Associations between Education Years and Resting-state Functional Connectivity Modulated by APOE ε4 Carrier Status in Cognitively Normal Older Adults

Objective@#Cognitive reserve has emerged as a concept to explain the variable expression of clinical symptoms in the pathology of Alzheimer’s disease (AD). The association between years of education, a proxy of cognitive reserve, and resting-state functional connectivity (rFC), a representative intermediate phenotype, has not been explored in the preclinical phase, considering risk factors for AD. We aimed to evaluate whether the relationship between years of education and rFC in cognitively preserved older adults differs depending on amyloid-beta deposition and APOE ε4 carrier status as effect modifiers. @*Methods@#A total of 121 participants underwent functional magnetic resonance imaging, [ 18F] flutemetamol positron emission tomography-computed tomography, APOE genotyping, and a neuropsychological battery. Potential interactions between years of education and AD risk factors for rFC of AD-vulnerable neural networks were assessed with wholebrain voxel-wise analysis. @*Results@#We found a significant education years-by-APOE ε4 carrier status interaction for the rFC from the seed region of the central executive (CEN) and dorsal attention networks. Moreover, there was a significant interaction of rFC between right superior occipital gyrus and the CEN seed region by APOE ε4 carrier status for memory performances and overall cognitive function. @*Conclusion@#In preclinical APOE ε4 carriers, higher years of education were associated with higher rFC of the AD vulnerable network, but this contributed to lower cognitive function. These results contribute to a deeper understanding of the impact of cognitive reserve on sensitive functional intermediate phenotypic markers in the preclinical phase of AD.

Development of Efficient Brain Age Estimation Method Based on Regional Brain Volume From Structural Magnetic Resonance Imaging

Objective@#We aimed to create an efficient and valid predicting model which can estimate individuals’ brain age by quantifying their regional brain volumes. @*Methods@#A total of 2,560 structural brain magnetic resonance imaging (MRI) scans, along with demographic and clinical data, were obtained. Pretrained deep-learning models were employed to automatically segment the MRI data, which enabled fast calculation of regional brain volumes. Brain age gaps for each subject were estimated using volumetric values from predefined 12 regions of interest (ROIs): bilateral frontal, parietal, occipital, and temporal lobes, as well as bilateral hippocampus and lateral ventricles. A larger weight was given to the ROIs having a larger mean volumetric difference between the cognitively unimpaired (CU) and cognitively impaired group including mild cognitive impairment (MCI), and dementia groups. The brain age was predicted by adding or subtracting the brain age gap to the chronological age according to the presence or absence of the atrophy region. @*Results@#The study showed significant differences in brain age gaps among CU, MCI, and dementia groups. Furthermore, the brain age gaps exhibited significant correlations with education level and measures of cognitive function, including the clinical dementia rating sum-of-boxes and the Korean version of the Mini-Mental State Examination. @*Conclusion@#The brain age that we developed enabled fast and efficient brain age calculations, and it also reflected individual’s cognitive function and cognitive reserve. Thus, our study suggested that the brain age might be an important marker of brain health that can be used effectively in real clinical settings.

Clinical Utilization of Brain Magnetic Resonance Imaging-Based Artificial Intelligence Software in the Spectrum of Alzheimer’s Disease: Case Series / 신경정신의학

Brain magnetic resonance imaging (MRI) is a key tool for diagnosing neurodegenerative diseases such as Alzheimer’s disease (AD). However, MRI analysis by visual interpretation and reading can be time-consuming and requires specialized expertise. Brain MRI-based artificial intelligence (AI) software has been developed to aid clinicians in diagnosing and managing neurodegenerative disorders, including AD. This study demonstrates the clinical application of the AI software for volumetric analysis of brain MRI scans in patients within the AD spectrum. In the current case series, four patients with memory impairment visited the memory clinic of Yeouido St. Mary’s Hospital. They underwent a series of assessments, including automated analysis of AI-based software for brain MRI volumetric measurements. The information provided by the software was highly accurate, consistent, and was especially valuable for the early diagnosis and monitoring of disease progression. The results imply that this technology potentially aids in the early detection and management of AD, making it a valuable tool for clinicians in the diagnosis of neurodegenerative diseases.

Intrahepatic Bile Duct Dilatation Caused by Pancreatic Pseudocyst: A Case Report

Pancreatic pseudocyst can fistulize to adjacent organs such as stomach, duodenum, colon, and esophagus. Fistula formation with bile duct is rare. Reported cases of biliary involvement of pancreatic pseudocyst include fistula formation between the pancreatic pseudocyst and common bile duct. Intrahepatic bile duct dilatation caused by fistula formation with pancreatic pseudocyst is extremely rare. There are no published reports to the best of our knowledge. Herein, we report a case of intrahepatic bile duct dilatation caused by fistulous communication with a pancreatic pseudocyst. The peripheral intrahepatic bile duct surrounding the pseudocyst was dilated without involving the common bile duct. Magnetic resonance cholangiopancreatography image showed a connection between the pancreatic pseudocyst and dilated intrahepatic bile ducts with a multifocal cystic and beaded appearance.

