THE ELECTROENCEPHALOGRAM IN PORENCEPHALY

Abstract

PORENCEPHALY has been defined as a defect in cerebral or cerebellar structure appearing as a cystlike cavity communicating with the ventricles or separated from them only by a thin layer of brain tissue, covered on the outside by the pia-arachnoid and filled with a clear, colorless fluid.¹ The etiologic factors in this condition, which is usually initiated during the developmental period, may be various—inflammatory process, embolism or thrombosis, internal hydrocephalus or trauma.² Most probably, whatever the fundamental cause, the porencephalic cyst results from ischemic necrosis of the brain tissue and resorption of the products of liquefaction.³ A history of birth injury, failure of growth and paresis of one side of the body, and of convulsive seizures, together with physical findings of spastic hemiparesis, with sensory (particularly topognostic) defect and hypoplasia, is common in cases of porencephaly, since most often this defect of the brain lies in the