Publications by authors named "Yong An Chung"

Article Synopsis
  • Tumor-to-tumor metastasis is a rare occurrence, where cancer spreads from one tumor to another.
  • A 67-year-old woman with lung cancer underwent a PET/CT scan that showed an unusual pelvic mass, raising concerns about metastasis.
  • Surgical analysis confirmed that the pelvic mass contained metastatic lung adenocarcinoma within a struma ovarii, highlighting this unusual case of tumor-to-tumor metastasis.
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Background: Compared to functional magnetic resonance imaging (fMRI), source localization of a scalp-recorded electroencephalogram (EEG) provides higher temporal resolution and frequency synchronization to better understand the potential neurophysiological origins of disrupted functional connectivity (FC) in major depressive disorder (MDD). The present study aimed to investigate EEG-sourced measures to examine the FC in drug-free patients with MDD.

Method: Resting-state 32-channel EEG were recorded in 84 drug-free patients with MDD and 143 healthy controls, and the cortical source signals were estimated.

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Aims: Schizophrenia, a debilitating mental disorder, is characterized by persistent negative symptoms such as avolition and anhedonia. Currently, there are no effective treatments available for these symptoms. Thus, our study aims to assess the efficacy of online high-definition transcranial direct current stimulation (online HD-tDCS) in addressing the negative symptoms of schizophrenia, utilizing a double-blind, randomized, sham-controlled trial design.

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Our aim was to evaluate the effect of prophylactic pilocarpine on acute salivary symptoms after radioactive iodine (RAI) therapy in patients with differentiated thyroid cancer. We enrolled 88 patients (76 women and 12 men; mean age: 47 years; range: 20-74 years) with differentiated thyroid cancer who received RAI. Patients were divided into pilocarpine (51 patients) and control (37 patients) groups.

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Article Synopsis
  • Researchers are studying a method called tDCS to help improve certain symptoms in schizophrenia, especially negative ones like lack of motivation.
  • They found that doing a specific brain task, called the 2-back task, can effectively activate an important part of the brain (left DLPFC) in patients with these symptoms.
  • The researchers think that combining this brain task with tDCS might be a powerful way to treat these negative symptoms, and they plan to test it in a controlled trial.
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  • A study evaluated the effectiveness of SPECT/CT radiomics parameters to distinguish between enchondromas and atypical cartilaginous tumors (ACTs) in long bones, analyzing data from 49 patients.
  • Using LASSO regression for feature selection, two key radiomics features were identified: zone-length non-uniformity for zone (ZLNU) and coarseness for neighborhood grey-level difference.
  • The results indicated that higher ZLNU was a significant indicator for diagnosing ACTs, achieving sensitivity and specificity rates of 85.0% and 58.3% in training data, and 83.3% and 90.9% in test data.
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There has been an increasing demand for robotic coil positioning during repetitive transcranial magnetic stimulation (rTMS) treatment. Accurate coil positioning is crucial because rTMS generally targets specific brain regions for both research and clinical application with other reasons such as safety, consistency and reliability and individual variablity. Some previous studies have employed industrial robots or co-robots and showed they can more precisely stimulate the target cortical regions than traditional manual methods.

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: Attentional dysfunction has long been viewed as one of the fundamental underlying cognitive deficits in schizophrenia. There is an urgent need to understand its neural underpinning and develop effective treatments. In the process of attention, neural oscillation has a central role in filtering information and allocating resources to either stimulus-driven or goal-relevant objects.

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EEG studies indicated that schizophrenia patients had increased resting-state theta-band functional connectivity, which was associated with negative symptoms. We recently published the first study showing that theta (6 Hz) transcranial alternating current stimulation (tACS) over left prefrontal and parietal cortices during a working memory task for accentuating frontoparietal theta-band synchronization (in-phase theta-tACS) reduced negative symptoms in schizophrenia patients. Here, we hypothesized that in-phase theta-tACS can modulate theta-band large-scale networks connectivity in schizophrenia patients.

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Reduced left-lateralized electroencephalographic (EEG) frontal alpha asymmetry (FAA), a biomarker for the imbalance of interhemispheric frontal activity and motivational disturbances, represents a neuropathological attribute of negative symptoms of schizophrenia. Unidirectional high-frequency transcranial random noise stimulation (hf-tRNS) can increase the excitability of the cortex beneath the stimulating electrode. Yet, it is unclear if hf-tRNS can modulate electroencephalographic FAA in patients with schizophrenia.

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Schizophrenia is associated with increased resting-state large-scale functional network connectivity in the gamma frequency. High-frequency transcranial random noise stimulation (hf-tRNS) modulates gamma-band endogenous neural oscillations in healthy individuals through the application of low-amplitude electrical noises. Yet, it is unclear if hf-tRNS can modulate gamma-band functional connectivity in patients with schizophrenia.

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Article Synopsis
  • This study looked at how breast cancer patients with brown adipose tissue (BAT) activity in their scans survived compared to those without BAT.
  • Only 2% of the patients had BAT activity, but those with it had fewer cancer recurrences over time.
  • The results suggest that having BAT might help patients survive longer without their cancer getting worse, so more research is needed to understand why this happens.
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Background And Objective: As a novel non-invasive human brain stimulation method, transcranial focused ultrasound (tFUS) is receiving growing attention due to its superior spatial specificity and depth penetrability. Since the focal point of tFUS needs to be fixated precisely to the target brain region during stimulation, a critical issue is to identify and maintain the accurate position and orientation of the tFUS transducer relative to the subject's head. This study aims to propose the entire framework of tFUS stimulation integrating the methods previously proposed by the authors for tFUS transducer configuration optimization and a subject-specific 3D-printed helmet, and to validate this complete setup in a human behavioral neuromodulation study.

