Background: Primary Merkel cell carcinoma of the salivary gland is currently not listed in the World Health Organization classification. However, cases of Merkel cell type neuroendocrine carcinomas of the salivary gland with perinuclear cytokeratin 20 positivity have been intermittently reported. We here investigated the clinicopathologic features of additional cases. Methods: Data of four cases of Merkel cell type small cell neuroendocrine carcinoma of the salivary gland were retrieved. To confirm the tumors’ primary nature, clinical records and pathologic materials were reviewed. Optimal immunohistochemical staining was performed to support the diagnosis. Results: All tumors were located in the parotid gland. Possibilities of metastasis were excluded in all cases through a meticulous clinicopathological review. Tumor histology was consistent with the diagnosis of small cell neuroendocrine carcinoma. Tumors’ immunohistochemical phenotypes were consistent with Merkel cell carcinoma, including Merkel cell polyomavirus large T antigen positivity in two of the four cases. Conclusions Merkel cell carcinomas can originate in salivary glands and are partly associated with Merkel cell polyomavirus infection as in cutaneous Merkel cell carcinomas.

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is a neurodegenerative disorder caused by a biallelic expansion of pentanucleotide repeats in the RFC1 gene. Previous studies have reported up to 22% of patients with late-onset ataxia harbor this pathogenic repeat expansion. Despite its relatively high prevalence, CANVAS is often underdiagnosed because the disease is not well recognized and genetic testing is not performed in clinical practice. Here, we present a patient with characteristic clinical features, confirmed by genetic testing.

Background: Despite the critical importance of sleep medicine within neurology, notable gaps in education and clinical practice persist among neurologists. This study aims to explore the extent of involvement and the challenges faced by Korean neurologists in sleep medicine, focusing on awareness of polysomnography training program, the operation of sleep study facilities, and educational exposure. Methods: An online survey collected responses from 233 neurologists, focusing on their demographics, knowledge of and involvement in sleep medicine, operation of sleep study facilities, and participation in residency training. Results: The findings indicated that 84.9% of neurologists were aware of polysomnography training program, primarily through professional societies. Nonetheless, 15.1% reported unfamiliarity with these initiatives, with 72.7% of this subgroup expressing interest in sleep medicine yet lacking access to information. In terms of clinical practice, 74 neurologists operated sleep study facilities, with 63% intending to expand. Key operational challenges included staff management, maintaining patient volumes, and inadequate institutional support. Among respondents from teaching hospitals, only 36 out of 114 reported active resident involvement in sleep study interpretations, predominantly hindered by excessive workloads and insufficient staffing. Conclusions A significant number of neurologists have an interest in sleep medicine; however, substantial challenges impede effective education and clinical practice. These results underscore the need for improved educational resources and institutional support to enhance the growth and effectiveness of sleep medicine practices among neurologists.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background: Remimazolam is a novel ultra-short-acting benzodiazepine known for its hemodynamic stability over propofol. However, its hemodynamic effects compared to those of etomidate are not well established. This study aimed to determine whether the use of remimazolam is non-inferior to etomidate with regard to the occurrence of post-induction hypotension in patients undergoing coronary artery bypass grafting. Methods: Patients were randomly assigned to either the remimazolam group (6 mg/kg/h) or the etomidate group (0.3 mg/kg) for induction of anesthesia. Anesthetic depth was adjusted based on the bispectral index. Primary outcome was the incidence of post-induction hypotension, defined as a mean arterial pressure less than 65 mmHg within 15 min after endotracheal intubation, with a non-inferiority margin of 12%. Results: A total of 144 patients were finally analyzed. Incidence of post-induction hypotension was 36/71 (50.7%) in the remimazolam group and 25/73 (34.2%) in the etomidate group, with a rate difference of 16.5% (95% CI [3.0–32.6]) between the two groups that was beyond the prespecified non-inferiority margin of 12.0%. The number of patients who needed vasopressors was similar in the two groups. Conclusions In this non-inferiority trial, remimazolam failed to show non-inferiority to etomidate in terms of post-induction hypotension when used as an induction drug for general anesthesia in patients undergoing coronary artery bypass grafting. However, different doses or infusion techniques of remimazolam should be compared with etomidate in various patient groups to fully assess its hemodynamic non-inferiority during induction of anesthesia.

Background: We hypothesized that intranasal combination of dexmedetomidine (2 μg/kg) and ketamine (3 mg/kg) (IN DEXKET) improves the success rate of sedation in pediatric patients compared with chloral hydrate (CH; 50 mg/kg). Methods: This prospective, two-center, single-blinded, randomized controlled trial involved 136 pediatric patients (aged < 7 years) requiring procedural sedation. The participants were randomized to receive CH or IN DEXKET via a mucosal atomizer device. The primary outcome was the success rate of sedation (Pediatric Sedation State Scale, scores 1–3) within 15 min. The secondary outcomes included sedation failure at 30 min and overall complications of first-attempt sedation. Results: After excluding eight patients, 128 were included (CH = 66, IN DEXKET = 62). IN DEXKET showed a similar sedation success rate (75.8% [47/62] vs. 66.7% [44/66]; P = 0.330) but a lower complication rate (3.2% [2/62] vs. 16.7% [11/66]; P = 0.017) than CH. In the subgroup analysis for patients aged < 1 year, IN DEXKET showed a reduced complication rate than CH (2.6% [1/38] vs. 22.9% [8/35]; P = 0.012). In the subgroup analysis of children aged 1–7 years, IN DEXKET showed a higher sedation success rate within 15 min (79.2% [19/24] vs. 51.6% [16/31]; P = 0.049) and a lower sedation failure after 30 min (0% vs. 29.0% [9/31]; P = 0.003) than CH. Conclusions The intranasal combination of dexmedetomidine (2 μg/kg) and ketamine (3 mg/kg) is a safe and effective alternative to CH (50 mg/kg) for sedation in pediatric patients aged < 7 years.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.