Feasibility of Single-Shot Whole Thoracic Time-Resolved MR Angiography to Evaluate Patients with Multiple Pulmonary Arteriovenous Malformations

Objective@#To evaluate the feasibility of single-shot whole thoracic time-resolved MR angiography (TR-MRA) to identify the feeding arteries of pulmonary arteriovenous malformations (PAVMs) and reperfusion of the lesion after embolization in patients with multiple PAVMs. @*Materials and Methods@#Nine patients (8 females and 1 male; age range, 23–65 years) with a total of 62 PAVMs who underwent percutaneous embolization for multiple PAVMs and were subsequently followed up using TR-MRA and CT obtained within 6 months from each other were retrospectively reviewed. All imaging analyses were performed by two independent readers blinded to clinical information. The visibility of the feeding arteries on maximum intensity projection (MIP) reconstruction and multiplanar reconstruction (MPR) TR-MRA images was evaluated by comparing them to CT as a reference. The accuracy of TR-MRA for diagnosing reperfusion of the PAVM after embolization was assessed in a subgroup with angiographic confirmation. The reliability between the readers in interpreting the TR-MRA results was analyzed using kappa (κ) statistics. @*Results@#Feeding arteries were visible on the original MIP images of TR-MRA in 82.3% (51/62) and 85.5% (53/62) of readers 1 and 2, respectively. Using the MPR, the rates increased to 93.5% (58/62) and 95.2% (59/62), respectively (κ = 0.760 and 0.792, respectively). Factors for invisibility were the course of feeding arteries in the anteroposterior plane, proximity to large enhancing vessels, adjacency to the chest wall, pulsation of the heart, and small feeding arteries. Thirty-seven PAVMs in five patients had angiographic confirmation of reperfusion status after embolization (32 occlusions and 5 reperfusions).TR-MRA showed 100% (5/5) sensitivity and 100% (32/32, including three cases in which the feeding arteries were not visible on TR-MRA) specificity for both readers. @*Conclusion@#Single-shot whole thoracic TR-MRA with MPR showed good visibility of the feeding arteries of PAVMs and high accuracy in diagnosing reperfusion after embolization. Single-shot whole thoracic TR-MRA may be a feasible method for the follow-up of patients with multiple PAVMs.

Intracystic Hemorrhage of an Arachnoid Cyst: a Case with Prediagnostic Imaging of an Intact Cyst

Arachnoid cysts are benign lesions that are formed between the inner and outer layers of the arachnoid, accounting for 1% of all intracranial space occupying lesions. Usually, arachnoid cysts are asymptomatic. It can be symptomatic in case of complication such as intracystic hemorrhage or acute cyst expansion. We present a case of incidentally prediagnosed arachnoid cyst which undergone intracystic hemorrhage combined with ipsilateral SDH in a young male.

Intracystic Hemorrhage of an Arachnoid Cyst: a Case with Prediagnostic Imaging of an Intact Cyst

Arachnoid cysts are benign lesions that are formed between the inner and outer layers of the arachnoid, accounting for 1% of all intracranial space occupying lesions. Usually, arachnoid cysts are asymptomatic. It can be symptomatic in case of complication such as intracystic hemorrhage or acute cyst expansion. We present a case of incidentally prediagnosed arachnoid cyst which undergone intracystic hemorrhage combined with ipsilateral SDH in a young male.

Effects of electrode displacement in high-definition transcranial direct current stimulation: A computational study.

In order to understand better the ways in which cortical excitability is linked to target brain areas, this study describes the effects of focalized high-definition transcranial direct current stimulation (HD-tDCS), and investigates the way in which these effects persisted after the stimulus electrodes were displaced from the target area. We constructed a 3D volume conduction model of an anatomically realistic head that is ideal for HD-tDCS, as well as compartmental models of layer 3 and layer 5 pyramidal neurons. Using extracellular approaches, we observed stimulus-induced electric fields and simulated neuronal responses by combining stimulus-induced potential fields with pyramidal neuronal models coupled with the head model. We found that the stimulus-induced electric fields were focused on the hand-knob when the electrodes were placed directly above the target region; further, the neuronal responses varied, such that the upper parts of the dendrites were hyperpolarized, while the soma and axons were depolarized. The magnitude of the electric fields, as well as the maximum polarizations at each compartment decreased according to the displacement of the electrodes from the target area. Considerable excitability at the target area within the range of 5 mm displacement between electrodes and the target area was shown by means of stimulus-induced electric fields and membrane polarization. In conclusion, using detailed computational approaches, we discovered the ways in which excitability in the target area persisted even with increased distance from the active electrode.

