Recently, advanced magnetic resonance imaging has been widely adopted to investigate altered structure and functional activities in patients with diffuse axonal injury (DAI), this patient presumed to ...be caused by shearing forces and results in significant neurological effects. However, little is known regarding cerebral temporal dynamics and its predictive ability in the clinical dysfunction of DAI.
In this study, static and dynamic fractional amplitude of low-frequency fluctuation (fALFF), an improved approach to detect the intensity of intrinsic neural activities, and their temporal variability were applied to examine the alteration between DAI patients (n = 24) and healthy controls (n = 26) at the voxel level. Then, the altered functional index was used to explore the clinical relationship and predict dysfunction in DAI patients.
We discovered that, compared to healthy controls, DAI patients showed commonly altered regions of static fALFF, and its variability was mainly located in the left cerebellum posterior lobe. Furthermore, decreased static fALFF values over the left cerebellum posterior lobe and bilateral medial frontal gyrus showed significant correlations with disease duration and Mini-Mental State Examination scores. More important, the increased temporal variability of dynamic fALFF in the left caudate could predict the severity of the Glasgow Coma Scale score in DAI patients.
Overall, these results suggested selective abnormalities in intrinsic neural activities with reduced intensity and increased variability, and this novel predictive marker may be developed as a useful indicator for future connectomics or artificial intelligence analyses.
Previous neuroimaging studies have shown that functional changes occur after acute sleep deprivation, which suggest detrimental effects of a lack of sleep on the intrinsic functional architecture of ...the brain. We aimed to identify regional resting perfusion changes in subjects with acute sleep deprivation.Thirty-three healthy subjects with habitual good sleep participated in 36 hours (2 days and 1 night) of sleep deprivation and then underwent the attention network test and pseudo-continuous arterial spin labeling scanning. Regional cerebral blood flow was used to compare cerebral perfusion before and after sleep deprivation. Correlation analyses of regional perfusion changes and scores on the attention network test were performed.Compared with the baseline (n = 20) scans, the scans of subjects after sleep deprivation (n = 26) revealed a slower response time (549.99 milliseconds vs 603.36 milliseconds; t = -2.301; P = .028) and a significantly higher lapse rate (0.88% vs 22.85%; t = -2.977; P = .006). The sleep deprivation subjects showed lower cerebral blood flow (CBF) in the left parahippocampal gyrus/fusiform cortex (pHipp/Fus), right pHipp/Fus, and right prefrontal cortex (PFC) relative to the baseline subjects (Gaussian random field correction, voxel level P < .01, and cluster level P < .05). Although no significant relationships were observed between the altered regional CBF (rCBF) values and the attention network test scores, the receiver-operating characteristic and leave-one-out cross-validation analyses revealed that significant decreases in rCBF in the bilateral pHipp/Fus and right PFC could discriminate between sleep deprivation and good sleep status.We observed that rCBF was reduced after 36 hours (2 days and 1 night) of sleep deprivation. Our preliminary findings suggest an acute vulnerability to hypoperfusion due to lack of sleep.
Disrupted white matter structure has been established in patients with diffuse axonal injury (DAI), but morphological changes in gray matter and local intrinsic activity in the short and midterm ...(before 6 months) have not been documented in DAI patients. We hypothesized that regionally selective atrophy observed in deep gray matter in the short-term and mid-term periods in patients with mild-to-moderate DAI, local atrophy, and/or dysfunction would be related to clinical characteristics. We evaluated the changes in regional density and synchronization in 18 DAI patients separately using Diffeomorphic Anatomical Registration through Exponentiated Lie algebra-enhanced voxel-based morphometry and regional homogeneity (ReHo). Compared with the controls, DAI patients showed a decreased density in the bilateral thalami and decreased ReHo values in the ventral anterior and ventral lateral nuclei of the bilateral thalami. Pearson's correlation analysis showed that decreased density in the bilateral thalami was correlated negatively with time since injury and decreased ReHo values in the ventral anterior and ventral lateral nuclei of the bilateral thalami were associated with a worsened motor assessment scale. These findings suggest that mild-to-moderate traumatic DAI within the short and midterm could lead to thalamic atrophy and that dysfunction in the bilateral thalami is associated with declining motor function. This study could potentially provide complementary evidence as an important element in longitudinal studies.
