-Abstract-
Neonatal seizures are only a manifestation of a variety of organic, metabolic or
functional disorders of the neonatal brain. Most are caused by acute brain insults such
as perinatal hypoxic-ischemic encephalopathy, intracranial hemorrhage or CNS infections.
Recent years have witnessed a remarkable reduction of simple hypocalcemia, resulting in
a relative increase of hypoxic-ischemic encephalopathy. These acute symptomatic
seizures are different from epilepsy, a chronic seizure disorder. Most previous studies
concerning seizure manifestations of the newborn have dealt with all types of neonatal
seizures together, regardless of etiology.
It is true that seizures in the neonate pose unique diagnostic and therapeutic problems
because of the immaturity of the neonatal brain, but it is not appropriate to study
seizure types in the newborn on the basis of acute symptomatic seizures such as those
occurring in hypoxic-ischemic encephalopathy in which acute brain swelling or neuronal
necrosis may obscure the unique developmental state of the neonatal brain. No one
would attempt to classify the seizure types in older children with acute encephalitis and
epilepsy together. Such acute symptomatic neonatal seizures should be excluded from the
classification of epileptic seizures and syndromes, although they may evolve into
symptomatic epilepsy later as a sequel. The current International Classification of
Epilepsies and Epileptic Syndromes lists five epileptic syndromes in which neonatal
seizures are a major manifestation; benign familial neonatal convulsions(BFNC), benign
neonatal convulsion(BNC), early infantile epileptic encephalopathy with
suppression-burst(EIEE), early myoclonic enecphalopathy(EME), and neonatal seizures.
BFNC and BNC are categorized in idiopathic generalized epilepsies according to the
International Classification.
BFNC are described as being associated with clonic or apneic seizures, although the
ictal EEGs of these seizures have been well documented in only a small number of
cases. Seizure types reported to date were partial or generalized. Three of four patients
in whom we were able to record ictal EEGs displayed definite partial seizures. One
diagnosed as haying generalized seizures did not show typical electroclinical features of
generalized tonic-clonic convulsions.
|