IMAGING STUDY OF CONGENITAL BRAIN LESIONS

Abstract

The range of congenital malfonnations involving the brain and the neuro-axis is enormous with almost infinite variations on a large number of basic patterns most of which are untreatable (Lane, et al., 1999)0J.

The discussion of congenital brain lesions and malformations is devoted to the macroscopic changes that result from failure of and arrest in cerebral development, and also to the degenerations that appear during the fetal and infantile periods. The causal factors have not been satisfactorily established, many are developmental, and others may be sequelae to injuries and unrecognized infections (Kesaree, et al., 1976/2 .

The congenital brain lesions include neural tube closure defects, cerebral hemisphere formation defects, aqueduct obstruction, cerebral cortex dysplasia, cerebellar dysplasias, neurocutaneous syndromes and miscellaneous anomalies (Naidich, and Zimmerman, 1987; Barkovich, and Norman, 1988/3 4 .

Hydrocephalus is the most common clinical problem encountered by pediatric neurosurgeons (Hammock, et a!., 1981/5 . Most cases of hydrocephalus are congenital in origin, which present early during infancy period. On the other hand, hydrocephalus presenting after the age of six months is less likely to be congenital and a tumor must be excluded (Fitz, 1988/6 .

Most of congenital brain lesions are well demonstrated by CT or MRI. Moreover, ultrasound is also widely used for the examination of neonate and infant brain. It is an exciting new field devoid of tissue ionization (Sutton, 1998) (7 .