•dFC reveals the time-varying characteristic of attention networks better than sFC.•Alterations dFC pattern of attention network in RRMS are linked to lesions damage.•Adaptive mechanism that maintain ...stable interactions occur in remission RRMS patients.
Using time-variant of blood oxygenation level dependent (BOLD) signal to investigate the temporal changes in functional connectivity (FC) between key nodes may shed light on the dynamic characteristics of network. Twenty-two relapsing-remitting multiple sclerosis (RRMS) and 22 well-matched healthy control subjects (HCs) participated in this study. Previously validated key nodes of attention network seeds were defined as spherical regions of interests (ROIs); then, we captured the pattern of dFC using sliding window correlation of ROIs in the RRMS and HCs during rest. Furthermore, correlation analysis between altered dFC of paired-ROIs with clinical measures in RRMS were performed. Compared with the HCs, the RRMS showed: a certain specificity transient pattern of FC of attention network at time window levels, including decreased dFC within dorsal attention network connections of left intraparietal sulcus (LIPS)-right intraparietal sulcus (RIPS), LIPS-right frontal eye field (RFEF) and left frontal eye field (LFEF)-RIPS and ventral attention network connection of right ventral frontal cortex (RVFC)-right temporal parietal junction (RTPJ), increased dFC between dorsal and ventral attention network (connections of LIPS-RTPJ and LIPS-RVFC). Secondary analysis indicated that the dFC coefficients of the connections of LIPS-RIPS (r = −0.467, P = 0.023) and RVFC-RTPJ (r = −0.452, P = 0.043) were significant negative correlated with the total white matter lesion load. In conclusion, we found that the instantaneous configuration pattern of FC in attention network of RRMS are relate to lesions loads.
To evaluate the altered network topological properties and their clinical relevance in patients with posttraumatic diffuse axonal injury (DAI). Forty-seven participants were recruited in this study, ...underwent 3D T1-weighted and resting-state functional MRI, and had single-subject morphological brain networks (MBNs) constructed by Kullback–Leibler divergence and functional brain networks (FBNs) constructed by
Pearson
correlation measurement interregional similarity. The global and regional properties were analyzed and compared using graph theory and network-based statistics (NBS), and the relationship with clinical manifestations was assessed. Compared with those of the healthy subjects, MBNs of patients with DAI showed a higher path length (
Lp
:
P
= 0.021,
λ
:
P
= 0.011), lower clustering (
γ
:
P
= 0.002) and less small-worldness (
σ
:
P
= 0.002), but there was no significant difference in the global properties of FBNs (
P
: 0.161–0.216). For nodal properties of MBNs and FBNs, several regions showed significant differences between patients with DAI and healthy controls (HCs) (
P
< 0.05, FDR corrected). NBS analysis revealed that MBNs have more altered morphological connections in the frontal parietal control network and interhemispheric connections (
P
< 0.05). DAI-related global or nodal properties of MBNs were correlated with physical disability or dyscognition (
P
< 0.05/7, with Bonferroni correction), and the alteration of functional topology properties mediates this relationship. Our results suggested that disrupted morphological topology properties, which are mediated by FBNs and correlated with clinical manifestations of DAI, play a critical role in the short-term and medium-term phases after trauma.
Soft-tissue myoepithelioma is a rare neoplasm. It usually occurs in the distal or proximal extremities, but seldomly arises in the abdominal wall.
The patient is a 40-year-old woman who presented ...with a painless mass at the lateral abdominal wall for 6 months. Computed tomography scan revealed a lobulated and well-defined iso-density mass showing heterogeneously moderate enhancement. The mass exhibited intermediate T1 signal and obvious high T2 signal on magnetic resonance imaging.
The tumor was excised. Hematoxylin-eosin stain and immunohistochemical stain showed that the tumor was myoepithelioma.
The patient did not undergo chemotherapy and radiotherapy. No recurrence or metastasis was noted during the 1 year follow-up.
