Reduced fractional anisotropy in projection, association, and commissural fiber networks in neonates with prenatal methamphetamine exposure

Coupling analysis of diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) with abnormal cerebral blood flow in methamphetamine-dependent patients and its application in machine-learning-based classification

BACKGROUND

Diffusion tensor imaging (DTI) analysis along the perivascular space (ALPS) index is currently widely employed to evaluate the neurophysiological activity in various neuropsychiatric disorders. However, there remains a scarcity of studies assessing the DTI-ALPS index in individuals with methamphetamine (MA) dependence. Recent studies on animals have demonstrated a significant correlation between glymphatic activity and alterations in cerebral blood flow (CBF). Hence, investigating the DTI-ALPS index and its coupling with CBF could yield novel insights for MA-dependent patients.

METHODS

In this study, we employed DTI and arterial spin labeling to investigate the ALPS index and CBF in 46 MA-dependent patients and 46 control subjects. By using DTI-ALPS, we evaluated a comprehensive diffusivity parameter that encompasses contributions from both the perivascular spaces and fiber tracts. Furthermore, a two-sample t-test was employed to assess inter-group differences. Partial correlation analysis was used to evaluate the correlations of the ALPS index with age, clinical parameters, and CBF, respectively. In addition, a causal mediation analysis was conducted to explore whether CBF mediates the causal relationship between MA-related clinical characteristics and the ALPS index. Finally, a support vector machine (SVM) was trained by the ALPS-related features and CBF features for the purpose of distinguishing MA-dependent subjects from control subjects.

RESULTS

Compared to the control group, the MA-dependent group presented a decreased ALPS index, particularly in the right hemisphere. Moreover, increased diffusivities were observed along the projection fibers in the right Y-axis and the association fibers in the right Z-axis, while the AI of the diffusivity along the Z-axis association fibers decreased in patients with MA dependence. The study observed a tight coupling between the ALPS index and CBF in MA-dependent patients, and revealed significant positive correlations between the ALPS index and CBF in specific brain regions, including the right precentral sulcus, right anterior transverse collateral sulcus, left postcentral sulcus, left superior parietal lobule, left superior occipital sulcus and transverse occipital sulcus, and right temporal pole. The causal mediation analysis suggested that CBF partially mediated the alteration of the ALPS index induced by the duration of MA consumption in MA-dependent patients. Additionally, CBF/ALPS ratio was lower in the MA-dependent group compared to the controls group. An SVM trained with the ALPS-related indicators and CBF indicators achieved classification accuracy, sensitivity, specificity, and kappa values of 93.31 % ± 5.72 %, 91.56 % ± 9.14 %, 95.05 % ± 7.91 % and 86.60 % ± 11.44 %, respectively, for identifying patients with MA dependence.

CONCLUSIONS

The study identified abnormal ALPS index, which has the potential to be a meaningful imaging marker for MA-dependent patients. The findings emphasized the strong coupling between the ALPS index and CBF in MA-dependent individuals, providing indirect imaging references for future research on the relationship between the glymphatic system and CBF. Moreover, the abnormal ALPS-related features and CBF features hold promise as valuable features for developing highly effective classification models.

Maternal use of methamphetamine alters cardiovascular function in the adult offspring

Methamphetamine is one of the most commonly used illicit drugs during pregnancy. Most studies investigating the impact of maternal use of methamphetamine on children have focused on neurological outcomes. In contrast, cardiovascular outcomes in these children have not been characterized. Recent studies in rodents provide evidence that prenatal exposure to methamphetamine induces changes in cardiac gene expression, changes in the heart's susceptibility to ischemic injury, and changes in vascular function that may increase the risk of developing cardiovascular disorders later in life. Importantly, these changes are sex-dependent. This review summarizes our current understanding of how methamphetamine use during pregnancy impacts the cardiovascular function of adult offspring and highlights gaps in our knowledge of the potential cardiovascular risks associated with prenatal exposure to methamphetamine.

