Teratogenetic periods for the principal malformations of the central nervous system.

The teratogenetic periods of the most important CNS malformations are defined and briefly discussed. The results are presented in a synoptic figure. The present study is based on the analysis of normal CNS development and on morphogenetic interpretations of the pertinent anomalies. The data compiled from the literature concerning normal development are presented in an analytical table and are also summarized in a synoptic figure.