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Advanced Neurology Cortical thickness and regional homogeneity in CSVD

diameter; (2) cerebral hemorrhage; (3) internal carotid with a Philips 3.0-T scanner (Philips Medical Systems,
artery or vertebral artery stenosis (>50%) or coronary Netherlands). The multimodal MRI scans included:
atherosclerosis heart disease; (4) other neurological (1) The high-resolution T1-weighted turbo gradient
disorders, such as Alzheimer’s disease (AD), Parkinson’s echo sequence, with repetition time (TR) = 9.8 ms, flip
disease, epilepsy, or mental disorders; (6) serious physical angle (FA) = 8°, echo time (TE) = 4.6 ms, field of view
illnesses, such as cancer; and (7) any conditions that (FOV) = 250 mm × 250 mm, number of slices = 192,
interfere with cognitive examination, such as blindness, acquisition matrix = 256 × 256, and thickness = 1.0 mm,
deafness-muteness, or physical disability. (2) the FLAIR sequence, with TR = 4500 ms, TE = 333 ms,
The inclusion criteria for the NC group were as follows: time interval (TI) = 1600 ms, number of slices = 200, voxel
(1) Age between 50 and 80 years; (2) no clinical symptoms size = 0.95 mm × 0.95 mm × 0.95 mm, and acquisition
of CSVD or MRI presentative characteristics of CSVD; and matrix = 270 × 260, and (3) the blood oxygen level
(3) normal cognitive function. dependent (BOLD) sequence, with TR = 2000 ms, TE = 30
ms, number of slices = 35, voxel size = 3.00 mm × 3.00 mm
The Montreal Cognitive Assessment (MoCA) test × 4.00 mm, and acquisition matrix = 64 × 62.
was used to define whether the participants had CI. The
education-adjusted cutoff values for the MoCA were ≤19 2.4. Structural MRI data
for 1–6 years of education, ≤24 for 7–12 years of education, 2.4.1. Preprocessing of T1-weighted MRI
and <26 for >12 years of education . Participants with
[18]
[19]
MoCA scores lower than education-adjusted norms were FreeSurfer (version 6.0 for Linux) was used to process
classified as having CI. According to MoCA scores, CSVD the T1-weighted MRI scans. The detailed steps included:
patients were divided into two groups, the CSVD-CI group (1) Automated Talairach transformation, (2) subcortical
(n = 106) and the CSVD-no-CI group (n = 77). segmentation of the WM and the deep gray matter (GM)
volumetric structures, (3) intensity normalization , (4)
[20]
2.2. Clinical assessments segmentation of the brain tissue, including GM, WM, and
All participants underwent the same standardized cerebrospinal fluid (CSF), (5) surface modeling for the GM/
[23]
neuropsychological test protocols, including the Hamilton WM and GM/CSF borders [21,22] , (6) surface inflation ,
Depression Rating Scale (HAMD) which evaluates (7) registration to a spherical atlas that utilized individual
depression, Hamilton Anxiety Rating Scale (HAMA) which cortical folding patterns to match cortical geometry across
[24]
evaluates anxiety, MoCA (Beijing version August 26, 2006, participants , (8) ROI establishment of the cerebral
translated by Wang and Xie, www.mocatest.org), Auditory cortex on the basis of gyral and sulcal structure [25,26] ,
Verbal Learning Test (AVLT), Digit Span Test (DST), Boston and (9) cortical thickness calculation. Both intensity
Naming Test (BNT), and Stroop Color Word Test (SCWT). and continuity information of the whole 3D MR image
The AVLT, DST, BNT, and SCWT were used to conduct a volumes in the segmentation and deformation procedures
detailed cognitive assessment involving multiple cognitive were used during the process to produce representations of
domains. The AVLT is a widely used test of verbal memory cortical thickness. At each vertex, the cortical thickness was
and contains three main indicators: AVLT immediate recall calculated as the closest distance from the inner surface to
[27]
(AVLTIR), AVLT-short time delay recall (AVLTSTDR), the outer surface . The Desikan–Killiany (DK) atlas was
[28]
and AVLT-long time delay recall (AVLTLTDR). The chosen for consistent brain measurements , because the
DST is a simple method for evaluating working memory, boundaries it contains were suitable for the FreeSurfer
executive function, and attention. There are two parts in classifier.
the DST: DST-forward (DSF) and DST-backward (DSB).
To conduct a more comprehensive memory evaluation, 2.4.2. Cortical thickness analysis
the Wechsler Memory Scale-Visual Reproduction (VR) Glmfit (analytic software in FreeSurfer) was used to
was also conducted for visual memory assessment and the analyze the whole-brain vertex-wise surface-based
scores of VR-Copy (VRC), VR-Immediate Recall (VRIR), cortical thickness. To improve the signal-to-noise ratio,
and VR-Delayed Recall (VRDR) were statistically analyzed. a 10 mm full width half maximum (FWHM) Gaussian
The congruent part of the SCWT was used to evaluate spatial smoothing kernel was performed before analysis.
processing speed, and the incongruent part of SCWT was A different offset same slope method was used to build a
used to assess executive function. general linear model (GLM), which was a built-in analysis
method in glmfit. Because of the variability in participants’
2.3. MRI data acquisition demographic characteristics (sex, age, and years of
The MRI scanning was conducted at the Affiliated Drum education) served as the covariances for the GLM analysis.
Tower Hospital of Nanjing University Medical School Multiple comparison corrections were performed using

Volume 1 Issue 1 (2022) 3 https://doi.org/10.36922/an.v1i1.48