Porencephaly refers to –

Porencephaly Refers to the presence of cysts or cavities within the brain, that may results from Developniental defects (True porencephalic cysts). Acquired lesions of infarction of tissues.        (i.e. Vascular lesions) - AV malformation or infarcts or (Pseudo-porencephalic cysts). Defects of NeuronalMigration : malformations of cortical development Lissencephaly        -          Also called agyria Characterized by absence of cerebral convolutions and poorly formed sylvian fissure giving the appearance of 3-4 months fetal brain. Schizencephaly       -        Presence of unilateral or bilateral clefts within the cerebral hemisphere due to an Abnormality of morphogenesis Porencephaly        -          Presence of cysts cavities within the brain that result from developmental defects or acquired lesions including infarction of tissue. Holoprosencephaly   -     Developmental disorder of brain that results from defective cleavage of prosencephalon.