Fetal alcohol syndrome: report of three siblings

Magnetic resonance imaging of brain anomalies in fetal alcohol syndrome

OBJECTIVE

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.

METHODOLOGY

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.

RESULTS

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.

CONCLUSION

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.

Teratogenic effects of ethanol in the Quackenbush special mouse

The intragastric exposure of QS mice to alcohol both under short-term (6-day period) (3.0 g/kg, but not 1.5 g/kg, body weight/day through gestation day (GD) 7 to GD 12) and long-term (chronic) (15% ethanol in drinking water beginning several weeks before mating and continuing into pregnancy) conditions reduced the weight, size, and protein content of GD 12 embryos, and the weight of GD 18 embryos. The incidence of brachydactyly with delayed ossification was also significantly greater in embryos chronically exposed to alcohol than in controls (45% vs. 6.7%). The short-term and long-term exposure regimens produced incidences of only 1% and 5.8%, respectively, of forelimb ectrodactyly in GD 18 embryos. It was concluded that alcohol exerts embryo growth retarding effects in pregnant QS mice without inducing a high incidence of skeletal defects. Thus, the QS mouse could serve as an excellent model to resolve the mechanisms whereby alcohol induces pre- and post-natal growth restrictions during pregnancy.