Whole-Body Muscle Magnetic Resonance Imaging in 81 Patients with Spinal and Bulbar Muscular Atrophy: A Prospective Study.

OBJECTIVE: Spinal and bulbar muscular atrophy (SBMA) is characterized by slow, progressive bulbar and limb muscle weakness; however, the pattern of progression of muscle fat infiltration remains unclear. We assessed the progression of muscle involvement in 81 patients with SBMA using whole-body muscle magnetic resonance imaging (MRI), alongside clinical and laboratory findings. METHODS: This prospective study included patients with genetically confirmed SBMA who underwent whole-body muscle MRI. We analyzed muscle fat infiltration and the pattern of involved muscles using cluster analysis, visualizing the sequential progression of fat infiltration. Muscle clusters demonstrated correlation with clinical scales and laboratory findings. Additionally, linear regression analysis was performed to identify the MRI section most strongly associated with 6-minute walk test (6MWT). RESULTS: We included 81 patients with SBMA (age = 54.3 years). After categorizing the patients into 6 clusters based on the pattern of muscle fat infiltration, we observed that muscle involvement began in the posterior calf and progressed to the posterior thigh, pelvis, trunk, anterior thigh, medial thigh, anterior calf, and upper extremity muscles. These muscle clusters correlated significantly with disease duration (τ = 0.47, p < 0.001), 6MWT (τ = -0.49, p < 0.001), and serum creatinine level (τ = -0.46, p < 0.001). The whole-body MRI indicated the thigh as the section most significantly correlated with 6MWT. INTERPRETATION: We used whole-body muscle MRI to determine the sequential progression of the fat infiltration in SBMA. Our findings may enable the identification of objective and reliable imaging outcome measures in the study of the natural history or future clinical trials of SBMA. ANN NEUROL 2024;95:596-606.

Neurofilament light chain as a biomarker in neuromyelitis optica spectrum disorder: a comprehensive review and integrated analysis with glial fibrillary acidic protein.

BACKGROUND: In the context of neuromyelitis optica spectrum disorder (NMOSD), there are several measures that serve as a biomarker. However, each of the methods has the intrinsic limitations. While neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) have emerged as an additional biomarker for NMOSD, a thorough investigation of their role remains incomplete. Our aim is to provide a comprehensive review of the current literature regarding NfL and GFAP as a biomarker and explore their potential utility in NMOSD. METHODS: We performed a comprehensive search using PubMed and Google Scholar to identify peer-reviewed articles investigating NfL and GFAP as a biomarker in NMOSD. RESULTS: Our search identified 13 relevant studies. NfL consistently showed promise in distinguishing NMOSD patients from healthy individuals, although it had limited specificity in distinguishing NMOSD from other demyelinating diseases. NfL offered certain advantages over GFAP, notably its ability to predict disability worsening during attacks. In contrast, GFAP provided valuable insight, particularly in distinguishing NMOSD from multiple sclerosis and identifying clinical relapses. In addition, GFAP showed predictive potential for future attacks. Some studies even suggested that NfL may serve as an indicator of treatment response in NMOSD. CONCLUSIONS: NfL and GFAP hold promise as biomarkers for NMOSD, demonstrating their usefulness in distinguishing patients from healthy individuals, assessing disease severity, and possibly reflecting treatment response. However, it is important to recognize that NfL and GFAP may, at some point, have different roles.

Reversible cerebral vasoconstriction syndrome in Guillain-Barre syndrome: a case report and literature review.

