Although a great deal has been written about porencephaly during the past 100 years, there is much that remains obscure. The clinical recognition of porencephaly is important because it occurs with sufficient frequency to require consideration in the differential diagnosis of focal cerebral lesions. The study of a group of patients is reported in order to clarify some of its clinical features. The patients considered to fulfill the criteria for this study were those with cystic defects of the cerebrum whose lesions were present at, or very shortly after, birth, excluding those with destructive lesions occurring later in life.
The term porencephaly has undergone considerable change in its meaning since Heschl1 first used it in 1859. The lesions included under the loose coverage of porencephaly vary widely. Heschl proposed the term porencephaly to designate specifically the types of circumscribed defects which "have this in common, that in