Neonatal Seizures

About 2–4/1000 live births suffers of seizure disorder. Usually occur 12–48hr after delivery. Can be generalized or focal, and tonic, clonic, or myoclonic. Subtle seizure patterns (lip-smacking, limb-cycling, eye deviation, apnoeas, etc.) can be difficult to identify or differentiate from other benign conditions that may mimic seizures as: Startle or Moro reflexes, normal jittery’ movements (fine, fast limb movements that are abated by holding affected limb), Sleep myoclonus (REM movements).

Causes: -Brain injury as: *hypoxic ischaemic encephalopathy (HIE). *intracranial haemorrhage. *cerebral infarction (ischaemic or haemorrhagic). *cerebral oedema. *birth trauma. -CNS infection: *meningitis (e.g. GBS, coliforms). *encephalitis (e.g. HSV, CMV). -Cerebral malformations.

-Metabolic: *Hypoglycaemia. *hypo- or hypernatraemia. *hypocalcaemia, hypomagnesia. *pyridoxine dependent seizures. *non-ketotic hyperglycinaemia. -Neonatal withdrawal from maternal medication or substance abuse. -Kernicterus. -Rare syndromes: * benign familial neonatal seizures (autosomal dominant). * early myoclonic encephalopathy.

With improved access to neuroimaging, fewer infants are being categorized as ‘benign’ or ‘idiopathic’ seizures. Neonatal stroke is increasingly recognized.

Treatment of neonatal seizures: Immediate: give oxygen,maintain airway, insert IV canula. When to start anticonvulsants? usual indication is >3seizures/hr or single seizure lasting >3–5min particularly if evidence of cardio-respiratory compromise. First-line anticonvulsant: IV phenobarbital (10–20mg/kg bolus; give further 10–15mg if seizures persist after 30min; maintenance dose 5mg/kg/day). Then treat the underlying cause.