Magnetic resonance imaging of brain anomalies in fetal alcohol syndrome

Postmortem studies of fetuses, infants, and young children with fetal alcohol syndrome (FAS) have demonstrated a variety of severe central nervous system (CNS) anomalies. We undertook this magnetic resonance study (1) to assess the spectrum of CNS anomalies that occur in a clinical sample of typical patients with FAS who are medically stable; and (2) to examine the relationship between CNS and facial anomalies.

Magnetic resonance imaging was performed on a series of 10 patients (4 children, 3 adolescents, and 3 adults) who met criteria for FAS. We systematically evaluated each scan for brain anomalies and compared total brain tissue volume with that of healthy child, adolescent, and adult control subjects.

Six patients had some type of midline anomaly, ranging from partial to complete callosal agenesis (three patients) to hypoplastic corpus callosum (one patient), cavum septi pellucidi (three patients), and cavum vergae (two patients). These midline anomalies were associated with a greater number of facial anomalies. Other brain anomalies identified included micrencephaly, ventriculomegaly, and hypoplasia of the inferior olivary eminences.

Patients with classic FAS have a high incidence of midline brain anomalies. This finding is consistent with the concept that the midline CNS is a developmental field that is particularly susceptible to the teratogenic effects of alcohol. Furthermore, patients with more severe facial dysmorphologic characteristics are more likely to have midline brain anomalies. In addition, we observed a high incidence of micrencephaly with a wide range of severity.