IQ and its predictors in childhood hemiplegia.

In a population-based sample of 149 children with hemiplegia, IQ was highly correlated with a simple-to-calculate index of neurological severity. Performance IQ was an average of 13 points lower then verbal IQ-a difference that seemed to reflect specific visuospatial difficulties rather than an effect of the motor disability itself. Side of lesion was not significantly related to either IQ or verbal-performance discrepancy. Neurological factors and social class had additive effects on IQ, suggesting that neurological damage neither amplified nor obliterated the impact of ordinary psychosocial and genetic factors on IQ.