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Jani Saunavaara

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2 papers

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YNICL Journal 2020 Journal Article

Newborn amygdalar volumes are associated with maternal prenatal psychological distress in a sex-dependent way

Satu J. Lehtola
Jetro J. Tuulari
Noora M. Scheinin
Linnea Karlsson
Riitta Parkkola
Harri Merisaari
John D. Lewis
Vladimir S. Fonov

Maternal psychological distress during pregnancy (PPD) 1 1 prenatal psychosocial distress has been associated with changes in offspring amygdalar and hippocampal volumes. Studies on child amygdalae suggest that sex moderates the vulnerability of fetal brains to prenatal stress. However, this has not yet been observed in these structures in newborns. Newborn studies are crucial, as they minimize the confounding influence of postnatal life. We investigated the effects of maternal prenatal psychological symptoms on newborn amygdalar and hippocampal volumes and their interactions with newborn sex in 123 newborns aged 2–5 weeks (69 males, 54 females). Based on earlier studies, we anticipated small, but statistically significant effects of PPD on the volumes of these structures. Maternal psychological distress was measured at gestational weeks (GW) 2 2 gestational weeks 14, 24 and 34 using Symptom Checklist-90 (SCL-90, anxiety scale) 3 3 Symptom Checklist-90 and Edinburgh Postnatal Depression Scale (EPDS) 4 4 Edinburgh Postnatal Depression Scale questionnaires. Newborn sex was found to moderate the relationship between maternal distress symptoms at GW 24 and the volumes of left and right amygdala. This relationship was negative and significant only in males. No significant main effect or sex-based moderation was found for hippocampal volumes. This newborn study provides evidence for a sex-dependent influence of maternal psychiatric symptoms on amygdalar structural development. This association may be relevant to later psychopathology.

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YNIMG Journal 2019 Journal Article

Test-retest reliability of Diffusion Tensor Imaging metrics in neonates

Harri Merisaari
Jetro J. Tuulari
Linnea Karlsson
Noora M. Scheinin
Riitta Parkkola
Jani Saunavaara
Tuire Lähdesmäki
Satu J. Lehtola

Diffusion tensor imaging (DTI) has been widely used in children and adults to study the microstructural features of the brain. Its use in neonate brains has been limited. Neonate brains are almost completely unmyelinated, and this together with the tendency for babies to move during a scanning session may affect the reliability of the measurements. Here we divided a 96 direction acquisition into three segments, and analysed the intra scan test-retest reliability for pairs of segments. Each segment was subjected to a rigorous quality control, and from the surviving data we chose 25 diffusion encoding directions from each segment, and assessed the pairwise reliability of the most common DTI metrics. This pairwise reliability was assessed for data from 86 infants. We used tract-based spatial statistics (TBSS), voxelwise and ROI analysis schemes, to see potential differential effects of analysis strategy and post processing on the obtained DTI metrics. We found that intra class correlation coefficient (ICC) values were generally high (ICC > 0. 80). Residual motion in the data, after quality control, was not found to associate with the diffusion metrics. The results indicate that DTI metrics from neonate data can be reliable, even at relatively low angular resolution that are common for neonate scans. The results lend confidence to the use of neonate DTI data in cross sectional and longitudinal analyses in brain white matter skeleton. Future studies should assess the reliability of fiber tracking techniques in neonate data.

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