Background: The clinical implications of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Abs) are increasing. Establishing MOG-Ab assays is essential for effectively treating patients with MOG-Abs. We established an in-house cell-based assay (CBA) to detect MOG-Abs to identify correlations with patients’ clinical characteristics. Methods: We established the CBA using HEK 293 cells transiently overexpressing fulllength human MOG, tested it against 166 samples from a multicenter registry of central nervous system (CNS) inflammatory disorders, and compared the results with those of the Oxford MOG-Ab-based CBA and a commercial MOG-Ab CBA kit. We recruited additional patients with MOG-Abs and compared the clinical characteristics of MOG-Ab-associated disease (MOGAD) with those of neuromyelitis optica spectrum disorder (NMOSD). Results: Of 166 samples tested, 10 tested positive for MOG-Abs, with optic neuritis (ON) being the most common manifestation (4/15, 26.7%). The in-house and Oxford MOG-Ab CBAs agreed for 164/166 (98.8%) samples (κ = 0.883, P < 0.001); two patients (2/166, 1.2%) were only positive in our in-house CBA, and the CBA scores of the two laboratories correlated well (r = 0.663, P < 0.001). The commercial MOG-Ab CBA kit showed one falsenegative and three false-positive results. The clinical presentation at disease onset differed between MOGAD and NMOSD; ON was the most frequent manifestation in MOGAD, and transverse myelitis was most frequent in NMOSD. Conclusions The in-house CBA for MOG-Abs demonstrated reliable results and can potentially be used to evaluate CNS inflammatory disorders. A comprehensive, long-term study with a large patient population would clarify the clinical significance of MOG-Abs.

Complications that occur during cancer therapy have emerged as a major contributor to the poor quality of life experienced by cancer patients as they live longer due to improved treatments. Many studies have investigated chemotherapy-induced peripheral neuropathy, but few have investigated the autonomic nervous system. Cardiovascular autonomic dysfunction (CAD) contributes to the distressing symptoms experienced by cancer patients, and it is also related to poor treatment outcomes. CAD has a multifactorial etiology in patients with cancer:it can be caused by the cancer itself, chemotherapy or radiation therapy, or other comorbidities. Its symptoms are nonspecific, and they include orthostatic hypotension, resting tachycardia, dizziness, chest tightness, and exertional dyspnea. It is important to suspect CAD and perform therapeutic interventions in a clinical context, because a patient who is more frail is less like to endure the treatment process. The quality of life of patients receiving active cancer treatments can be improved by evaluating the risk of CAD before and after chemotherapy, and combining both nonpharmacological and pharmacological management. Here we review the prevalence, pathogenesis, diagnosis, and treatment of CAD, which is the most common and a sometimes serious symptom in cancer patients.

Complications that occur during cancer therapy have emerged as a major contributor to the poor quality of life experienced by cancer patients as they live longer due to improved treatments. Many studies have investigated chemotherapy-induced peripheral neuropathy, but few have investigated the autonomic nervous system. Cardiovascular autonomic dysfunction (CAD) contributes to the distressing symptoms experienced by cancer patients, and it is also related to poor treatment outcomes. CAD has a multifactorial etiology in patients with cancer:it can be caused by the cancer itself, chemotherapy or radiation therapy, or other comorbidities. Its symptoms are nonspecific, and they include orthostatic hypotension, resting tachycardia, dizziness, chest tightness, and exertional dyspnea. It is important to suspect CAD and perform therapeutic interventions in a clinical context, because a patient who is more frail is less like to endure the treatment process. The quality of life of patients receiving active cancer treatments can be improved by evaluating the risk of CAD before and after chemotherapy, and combining both nonpharmacological and pharmacological management. Here we review the prevalence, pathogenesis, diagnosis, and treatment of CAD, which is the most common and a sometimes serious symptom in cancer patients.

Complications that occur during cancer therapy have emerged as a major contributor to the poor quality of life experienced by cancer patients as they live longer due to improved treatments. Many studies have investigated chemotherapy-induced peripheral neuropathy, but few have investigated the autonomic nervous system. Cardiovascular autonomic dysfunction (CAD) contributes to the distressing symptoms experienced by cancer patients, and it is also related to poor treatment outcomes. CAD has a multifactorial etiology in patients with cancer:it can be caused by the cancer itself, chemotherapy or radiation therapy, or other comorbidities. Its symptoms are nonspecific, and they include orthostatic hypotension, resting tachycardia, dizziness, chest tightness, and exertional dyspnea. It is important to suspect CAD and perform therapeutic interventions in a clinical context, because a patient who is more frail is less like to endure the treatment process. The quality of life of patients receiving active cancer treatments can be improved by evaluating the risk of CAD before and after chemotherapy, and combining both nonpharmacological and pharmacological management. Here we review the prevalence, pathogenesis, diagnosis, and treatment of CAD, which is the most common and a sometimes serious symptom in cancer patients.

