Topiramate dosage optimization for effective antiseizure management via population pharmacokinetic modeling

OBJECTIVE

Despite the suggested topiramate serum level of 5-20 mg/L, numerous institutions have observed substantial drug response at lower levels. We aim to investigate the correlation between topiramate serum levels, drug responsiveness, and adverse events to establish a more accurate and tailored therapeutic range.

METHODS

We retrospectively analyzed clinical data collected between January 2017 and January 2022 at Seoul National University Hospital. Drug responses to topiramate were categorized as "insufficient" or "sufficient" by reduction in seizure frequency ≥ 50%. A population pharmacokinetic model estimated serum levels from spot measurements. ROC curve analysis determined the optimal cutoff values.

RESULTS

A total of 389 epilepsy patients were reviewed having a mean dose of 178.4 ± 117.9 mg/day and the serum level, 3.9 ± 2.8 mg/L. Only 5.6% samples exhibited insufficient response, with a mean serum level of 3.6 ± 2.5 mg/L while 94.4% demonstrated sufficient response, with a mean 4.0 ± 2.8 mg/L, having no statistical significance. Among the 69 reported adverse events, logistic regression analysis identified a significant association between ataxia and serum concentration (p = 0.04), with an optimal cutoff value of 6.5 mg/L.

INTERPRETATION

This study proposed an optimal therapeutic concentration for topiramate based on patients' responsiveness to the drug and the incidence of adverse effects. We recommended serum levels below 6.5 mg/L to mitigate the risk of ataxia-related side effects while dose elevation was found unnecessary for suboptimal responders, as the drug's effectiveness plateaus at minimal doses.

Gut microbiome diversity in a febrile seizure mouse model

Purpose

Febrile seizures at a young age can provoke late-onset temporal lobe epilepsy. Since recent evidence has suggested that the gut microbiome affects central nervous system pathology across the blood-brain barrier, we hypothesized that febrile seizures alter the composition of the gut microbiome to provoke epilepsy.

Methods

Third-generation C57BL/6 mice were separated into two groups (n = 5 each), and hot air was applied to only one group to cause febrile seizures. After two weeks of heat challenge, the fecal pellets acquired from each group were analyzed.

Results

The gut microbiota of fecal pellets from each group revealed five taxa at the genus level and eight taxa at the species level that were significantly different in proportion between the groups.

Conclusion

Although there was no significant difference in the overall diversity of the gut microbiota between the two groups, the identified heterogeneity may imply the pathognomonic causative relevance of febrile seizures and the development of epilepsy.

Teratoma pathology and genomics in anti-NMDA receptor encephalitis

INTRODUCTION

Ovarian teratoma is a common occurrence in patients with anti-NMDA receptor encephalitis (NMDARe), and its removal is crucial for a favorable prognosis. However, the initial pathogenesis of autoimmunity in the encephalitic teratoma remains unclear. In this study, we aimed to investigate the genomic landscape and microscopic findings by comparing NMDARe-associated teratomas and non-encephalitic control teratomas.

MATERIALS AND METHODS

A prospective consecutive cohort of 84 patients with NMDARe was recruited from January 2014 to April 2020, and among them, patients who received teratoma removal surgery at Seoul National University Hospital were enrolled. We conducted a comparison of whole-exome sequencing data and pathologic findings between NMDARe-associated teratomas and control teratomas.

RESULTS

We found 18 NMDARe-associated teratomas from 15 patients and compared them with 17 non-encephalitic control teratomas. Interestingly, the genomic analysis revealed no significant differences in mutations between encephalitic and non-encephalitic teratomas. Pathologic analysis showed no discrepancies in terms of the presence of neuronal tissue and lymphocytic infiltration between the encephalitic teratomas (n = 14) and non-encephalitic teratomas (n = 18). However, rituximab-naïve encephalitic teratomas exhibited a higher frequency of germinal center formation compared to non-encephalitic teratomas (80% vs. 16.7%, P = 0.017). Additionally, rituximab-treated encephalitic teratomas demonstrated a reduced number of CD20+ cells and germinal centers in comparison to rituximab-naïve encephalitic teratomas (P = 0.048 and 0.023, respectively).

DISCUSSION

These results suggest that the initiation of immunopathogenesis in NMDARe-associated teratoma is not primarily attributed to intrinsic tumor mutations, but rather to immune factors present in the encephalitic patient group, ultimately leading to germinal center formation within the teratoma.

Anti-seizure medication prescription in epilepsy patients in South Korea: A seven-year population-based retrospective cohort study

BACKGROUND AND OBJECTIVES

This study aimed to explore the natural history of patients with epilepsy using overall antiseizure-medication (ASM) treatment patterns on a nationwide scale in South Korea.

METHODS

We investigated a retrospective longitudinal cohort of patients with epilepsy in South Korea using nationwide data from the Korean National Health Information Database of the Health Insurance and Review Assessment Service between January 1st, 2009, and December 31st, 2018. Histories of each patient's ASM prescription were followed for up to 7 years from the index date, the first observed date of ICD-10 epilepsy diagnosis codes with at least one ASM prescription.