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by transient constriction of cerebral arteries, leading to severe headache and potential complications. The association between RCVS and Guillain-Barre syndrome (GBS) is rare and poorly understood and warrants further investigation. METHODS: A detailed case of RCVS in a patient with GBS was presented, followed by a comprehensive literature review. PubMed, Embase, and Google Scholar were searched for relevant cases and studies. RESULTS: The case involved a 62-year-old woman with GBS who developed RCVS. The literature review identified three additional reported cases. RCVS in GBS primarily affected middle-aged women and presented with a variety of neurological symptoms. Neuroimaging showed reversible vasoconstriction in the cerebral arteries, along with other complications such as posterior reversible encephalopathy syndrome, subarachnoid hemorrhage, and infarcts. While the treatment for GBS consisted mainly of intravenous immunoglobulin, specific treatments for RCVS remain unclear. CONCLUSIONS: The coexistence of RCVS and GBS is a rare occurrence. RCVS in GBS may result from the disruption of cerebral vascular tone regulation, possibly influenced by GBS-related dysautonomia and consequent high blood pressure. Recognizing RCVS in GBS patients is critical for appropriate management.

Impact of COVID-19 Infection and Its Association With Previous Vaccination in Patients With Myasthenia Gravis in Korea: A Multicenter Retrospective Study.

BACKGROUND: During the coronavirus disease 2019 (COVID-19) pandemic, patients with myasthenia gravis (MG) were more susceptible to poor outcomes owing to respiratory muscle weakness and immunotherapy. Several studies conducted in the early stages of the COVID-19 pandemic reported higher mortality in patients with MG compared to the general population. This study aimed to investigate the clinical course and prognosis of COVID-19 in patients with MG and to compare these parameters between vaccinated and unvaccinated patients in South Korea. METHODS: This multicenter, retrospective study, which was conducted at 14 tertiary hospitals in South Korea, reviewed the medical records and identified MG patients who contracted COVID-19 between February 2022 and April 2022. The demographic and clinical characteristics associated with MG and vaccination status were collected. The clinical outcomes of COVID-19 infection and MG were investigated and compared between the vaccinated and unvaccinated patients. RESULTS: Ninety-two patients with MG contracted COVID-19 during the study. Nine (9.8%) patients required hospitalization, 4 (4.3%) of whom were admitted to the intensive care unit. Seventy-five of 92 patients were vaccinated before contracting COVID-19 infection, and 17 were not. During the COVID-19 infection, 6 of 17 (35.3%) unvaccinated patients were hospitalized, whereas 3 of 75 (4.0%) vaccinated patients were hospitalized (P < 0.001). The frequencies of ICU admission and mechanical ventilation were significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.019 and P = 0.032, respectively). The rate of MG deterioration was significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.041). Logistic regression after weighting revealed that the risk of hospitalization and MG deterioration after COVID-19 infection was significantly lower in the vaccinated patients than in the unvaccinated patients. CONCLUSION: This study suggests that the clinical course and prognosis of patients with MG who contracted COVID-19 during the dominance of the omicron variant of COVID-19 may be milder than those at the early phase of the COVID-19 pandemic when vaccination was unavailable. Vaccination may reduce the morbidity of COVID-19 in patients with MG and effectively prevent MG deterioration induced by COVID-19 infection.

Evaluation of the safety profile of COVID-19 vaccines in patients with MS, NMOSD, and MOGAD.

INTRODUCTION: Vaccination against the coronavirus disease 2019 (COVID-19) is recommended for patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, vaccine safety in these patients taking immunotherapeutic agents is unclear as they were not included in the vaccine trials. OBJECTIVES: To evaluate the safety of COVID-19 vaccines in patients with MS, NMOSD, and MOGAD. METHODS: We reviewed the medical records of MS, NMOSD, and MOGAD patients at the Keimyung University Dongsan Hospital. Information regarding vaccination schedules and adverse events was collected. RESULTS: A total of 56 patients (19, 22, and 15 patients with MS, NMOSD, and MOGAD, respectively) with a median age of 48.18 ± 15.72 years (range, 16-81 years) were included. Of them, 42 (75.0%) were female. In total, 76.8% (43/56) of all patients were vaccinated, and the vaccination rate was the highest for NMOSD patients (81.8%) and the lowest for MS patients (68.4%). All vaccinated patients were administered mRNA vaccines at least once in single or multiple vaccination doses. Only 3 of 43 (7.0%) vaccinated patients experienced clinical relapse following vaccination. Facial sensory changes with a brainstem lesion developed in an MS patient taking dimethyl fumarate, while myelitis occurred in a MOGAD patient receiving azathioprine maintenance therapy. The first episode of optic neuritis occurred in a patient who was later diagnosed with MOGAD. CONCLUSIONS: Our study demonstrated a favorable safety profile with no serious adverse events associated with COVID-19 vaccines in patients with MS, NMOSD, and MOGAD.

