DIAGNOSIS OF KERNICTERUS IN THE NEONATAL PERIOD

In a series of 882 infants with hemolytic disease of the newborn (erythroblastosis fetalis), 31 infants developed kernicterus. In the neonatal period the diagnosis of kernicterus was established firmly in 65%, remained uncertain in 19% and was not suspected in 16%. This diagnosis was established firmly in the neonatal period when spasticity was moderate to marked. The diagnosis of kernicterus remained uncertain when spasticity was mild and short-lived. This diagnosis was not suspected when spasticity was not observed. Characteristically, a progression of three distinct clinical phases was observed in infants with kernicterus during the neonatal period. A fourth clinical phase appeared later in infancy. The first clinical phase was characterized by hypotonia, lethargy and a poor sucking reflex; the second by spasticity, opisthotonos and fever; the third by the diminution or disappearance of spasticity; and the fourth by the progressive appearance ance of the relatively permanent signs of post-kernicteric extrapyramidal cerebral palsy. The hypotonia, lethargy and poor sucking reflex of the first phase of kernicterus appeared highly significant because of the great importance of this phase concerning the infant's neurologic prognosis. But these critical signs were nonspecific, being associated also with major pulmonary, cardiovascular and other central nervous system pathology in non-kernicteric infants with hemolytic disease. The spasticity of the second phase indicated with great accuracy that kernicterus had occurred in the first clinical phase. The diagnostic reliability of spasticity was not related to its intensity or duration. A kernicterus-like syndrome related to hemorrhages within the basal ganglia was the only observed exception to the otherwise complete diagnostic reliability of spasticity. The true absence of any spasticity throughout the first week of life appeared to indicate with great reliability in the neonatal period that kernicterus had not occurred. The lessening or disappearance of spasticity in the third clinical phase erroneously led to diagnostic uncertainty in the neonatal period concerning the presence or absence of kernicterus. It is hoped that accuracy in the diagnosis of the presence or absence of kernicterus in the neonatal period may be increased by an understanding of the three neonatal clinical phases, their cardinal signs, their progression and the diagnostic problems of each phase.