The contributions of Dr. Kathleen K. Sulik to fetal alcohol spectrum disorders research and prevention

Gestational choline supplementation ameliorates T-maze reversal learning deficits induced by first trimester binge alcohol exposure in weanling lambs

In rodent models of fetal alcohol spectrum disorders (FASD), cognitive deficits are implicated in impaired T-maze spatial reversal learning. Rat studies have indicated supplemental administration of choline during the developmental period of alcohol exposure can ameliorate spatial reversal deficits. This study tested whether beneficial effects of prenatal choline supplementation could be confirmed in a sheep model of binge exposure in the first trimester equivalent. Two hypotheses were tested: 1) alcohol exposure would produce deficits in reversal of a T-maze position discrimination; and 2) gestational dietary supplementation of choline would ameliorate those deficits. Mated ewes were assigned to one of seven groups-a normal control (NC) group or one of six infusion treatment groups: saline control (SC; isotonic saline), saline control plus choline (SC-CH; isotonic saline plus choline, 10 mg/kg administered orally throughout each day of gestation), binge alcohol (BA; 1.75 g/kg alcohol per infusion day), binge alcohol plus choline (BA-CH; 1.75 g/kg/day alcohol plus choline), heavy binge alcohol (HBA; 2.5 g/kg/day alcohol), or heavy binge alcohol plus choline (HBA-CH; 2.5 g/kg/day alcohol plus choline). The alcohol infusions modeled a weekend binge drinking pattern over the first trimester-equivalent (gestational day 4-41). T-maze training began at 12 weeks of age, with daily sessions occurring 5 days/week. Lambs were given five days of habituation training, followed by five days of position discrimination training (3 trials per daily session, intertrial interval of 3 h, reinforced side randomly assigned across subjects). Lambs were then given 10 days of training on the reversal task. There was no difference among groups during acquisition. Alcohol impaired reversal learning, and choline supplementation mitigated these deficits in the HBA-CH group. These results suggest that maternal dietary choline supplementation can ameliorate or prevent some impairments of executive function in a sheep model of FASD.

Review of Evidence for Environmental Causes of Uveal Coloboma

Uveal coloboma is a condition defined by missing ocular tissues and is a significant cause of childhood blindness. It occurs from a failure of the optic fissure to close during embryonic development,and may lead to missing parts of the iris, ciliary body, retina, choroid, and optic nerve. Because there is no treatment for coloboma, efforts have focused on prevention. While several genetic causes of coloboma have been identified, little definitive research exists regarding the environmental causes of this condition. We review the current literature on environmental factors associated with coloboma in an effort to guide future research and preventative counseling related to this condition.

Thinner retinal nerve fibre layer in young adults with foetal alcohol spectrum disorders

BACKGROUND/AIMS

Ophthalmological abnormalities such as ptosis, strabismus, refractive errors and optic nerve hypoplasia have been reported in foetal alcohol spectrum disorders (FASD). The purpose of this study was to investigate whether retinal thickness, retinal nerve fibre layer (RNFL) and optic disc area (ODA) differ between individuals with FASD and healthy controls.

METHODS

Best-corrected visual acuity (BCVA) in terms of logarithm of the minimum angle of resolution (logMAR), refraction, and fundus variables measured by optical coherence tomography were obtained from 26 young adults with FASD (12 women, median age 23 years) and 27 controls (18 women, median age 25 years).

RESULTS

The total thickness of the peripapillary RNFL was significantly lower in the FASD group than in controls; median (range) in the right/left eye was 96.5 (60-109)/96 (59-107) µm in the FASD group and 105 (95-117)/103 (91-120) µm among controls (p=0.001 and p=0.0001). Macular RNFL and retinal thickness measurements from the FASD group were also lower in most of the nine ETDRS areas, except for the central parts. Median (range) BCVA in the best eye was 0.00 (-0.1-0.3) logMAR in the FASD group and 0.00 (-0.2-0.0) logMAR in controls (p=0.001). No significant differences between the groups were found regarding ODA or refraction.

CONCLUSION

Significant differences in peripapillary and macular RNFL, retinal thickness and BCVA were found in this group of young adults with FASD compared with healthy controls. However, there were no differences in the size of the optic disc.

Clinical presentation, diagnosis, and management of fetal alcohol spectrum disorder

Although prenatal alcohol exposure causes craniofacial anomalies, growth retardation, neurological abnormalities, cognitive impairment, and birth defects, fetal alcohol spectrum disorder is underdiagnosed. Global prevalence of fetal alcohol spectrum disorder is 0·77%, with a higher prevalence of 2-5% in Europe and North America, highlighting the need for increased diagnosis and treatment. However, diagnosis remains challenging because of the poor reliability of self-reported maternal drinking histories, an absence of sensitive biomarkers, and the infrequency of diagnostic dysmorphic facial features among individuals with fetal alcohol spectrum disorder. Different diagnostic systems and disagreements over criteria have slowed progress in the diagnosis and management of the disorder. Neuroimaging shows abnormalities in brain structure, cortical development, white matter microstructure, and functional connectivity in individuals with fetal alcohol spectrum disorder. These abnormalities modify developmental trajectories and are associated with deficits in cognition, executive function, memory, vision, hearing, motor skills, behaviour, and social adaptation. Promising trials of nutritional interventions and cognitive rehabilitation therapies are underway, with the aim of treating cognitive deficits in fetal alcohol spectrum disorders.