The frequency and characteristics of saccadic dysmetria in isolated cerebellar infarction.

OBJECTIVES: To investigate the frequency and pattern of horizontal saccadic dysmetria in unilateral cerebellar infarction and identify the responsible region for horizontal saccadic dysmetria. METHODS: From the acute stroke registry of Keimyung University Dongsan Medical Center between July 2016 and October 2020, 43 patients with acute unilateral cerebellar infarction were enrolled. Eye movements were recorded during the acute period and the lesion was mapped using MRIcron software for subtraction analysis. Saccadic dysmetria was marked as hypometric when the gain is < 0.85 and hypermetric when > 1.0. RESULTS: Among the 43 participants, 30 patients (69.8%) demonstrated saccadic dysmetria. The age was significantly higher in patients with dysmetria (66.87 ± 12.82 vs. 53.54 ± 14.09, p = 0.004). Type of dysmetria showed a significant difference according to the vascular territory of the lesion. The posterior inferior cerebellar artery (PICA) infarction group presented ipsiversive saccadic dysmetria, while the superior cerebellar artery (SCA) group showed contraversive dysmetria (p < 0.001). In the SCA group, the culmen, fastigium, and dentate were the most frequently damaged regions, while the tonsil and inferior semilunar lobule were in the PICA group. CONCLUSION: Saccadic dysmetria was observed in a large proportion of cerebellar stroke patients, and the types of saccades were distinctive according to the vascular territory of the lesion.

QUANTIFIED ANASTOMOTIC AREAS OF NEOVASCULARIZATION AS FACTORS ASSOCIATED WITH FREQUENT RECURRENCE IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To investigate the quantitative characteristics of anastomoses of macular neovascularization (MNV) in neovascular age-related macular degeneration using optical coherence tomography angiography according to the frequency of intravitreal injections. METHODS: Eighty-six eyes of 86 patients treated for neovascular age-related macular degeneration were classified into two groups based on the number of intravitreal injections administered over 12 months: stable (<3) and unstable (≥3). Anastomotic areas were defined as areas surrounded by neighboring vessels in the MNV; their total number, mean area, maximal and minimal diameters (i.e., maximal and minimum Feret diameters), and ratio (Feret aspect ratio) were analyzed in the inner and outer areas of the MNV. RESULTS: Forty-four and 42 eyes were classified into the stable and unstable groups, respectively. The eyes in the unstable group had larger anastomotic areas with longer minimum Feret diameters and longer perimeters in the outer MNV. In the logistic regression analysis, instability was associated with a larger anastomotic area and a longer minimum Feret diameter in the outer MNV. Multivariate analysis revealed that a longer minimum Feret diameter in the outer MNV was the most significant factor ( P = 0.03). CONCLUSION: The quantitative characteristics of the anastomotic areas in the MNV might indicate the need for intravitreal injections in patients with neovascular age-related macular degeneration.

Dysfunctional Glucose Metabolism in Alzheimer's Disease Onset and Potential Pharmacological Interventions.

Alzheimer's disease (AD) is the most common age-related dementia. The alteration in metabolic characteristics determines the prognosis. Patients at risk show reduced glucose uptake in the brain. Additionally, type 2 diabetes mellitus increases the risk of AD with increasing age. Therefore, changes in glucose uptake in the cerebral cortex may predict the histopathological diagnosis of AD. The shifts in glucose uptake and metabolism, insulin resistance, oxidative stress, and abnormal autophagy advance the pathogenesis of AD syndrome. Here, we summarize the role of altered glucose metabolism in type 2 diabetes for AD prognosis. Additionally, we discuss diagnosis and potential pharmacological interventions for glucose metabolism defects in AD to encourage the development of novel therapeutic methods.

