Analysis of cerebral gray matter structure in multiple sclerosis and neuromyelitis optica / 解剖学报

Objective The volume and cortical thickness of gray matter in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) were compared and analyzed by voxel⁃based morphometry (VBM) and surface⁃based morphometry (SBM), and the differences in the structural changes of gray matter in the two diseases were discussed. Methods A total of 21 MS patients, 16 NMO patients and 19 healthy controls were scanned by routine MRI sequence. The data were processed and analyzed by VBM and SBM method based on the statistical parameter tool SPM12 of Matlab2014a platform and the small tool CAT12 under SPM12. Results Compared with the normal control group (NC), after Gaussian random field (GRF) correction, the gray matter volume in MS group was significantly reduced in left superior occipital, left cuneus, left calcarine, left precuneus, left postcentral, left central paracentral lobule, right cuneus, left middle frontal, left superior frontal and left superior medial frontal (P<0. 05). After family wise error (FWE) correction, the thickness of left paracentral, left superiorfrontal and left precuneus cortex in MS group was significantly reduced (P<0. 05). Compared with the NC group, after GRF correction, the gray matter volume in the left postcentral, left precentral, left inferior parietal, right precentral and right middle frontal in NMO group was significantly increased (P<0. 05). In NMO group, the volume of gray matter in left middle occipital, left superior occipital, left inferior temporal, right middle occipital, left superior frontal orbital, right middle cingulum, left anterior cingulum, right angular and left precuneus were significantly decreased (P<0. 05). Brain regions showed no significant differences in cortical thickness between NMO groups after FWE correction. Compared with the NMO group, after GRF correction, the gray matter volume in the right fusiform and right middle frontal in MS group was increased significantly(P<0. 05). In MS group, the gray matter volume of left thalamus, left pallidum, left precentral, left middle frontal, left middle temporal, right pallidum, left inferior parietal and right superior parietal were significantly decreased (P<0. 05). After FWE correction, the thickness of left inferiorparietal, left superiorparietal, left supramarginal, left paracentral, left superiorfrontal and left precuneus cortex in MS group decreased significantly (P<0. 05). Conclusion The atrophy of brain gray matter structure in MS patients mainly involves the left parietal region, while NMO patients are not sensitive to the change of brain gray matter structure. The significant difference in brain gray matter volume between MS patients and NMO patients is mainly located in the deep cerebral nucleus mass.

Multi-index analysis of regional brain activity in patients with Alzheimer's disease during resting state / 解剖学报

Objective To investigate the spontaneous neural activity in the brain of patients with Alzheimer' s disease (AD) used 3 indicators of resting state-functional magnetic resonance (rs-fMRI) amplitude of low frequency fluctuation (ALFF), fractional amplitude of low frequency fluctuation (fALFF) and percentage amplitude fluctuation (PerAF). Methods Totally 36 clinically diagnosed AD patients and 40 healthy volunteers were scanned by fMRI in resting state respectively. ALFF, fALFF and PerAF were used to calculate and compare the changes of brain regions between the two groups. Results Compared with the normal control group, mALFF value in AD group increased significantly in bilateral caudate nucleus, medial frontal gyrus, superior frontal gyrus, gyrus rectus, anterior cingulate gyrus, olfactive cortex, left middle frontal gyrus and inferior frontal gyrus (P<0. 05). mALFF values decreased significantly in the right middle temporal gyrus, inferior temporal gyrus, inferior occipital gyrus, middle occipital gyrus, bilateral calcarine, cuneus, lingual gyrus, superior occipital gyrus, vermis, precuneus and other regions (P<0. 05). In AD group, mfALFF value of right inferior temporal gyrus, anterior cerebellar lobe, fusiform gyrus, left superior frontal gyrus, medial frontal gyrus, middle frontal gyrus, inferior frontal gyrus, gyrus rectus and anterior cingulate gyrus increased significantly (P<0. 05); mfALFF values decreased significantly in bilateral lingual gyrus, left calcarine, cuneus, superior occipital gyrus, middle occipital gyrus and vermis (P<0. 05). In AD group, mPerAF value increased significantly in bilateral gyrus rectus, anterior cingulate gyrus, medial frontal gyrus, left superior frontal gyrus, caudate nucleus, middle frontal gyrus, inferior frontal gyrus, olfactive cortex and insula (P<0. 05); mPerAF values decreased significantly in bilateral calcarine, cuneus, superior occipital gyrus, lingual gyrus, precuneus, left fusiform gyrus, inferior occipital gyrus, right superior parietal lobule, angular gyrus, middle temporal gyrus, inferior temporal gyrus and middle occipital gyrus (P < 0. 05). Conclusion The default mode network (DMN) and visual network of AD patients are characterized by abnormal brain activity, with the most significant neural activity in the prefrontal cortex and visual cortex.

Superficial veins located in dorsolateral aspect of hemispheres on susceptibility-weighted imaging / 解剖学报

Objective To investigate whether physiological asymmetry of normal bilateral superficial veins located in dorsolateral aspects of hemispheres is existed on susceptibility-weighted imaging (SWI). Methods There were 45 healthy young volunteers in this study. After exclusion of intracranial lesions by using common brain magnetic resonance imaging examination, they underwent SWI examination. We observed the number, diameter and signal intensity of superficial veins located in dorsolateral aspects of hemispheres according to the images of SWI on transverse sections through the centrum semiovale, trunk of corpus callosum, splenium of corpus callosum, and superior colliculus. Results The frequencies of asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on transverse sections through the centrum semiovale, trunk of corpus callosum, splenium of corpus callosum, and superior colliculus were 20.0%, 37.8%, 35.6% and 26.7%, respectively. The frequencies of mild asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on above transverse sections were 17.8%, 31.1%, 31.1% and 24.4% respectively, and the frequencies of prominent asymmetry were 2.2%, 6.7%, 4.4% and 2.2%, respectively. According to chi square test, there was no gender difference in asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres. Conclusion SWI technique was used to show the physiological asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres on different transverse sections. Most of them are mild. Therefore, when cerebrovascular disease occurs, if transverse sections of images by SWI show asymmetry of the bilateral superficial veins located in dorsolateral aspects of hemispheres, the possibility of physiological phenomenon is needed to take into consideration.