Seizures

Febrile convulsions (3-4 % of all children)

• uncomplicated (75%): tonic-clonic generalized convulsion seen in a febrile illness. No cerebral etiology, commonly seen in children 6 month – 6 years of age
• complicated – at least one of the following characteristics: focal beginning, longer than 15 minutes, more than one convulsion within 24 hours, younger than 6 month or older than 6 years, cerebral etiology
Examination: Look for focus of fever (Malaria, Upper respiratory infection, Urinary tract infection, exanthema subitum)

Investigations: MPs always, Lumbal puncture if clinical picture of meningitis or encephalitis, and in all complicated febrile convulsions

Epilepsy

Definition: sudden change in cortical electrical activity, manifested through motor, sensory, or behavioral changes and/or an alteration in consciousness

• At least two seizures occurring more than 24 hours apart
• One unprovoked seizure and a high probability of further seizures like in stroke, central nervous system infection, or traumatic brain injury

Types

• Focal (partial) seizures – secondary to electrical discharge from a specific area of the brain, limited to one hemisphere
  • simple partial seizure (remain consciousness):
  • focal motor activity (Jackson), versive movement (turning of the eyes, head and/or trunk), vocalization, or arrest of speech
  • Sensory seizures: paresthesias, feelings of distortion of an extremity, vertigo, gustatory sensation, olfactory symptoms, auditory symptoms, and visual phenomena such as flashing lights
  • Auras- dysphasia, feelings of familiarity ("deja-vu"), distortions of time, affective changes (particularly fear), illusions, and formed hallucinations.
  • complex partial seizure (impaired consciousness)
    • repetitive motor automatisms as chewing, swallowing, sucking, complex motor phenomena including bicycling and kicking movements

• Generalized seizures

  rapidly engaging, bilaterally distributed networks. Consciousness usually impaired, motor manifestations are bilateral

  • Tonic-clonic: sudden loss of consciousness (tonic phase) than rhythmic contractions of all four extremities. Afterwards postictal phase with headache, confusion and fatigue. Often tongue bite, enuresis, encopresis
  • Absence: Impaired awareness and responsiveness. cannot be interrupted by tactile stimulation, often interrupt conversation or ongoing physical activity such as eating and play, usually occur multiple times during the day and last only a few seconds.
  • Atonic: abrupt loss of muscle tone
  • Myoclonic: repetitive muscle contractions

  subtle (minimal clinical expression)
  subclinical (no clinical or outward manifestation of the electrical seizure activity).

Important points in history

Seizures in epilepsy are usually stereotyped (each one is like the previous one), random (occur at any time of the day or night), and are rarely precipitated by specific environmental, psychological, or physiological events

• family history of epilepsy
• prior seizures
• trauma, diarrhoea (electrolyte imbalance), fever, local mankhala
• birth history

Important points on examination

Full neurological exam

Investigations

• Glucose
• Mps, PCV
• if afebrile seizure consider sodium, calcium, potassium
• if febrile or BCS reduced lumbal puncture, blood culture
• consider MRI in focal seizures with focal pathology on neurological examination
• consider EEG if uncertain if child having a sub-clinical seizure. Organize via malaria research ward

Epidemiology

Etiology

• idiopathic
• Infection: Meningitis, Abscess, Encephalitis, Sepsis
• Metabolic and Endocrine disorders (hyponatremia, hypocalcemia, hyperthyreodism)
• Trauma: intracranial bleeding
• Drugs and alcohol (and its withdrawel)
• Tumors
• Vascular disease (sickle cell, vasculitis, ischemia, brain malformations)
• neurodegenerative or neurometabolic disease
• Syndromes: Lennox Gestaut, Sturge weber, beningn familial, myoclonic epilepsy of the infant

In neonates and infancy most seizures are symptomatic of an identifiable etiology - HIE, metabolic disturbances metabloic: hypoglycaemia, hypocalcaemia, vit b 6 deficiency, phenylketonuria, central nervous system or systemic infection.

In HIV/Aids consider CNS Toxoplasmosis, Crzptococcal meningitis, Herpes encephalitis, bacterial meningitis, CNS lymphoma, neurosyphilis

Differential diagnosis

• Syncope:
  • Orthostase, vagovasal
• cardiogenic (long QT syndrome, congenital heart diseases): Episodes of sudden loss of tone with or without loss of consciousness
• cyanotic breath-holding spell: Consistent crying before a "seizure" in infants
• psychogenic non-epileptic seizures

Treatment

Long term treatment:

Monotherapy prefered

• Phenobarbital (not the best, but on long term available): 20 mg/kg stat, than 5 mg/kg nocte. Side effects include – Fatigue, hyperactivity, depression, constipation, leucopenia

if seizures not controlled switch

in generalised seizures:

• Sodium valproate 20-30 mg/kg/d in two divided doses. Start with 10 mg/kg, increase in second week. Side effects include – emesis, increased appetite, tremor, hepathopathy, thrombocytopenia

in focal seizures (rarely controlled with Phenobarbital):

1. Carbamazepine 20-30 mg//kg/day devided in two doses, start with 15mg/kg, increase in second week. Side effects include – fatigue, Vision impairement, Emesis, constipation, diarrhoea, dermatitis, increased LFTs, Thrombopenia
2. Valproate. s. above

Follow up