Cerebral cortical function in infants at risk for sudden infant death syndrome.
Cerebral cortical function was prospectively examined by electroencephalography (EEG) in 3 subgroups of 257 infants at risk for sudden infant death syndrome (SIDS). Group 1 consisted of apparently healthy infants with near-miss SIDS episodes; Group 2 consisted of siblings of SIDS victims; and Group 3 consisted of neurologically suspect infants with apnea. The usual abundance and distribution of sharp EEG transients (SETs) were determined from 69 Group 1 infants. EEGs were interpreted as abnormal in the presence of ictal apnea, excessively abundant SETs, or immaturity of EEG background for conceptional age. Ninety percent of infants in Group 1 had entirely normal EEGs. There was no significant difference in the abundance or distribution of SETs between infants with normal breathing patterns and those with excessively periodic respirations. Nonictal apnea was recorded in 7% of Group 1 infants. The unexpected diagnosis of ictal apnea was confirmed in 2 Group 1 infants (1.2%), and 5 (2.9%) had excessive SETs but no recorded seizures. Only 4 infants (2.3%) had abnormally immature EEGs for conceptional age. Nonictal apnea occurred in 5 of 33 (15.2%) Group 3 infants and ictal apnea was confirmed in 2 others (6.1%). We conclude that the majority of Group 1 and 2 infants have normal cerebral cortical activity between and during apnea and that central nervous system cortical immaturity, as measured by EEG, plays no important role in the pathogenesis of SIDS. SETs are commonly recorded in these infants and must be conservatively interpreted. However, an EEG examination was critical in establishing the unexpected diagnosis of ictal apnea in a small percentage of Group 1 and 3 infants and materially influenced subsequent evaluation, management, and prognosis.
D001049:Apnea / Q000150:complications / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology*; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000150:complications / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000150:complications / Q000503:physiopathology; D012306:Risk; D013398:Sudden Infant Death / Q000209:etiology / Q000503:physiopathology*