The effects of prenatal methamphetamine on the resting state networks of the developing brain
Date
2020-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Introduction
Prenatal exposure to methamphetamine is known to cause structural brain anomalies as well as cognitive-behavioral changes which often persist till adulthood. There has not been any resting state functional connectivity studies of prenatal methamphetamine exposure (PME) in children, particularly during critical periods of development when formal initiation of learning occurs.
Methodology
This case-controlled cohort study investigated temporal changes in cognition of methamphetamine exposed (n=20) and unexposed (n=23) children at ages 6 and 8 years. Cognitive performance was assessed using KABC-II scales, KABC-II Atlantis and Atlantis delayed scales, the Boston Naming Test, and the Grooved Pegboard “correct” insertion time. Group differences in whole- brain resting state functional connectivity to six seeds in the striatum, as well as in connectivity between each of the seeds, were investigated in a subset of 9 exposed and 9 unexposed children. The whole- brain relationship between striatal connectivity and cognitive scores was assessed at baseline (6 years), as was the relationship between change in between-seed connectivity and change in cognitive test performance with age.
Results
Hierarchical regression analysis found that PME has significant detrimental effects on overall cognitive performance; Total KABC Scaled score (p= 0.036), KABC-II-NVI Atlantis (p=0.028), Atlantis delayed (p=0.044 ), Boston Naming Test (p= 0.001) and the Grooved Pegboard “correct” insertion time for the non-dominant hand (p=0.047 ), although some improvement was noted on re-evaluation 2 years later. Whole-brain connectivity at the 6 years’ time point did not show group differences for any of the striatal seeds. When striatal seed connectivity was analyzed as a moderator of neurocognitive function at the 6 years’ time point across the entire sample, increased scores during performance of the Total KABC-NVI-II was associated with connectivity between the dorsal caudate seeds and the left inferior parietal lobe; a slower completion of the Grooved Pegboard insertion with the dominant hand, was associated with decreased connectivity between the superior ventral striatal seeds and the left supplementary motor area, right and left supramarginal as well as ventral rostral putamen (VRP) seed with the right supplementary motor area. When assessing for the change in resting state functional connectivity in association with cognitive test performance over time, performance of the Beery VMI -Visual test was associated with decreasing connectivity between the dorsal caudate (DC) and the dorsal rostral putamen (DRP) and this was likely to be more significant for the exposed than the non- exposed children. Conclusion This study contributes to the growing evidence of PME neurotoxicity on the developing brain. Although significant detrimental effects on overall cognitive performance were evident in the exposed group, there was no real differences in functional connectivity related to PME. Preliminary evidence from this study suggests that cognition improvement may ensue with development, a finding we postulate as most likely attributable to compensatory neuroplasticity (rewiring of corticostriatal networks). Further studies are required to evaluate the prognostic role of resting state fMRI in PME, especially in relation to the optimal age of imaging and the effects on neuroplasticity.
"Geen opsomming bskikbaar"
"Geen opsomming bskikbaar"
Description
Thesis (MPhil)--Stellenbosch University, 2020.
Keywords
Substance abuse in pregnancy, Methamphetamine, Structural brain anomalies, UCTD