RESULTS

Of 82,390 incident patients analyzed, ten thousand and fifty-nine were followed up to seven years, and nearly 60% of them discontinued the ASM(s). The proportion of patients with possible drug-resistant epilepsy (DRE), who experience three or more types of ASMs, gradually increased, reaching approximately 8.8% of the total number of patients in the seventh year (6.45% for adults, 21.8% for children). The duration of progression for half of the patients with possible DRE was 1.29 years for children, 1.79 years for adults, and 1.62 years for mixed-age patients. However, even in the sixth year, 72 cases progressed to possible DRE, and 6 cases with possible DRE discontinued ASMs in the next year, showing a dynamic process.

DISCUSSION

Our population-based study showed the dynamic changes of anti-seizure medication prescription in epilepsy patients with real-world data, which slowly stabilizes over years after the first diagnosis of epilepsy.

Trends in sleep duration in Korea: The Korean time use survey

OBJECTIVES

An accurate assessment of sleep duration is important in that it can be one of the indicators of a country's overall health and well-being. The global trend in sleep duration is controversial according to study types. We investigated trends in sleep duration in South Korea with a time diary method.

METHODS

Data from the Korean Time Use Survey (KTUS) in 2004, 2009, 2014, and 2019, were analyzed. The KTUS is a nationwide, cross-sectional survey that measures daily time use patterns of individuals and has been performed every five years by Statistics Korea. For this survey, all participants were asked to record their activities for 2 continuous days in 10-min intervals.

RESULTS

Among the 168,682 people who completed the survey in 2004 through 2019, the final analytical sample consisted of 91,998 individuals. Over 15 years, the sleep duration of the Korean population increased from 411.1 min (SD 22.5) in 2004 to 434.5 min (SD 26.1) in 2019 (p for trend <0.001). This increase was observed for all age groups. Over the study period, while bedtime showed no significant change, wake time was generally delayed for all age groups. The increase in sleep duration in the Korean population was largely due to catch-up sleep on Saturdays, which was substantially prolonged with belated wake times.

CONCLUSION

Our nationwide time use survey data showed that sleep duration in South Korea has increased over the past 15 years but still has room for improvement in terms of weekday sleep duration.

Clinicoradiologic data of familial cerebral cavernous malformation with age-related disease burden

OBJECTIVE

Familial cerebral cavernous malformation (FCCM) is an autosomal dominant disease induced by loss-of-function mutations in three CCM genes, KRIT1, CCM2, and PDCD10. However, previous studies paid little attention to analyzing the radiologic features and age-related disease burden according to the genes. Therefore, we retrospectively reviewed the genetic tests of our center's clinical FCCM patients.

METHOD

This study investigated clinical FCCM patients with multiple lesions or a family history of CCMs who underwent the FCCM gene (KRTI1, CCM2, and PDCD10) panel test. The clinical, genetic, and radiologic features were analyzed.

RESULT

Among the patients (n = 34) undergoing the FCCM gene test, twenty-seven patients had CCM confirmed by brain MRI, and twenty-one patients were considered to have FCCM (cohort 1). In cohort 1, thirteen patients had mutations in the FCCM gene, but eight did not. Cohort 2 comprised cohort 1 and four family members with the same mutation as the probands. Six novel variants in CCM genes were detected (KRIT1 c.22_26del, c.815dup, c.1094_1098del, c.1147-2A>G, c.2124dup, and PDCD10 c.150 + 1dup). Cohort 1 demonstrated that brainstem lesions were mostly associated with the mutation detection in CCM genes (brainstem, lateral temporal, and parietal lesions vs. lateral temporal and parietal lesions, AUC 0.928 vs. 0.779, P = 0.0389). The radiologic severity worsened according to age in the KRIT1 group compared with the Mutation not detected group (correlation coefficient 0.75 (P < 0.001) versus 0.53 (P = 0.004)).

CONCLUSION

The brainstem lesion could be the radiologic marker for FCCM with the mutation detected. The age-related disease burden regarding FCCM according to genetic information was demonstrated.

Predictors of critical illness among young males with chest pain, abdominal pain, or headaches in the Republic of Korea Army

Purpose

Chest pain, abdominal pain, and headache are common symptoms associated with critical illness. Here, we aimed to evaluate predictors associated with critical illness in young males of the Republic of Korea Army.

Methods

We retrospectively reviewed previously healthy young males with chest pain, abdominal pain, or headaches who visited Armed Forces Seoul District Hospital between January 2019 and December 2020. Critical illness was defined as a condition that required hospitalization, a procedure or surgery, or referral to a tertiary hospital. The symptoms and signs of critical illness were evaluated.

Results

Of the 762 enrolled patients, a critical illness was diagnosed in 45 patients (5.9%). Among chest pain signs, palpitation (odds ratio [OR], 22.8; 95% confidence interval [CI], 5.08-102.4; p < 0.001), exertional dyspnea (OR, 16.3; 95% CI, 3.38-78.8; p = 0.001), duration (> 5 minutes) (OR, 7.54; 95% CI, 1.93-29.49; p = 0.004), and squeezing type (OR, 5.28; 95% CI, 1.11-25.11; p = 0.037) were significantly associated with critical illness. Among abdominal pain signs, right-lower-quadrant tenderness (OR, 11.87; 95% CI, 4.671-31.87; p < 0.001) was an alarming sign. For headaches, criticality was low (1.5%), and half of patients with critical illness were diagnosed incidentally regardless of headache.

Conclusion

We identified symptoms and signs significantly associated with critical illness in young male patients. This study might serve as a reference for deciding when to transfer soldiers in the field to a rear hospital, thereby contributing to the welfare and combat power of soldiers.