Radiologists should consider myoepithelioma in the differential diagnosis when finding a tumor in the abdominal wall.
Traumatic axonal injury (TAI) may result in the disruption of brain functional networks and is strongly associated with cognitive impairment. However, the neural mechanisms affecting the ...neurocognitive function after TAI remain to be elucidated. We collected the resting-state functional magnetic resonance imaging data from 28 patients with TAI and 28 matched healthy controls. An automated anatomical labeling atlas was used to construct a functional brain connectome. We utilized a graph theoretical approach to investigate the alterations in global and regional network topologies, and network-based statistics analysis was utilized to localize the connected networks more precisely. The current study revealed that patients with TAI and healthy controls both showed a typical small-world topology of the functional brain networks. However, patients with TAI exhibited a significantly lower local efficiency compared to healthy controls, whereas no significant difference emerged in other small-world properties (Cp, Lp, γ, λ, and σ) and global efficiency. Moreover, patients with TAI exhibited aberrant nodal centralities in some regions, including the frontal lobes, parietal lobes, caudate nucleus, and cerebellum bilaterally, and right olfactory cortex. The network-based statistics results showed alterations in the long-distance functional connections in the subnetwork in patients with TAI, involving these brain regions with significantly altered nodal centralities. These alterations suggest that brain networks of individuals with TAI present aberrant topological attributes that are associated with cognitive impairment, which could be potential biomarkers for predicting cognitive dysfunction and help understanding the neuropathological mechanisms in patients with TAI.
Objective
This study aimed to explore the interhemispheric intrinsic connectivity in traumatic axonal injury (TAI) patients.
Methods
Twenty-one patients with TAI (14 males, seven females; mean age, ...38.71 ± 15.25 years) and 22 well-matched healthy controls (16 males, six females; mean age, 38.50 ± 13.82 years) were recruited, and from them we obtained resting-state fMRI data. Interhemispheric coordination was examined using voxel-mirrored homotopic connectivity (VMHC) and seed-based functional connectivity analysis was performed.
Results
We observed significantly decreased VMHC in a number of regions in TAI patients, including the prefrontal, temporal, occipital, parietal, and posterior cingulate cortices, thalami and cerebellar posterior lobes. Subsequent seed-based functional connectivity analysis revealed widely disrupted functional connectivity between the regions of local homotopic connectivity deficits and other areas of the brain, particularly the areas subserving the default, salience, integrative, and executive systems. The lower VMHC of the inferior frontal gyrus and basal ganglia, thalamus, and caudate were significant correlated with the Beck Depression Inventory score, Clinical Dementia Rating score, and Mini-Mental State Examination score, respectively.
Conclusion
TAI is associated with regionally decreased interhemispheric interactions and extensively disrupted seed-based functional connectivity, generating further evidence of diffuse disconnection being associated with clinical symptoms in TAI patients.
Key Points
•
Traumatic axonal injury is associated with decreased interhemispheric connectivity
•
Traumatic axonal injury couples with widely disrupted functional connectivity
•
These alterations support the default, salience, integrative, and executive functions
Mild traumatic brain injury (mTBI) is characterized by structural disconnection and large-scale neural network dysfunction in the resting state. However, little is known concerning the intrinsic ...changes in local spontaneous brain activity in patients with mTBI. The aim of the current study was to assess regional synchronization in acute mTBI patients. Fifteen acute mTBI patients and 15 sex-, age-, and education-matched healthy controls (HCs) were studied. We used the regional homogeneity (ReHo) method to map local connectivity across the whole brain and performed a two-sample t-test between the two groups. Compared with HCs, patients with acute mTBI showed significantly decreased ReHo in the left insula, left precentral/postcentral gyrus, and left supramarginal gyrus (p < 0.05, AlphaSim corrected). The ReHo index of the left insula showed a positive correlation with the Mini-Mental State Examination (MMSE) scores across all acute mTBI patients (p < 0.05, uncorrected). The ReHo method may provide an objective biomarker for evaluating the functional abnormity of mTBI in the acute setting.
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