Data from: Microstructure and cerebral blood flow within white matter of the human brain: a TBSS analysis

Background: White matter (WM) fibers connect different brain regions and are critical for proper brain function. However, little is known about the cerebral blood flow in WM and its relation to WM microstructure. Recent improvements in measuring cerebral blood flow (CBF) by means of arterial spin labeling (ASL) suggest that the signal in white matter may be detected. Its implications for physiology needs to be extensively explored. For this purpose, CBF and its relation to anisotropic diffusion was analyzed across subjects on a voxel-wise basis with tract-based spatial statistics (TBSS) and also across white matter tracts within subjects. Methods: Diffusion tensor imaging and ASL were acquired in 43 healthy subjects (mean age = 26.3 years). Results: CBF in WM was observed to correlate positively with fractional anisotropy across subjects in parts of the splenium of corpus callosum, the right posterior thalamic radiation (including the optic radiation), the forceps major, the right inferior fronto-occipital fasciculus, the right inferior longitudinal fasciculus and the right superior longitudinal fasciculus. Furthermore, radial diffusivity correlated negatively with CBF across subjects in similar regions. Moreover, CBF and FA correlated positively across white matter tracts within subjects. Conclusion: The currently observed findings on a macroscopic level might reflect the metabolic demand of white matter on a microscopic level involving myelination processes or axonal function. However, the exact underlying physiological mechanism of this relationship needs further evaluation

TBSS_FA_CBF_N43data

N=43 files for TBSS analysis of FA and CBF dat

Scatterplot between FA and CBF values.

<p>Each symbol represents data from one WM region averaged over all subjects. The error bars indicate the standard deviation over all subjects. The mean FA over all subjects was positively correlated with mean CBF of all subjects across WM regions (Pearson’s <i>r</i> = 0.32, <i>p</i> = 0.02). The legend on the right side refers to the different WM regions.</p

Summary of the regions including volume (mm), FA, CBF (ml/100g/min) and <i>t</i> values where a significant positive relationship between CBF and FA values was found across subjects.

<p>The values were extracted by masking the respective skeletons with the JHU WM labels and tracts and the significant regions (TFCE corrected <i>p</i> < 0.05). The values are listed as mean ± standard deviation.</p

Microstructure and Cerebral Blood Flow within White Matter of the Human Brain: A TBSS Analysis - Fig 2

<p>A) Regions of significant negative correlation between CBF and RD values overlaid on the MNI template at x = 60, y = 72, z = 89 (TFCE corrected <i>p</i> < 0.05). Regions of significant positive correlation between CBF and RD across subjects are indicated in red (tbss_fill was used here which “thickened” the TBSS results). B) The plot displays the mean RD and CBF values, extracted from each subject in the significant regions indicated in red.</p

The scatterplot displays the mean RD, AD and MD as a function of the mean FA values across subjects, all extracted from the significant regions indicated in red in Fig 1.

<p>A) The correlation between FA and RD was negative (Pearson’s <i>r</i> = -0.93, <i>p</i> < 0.0001). B) The correlation between FA and AD was positive (Pearson’s <i>r</i> = 0.55, <i>p</i> < 0.001). C) The correlation between FA and MD was negative (Pearson’s <i>r</i> = -0.66, <i>p</i> < 0.0001).</p

Alterations of White Matter Integrity Related to the Season of Birth in Schizophrenia: A DTI Study

<div><p>In schizophrenia there is a consistent epidemiological finding of a birth excess in winter and spring. Season of birth is thought to act as a proxy indicator for harmful environmental factors during foetal maturation. There is evidence that prenatal exposure to harmful environmental factors may trigger pathologic processes in the neurodevelopment, which subsequently increase the risk of schizophrenia. Since brain white matter alterations have repeatedly been found in schizophrenia, the objective of this study was to investigate whether white matter integrity was related to the season of birth in patients with schizophrenia. Thirty-four patients with schizophrenia and 33 healthy controls underwent diffusion tensor imaging. Differences in the fractional anisotropy maps of schizophrenia patients and healthy controls born in different seasons were analysed with tract-based spatial statistics. A significant main effect of season of birth and an interaction of group and season of birth showed that patients born in summer had significantly lower fractional anisotropy in widespread white matter regions than those born in the remainder of the year. Additionally, later age of schizophrenia onset was found in patients born in winter months. The current findings indicate a relationship of season of birth and white matter alterations in schizophrenia and consequently support the neurodevelopmental hypothesis of early pathological mechanisms in schizophrenia.</p></div

Interaction of group and season of birth.

<p>(A) Summer-born patients with schizophrenia showed reduced FA values compared to winter-born patients with schizophrenia within the areas indicated in red. (B) The plot shows the mean FA values within the significant TBSS clusters highlighted in red in summer and winter-born patients. For the purpose of comparison, mean FA values extracted from the same areas indicated in red were additionally displayed for summer and winter-born controls. The TBSS images show results at <i>p</i><0.03 corrected for multiple comparisons.</p

Interaction of group and season of birth shows reduced FA values in summer-born patients compared to winter-born patients with schizophrenia.

<p>MNI, Montreal Neurological Institute; FA, fractional anisotropy; SD, standard deviation.</p

Demographic data of patients with schizophrenia and controls, separated for seasons of birth.

<p>Except for age range, gender, migration, social adversity and cannabis use, values are represented as mean ± standard deviation. M, male; F, female; PANSS, Positive and Negative Syndrome Scale; PANSS-P, subscale for positive symptoms; PANSS-N, subscale for negative symptoms; PANSS-T, total score of PANSS, CPZ, chlorpromazine equivalents.</p