Telemedicine in epilepsy and encephalitis: previous research and indication guidelines in Korea

Telemedicine is an emerging field of medicine that has become more important during the coronavirus disease 2019 (COVID-19) pandemic era and is being studied actively in various medical fields. In neurology, the introduction of telemedicine is accelerating worldwide under the label of teleneurology. So far, few studies have been conducted on telemedicine for patients with epilepsy. In nonmetropolitan areas, video-based clinics have been demonstrated to be effective for seizure control, and smartphone-based diagnosis has also been confirmed to be accurate. Indeed, after the onset of the COVID-19 pandemic, telemedicine has been used to treat patients with epilepsy around the world. Few studies have examined the use of telemedicine for patients with autoimmune encephalitis. One showed that telephone-based evaluation is sufficient to assess the cognitive reserve of leucine-rich glioma inactivated-1-antibody encephalitis patients, thereby diagnosing their dementia. Telephone-based outpatient clinics are temporarily permitted under Korean medical law, and telemedicine can be attempted for clinically stable patients with epilepsy in Korea. In addition, patients with autoimmune encephalitis in stable or improving status may also be candidates for treatment with telemedicine. This review presents evidence for the safety and efficacy of telemedicine to treat epilepsy and encephalitis patients and discusses indication guidelines. Based on our literature review and current Korean medical law, we suggest tentative guidelines for telemedicine in the fields of epilepsy and autoimmune encephalitis.

Nanopore 16S sequencing enhances the detection of bacterial meningitis after neurosurgery

Objective

Nosocomial bacterial meningitis is one of the major complications after neurosurgery. We performed nanopore 16S amplicon sequencing from cerebrospinal fluid (CSF) to evaluate bacterial meningitis in patients who underwent neurosurgery.

Methods

Among the patients who visited the neurosurgery department of Seoul National University Hospital between July 2017 and June 2020, those with clinically suspected bacterial meningitis were included. 16S rDNA PCR was performed from the CSF, and nanopore sequencing was performed for up to 3 h. The reads were aligned to the BLAST database. In each case, the culture and the 16S rRNA gene amplicon analysis were simultaneously performed and compared with each other, and we retrospectively reviewed the medical records. Genuine infection was determined by the identical results between conventional culture study and the sequencing, or clinically determined in cases with inconsistent results between the two methods.

Results

Of the 285 samples obtained from 178 patients who had 16S rDNA PCR, 41 samples (14.4%) were diagnosed with genuine infection. A total of 56.1% (23/41) of the samples with genuine infection showed a false‐negative culture test. In particular, 16S amplicon sequencing was useful in evaluating patients at the initial tests who had infection with intraventricular hemorrhage (Culture false‐negative rate = 100%), subarachnoid hemorrhage (Culture false‐negative rate = 77.8%), and systemic cancer (Culture false‐negative rate = 100%), which are risk factors for central fever. Moreover, 16S amplicon sequencing could suggest the possibility of persistent bacterial meningitis in empirical antibiotic use.

Conclusion

CSF nanopore 16S sequencing was more effective than conventional CSF culture studies in postoperative bacterial meningitis and may contribute to evidence‐based decisions for antibiotic maintenance and discontinuation.

Anakinra treatment for refractory cerebral autoinflammatory responses

Refractory cerebral autoinflammatory–autoimmune diseases are often associated with dysregulated innate immunity and are targeted by anakinra, an interleukin‐1 receptor antagonist. We analyzed the therapeutic effect of anakinra in refractory cerebral autoinflammatory response (CAIR) at a single institution from January 2017 to May 2021. In total, 12 patients with various etiologies were sympathetically treated with anakinra (100 mg/day subcutaneously). Four patients showed good responses, and among these patients, three patients had pathologically demonstrated CAIR. The other eight patients were nonresponsive. No patient had a serious adverse effect. Thus, anakinra may be a therapeutic option for refractory cerebral autoinflammatory diseases.

Optimal application of compressive palatal stents following mesiodens removal in pediatric patients: A Randomized Controlled Trial

Background

There is no scientific evidence supporting the choice of a palatal stent in patients who underwent removal of an impacted supernumerary tooth. We aimed to investigate the effects of palatal stents in patients who underwent supernumerary tooth removal through a palatal approach and to suggest the optimal stent thickness and material.

Material and Methods

We recruited 144 patients who underwent extraction of a supernumerary tooth between the maxillary anterior teeth. Subjects were assigned to a control group (CG) or one of four compressive palatal stent groups (CPSGs) classified by the thickness and material of the thermoplastic acrylic stent used. Palatal gingival swelling and objective indices (healing, oral hygiene, gingival, and plaque) were evaluated before surgery and on postoperative days (PODs) 3, 7, and 14; pain/discomfort and the Child Oral Health Impact Profile (COHIP) were assessed as subjective indices of the effects of the stent.

Results

The CPSGs showed faster healing than did the CG on PODs 7 (P<0.001) and 14 (P=0.043); swelling was measured by 1.64±0.88 mm and 4.52±0.39 mm, respectively. Although swelling was least in the 4-mm hard group (0.92±0.33 mm), the difference compared with that in the 2-mm hard group (1.01±0.18 mm) was not significant (P=0.077). The CPSGs showed better COHIP (P<0.001-0.036) and pain scores (P<0.001) than did the CG on PODs 1-3.

Conclusions

Compressive palatal stents reduce discomfort by decreasing pain and alleviating swelling. Although a stent is effective regardless of its thickness and material, 2-mm hard stents maximized such positive effects with minimal discomfort.

