The problem of the cerebral birth palsies remains in a state of confusion, despite the many investigations on the subject. One reason lies in the fact that not enough cognizance has been taken of the probability that there are many different causes and pathologic substrata for conditions which appear clinically similar. Another reason is that it has been extremely difficult to discriminate between congenital and acquired lesions in many cases of early involvement. Finally, there has frequently been confusion between cause and lesion; this has resulted in an effort to assign to a single clinical group a single cause.
For this reason we have chosen to study the cerebral diplegias as representing a unit in the entire group of cerebral birth palsies, hoping at least to clarify thereby the pathologic background of such conditions and possibly at the same time to indicate the etiologic factors in some instances.