Mariyemuguli Reheman1, Naying He1, Sagar Buch2, Huang Pei 3, Peng Wu4, Shengdi Chen3, Haacke E. Mark2,5, and Fuhua Yan1
1Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 2Department of Radiology, Wayne State University, Detroit, MI, United States, 3Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, Shanghai, China, 4Philips Healthcare, Shanghai, China, 5Department of Neurology, Wayne State University, Detroit, MI, United States
Synopsis
Keywords: Parkinson's Disease, White Matter
Motivation: White matter damage has been known to accumulate prior to the onset of white matter hyperintensity, but there is currently no way to calculate the extent of damage.
Goal(s): Quantification of high-water content regions in Parkinson's patients based on proton spin density maps provides a new biomarker for mapping tissue damage and interpretation of WMH evolution.
Approach: Distribution of high-water content regions and WMH were mapped for Parkinson patients with different cognitive levels. Heatmaps were created for groups.
Results: High water content regions were mainly distributed along the ventricular wall. Water content and WMH correlated with CSF volumes with significant differences between groups.
Impact: Segmentation of the high-water
content regions based on proton spin density maps provides the ability to
interpret WMH
evolution and provide a new potential biomarker to guide the early detection.
These effects were dramatically seen in Parkinson’s patients with dementia.
Introduction
White matter damage is the result of ischemia,
inflammation and degeneration of the lateral ventricular wall. The ventricular
walls of the anterior and posterior horns of the lateral ventricles are
subjected to increased mechanical tension, and this tension is further amplified
with age-related ventricular enlargement, resulting in ventricular wall
thinning, brain-fluid barrier dysfunction, and subsequent CSF leakage into the
brain parenchyma [1-3]. Studies
based on diffusion tensor imaging (DTI) fractional anisotropy (FA) have shown
that normal-appearing white matter already begin to suffer from impaired fiber
integrity [4-7]. Cerebral
white matter hyperintensity (WMH) is characterized by the accumulation of
pathologic changes in the white matter before the onset of WMH, but to date
there is no method to assess the damage at any given time. Using STAGE
(Strategic Acquisition of Gradient Echo) imaging[8],
proton spin density maps can be generated. The proton spin density map can be
used to identify the high-water content regions. Regions of abnormally
high-water content can serve as new biomarkers of localized tissue damage and
characterize Parkinson’s disease (PD) patients.Methods
A total of 23 healthy controls (HCs) and 138 PD patients
were scanned at 3T using T1W, FLAIR and STAGE. The STAGE data were used to
create proton spin density (water content) maps. Patients were divided into 3
groups based on their MoCA score, without dementia (NC), with dementia (PDD),
and with mild cognitive impairment (MCI). The T2 FLAIR data was used to segment
the WMH lesions and the proton spin density map was used to further segment
high water content regions using a threshold of 0.85. The probability heat maps
of WMH lesions and high-water content regions across for groups were generated
by registering the subject data to the MNI atlas. The data were processed by
SPM12, FSL, advanced normalization tool and Freesurfer. Tukey`s HSD were used
for the statistical tests comparing the volumes of total WMH and high-water
content regions in white matter for different groups. Results
Figure 1 illustrates the segmentations of the total WMH and high-water content
regions in six subjects. High water content regions were distributed along the
ventricular wall, and the highest occurrence of high-water content lesions was
in the anterior and posterior corners of the lateral ventricles and in the
septum (Figure 2). Figure 3 displays that the difference in the
volume of high-water regions between patients with PDD and HC, PDNC, and MCI,
respectively, was statistically significant (P < 0.001). There was no
difference between HC and PDD but there was a difference between PDD and PDNC
(P=0.0139) and MCI (P=0.0182) and MCI (P=0.0182). Water content positively
correlated with CSF volumes with significant differences between groups with
different cognitive levels (rs= 0.49 with p < 0.001), as seen in Figure
4.Discussion
This study found that the distribution of high-water
content regions around the white matter and the total CSF were significantly
correlated. This suggests a relationship between the ventricles and the
development of WMH. It may be caused by CSF gradually leaking into the adjacent
brain parenchyma. The differences between various cognitive groups suggest that
in healthy individuals, the self-protective mechanism protects adjacent tissue,
while in PD patients, due to oxidative stress, mitochondrial dysfunction of
ventricular cells and other pathologic alterations, the high-water content
regions are unable to regress, and progresses gradually into WMHs[9,
10].
Therefore, volumetric quantification of the high-water content region holds
significance for the study of WMH lesion evolution. In summary, segmentation of
the high-water content regions based on proton spin density maps provides the
ability to interpret WMH lesion evolution along the lateral ventricular wall.
Mapping this information longitudinally could provide a new potential biomarker
to guide the early detection and possible future interventions to prevent white
matter damage. These effects were most dramatically seen in the Parkinson’s
patients with severe cognitive impairment.Acknowledgements
This
work was supported, in part, by the National Natural Science Foundation of
China (grant number: 82271954, 81971576); Chinese National Science &
Technology Pillar Program (grant number: 2022YFC2009900/2022YFC2009905) and the
Innovative Research Team of High-level Local Universities in Shanghai.References
1. Caçoilo, A., et al., A multiphysics model to predict periventricular white matter hyperintensity growth during healthy brain aging. Brain Multiphys, 2023. 5.
2. Visser, V.L., H. Rusinek, and J. Weickenmeier, Peak ependymal cell stretch overlaps with the onset locations of periventricular white matter lesions. Sci Rep, 2021. 11(1): p. 21956.
3. Shook, B.A., et al., Ventriculomegaly associated with ependymal gliosis and declines in barrier integrity in the aging human and mouse brain. Aging Cell, 2014. 13(2): p. 340-50.
4. Maillard, P., et al., White matter hyperintensity penumbra. Stroke, 2011. 42(7): p. 1917-22.
5. Maillard, P., et al., White matter hyperintensities and their penumbra lie along a continuum of injury in the aging brain. Stroke, 2014. 45(6): p. 1721-6.
6. de Groot, M., et al., Changes in normal-appearing white matter precede development of white matter lesions. Stroke, 2013. 44(4): p. 1037-42.
7. Muñoz Maniega, S., et al., Spatial Gradient of Microstructural Changes in Normal-Appearing White Matter in Tracts Affected by White Matter Hyperintensities in Older Age. Front Neurol, 2019. 10: p. 784.
8. Wang, Y., et al., STrategically Acquired Gradient Echo (STAGE) imaging, part II: Correcting for RF inhomogeneities in estimating T1 and proton density. Magn Reson Imaging, 2018. 46: p. 140-150.
9. Jiménez, A.J., et al., Structure and function of the ependymal barrier and diseases associated with ependyma disruption. Tissue Barriers, 2014. 2: p. e28426.
10. Subramaniam, S.R. and M.F. Chesselet, Mitochondrial dysfunction and oxidative stress in Parkinson's disease. Prog Neurobiol, 2013. 106-107: p. 17-32.