Key words:Supernumerary tooth, tooth Extraction, postoperative care, oral Health, pediatric dentistry.

Paraneoplastic encephalitis associated with renal cell carcinoma

Purpose

Paraneoplastic encephalitis is autoimmune encephalitis accompanied by tumors. Renal cell carcinoma (RCC) is a kidney cancer originating from various types of renal cells and rarely has been associated with paraneoplastic neurologic manifestation. We identified a case series of paraneoplastic encephalitis-associated RCC.

Methods

From a prospective institutional cohort, we identified autoimmune encephalitis patients with RCC. The association between RCC and encephalitis was determined by the following criteria: (1) possible autoimmune encephalitis according to the operational autoimmune encephalitis diagnostic criteria and (2) RCC simultaneously diagnosed with neurological manifestation of encephalitis.

Results

A total of three patients presented encephalitis accompanied by RCC. Two patients had clear cell RCC, and one had chromophobe RCC. All patients showed limbic encephalitis with cognitive decline, memory impairment, or seizure. Brain magnetic resonance imaging showed T2 hyperintensities at the mesial temporal lobe in two patients with clear cell RCC but no remarkable findings in one patient with chromophobe RCC. While one patient who had early surgery within one month of RCC onset had a favorable response to the treatment, the other two patients showed a partial response and a detrimental result.

Conclusion

Paraneoplastic encephalitis associated with RCC presented as limbic encephalitis and was responsive to immunotherapy combined with tumor resection. As our cases identified, RCC should be considered as a cause of seronegative autoimmune encephalitis.

A new rapid titration protocol for lamotrigine that reduces the risk of skin rash

Objective

Lamotrigine is one of the most widely used antiepileptic drugs, but it has a critical issue of a skin rash if the starting dose is too high or the escalation rate is too rapid. We investigated the efficacy and safety of a novel and rapid titration protocol for lamotrigine that takes only 11 days to reach a daily dose of 200 mg.

Methods

We prospectively enrolled 33 adult patients (age 18‐85) who were diagnosed with epilepsy and started lamotrigine administration for the first time at a single tertiary hospital. Our new protocol starts with a subthreshold dose of the drug and then administers a stepwise‐incremental dose until reaching the full therapeutic dose within 11 days.

Results

Of 29 patients analyzed, only two (6.9%) experienced idiosyncratic skin rash before the first follow‐up visit at 2 weeks (±3 days). In addition, a therapeutic concentration was reached in more than 75% of studied patients after 2 weeks of lamotrigine administration.

Significance

These findings demonstrate the value of the novel tolerance induction protocol for lamotrigine, which could widen the available application of lamotrigine in various situations. However, this study is a preliminary study limited by a small number of patients and its nonrandomized and open‐label design, so the current protocol needs more rigorous clinical evaluations before the application to the real clinical setting.

Population pharmacokinetic model development and its relationship with adverse events of oxcarbazepine in adult patients with epilepsy

This study aimed to develop a pharmacokinetic (PK) model of oxcarbazepine (OXC) and analyse the relationship between monohydroxylated derivative (MHD), an active metabolite of OXC, and the adverse events of OXC. We obtained 711 OXC samples from 618 patients with epilepsy who were enrolled in the Epilepsy Registry Cohort of Seoul National University Hospital from February 2011 to January 2014. The plasma PK model was developed using a nonlinear mixed-effect modelling method with NONMEM (ver 7.3). A one-compartment model with a first-order absorption model and proportional residual error adequately described the MHD concentration–time profiles. The only covariate incorporated for CL/F and V/F was body weight. Of the 447 patients analysed, 28 (6.26%) had dose-related adverse events (DRAEs), which were dizziness, somnolence, headache, and diplopia. For DRAE occurrence, the cut-off values of the MHD trough and AUC were 12.27 mg/L (specificity 0.570, sensitivity 0.643) and 698.5 mg h/L (specificity, sensitivity 0.571), respectively. Multivariate analysis showed the sole dizziness symptom was significantly associated with both the MHD trough and the AUC (p = 0.013, p = 0.038, respectively). We newly developed a population PK model using sparse sampling data from patients with epilepsy, and the model better reflects the actual clinical situation.

Tofacitinib treatment for refractory autoimmune encephalitis

To treat intractable cases of autoimmune encephalitis, the need for novel immunotherapy that penetrates the blood-brain barrier (BBB) is increasing. Tofacitinib is a Janus kinase (JAK) inhibitor used to treat refractory immune-mediated diseases that effectively penetrates the BBB. Accordingly, tofacitinib could be a new option for patients with refractory autoimmune encephalitis. Patients treated with tofacitinib were selected from Seoul National University Hospital cohort for autoimmune encephalitis from April 2019 until July 2020. We retrospectively analyzed the efficacy of tofacitinib in patients with autoimmune encephalitis who showed insufficient responses to multimodal conventional immunotherapies. Tofacitinib was administered orally at a dose of 5 mg twice daily. A total of eight patients were treated with tofacitinib; two had good responses (clinical global impression-improvement score [CGI-I] = 1 or 2), three had partial responses (CGI-I = 3), and three showed no significant improvements (CGI-I = 4) in response to tofacitinib. The two good responders showed the improvement of chronic autoimmune meningoencephalitis and the cessation of the new-onset refractory status epilepticus in anti-myelin oligodendrocyte glycoprotein (MOG)-associated disorder, which was previously intractable to anesthetics and the other immunotherapies. No patients had serious side effects. Our findings suggest the potential of tofacitinib as a therapeutic option for central nervous system autoimmune diseases.

