Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study. Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death. Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04–1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality. Conclusion This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study. Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death. Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04–1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality. Conclusion This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study. Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death. Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04–1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality. Conclusion This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study. Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death. Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04–1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality. Conclusion This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study. Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death. Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04–1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality. Conclusion This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.

Objectives: . The recent expansion of eligibility for cochlear implantation (CI) by the U.S. Food and Drug Administration (FDA) to include infants as young as 9 months has reignited debates concerning the clinically appropriate cut-off age for pediatric CI. Our study compared the early postoperative trajectories of receptive and expressive language development in children who received CI before 9 months of age with those who received it between 9 and 12 months. This study involved a unique pediatric cohort with documented etiology, where the timing of CI was based on objective criteria and efforts were made to minimize the influence of parental socioeconomic status. Methods: . A retrospective review of 98 pediatric implantees recruited at a tertiary referral center was conducted. The timing of CI was based on auditory and language criteria focused on the extent of delay corresponding to the bottom 1st percentile of language development among age-matched controls, with patients categorized into very early (CI at <9 months), early (CI at 9–12 months) and delayed (CI at 12–18 months) CI groups. Postoperative receptive/expressive language development was assessed using the Sequenced Language Scale for Infants receptive and expressive standardized scores and percentiles. Results: . Only the very early CI group showed significant improvements in receptive language starting at 3 months post-CI, aligning with normal-hearing peers by 9 months and maintaining this level until age 2 years. During this period (<2 years), all improvements were more pronounced in receptive language than in expressive language. Conclusion . CI before 9 months of age significantly improved receptive language development compared to later CI, with improvements sustained at least up to the age of 2. This study supports the consideration of earlier CI, beyond pediatric Food and Drug Administration labeling criteria (>9 months), in children with profound deafness who have a clear deafness etiology and language development delays (<1st percentile).

Background: The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI). Methods: A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed. Results: A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (rs = −0.430, P = 0.036), H. influenzae (rs = −0.922, P < 0.001), while trend toward an increase in the relative proportion of S. aureus (rs = 0.850, P < 0.001), S. agalactiae (rs = 0.615, P = 0.001), and S. pyogenes (rs = 0.554, P = 0.005). Conclusion In the proportion of IBIs over a 24-year period between 1996 and 2019, we observed a decreasing trend for S. pneumoniae and H. influenzae and an increasing trend for S. aureus, S. agalactiae, and S. pyogenes in children > 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.