Interhemispheric transfer in children with early-treated phenylketonuria
M L Gourovitch1, S Craft, S B Dowton
1Washington University, Department of Pediatrics, St. Louis, MO 63130.
Journal of Clinical and Experimental Neuropsychology
|June 1, 1994
Summary
Children with early-treated phenylketonuria (PKU) show delayed brain signal transfer between hemispheres, linked to myelination issues. This impacts interhemispheric connections, particularly from the left to the right hemisphere.
Area of Science:
- Neuroscience
- Metabolic disorders
- Developmental psychology
Background:
- Phenylketonuria (PKU) is a genetic metabolic disorder affecting amino acid metabolism.
- PKU is associated with brain catecholamine depletion and impaired myelination.
- Neuropsychological deficits are known in early-treated PKU (ETPKU), but myelination effects are understudied.
Purpose of the Study:
- To investigate the impact of impaired myelination on interhemispheric connections in children with ETPKU.
- To assess interhemispheric transfer time in ETPKU patients compared to control groups.
Main Methods:
- A manual reaction time paradigm was used to measure interhemispheric transfer time.
- Participants included 14 children with ETPKU, 22 with ADHD, and 48 typically developing children.
- The reaction time paradigm was previously validated in patients with callosal agenesis.
Main Results:
- Children with ETPKU exhibited significantly slowed interhemispheric transfer from the left to the right hemisphere.
- The degree of transfer slowing correlated with patient age and phenylalanine levels at birth.
- These findings suggest disrupted interhemispheric connections due to abnormal myelination in ETPKU.
Conclusions:
- Abnormal myelination in ETPKU disrupts the development of interhemispheric connections.
- Left hemisphere projections appear particularly vulnerable to myelination deficits in ETPKU.
- This research highlights potential neurological consequences of metabolic disorders on brain development.
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