Brain structural connectome in neonates with prenatal opioid exposure

Introduction

Infants with prenatal opioid exposure (POE) are shown to be at risk for poor long-term neurobehavioral and cognitive outcomes. Early detection of brain developmental alterations on neuroimaging could help in understanding the effect of opioids on the developing brain. Recent studies have shown altered brain functional network connectivity through the application of graph theoretical modeling, in infants with POE. In this study, we assess global brain structural connectivity through diffusion tensor imaging (DTI) metrics and apply graph theoretical modeling to brain structural connectivity in infants with POE.

Methods

In this prospective observational study in infants with POE and control infants, brain MRI including DTI was performed before completion of 3 months corrected postmenstrual age. Tractography was performed on the whole brain using a deterministic fiber tracking algorithm. Pairwise connectivity and network measure were calculated based on fiber count and fractional anisotropy (FA) values. Graph theoretical metrics were also derived.

Results

There were 11 POE and 18 unexposed infants included in the analysis. Pairwise connectivity based on fiber count showed alterations in 32 connections. Pairwise connectivity based on FA values showed alterations in 24 connections. Connections between the right superior frontal gyrus and right paracentral lobule and between the right superior occipital gyrus and right fusiform gyrus were significantly different after adjusting for multiple comparisons between POE infants and unexposed controls. Additionally, alterations in graph theoretical network metrics were identified with fiber count and FA value derived tracts.

Conclusion

Comparisons show significant differences in fiber count in two structural connections. The long-term clinical outcomes related to these findings may be assessed in longitudinal follow-up studies.

Methamphetamine exposure during pregnancy: A meta-analysis of child developmental outcomes

This paper examines developmental outcomes for children prenatally exposed to methamphetamine through maternal use. PSYCHINFO, Scopus, PubMed and ERIC databases were systematically searched for studies up to December 2020. The search identified 38 articles examining cognitive, language, motor and neuroanatomical outcomes in children from birth to 16 years. Study quality was appraised using the Newcastle Ottawa Quality Assessment Scale. Findings from neuroanatomical studies suggested that prenatal methamphetamine exposure may alter whole brain microstructure and reduce subcortical volumes across multiple brain regions. Meta-analysis of 14 studies using a random-effects model revealed associations between exposure and poorer intellectual functioning (Cohen's d = 0.89, 95 % CI: 0.47-1.30), problem solving skills (Cohen's d = 0.82, 95 % CI: 0.07 -1.56), short-term memory (Cohen's d = 0.91, 95 % CI: 0.38-1.43), and language development (Cohen's d = 0.74, 95 % CI: 0.30-1.18). These results emphasise the significant impact of intrauterine methamphetamine exposure across multiple areas of child development, noting that limited total sample size, heterogeneity between studies and control for confounds suggested further studies are required. There is a need for further intervention studies to identify effective prevention and harm minimisation approaches.

Effects of Prenatal Methamphetamine Exposure on the Developing Human Brain: A Systematic Review of Neuroimaging Studies

Methamphetamine (MA) can cross the placenta in pregnant women and cause placental abruption and developmental alterations in offspring. Previous studies have found prenatal MA exposure effects on the social and cognitive performance of children. Recent studies reported some alterations in structural and functional magnetic resonance imaging (MRI) of prenatal MA-exposed offspring. In this study, we aimed to investigate the effect of prenatal MA exposure on brain development using recently published structural, metabolic, and functional MRI studies. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed and SCOPUS databases for articles that used each brain imaging modality in prenatal MA-exposed children. Seventeen studies were included in this study. We investigated brain imaging alterations using 17 articles with four different modalities, including structural MRI, diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), and functional MRI (fMRI). The participants’ age range was from infancy to 15 years. Our findings demonstrated that prenatal MA exposure is associated with macrostructural, microstructural, metabolic, and functional deficits in both cortical and subcortical areas. However, the most affected regions were the striatum, frontal lobe, thalamus and the limbic system, and white matter (WM) fibers connecting these regions. The findings from our study might have valuable implications for targeted treatment of neurocognitive and behavioral deficits in children with prenatal MA exposure. Even so, our results should be interpreted cautiously due to the heterogeneity of the included studies in terms of study populations and methods of analysis.