Is Subtalar Joint Instability an Important Consideration When Treating Ankle Joint Instability? / 대한족부족관절학회지

Subtalar joint instability (STI) is one of the causes of persistent hindfoot pain even after treatment for ankle instability. Diagnosis of STI is often neglected because it is a poorly understood concept. However, understanding of the anatomy and injury mechanism of the subtalar joint is a prerequisite of appropriate treatment. Patients with STI usually complain of several symptoms, such as recurrent sprains or a giving way sensation and rolling over. Recently, various diagnostic tools and treatment methods have been investigated. This study was undertaken with the aim of helping clinicians by providing a comprehensive understanding of STI.

Oscillatory brain activity changes by anodal tDCS - An ECoG study on anesthetized beagles.

Measuring neuronal activity of transcranial direct current stimulation (tDCS) is essential for investigating tDCS in stimuli or after stimuli effects. The aim of this study was to investigate the oscillatory changes from anodal tDCS using electrocorticography (ECoG) on beagles. We applied 2 mA anodal tDCS and monitored the ECoG signals (32 channels, 512 Hz sampling rate) for 15 minutes in three anesthetized beagles. Then, we compared the power changes before, during, and after tDCS in six different bands (delta, theta, alpha, beta, low-gamma, and mid-gamma bands). The significantly increasing oscillatory changes from the mid-frequency bands (theta, alpha, and beta bands) to the high-frequency bands (low-gamma and mid-gamma bands) were observed. The results suggest that anodal tDCS may modulate high-frequency bands in the focal area of the cortex, which is relevant to electroencephalogram (EEG) studies.

Treatment of a Huge Aneurysmal Bone Cyst of the Talus through a Segmental Bone Graft of the Tricortical Bone: A Case Report / 대한족부족관절학회지

An aneurysmal bone cyst (ABC) can occur in many parts of the human body, but a primary ABC of the talus is extremely rare. ABCs are benign, but aggressively growing tumors that usually occur in the first two decades of life. Patients mainly complain of pain, limited movement of the involved joint or a palpable mass. Pain may worsen suddenly because of pathological fractures. If not treated properly, ABC has a risk of local recurrence, followed by the destruction of the joint and a significant functional deficit. While the complete removal of the bone tumor is essential, it is also important to treat the resultant bone defect after removal. The talus has an important part to play in weight-bearing. Therefore, an appropriate bone graft is required for large bone defects that occur after an ABC removal from the talus. We report a primary ABC of the talus in a 28-year-old male that was treated by curettage and a bone pillar pattern graft of autologous tricortical iliac crest bone. The patient had an excellent functional outcome with early weight-bearing, and there was no recurrence at 16 months of follow-up.

Development of Random Forest Algorithm Based Prediction Model of Alzheimer’s Disease Using Neurodegeneration Pattern

Objective@#Alzheimer’s disease (AD) is the most common type of dementia and the prevalence rapidly increased as the elderly population increased worldwide. In the contemporary model of AD, it is regarded as a disease continuum involving preclinical stage to severe dementia. For accurate diagnosis and disease monitoring, objective index reflecting structural change of brain is needed to correctly assess a patient’s severity of neurodegeneration independent from the patient’s clinical symptoms. The main aim of this paper is to develop a random forest (RF) algorithm-based prediction model of AD using structural magnetic resonance imaging (MRI). @*Methods@#We evaluated diagnostic accuracy and performance of our RF based prediction model using newly developed brain segmentation method compared with the Freesurfer’s which is a commonly used segmentation software. @*Results@#Our RF model showed high diagnostic accuracy for differentiating healthy controls from AD and mild cognitive impairment (MCI) using structural MRI, patient characteristics, and cognitive function (HC vs. AD 93.5%, AUC 0.99; HC vs. MCI 80.8%, AUC 0.88). Moreover, segmentation processing time of our algorithm (<5 minutes) was much shorter than of Freesurfer’s (6–8 hours). @*Conclusion@#Our RF model might be an effective automatic brain segmentation tool which can be easily applied in real clinical practice.

