AGENESIS OF THE CORPUS-CALLOSUM WITH NEON ATAL MANIFESTATIONS

Four boys and four girls with agenesis of the corpus callosum were adm itted to the Neonatal Unit of the Caen Hospital between March 1989 and December 1993. The diagnosis was suspected based on prenatally-diagno sed ventricular dilation, hypotonia, or dysmorphism. A transfontanella r ultrasonogram established the diagnosis of partial (n = 3) or comple te (n = 5) agenesis of the corpus callosum. In two of the eight patien ts, additional abnormalities were seen on magnetic resonance imaging a nd computed tomography studies of the brain. The electroencephalogram was normal or showed nonspecific alterations. Two patients had evidenc e of hearing loss on the brainstem auditory evoked response study. Hyp opituitarism was diagnosed in one patient after an episode of hypoglyc emia. Routine tests done to look for other malformations detected a ca rdiac defect in three cases, a urinary tract defect in one patient, an d skeletal defects in one patient. The karyotype was normal in all eig ht patients. The brain defect was fatal in two cases. The six survivor s demonstrated evidence of developmental retardation after a follow-up of 14 to 45 months. Agenesis of the corpus callosum is a congenital d efect in which all or part of the corpus callosum is absent. Partial f orms usually affect the posterior part of the corpus callosum. The dia gnosis is made by prenatal and neonatal imaging studies. Diagnosis at a young age and presence of other brain defects may be indicative of a n adverse neurologic prognosis.