Clinical features, evaluation, and diagnosis of neonatal seizures
- Renee Shellhaas, MD, MS
Renee Shellhaas, MD, MS
- Clinical Associate Professor, Dept of Pediatrics
- University of Michigan Pediatric Neurology
- Section Editors
- Douglas R Nordli, Jr, MD
Douglas R Nordli, Jr, MD
- Section Editor — Pediatric Neurology
- Chief of Neurology
- Children’s Hospital Los Angeles
- Vice Chair of Neurology
- USC Keck School of Medicine
- Joseph A Garcia-Prats, MD
Joseph A Garcia-Prats, MD
- Section Editor — Neonatology
- Professor of Pediatrics
- Baylor College of Medicine
The occurrence of neonatal seizures may be the first, and perhaps the only, clinical sign of a central nervous system (CNS) disorder in the newborn infant. As such, seizures may indicate the presence of a potentially treatable etiology and should prompt an immediate evaluation to determine cause and to institute etiology-specific therapy. In addition, seizures themselves may require emergent therapy, since they may adversely affect the infant's homeostasis or they can contribute to further brain injury.
The clinical features, evaluation, and diagnosis of neonatal seizures will be reviewed here. The etiology and treatment of neonatal seizures and associated epileptic syndromes are discussed separately. (See "Etiology and prognosis of neonatal seizures" and "Neonatal epilepsy syndromes" and "Treatment of neonatal seizures".)
Seizures occur more often in the neonatal period than at any other time of life; during this period, they most often occur within the first week of life [1,2]. Reported incidence ranges from 1.5 to 5.5 per 1000 in newborns [2-4] and may be even higher in premature infants . Seizure incidence varies with some specific risk factors. Occurrence increases with decreasing gestational age and birth weight, and with increasing acuity of illness [2,6,7].
Most neonatal seizures (approximately 85 percent) are "symptomatic" seizures, occurring as a consequence of a specific identifiable etiology (table 1 and table 2) [8-12]. These etiologies can be broadly categorized as:
●Neonatal encephalopathy and hypoxic-ischemic encephalopathy
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- CLINICAL FEATURES
- Clinical seizure types
- - Focal clonic
- - Focal tonic
- - Myoclonic
- - Epileptic spasms
- Autonomic signs
- Subclinical seizures
- DIFFERENTIAL DIAGNOSIS
- Non-seizure events
- Normal newborn behaviors
- Abrupt changes in vital signs
- Video EEG monitoring
- Serial routine-length EEGs
- Reduced-montage EEG
- ETIOLOGIC EVALUATION
- Physical examination
- Genetic testing
- SUMMARY AND RECOMMENDATIONS