Far-infrared rays enhance mitochondrial biogenesis and GLUT3 expression under low glucose conditions in rat skeletal muscle cells

Far-infrared rays (FIR) are known to have various effects on atoms and molecular structures within cells owing to their radiation and vibration frequencies. The present study examined the effects of FIR on gene expression related to glucose transport through microarray analysis in rat skeletal muscle cells, as well as on mitochondrial biogenesis, at high and low glucose conditions. FIR were emitted from a bio-active material coated fabric (BMCF). L6 cells were treated with 30% BMCF for 24 h in medium containing 25 or 5.5 mM glucose, and changes in the expression of glucose transporter genes were determined. The expression of GLUT3 (Slc2a3) increased 2.0-fold (p < 0.05) under 5.5 mM glucose and 30% BMCF. In addition, mitochondrial oxygen consumption and membrane potential (ΔΨm) increased 1.5- and 3.4-fold (p < 0.05 and p < 0.001), respectively, but no significant change in expression of Pgc-1a, a regulator of mitochondrial biogenesis, was observed in 24 h. To analyze the relationship between GLUT3 expression and mitochondrial biogenesis under FIR, GLUT3 was down-modulated by siRNA for 72 h. As a result, the ΔΨm of the GLUT3 siRNA-treated cells increased 3.0-fold (p < 0.001), whereas that of the control group increased 4.6-fold (p < 0.001). Moreover, Pgc-1a expression increased upon 30% BMCF treatment for 72 h; an effect that was more pronounced in the presence of GLUT3. These results suggest that FIR may hold therapeutic potential for improving glucose metabolism and mitochondrial function in metabolic diseases associated with insufficient glucose supply, such as type 2 diabetes.

Far-infrared rays enhance mitochondrial biogenesis and GLUT3 expression under low glucose conditions in rat skeletal muscle cells

Far-infrared rays (FIR) are known to have various effects on atoms and molecular structures within cells owing to their radiation and vibration frequencies. The present study examined the effects of FIR on gene expression related to glucose transport through microarray analysis in rat skeletal muscle cells, as well as on mitochondrial biogenesis, at high and low glucose conditions. FIR were emitted from a bio-active material coated fabric (BMCF). L6 cells were treated with 30% BMCF for 24 h in medium containing 25 or 5.5 mM glucose, and changes in the expression of glucose transporter genes were determined. The expression of GLUT3 (Slc2a3) increased 2.0-fold (p < 0.05) under 5.5 mM glucose and 30% BMCF. In addition, mitochondrial oxygen consumption and membrane potential (ΔΨm) increased 1.5- and 3.4-fold (p < 0.05 and p < 0.001), respectively, but no significant change in expression of Pgc-1a, a regulator of mitochondrial biogenesis, was observed in 24 h. To analyze the relationship between GLUT3 expression and mitochondrial biogenesis under FIR, GLUT3 was down-modulated by siRNA for 72 h. As a result, the ΔΨm of the GLUT3 siRNA-treated cells increased 3.0-fold (p < 0.001), whereas that of the control group increased 4.6-fold (p < 0.001). Moreover, Pgc-1a expression increased upon 30% BMCF treatment for 72 h; an effect that was more pronounced in the presence of GLUT3. These results suggest that FIR may hold therapeutic potential for improving glucose metabolism and mitochondrial function in metabolic diseases associated with insufficient glucose supply, such as type 2 diabetes.

Intraosseous Malignant Peripheral Nerve Sheath Tumor of Multiple Bones of the Midfoot: A Case Report / 대한족부족관절학회지

Malignant peripheral nerve sheath tumors (MPNSTs) usually arise in soft tissues; they are rarely found in the bone. This paper reports a case of MPNST in the foot and ankle joint involving the distal tibia, talus, calcaneus, navicular, medial intermediate, and lateral cuneiform, cuboid, and 2nd to 4th metatarsal bone. Palliative treatment was performed. The authors encountered a patient with intraosseous MPNST of the midfoot who presented with nonspecific clinical and radiologic findings. This case shows that a high index of suspicion and a histopathology examination, including immunohistochemistry, will be necessary for an accurate diagnosis.

Intraosseous Malignant Peripheral Nerve Sheath Tumor of Multiple Bones of the Midfoot: A Case Report / 대한족부족관절학회지

Malignant peripheral nerve sheath tumors (MPNSTs) usually arise in soft tissues; they are rarely found in the bone. This paper reports a case of MPNST in the foot and ankle joint involving the distal tibia, talus, calcaneus, navicular, medial intermediate, and lateral cuneiform, cuboid, and 2nd to 4th metatarsal bone. Palliative treatment was performed. The authors encountered a patient with intraosseous MPNST of the midfoot who presented with nonspecific clinical and radiologic findings. This case shows that a high index of suspicion and a histopathology examination, including immunohistochemistry, will be necessary for an accurate diagnosis.