Anti-N-methyl-D-aspartate receptor encephalitis 8 years after serial herpes simplex virus type 1 and human herpesvirus type 7 encephalitis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is triggered by herpesvirus encephalitis. Human herpesvirus type 7 (HHV-7) is a recently described herpesvirus for which neuroinvasion has been reported rarely. We report a case of anti-NMDAR encephalitis detected 8 years after recurrent herpes encephalitis associated with herpes simplex virus type 1 and HHV-7 in an immunocompetent host. Our case suggests that anti-NMDAR encephalitis may be triggered by HHV-7 meningoencephalitis in immunocompetent adults, and patients with a history of herpesvirus encephalitis should be vigilantly monitored.

High-Dose Diazepam Controls Severe Dyskinesia in Anti-NMDA Receptor Encephalitis

Objective

Because there is no standard treatment to control dyskinesia in anti-NMDA receptor (NMDAR) encephalitis, we analyzed the therapeutic efficacy of high-dose diazepam in dyskinesia associated with NMDAR encephalitis.

Methods

We reviewed patients with NMDAR encephalitis with dyskinesia who were admitted to Seoul National University Hospital between November 2012 and July 2018. High-dose diazepam was administered orally or via a nasogastric tube 3-6 times a day. We assessed the treatment effect by comparing dyskinesia severity between the first day of the highest dose of diazepam and one week after the treatment.

Results

Among 68 patients with NMDAR encephalitis during the study period, 33 patients were treated with enteral diazepam (ranging from 6 to 180 mg) to control dyskinesia, along with immunotherapy. The severity of dyskinesia improved from average grade 2.4 ± 0.6 to 1.1 ± 0.7 after 1 week of the highest dose of diazepam (mean severity change -1.4 ± 0.6, 95% confidence interval -1.2 to -1.6; p < 0.001). No patients had serious adverse events except for mild sedation.

Conclusions

Dyskinesia in NMDAR encephalitis improved after treatment with enteral diazepam without significant side effects. This study suggests that enteral diazepam could be a treatment option for control dyskinesia in NMDAR encephalitis.

Classification of Evidence

This study provides Class IV evidence that for patients with dyskinesias associated with NMDAR encephalitis, enteral diazepam is effective and safe in dyskinesia control.

Machine learning for predicting fractional flow reserve based on optical coherence tomography in intermediate coronary stenosis

Background

Machine learning approaches using intravascular optical coherence tomography (OCT) to predict fractional flow reserve (FFR) have not been previously investigated. The objective of the study was to evaluate a machine learning method to estimate FFR based on intravascular OCT images in intermediate coronary lesions.

Methods

Data from both OCT- and wire-based FFR methods were obtained for lesions of the left anterior descending artery in 125 patients. Based on the total number of lesions, training and testing groups were partitioned at a ratio of 5:1. For the training group, 36 features, including 16 clinical and lesion characteristics, and 21 OCT features, were used to model machine learning-FFR. machine learning-FFR values were then derived for the testing group and compared with wire-based FFR values in terms of a diagnosis of ischemia (FFR &lt;0.8).

Results

Clinical and lesion characteristics and OCT features between the training and testing groups were similar. During the machine learning modeling of the training group, six important features of machine learning-FFR were identified: minimal luminal area, percentage of the stenotic area, lesion length, proximal luminal area, pre-procedural platelet count, and hypertension. machine learning-FFR values showed a good correlation (r=0.853, P&lt;0.001) with wire-based FFR values (Figure 1A). The diagnostic power of an FFR value less than 0.8, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of machine learning-FFR values for the testing group were 85.7%, 100%, 100%, 77.8%, and 90.5%, respectively (Figure 1B). Additionally, OCT-based machine learning-FFR values showed a good diagnostic accuracy compared with other image-based FFR values.

Conclusions

The OCT-based machine learning-FFR method can be used to simultaneously acquire information on both image and functional modalities using one invasive procedure, suggesting that it may be used to optimize treatments for intermediate coronary artery stenosis, as well as save time and cost.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Funded by the Korean government (MSIT) (no. 2017R1A2B2003191)

HLAs associated with perampanel-induced psychiatric adverse effects in a Korean population

Perampanel (PER) is a new-generation antiepileptic drug that has an occasional but significant shortcoming, psychiatric adverse effects (PAEs). Recently, antiepileptic drug-related adverse reactions, such as skin rash and even PAEs, have been discovered to be correlated with certain human leukocyte antigen (HLA) types. Thus, we aimed to analyze specific HLA alleles as risk factors for PER-PAEs. We prospectively enrolled 17 patients with epilepsy who were prescribed PER between May 2016 and Jul 2018 at Seoul National University Hospital and developed PAEs while taking PER. Their HLA types were analyzed compared to those of 19 patients in the PAE-tolerant group and the general Korean population. In silico docking was performed with two different computational programs, AutoDock Vina and SwissDock, to theoretically evaluate the binding affinity of PER in the grooves of the specific HLA alleles. The HLA-DQB1*06:01, DRB1*08:03, and B*54:01 alleles were significantly associated with the patients who developed PER-PAEs compared with the general Korean population (odds ratio [OR] 3.94, p = 0.008, OR 9.24, p = 0.037, and OR 3.25, p = 0.041, respectively). As a haplotype, the combination of the three alleles was significantly more frequent in the PER-PAE group than in both the PER-tolerant group and the general Korean population. DQB1*06:01 and B*54:01 also demonstrated higher docking scores with PER than other alleles. This is the first study to analyze the association of PER-PAEs with specific HLA genotypes. Our results suggest that an HLA-associated genetic predisposition and a possible immunological mechanism are involved in the occurrence of PER-PAEs.