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  • - Cervical dystonia is a disorder affecting brain networks, and deep brain stimulation (DBS) targeting the globus pallidus may help by altering these abnormal brain activities.
  • - In a study of 9 patients with idiopathic cervical dystonia, SPECT scans were used to track regional cerebral blood flow (rCBF) changes before and after DBS, showing significant activity changes in key brain areas.
  • - Results indicated that rCBF increased in some areas and decreased in others three months after DBS, correlating with a notable reduction in dystonia symptoms as measured by the Toronto Western Spasmodic Torticollis Rating Scale.
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  • This study explored the relationship between regional cerebral blood flow (rCBF) and neuropsychiatric symptoms in early Alzheimer’s disease (AD) through SPECT scans of 59 patients.* -
  • Results showed that different neuropsychiatric symptom domains (affective, apathy, hyperactivity, and psychotic) correlated with varying levels of rCBF in specific brain regions, particularly in the prefrontal cortex.* -
  • The findings suggest both common and distinct brain perfusion patterns linked to neuropsychiatric symptoms in early AD, indicating a need for further research with larger samples to validate the results.*
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Background: Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder that causes chronic dizziness interfering with daily activities. Transcranial direct current stimulation (tDCS) has reportedly improved dizziness in patients with phobic postural vertigo in an open-label trial. However, no randomized, double-blind, sham-controlled study has been conducted on its therapeutic efficacy in PPPD.

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Article Synopsis
  • Preclinical studies hint that low-intensity transcranial focused ultrasound (tFUS) could help Alzheimer's patients by potentially opening the blood-brain barrier (BBB), reducing amyloid buildup, and enhancing cognitive function.
  • In a clinical trial with eight AD patients, tFUS was applied to the right hippocampus, but no BBB opening was observed; however, immediate recall and recognition memory showed significant improvements.
  • PET scans revealed increased cerebral glucose metabolism in the right hippocampus, correlating with better memory performance, indicating short-term cognitive benefits from tFUS despite the lack of BBB opening; further research is needed to confirm efficacy and safety.
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Clinical and radiological findings on neurosyphilis are fairly non-specific and there is a paucity of functional neuroimaging studies on neurosyphilis other than case reports and case series. The purpose of this study was to investigate brain perfusion abnormalities in patients with neurosyphilis. Four HIV-negative neurosyphilis patients and 4 healthy controls underwent clinical evaluation, brain technetium-99m ethyl cysteinate dimer (99mTc-ECD) single-photon emission computed tomography (SPECT) imaging, and neuropsychological assessments which included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Clinical Dementia Rating-Sum of Boxes (CDR-SOB), and Global Deterioration Scale (GDS).

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Negative symptoms represent an unmet need for schizophrenia treatment. The effect of theta frequency transcranial alternating current stimulation (theta-tACS) applied during working memory (WM) tasks on negative symptoms has not been demonstrated as of yet. We conducted a randomized, double-blind, sham-controlled trial of 36 stabilized schizophrenia patients, randomized to receive either twice daily, 6 Hz 2 mA, 20 min sessions of in-phase frontoparietal tACS or sham for five consecutive weekdays.

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Growing evidence indicates that type 2 diabetes mellitus (T2DM)-related cognitive dysfunction may develop in the early stage of the disease and is often accompanied by hippocampal structural alterations. In the current study, we investigated volume and shape alterations of the hippocampus at a subregional level in patients with T2DM. With the use of high-resolution brain structural images that were obtained from 30 T2DM patients with less than 5 years of disease duration and 30 healthy individuals, volumetric and shape analyses were performed.

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Transcranial focused ultrasound (tFUS) is a promising non-invasive technique for treating neurological and psychiatric disorders. One of the challenges for tFUS is the disruption of wave propagation through the skull. Consequently, despite the risks associated with exposure to ionizing radiation, computed tomography (CT) is required to estimate the acoustic transmission through the skull.

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Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disease characterized by persistent dizziness, unsteadiness, and/or non-spinning vertigo, and is the most common vestibular syndrome in young adults. A stiffened postural control strategy, shift to reliance on visual over vestibular information, and hypervigilance to the environment have been suggested as possible pathophysiological mechanisms of PPPD. However, the exact mechanisms remain unclear.

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Article Synopsis
  • A pilot study examined the effects of low-intensity transcranial focused ultrasound (tFUS) on patients with Alzheimer's disease (AD), focusing on its impact on the blood-brain barrier, cerebral glucose metabolism, and cognition.
  • The study involved four AD patients receiving tFUS targeting the hippocampus, and assessments included MRI, PET scans, and cognitive tests before and after the procedure.
  • Results indicated improved glucose metabolism in specific brain regions and mild cognitive improvements, with no adverse effects reported, suggesting potential benefits of tFUS in AD that warrant further research.
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The incidence of neurosyphilis has declined since effective penicillin therapy against was introduced. However, the diagnosis of neurosyphilis early in the disease course is very important in order to select appropriate antibiotic therapy. We report brain MRI, SPECT with Tc-99m ECD, and PET with F-18 FDG findings before antibiotic therapy in a neurosyphilis patient with neurological symptoms.

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