Original articleDevelopment of epilepsy in newborns with moderate hypoxic-ischemic encephalopathy and neonatal seizures
Introduction
Hypoxic-ischemic encephalopathy (HIE) is one of the most frequent causes of neonatal death and neurological disabilities in children. It is estimated that about 1 to 2 per 1000 live term births [1], [2] suffer from HIE, mainly due to perinatal asphyxia. A percentage between 15% and 20% of the newborns developing HIE die during the neonatal period, whereas about 25% of the survivors will present neurological handicaps such as cerebral palsy, mental delay, and epilepsy [3].
The neurodevelopmental outcome can be predicted on the basis of the degree of HIE according to the Sarnat and Sarnat criteria [4]. However, predictivity of the final outcome based on the neurological features is known in the cases placed at the two extreme sides of the clinical spectrum, like the mild or severe HIE. In moderate conditions this predictivity results, to date, unsatisfying. For this reason and for a most adequate evaluation of the sick newborn, it is necessary to integrate the different clinical and instrumental indicators available.
An important consequence of a moderate or severe HIE are neonatal seizures which can cause an additional brain damage through an increment of the metabolic request by the central nervous system [5], [6], [7]. The exact frequency of neonatal seizures is not known. Some studies report an incidence varying from 0.15% to 0.5% [8], others from 22.7% of the premature newborns to 0.16% of the full-term newborns [9], [10], where HIE results to be the most frequent cause of seizures, accounting for 50–60% of all newborns with convulsions [11], [12].
To our knowledge, only few studies in literature focused on the relationship between moderate HIE and post-neonatal epilepsy [13], [14].
Therefore, the purpose of this prospective study was to appraise the development of post-neonatal epilepsy in a cohort of term infants with neonatal seizures due to moderate HIE.
Section snippets
Methods
This study considered all full-term newborns consecutively admitted to Neonatal Intensive Care Unit (NICU) of the Parma University between 2000 and 2002 for perinatal asphyxia, then followed by Neonatal Neurology Service. Among 1106 newborns admitted, 92 full-term newborns met the following criteria for perinatal asphyxia.
Perinatal asphyxia was defined on the basis of at least three of the following findings: intrapartum distress, as indicated by foetal bradycardia with a heart-rate of less
Results
Of the 92 newborns with perinatal asphyxia, only 57 subjects developed HIE later, 41 males and 16 females. Only 18 subjects (31.6%) presented neonatal seizures as consequence of HIE. Newborns with seizures had significant lower Apgar scores at 5, and 10 min, demonstrating a more difficult neonatal adaptation (p < 0.05). The value of the pH, measured out in 20/39 subjects without seizures and in 17/18 of the subjects with seizures, did not show significant differences between the two groups. The
Discussion
The interest for HIE is due to the still rather high frequency of occurrence and to the fact that it remains one of the most important cause of neonatal mortality and of severe neurological impairment [3], [25]. The prognosis of a hypoxic-ischemic insult to the term newborn depends on the degree of the encephalopathy. However, whether seizures superimposed on a moderate HIE would predispose to the risk of developing epilepsy later in life is still poorly investigated. To our knowledge, only few
References (36)
- et al.
Low Apgar scores and the definition of birth asphyxia
Pediatr Clin North Am
(2004) Neonatal seizures and electrographic analysis: evaluation and outcome
Pediatr Neurol
(1994)- et al.
Postneonatal epilepsy following amplitude-integrated EEG-detected neonatal seizures
Pediatr Neurol
(2005) Neonatal seizures: a clinician’s overview
Brain Dev
(1996)- et al.
Birth asphyxia: incidence, clinical course and outcome in a Swedish population
Acta Paediatr
(1995) - et al.
Falling incidence of hypoxic-ischaemic encephalopathy in term infants
Br J Obstet Gynaecol
(1992) Neurology of the newborn
(2001)- et al.
Neonatal encephalopathy following fetal distress: a clinical and electroencephalographic study
Arch Neurol
(1976) - et al.
Cerebral metabolic effects of neonatal seizures measured with in vivo 31P NMR spectroscopy
Ann Neurol
(1986) - et al.
Prediction of seizures in asphyxiated neonates: correlation with continuous video-electroencephalographic monitoring
Pediatrics
(2006)
Electrographic seizures in preterm and full-term neonates: clinical correlates, associated brain lesions, and risk for neurologic sequelae
Pediatrics
Evolution of neonatal seizures
Pediatr Clin North Am
Neonatal seizures recent aspect
Neuropediatrics
Early infantile epileptic encephalopathy: a long term follow up study
Childs Nerv Syst
Prognosis of hypoxic-ischaemic encephalopathy in full-term newborns – value of neonatal electroencephalography
Neuropediatrics
Birth asphyxia in the fullterm newborn: early assessment and outcome
Dev Med Child Neurol
Detection of inborn errors of metabolism in the newborn
Arch Dis Child Fetal Neonatal Ed
Neonatal Seizures: historic note and present controversies
Epilepsia
Cited by (53)
Neonatal Encephalopathy
2023, Avery's Diseases of the NewbornInvoluntary movements as a prognostic factor for acute encephalopathy with biphasic seizures and late reduced diffusion
2022, Brain and DevelopmentCitation Excerpt :Using data on the outcomes of AESD, we clarified the associations between underlying diseases and unfavorable outcomes. The underlying diseases in the patients assessed in this study, including neonatal hypoxic-ischemic encephalopathy, tuberous sclerosis complex, Sotos syndrome, and congenital cytomegalovirus infection, tend to result in the development of epileptic seizures [19–23]. Neuronal excitability due to these neurological background factors may cause susceptibility to excitotoxicity in early seizures and is associated with unfavorable outcomes.