Case study: mepolizumab prevents progression of eosinophilic granulomatosis with polyangiitis with involvement of the central nervous system which is refractory to conventional immunotherapy

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis involving small-sized vessel. It manifests mainly as asthma or eosinophilia, but the literature reported involvement of the central nervous system (CNS) in 5%, while isolated CNS involvement is very rare. We describe a case of isolated CNS involvement of EGPA which was refractory to conventional immunotherapy and treated with mepolizumab, an anti-interluekin-5 monoclonal antibody. A previously healthy 51-year-old man was referred to the neurology department for memory decline persisting for a month. Magnetic resonance imaging (MRI) showed the multifocal lesion in the periventricular and frontal lobe. Analysis of cerebrospinal fluid revealed an elevated protein concentration and leukocytosis. Considering his age, clinical course, and laboratory findings, steroid and intravenous immunoglobulin was started for autoimmune encephalopathy. Two months after discharge, the patient experienced new symptom – gait disturbance. The follow-up MRI showed increased extent of the previous lesions and the new lesions. To confirm the diagnosis, brain biopsy was done, and the finding was consistent with EGPA. We decided to start mepolizumab as second-line treatment, and observe the stationary course and absence of further progression of the lesion in the follow-up MRI. Mepolizumab for EGPA patients was introduced to achieve protocol-defined remission and clinical benefit compared to the placebo group in the several studies. Our case signifies possibility of mepolizumab to halt further progression of the disease clinically and radiologically, for the patient with isolated CNS involvement of EGPA which is unresponsiveness to conventional immunotherapy.

Modification of the RANKL-RANK-binding site for the immunotherapeutic treatment of osteoporosis

Here, we proposed the use of mutated RANKL as an immunogen for active immunization and to induce anti-cytokine antibodies for osteoporosis treatment.

INTRODUCTION

Osteoclasts are responsible for bone resorption in bone-related disorders. Anti-cytokine therapeutic antibodies such as denosumab are effective for the treatment of osteoporosis. However, problems with antibody manufacturing and the immunogenicity caused by multiple antibody doses have led to the use of auto-cytokines as immunogens to induce anti-cytokine antibodies.

METHODS

RANKL was point-mutated based on the crystal structure of the complex of RANKL and its receptor RANK.

RESULTS

As a proof of concept, immunization with RANKL produced high levels of specific antibodies and blocked osteoclast development in vitro and inhibited osteoporosis in RANKL-treated or ovariectomized mouse models.

CONCLUSIONS

The results demonstrate the successful use of mutated RANKL as an immunogen for the induction of anti-RANKL immune response. This strategy is useful in general anti-cytokine immunotherapy to avoid toxic side effects of osteoporosis treatment.

Immunotherapy in Probable autoimmune encephalitis without detected autoantibody

Along with the rapidly expanding spectrum of autoimmune encephalitis (AE), probable AE with no detected autoantibody (AE-NoDab) has become a major category of AE. However, its clinical features, treatment, and prognosis were not demonstrated. In our institutional cohort of all consecutive patients with possible AE in 2012 – 2018, patients diagnosed with AE-NoDab were included in this study. AE-NoDab was subcategorized into limbic encephalitis (LE), acute disseminated encephalomyelitis (ADEM), and antibody negative probable AE (pAE). Patients’ clinical severity was assessed at every week for the first 12 weeks, at every month for the next 9 months, and then at every three months, using the modified Rankin scale (mRS) and the Clinical Assessment Scales in Autoimmune Encephalitis (CASE, score range 0–27) scores. Combination immunotherapy regimens used at each time point were categorized as steroid+immunoglobulin (SI), SI+Rituximab (anti CD-20 mAb, SIR), and SIR+ Tocilizumab (anti IL-6 mAb, SIRT). 136 patients (LE 52[38.2%], ADEM 14[10.3%], and pAE 70 [51.5%]) were followed-up for 39.0±19.6 (range 10–80) months. At last follow-up, 76 (55.9%) patients had favorable mRS outcomes (scores 0–2). Compared to 55 anti-NMDA receptor encephalitis patients, baseline severity was higher, use of immunotherapy was lower, and outcome was poorer in AE-NoDab. There was no difference in clinical characteristics, treatment, and outcomes among subcategories of AE-NoDab. In a linear mixed model analysis, using the SIRT regimen was more effective than conventional regimens such as SIR or SI in lowering CASE scores (both, P=0.001). Early diagnosis and use of combined immunotherapy consisting of SIRT is warranted to improve the poor outcomes of AE-NoDab.

A new rapid titration protocol for lamotrigine with reduced risk of skin rash

Introduction

Lamotrigine is one of the most widely used antiepileptic drugs, but it has a critical issue of a skin rash if the starting dose is too high or the escalation rate is too rapid. We investigated the efficacy and safety of a novel and rapid titration protocol for lamotrigine that takes only 11 days to reach a daily dose of 200 mg.

