Dyskinetic cerebral palsy. II. Pathogenetic risk factors and intra-uterine growth.

In an unselected series of 116 dyskinetic cerebral palsy cases, 35 hyperkinetic and 81 dystonic, 21% of the cases were considered to derive from the prenatal period, 67% from the perinatal, and 7% from the postnatal period, while 5% were untraceable. Isolated risk factors were found in 24% of the hyperkinetic and 24% of the dystonic cases and various combinations in 68% and 72%, respectively. Preterm appropriate-for-gestational-age cases with hyperbilirubinemia were found significantly more often among the hyperkinetics (47%) than among the dystonics (11%). Term appropriate-for-gestational-age cases with asphyxia were found significantly more often among the dystonics (30%) than among the hyperkinetics (9%). Term and preterm small-for-gestational-age cases with asphyxia and/or perinatal hypoxia were only found in the dystonic subgroup (14%). Both the hyperkinetic and the dystonic subgroups had significantly lower mean birth weights--2795 g and 2872 g, respectively--than that of the general population, 3500 g. The dystonic subgroup had birth weights significantly below the mean for gestational age. Both subgroups had birth weights significantly below the mean for the respectively birth length. This was particularly pronounced for the cases with birth asphyxia. All infants with birth weights less than or equal to -2.0 SD below the mean for birth length had had birth asphyxia, and the proportion decreased successively to 0% among those greater than +1.0 SD.