Neuroepidemiology of Porencephaly, Schizencephaly, and Hydranencephaly in Miyagi Prefecture, Japan

Periventricular Venous Infarction in an Extremely Premature Infant as the Cause of Schizencephaly

“…11,12 In early development, arterial hypoperfusion secondarily destroys the overlying cortex, resembling middle cerebral artery stroke, and leading to schizencephaly. 7,9 The most frequent genetic cause of schizencephaly is heterozygous variations in COL4A1. COL4A1 is responsible for type-IV collagen, which is an important component of the basement membranes.…”

“…3 Schizencephaly is a heterogeneous condition and can develop as a result of genetic and acquired causes in early neuroembryogenesis, many of them being of vascular disruptive nature. [1][2][3][4][5][6][7][8] Rapid evolution of molecular biology, genetics, and imaging has led to the understanding that schizencephaly is not a malformation secondary to abnormal cortical organi-zation or focal cortical dysplasia as suggested earlier and the earlier agenesis hypothesis has been shifted in favor of an encephaloclastic process. 1 Furthermore, it is believed that both schizencephaly and porencephaly are caused by the same encephaloclastic process and can only be distinguished based on the time of insult.…”

“…In contrast, porencephaly is the result of stroke after completion of neuronal migration and leads to lesions without the gray matter lining of the cleft. 7,8 Prenatal vascular events result in destructive brain lesions that are genetic or infectious in origin; however, in many cases the origin is unknown. 7 The COL4A1 and COL4A2 gene mutations have been reported in relation to a broad spectrum of cerebrovascular diseases and are also the most frequent genetic mutations seen in schizencephaly and porencephaly.…”

“…7,8 Prenatal vascular events result in destructive brain lesions that are genetic or infectious in origin; however, in many cases the origin is unknown. 7 The COL4A1 and COL4A2 gene mutations have been reported in relation to a broad spectrum of cerebrovascular diseases and are also the most frequent genetic mutations seen in schizencephaly and porencephaly. 2,7 However, only a few cases have provided clear evidence of the development of schizencephaly after fetal stroke 8,9 and, to the best of our knowledge, no case report has described this sequence of events after neonatal periventricular venous infarction (PVI).…”

Porencephalic cyst: a rare cause of new-onset seizure in an adult

“…It is usually related to perinatal vascular events, including cerebral ischemia or hemorrhage [2]. The cyst is usually single and unilateral, but cases of multiple bilateral cysts have also been reported [3].…”