A longitudinal study of cognitive functioning in patients with classical galactosaemia, including a cohort treated with oral uridine.

Existing longitudinal data on patients with classical galactosaemia suggests that neurocognitive functioning is impaired and, in isolated case reports, may show a decline in performance over time. The present study explored whether there are long-term changes in cognitive abilities in patients with galactosaemia and whether oral uridine can improve neurocognitive performance. Thirty-five patients (18 males, 17 females), 29 of whom received oral uridine powder at 150 mg/kg per day (divided dose, three times daily), were evaluated over a 2-5-year period with the Woodcock-Johnson Revised Cognitive Abilities Test, three academic achievement tests, and the Beery Test of Visual Motor Integration. Results showed that the uridine cohort and a comparison group that received only dietary restriction made small gains in cognitive performance over the treatment period and the size of the gains did not differ significantly. Seven subjects who started uridine prior to the age of 14 months did not differ significantly in their cognitive test scores at an average age of 3.5 years from a group of older children who had begun treatment at 4.5 years of age. These results provide no support for any developmental or uridine-treatment-related change in cognitive functioning for this sample of galactosaemic subjects.