complex type, whose onset in starts in the first year of life commonly following birth asphyxia, with a poor prognosis.
      • The juvenile form that begins at age 12–16 years, among children that are neurologically and has a good response to treatment.
    • Clonic seizures, characterized by rhythmic jerking.
    • Tonic-clonic seizures characterized commonly by an aura with loss of sphincter control and post ictal deep sleep.
    • Atonic seizures characterized by sudden loss of muscle tone.
    • Infantile spasm, characterized by their initiation at age 4–8 months, sudden symmetrical contraction of all parts of body, and whose prognosis is poor if there is identifiable underlying pathology but good if there is not identifiable
      underlying pathology.

HISTORY TAKING

  • Meticulous history from parents and reliable witnesses is critical in diagnosing a seizure disorder.
  • It is important to find the details of the prodromal phase, aura, and the type, duration, frequency, and age of onset of seizures.
  • Details about the post ictal phase are important.
  • It is also important to determine the underlying pathology, for example birth asphyxia, neonatal jaundice, or infection of the
    central nervous system.

EXAMINATION

  • A careful and thorough physical examination is necessary to detect associated neurological dysfunction or abnormality.
  • Evaluation of blood pressure, head circumference in those aged less than 2 years, and fundoscopy are important in
    the examination of such children.

Investigations

  • If child has fever
    • Full haemogram
    • Malaria parasites
    • Lumbar puncture if meningitis
  • When metabolic conditions are suspected, do
    • Blood sugar
    • Urea and electrolytes and creatinine
  • Electroencephalography (EEG)
  • CT scan of the head
  • Magnetic resonance imaging (MRI), is of additional help

Management

During an epileptic attack, the following should be observed:

  • Place the patient on the left lateral position with the head turned to the same
    side;
  • Loosen or remove tight fitting clothing around the neck.
  • Do NOT attempt to insert any instrument into the mouth to avoid tongue biting, as this may have already happened.
  • Shield the patient from being surrounded by too many eager observers.
  • Allow seizure to complete its course without physically attempting to hold down the patient. However, the patient should be removed from danger like fire.

General Management of Seizures

For a child with seizure, the following should be observed:

  • Treat any underlying diagnosed condition.
  • For most patients with epilepsy, start on therapy as outpatients.
  • Counsel parents and patient that treatment is usually life long. Therapy may be discontinued after a seizure-free period of at least two years if the patient has no risk factors. Reduce dose gradually over many months. Sudden discontinuation of drugs may precipitate status epilepticus. Complex partial seizures will require lifelong drugs.

Pharmacological Management

  • Refer to Tables for a summary of the drugs of choice for common seizures and the appropriate paediatric dosages, respectively.
  • Start long-term therapy if patient has had 2 or more seizures within 1 year.
  • Start therapy with 1 drug, usually phenobarbital. Increase at regular intervals until seizures are controlled or side effects appear.
  • If side effects appear and seizures are still not controlled, introduce other drugs and taper off the first drug.
  • Admit for evaluation if underlying metabolic cause is suspected or raised intracranial pressure is present.
  • Refer to specialist if:
    • Seizures are not controlled with maximum drug dose.
    • Raised intracranial pressure is suspected.
    • Space occupying lesion is suspected.

Drugs of choice for common seizures

Main classification of convulsive disorder Subclassification of the main convulsive grouping Preferred drug of choice for treatment Other drugs that
can be used for treatment
Partial seizures Simple Phenytoin Carbarmazepine,
Valproic acid
Complex Carbamazepine Phenotoin
Secondarily generalized Phenobarbitone Phenotoin
Generalized seizures Absence Ethosuximide Valproic acid,
Clonazepam
Tonic-clonic, clonic, tonic, atonic Phenobarbitone Carbamazepine,
Phenytoin
Myoclonic Clonazepam Nitrazepam, Valproic
acid, Phenobarbitone

Parent and Patient Education

The following is important for the education of the patient and the parent:

  • Medication should be taken regularly and it should not be assumed that the child is healed when the seizures are controlled. Treatment in most cases is life long.
  • Ensure normal activity for the age of the child including school.
  • Child should avoid dangerous activities like climbing trees.
  • Protect child from falling into fires.
  • The patient should never swim alone and all precautions should be taken when swimming
  • The parent should not to be over protective for the child.

Paediatric dosages of common drugs for convulsive disorders

3 divided doses

Drug Dosage Frequency Remarks
Phenobarbitone 3–6mg/kg Once daily May cause hyperactivity in some children.
Phenytoin 4–7mg/kg Once daily Causes gum hypertrophy
Carbamazepine 20–30mg/kg/day 3 divided doses
Sodium valproate 30–60mg/kg/day 3 divided doses May precipitate, absence status if
given with clonazepam. Also causes transient alopecia.
Ethosuximide 20–40mg/kg/day 2–3 divided doses
Clonazepam 0.1–0.2mg/kg/day Once daily May precipitate absence status if
given with sodium valproate

NB: Sodium valproate is the most broad spectrum anticonvulsant, but it is very costly and is better used as a second line drug. If seizures are not controlled, drugs used at maximum recommended dose should be withdrawn gradually as another one is introduced.