Rare diseases are predominantly genetic or inherited, and patients with these conditions frequently exhibit neurological symptoms. Diagnosing and treating many rare diseases is a complex challenge, and their low prevalence complicates the performance of research, which in turn hinders the advancement of therapeutic options. One strategy to address this issue is the creation of national or international registries for rare diseases, which can help researchers monitor and investigate their natural progression. In the Republic of Korea, we established a registry across 5 centers that focuses on 3 rare diseases, all of which are characterized by gait disturbances resulting from motor system dysfunction. The registry will collect clinical information and human bioresources from patients with amyotrophic lateral sclerosis, spinocerebellar ataxia, and hereditary spastic paraplegia. These resources will be stored at ICreaT and the National Biobank of Korea. Once the registry is complete, the data will be made publicly available for further research. Through this registry, our research team is dedicated to identifying genetic variants that are specific to Korean patients, uncovering biomarkers that show a strong correlation with clinical symptoms, and leveraging this information for early diagnosis and the development of treatments.

Background: and Purpose We performed a population-based study to determine the prevalence and incidence of chronic inflammatory demyelinating polyneuropathy (CIDP) in South Korea using data from the Korean Health Insurance Review and Assessment Service (HIRA) database. Methods: Data recorded in the HIRA database between January 2016 and December 2020 were analyzed. The inclusion criteria in this study for patients with CIDP were a diagnostic code of G61.8 in the seventh and eighth revision of the Korean Standard Classification of Disease and a >3-month history of oral immunosuppressant use. The age-adjusted incidence rate and prevalence of CIDP in South Korea were also analyzed. Results: CIDP was newly diagnosed in 953 patients during the study period. The mean age at diagnosis was 58.36 years, and the male-to-female ratio was 1.74. The age-adjusted incidence rates were 0.22, 0.21, 0.23, 0.30, and 0.25 per 100,000 person-years in 2016, 2017, 2018, 2019, and 2020, respectively. The age-adjusted prevalence was estimated at 1.16 per 100,000 persons in 2020. Age and the Elixhauser Comorbidity Index were associated with the in-hospital mortality of patients with CIDP. Infection and cardiovascular disease (CVD) were also significantly associated with the in-hospital mortality of those patients. Acute-onset CIDP was initially diagnosed in an estimated 101 out of 953 patients with CIDP. Conclusions The prevalence and incidence rates of CIDP in South Korea were comparable between this nationwide cohort study and previous studies. Common comorbidities such as CVD and diabetes should be appropriately monitored in patients with CIDP to prevent a poor prognosis and socioeconomic burden.

Background: and Purpose Among patients with double-seronegative myasthenia gravis (dSN-MG) who do not have detectable antibodies against acetylcholine receptor or musclespecific tyrosine kinase, autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4-Ab) have been detected recently. The purpose of this study was to develop an in-house cell-based assay (CBA) to detect LRP4-Ab and to apply it to samples from patients with MG. Methods: The complementary DNA of LRP4 fused into a vector plasmid containing GFP was transfected into human embryonic kidney 293 (HEK293) cells. LRP4 expression in the transfected HEK293 cells was assessed using the reverse-transcription polymerase chain reaction (RT-PCR), Western blotting, and immunocytochemistry. The CBA included 252 sera collected from 202 patients with MG and 38 with other neuromuscular diseases, and 12 healthy controls. The transfected HEK293 cells were incubated using sera and antihuman immunoglobulin G antibodies conjugated with Alexa Fluor 594. The presence of LRP4-Ab was determined based on the fluorescence intensity and the localization in fluorescence microscopy. Results: The expressions of the mRNA and protein of LRP4 in the transfected HEK293 cells were confirmed using RT-PCR and Western blotting, respectively. Immunocytochemistry indicated LPR4 expression on the cell membrane. Among 202 patients with MG including 53 with dSN-MG, LRP4-Ab were positive in 3 patients who were all double seronegative. LRP4-Ab were not detected in the patients with other neuromuscular diseases or the healthy controls. Conclusions A CBA for detecting LRP4-Ab associated with MG has been developed, and was used to find LRP4-Ab in the sera of patients with MG.

Background: and Purpose The description of pain is the most-important indicator leading to the adequate treatment of patients with neuropathic pain (NeP). The purpose of this study was to identify and characterize the unique features of Korean verbal descriptions in patients with peripheral NeP. Methods: This study included 400 patients (167 males and 233 females) and their 1,387 paindescription responses. Patients with peripheral NeP freely described their symptoms in Korean. Collected verbal descriptions were grouped according to terminologies with similar meanings. Participants completed validated patient-reported outcome scales including the neuropathic pain symptom inventory (NPSI) and painDETECT questionnaire (PD-Q). The frequencies of each verbal pain descriptor were compared between the NPSI and PD-Q scores. Results: ‘Jeorim’ (tingling) was the most common among 17 types of organized verbal pain descriptors, and the ‘Sirim’ (cold) symptom had a significantly higher rate of use in the 2 highseverity groups when participants were classified by their total scores on the NPSI and PD-Q. Conclusions Korean verbal NeP descriptors were significantly diverse. The Jeorim (tingling) and Sirim (cold) descriptors can be utilized in evaluations of Korean patients with NeP.

Parry-Romberg syndrome is a rare acquired disease of unknown etiology that is classically characterized by progressive atrophy of the skin, subcutaneous tissues, and underlying bone structures. Eyelid myokymia is a disorder of involuntary, fine, continuous, undulating muscle fiber contractions, which is seen as a rippling of the overlying periorbital area. We report a patient with Parry-Romberg syndrome presenting eyelid myokymia.