MRI in motor delay: important adjunct to classification of cerebral palsy.

Cranial magnetic resonance imaging (MRI) was performed prospectively in 45 children (ages 3-27 months) with clinically documented motor delay to evaluate the ability of MRI to determine etiologic factors, to determine whether myelination correlated with motor delay, and whether the clinical category corresponded with the imaging findings. Of the 22 children diagnosed clinically as having major motor delay (i.e., cerebral palsy), 77% had magnetic resonance imaging abnormalities. In 23%, etiologic associations were established from MRI alone and in 32% a clinically suspected etiology was supported. No children had myelination delay as the sole abnormality. In 23 children with minor motor delay, only 17% had abnormal scans. Clearly, MRI provided useful information in the majority of children with cerebral palsy; therefore, a classification system is proposed in which MRI can be used in conjunction with clinical assessment to specify more precisely the etiologic factors in cerebral palsy.