Interfacial Defects Change the Correlation between Photoluminescence, Ideality Factor, and Open-Circuit Voltage in Perovskite Solar Cells.

The ideality factor (nid ) and photoluminescence (PL) analyses assess charge recombination characteristics in perovskite solar cells (PeSCs). However, their correlations with open-circuit voltage (Voc ) are often found to be complicated depending on the recombination types in the devices. Herein, the correlation of nid , PL characteristics and Voc is elucidated depending on the interfacial crystal quality in triple-cation mixed-halide perovskite, Cs0.05 (MA0.17 FA0.83 )0.95 Pb(I0.83 Br0.17 )3 , deposited on different hole transport layers (HTLs). In the devices with low quality interfacial crystals, Voc increases together with nid , which originates from the light intensity-dependence of majority carrier at the interface. Meanwhile, a negative correlation between Voc and nid is observed for devices with high quality interfacial crystals. The authors discuss the cases that PL enhancement by the improvement of overall crystal quality can fail to correlate with a Voc increase if interfacial crystal quality becomes worse. The study highlights that interfacial crystal quality evaluation can help to understand charge recombination via nid and PL measurements, and more importantly provide information of which defect engineering between at the interface and in the bulk would be more effective for device optimization.

Cerebral angiography using transauricular access in a rabbit model: a new technique.

BACKGROUND: Cerebral angiography in a rabbit model is widely used in the field of interventional radiology. Conventionally, the femoral artery is used for cerebral angiography in radiology departments. However, angiographic studies require surgical cutdown of the femoral artery, which is technically difficult. PURPOSE: To evaluate a new cerebral angiography technique involving a transauricular approach in a rabbit model. MATERIAL AND METHODS: In each of 10 rabbits, central auricular arteries were punctured in the right or left ear with a 20-gauge i.v. catheter. A microcatheter (2.0 F) with a 0.016-inch guide wire was introduced through the i.v. catheter and advanced to the aortic arch. The microcatheter and guide wire were advanced selectively into cerebral arteries and angiography was performed. RESULTS: Central auricular arteries were successfully punctured with 20-gauge i.v. catheters. After approaching the aortic arch, microcatheter tips and guide wires were advanced manually to cerebral arteries on both sides. Difficulties in selecting the carotid arteries were resolved by using a looping technique within the cardiac chamber. Microcatheter loops within the cardiac chamber disappeared or remained during artery superselection. CONCLUSION: Transauricular cerebral angiography appears to be a feasible technique for brain or carotid intervention studies in rabbits. In addition, vertebral angiography using a transauricular approach is possible using the looping technique. Selection of carotid or vertebral arteries on each side was not difficult when the microcatheter and guide wire were looped within the cardiac chamber. The ear chosen for the initial puncture does not appear to be important.

Engineering synaptic characteristics of TaOx/HfO2 bi-layered resistive switching device.

We performed various pulse measurements on an atomic layer deposited (ALD) HfO2-based resistive switching random access memory (RRAM) device and investigated its electronic synaptic characteristics. Unlike requirements for RRAM device application, to achieve the multi-state conductance changes required for the synaptic device, we employed additional sputtered TaOx thin film formation on the ALD HfO2 switching medium, which leads to engineering the concentration of oxygen vacancies and modulating the conductive filaments. With this TaOx/HfO2 bi-layered device, we attained gradual resistive switching, linear and symmetric conductance change, improved endurance and reproducibility characteristics compared to a single HfO2 device. Finally, we emulated spike-timing-dependent plasticity based learning rule with pulses inspired by neural action potential, indicating its potential as an electronic synaptic device in a hardware neuromorphic system.