Methods

We prospectively enrolled 33 adult patients (age 18–85) who were diagnosed with epilepsy and started lamotrigine administration for the first time at a single tertiary hospital. Our new protocol starts with a subthreshold dose of the drug and then administer a stepwise-incremental dose until reaching the full therapeutic dose within 11 days.

Results

Of 29 patients analyzed, only two (6.9%) experienced idiosyncratic skin rash before the first follow-up visit at 2 weeks (±3 days). In addition, a therapeutic concentration was reached in more than 75% of studied patients after 2 weeks of lamotrigine administration

Discussion

These findings demonstrate the value of the novel tolerance induction protocol for lamotrigine, which could widen the available application of lamotrigine in various situations.

Clinical Approach to Autoimmune Epilepsy

Autoimmune epilepsy is a newly emerging area of epilepsy. The concept of “autoimmune” as an etiology has recently been revisited thanks to advances in autoimmune encephalitis and precision medicine with immunotherapies. Autoimmune epilepsy presents with specific clinical manifestations, and various diagnostic approaches including cerebrospinal fluid analysis, neuroimaging, and autoantibody tests are essential for its differential diagnosis. The diagnosis is often indeterminate despite performing a thorough evaluation, and therefore empirical immunotherapy may be applied according to the judgment of the clinician. Autoimmune epilepsy often manifests as new-onset refractory status epilepticus (NORSE). A patient classified as NORSE should receive empirical immunotherapy as soon as possible. On the other hand, a morecautious, stepwise approach is recommended for autoimmune epilepsy that presents with episodic events. The type of autoimmune epilepsy is also an important factor to consider when choosing from among various immunotherapy options. Clinicians should additionally take the characteristics of antiepileptic drugs into account when using them as an adjuvant therapy. This expert opinion discusses the diagnostic and treatment approaches for autoimmune epilepsy from a practical point of view.

P4393Current smoking and gender difference in South Korean AMI patients who underwent PCI with DES

Background

There is some debate on whether or not there is a gender difference is present between current smoking and cardiovascular disease.

Purpose

We decide to evaluate the impact of sex difference on the 2-year clinical outcomes in Korean acute myocardial infarction (AMI) patients who currently smoke and who underwent percutaneous coronary intervention (PCI) with drug-eluting stents (DES).

Methods

The data of this study was obtained from the Korea Acute Myocardial Infarction (KAMIR) registry. More than fifty high-volume universites or community hospitals with facilities for primary PCI and onsite cardiac surgery participated in this KAMIR registry. A total of 12565 current smoker AMI patients were enrolled and divided into the male (n=11767, 93.6%) or female (n=798, 6.4%) group. The clinical endpoint was the occurrence of major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), and total repeat revascularization.

Results

Before risk adjustment, the cumulative incidences of MACE (7.2% vs. 10.0%, hazard ratio [HR], 1.419; 95% confidence interval [CI], 1.125–1.790; P=0.003), all-cause death (HR, 1.988; 95% CI, 1.417–2.789; P<0.001), and re-MI (HR, 1.885; 95% CI, 1.154–3.078; P=0.011) were significantly higher in the female group compared with the male group. However, after adjustment the cumulative incidences of MACE (adjusted HR, 1.047; 95% CI, 0.756–1.450; P=0.782), all-cause death, re-MI, total repeat revascularization, TLR, TVR, and non-TVR were similar between the two groups.

Clinical outcomes at 2-year Outcomes Cumulative Events at 2-year (%) Unadjusted Adjusted* Propensity-score adjusted Male Female Log-rank Hazard Ratio (95% CI) p value Hazard Ratio (95% CI) p value Hazard Ratio (95% CI) p value MACE 819 (7.2) 78 (10.0) 0.003 1.419 (1.125–1.790) 0.003 1.047 (0.756–1.450) 0.782 1.133 (0.871–1.473) 0.352 All-cause death 283 (2.5) 38 (4.8) <0.001 1.988 (1.417–2.789) <0.001 0.764 (0.457–1.279) 0.306 1.105 (0.744–1.641) 0.620 Cardiac death 224 (1.9) 25 (3.2) 0.016 1.654 (1.094–2.500) 0.017 0.512 (0.261–1.005) 0.052 0.822 (0.511–1.322) 0.419 Re-MI 142 (1.3) 18 (2.4) 0.010 1.885 (1.154–3.078) 0.011 1.741 (0.887–3.419) 0.107 1.835 (1.109–3.375) 0.062 Total revascularization 444 (4.0) 27 (3.6) 0.594 0.900 (0.610–1.327) 0.594 1.069 (0.654–1.748) 0.789 0.956 (0.627–1.458) 0.835 TLR 121 (1.1) 8 (1.1) 0.956 0.980 (0.479–2.004) 0.956 0.955 (0.366–2.497) 0.926 0.868 (0.395–1.910) 0.726 TVR 228 (2.1) 14 (1.9) 0.726 0.908 (0.529–1.558) 0.726 1.051 (0.518–2.135) 0.890 0.935 (0.519–1.684) 0.823 Non-TVR 223 (2.0) 13 (1.7) 0.602 0.862 (0.493–1.508) 0.602 1.060 (0.536–2.097) 0.867 0.942 (0.514–1.726) 0.847

Conclusion

Before risk adjustment, a gender difference was suggested in the female group compared with the male in these current smoker South Korean AMI patients during a 2-year follow-up period. However, after adjustment, gender difference was not observed in these AMI patients with a history of current smoking.

