The epidemiology of clinical neonatal seizures in Newfoundland: a population-based study.

OBJECTIVE

To study the incidence, clinical features, etiologic distribution, and day of seizure onset by etiology in neonates with seizures.

DESIGN

Prospective, population-based study involving all the obstetric and neonatal units across the province of Newfoundland, Canada. All units were given educational sessions on neonatal seizure symptomatology.

SUBJECTS

Detailed questionnaires were prospectively collected for all infants with probable neonatal seizures for a period of 5 years.

RESULTS

The incidence rate was 2. 6 per 1000 live births, 2.00 for term neonates, 11.1 for preterm neonates, and 13.5 for infants weighing <2500 g at birth. Seizures lasting 30 minutes or longer were present in 5%, and the neonatal death rate among infants with seizures was 9%. Hypoxic-ischemic encephalopathy was the presumed cause in 40%, infections in 20%, and metabolic abnormalities in 19%.

CONCLUSIONS

Clinical neonatal seizures occur 6 times more often in preterm infants than in term infants. Hypoxic-ischemic encephalopathy continues to be a major marker of the likelihood of seizures.