P833Two-year clinical outcomes between statin with ACE inhibitor or ARB in patients with ST-segment elevation myocardial infarction after successful PCI with DES

Background

Limited comparative data are available.

Purpose

We decided to compare 2-year major clinical outcomes between statin with ACEI and statin ARB therapy in patients with STEMI after PCI with drug-eluting stents (DES).

Methods

A total 11706 STEMI patients who underwent PCI with DES and who prescribed statin were enrolled and they were divided into two groups, the statin with ACEI group (n=8705) and the statin with ARB group (n=3001). The primary endpoint was the major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), target lesion revascularization (TLR), target vessel revascularization (TVR), non-TVR. The secondary endpoints were the cumulative incidences of individual components of MACE and target vessel failure (TVF), a composite of death related to the target vessel, re-MI, or clinically driven TVR.

Results

Two PSM groups (2835 pairs, n=5670, C-statistic = 0.680) were generated. The relative risk of MACE was higher in the statin with ARB group compared to statin with ACEI groups after propensity score-matched (PSM) analysis (hazard ratio [HR]: 1.323, 95% confidence interval [CI]: 1.085–1.613, p=0.006). The relative risks of cardiac death (HR: 1.831, 95% CI: 1.199–2.740, p=0.005), total repeat revascularization (HR: 1.487, 95% CI: 1.133–1.950, p=0.004), and non-TVR (HR: 1.696, 95% CI: 1.122–2.564, p=0.012) were also higher in the statin with ARB group after PSM.

Outcomes Cumulative Events at 2-year (%) Hazard Ratio (95% CI) p value Statin + ACEI Statin + ARB Log-rank Propensity score matched Patients MACE 173 (6.5) 225 (8.5) 0.006 1.323 (1.085–1.613) 0.006 All-cause death 58 (2.2) 80 (3.0) 0.054 1.391 (0.992–1.950) 0.056 Cardiac death 35 (1.3) 63 (2.3) 0.004 1.831 (1.199–2.740) 0.005 Re-MI 39 (1.5) 44 (1.7) 0.548 1.141 (0.742–1.756) 0.548 Total repeat revascularization 88 (3.4) 128 (4.9) 0.004 1.487 (1.133–1.950) 0.004 TLR 26 (1.0) 40 (1.5) 0.075 1.561 (0.953–2.558) 0.077 TVR 53 (2.0) 71 (2.8) 0.086 1.364 (0.955–1.946) 0.088 Non-TVR 36 (1.4) 60 (2.3) 0.011 1.696 (1.122–2.564) 0.012 TVF 140 (5.3) 173 (6.6) 0.050 1.249 (1.000–1.561) 0.050

Conclusions

In this study, we suggest that the combination of statin with ACEI may be beneficial for reducing the cumulative incidences of MACE, total repeat revascularization rate, and non-TVR rather than the statin with ARB after PCI with DES in STEMI patients.

P5362Impact of statin therapy on long-term clinical outcomes between STEMI and NSTEMI after stent implantation

Background

Although European guideline recommends that statin should be given to all patients with acute myocardial infarction (AMI), irrespective of cholesterol concentration, limited studies were focused on the long-term effects of statin therapy between ST-segment elevation MI (STEMI) and non-ST-segment elevation MI (NSTEMI).

Purpose

The authors conducted the study to compare the relative beneficial role of statin on 2-year major clinical outcomes between STEMI and NSTEMI in patients who underwent successful PCI with DES.

Methods

Finally, a total of 26317 AMI patients who underwent stent implantation and who were prescribed the statin were enrolled and they were separated into two groups; the STEMI group (n=15002) and the NSTEMI group (n=11315). The clinical endpoint was the occurrence of major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), total coronary revascularization (target lesion revascularization [TLR], target vessel revascularization [TVR], non-TVR) during 2-year follow-up period.

Results

After propensity score-matched (PSM) analysis, two PSM groups (7746 pairs, n=15492, C-statistic = 0.766) were generated. In the total study population, the cumulative incidences of MACE, all-cause death, and cardiac death were significantly higher in the NSTEMI group. However, after PSM, the cumulative incidence of all-cause death (Hazard ratio, 1.386; 95% CI, 1.133–1.696; p=0.002) was significantly higher in the NSTEMI group. The cumulative incidences of MACE, cardiac death, re-MI, total revascularization, TLR, TVR, and non-TVR were similar between the two groups (Table 1).

Outcomes Cumulative Events at 2-year (%) Hazard Ratio (95% CI) p value STEMI NSTEMI Log-rank Propensity score matched patients MACE 532 (7.2) 584 (8.1) 0.092 1.106 (0.984–1.244) 0.092 All-cause death 163 (2.2) 224 (3.1) 0.001 1.386 (1.133–1.696) 0.002 Cardiac death 121 (1.5) 148 (2.0) 0.088 1.232 (0.969–1.566) 0.089 Re-MI 117 (1.6) 107 (1.5) 0.545 0.922 (0.710–1.199) 0.545 Total revascularization 291 (4.1) 307 (4.4) 0.422 1.068 (0.910–1.254) 0.423 TLR 92 (1.3) 89 (1.2) 0.880 0.978 (0.731–1.309) 0.880 TVR 173 (2.4) 184 (2.6) 0.478 1.078 (0.876–1.327) 0.478 Non-TVR 123 (1.7) 130 (1.9) 0.593 1.070 (0.836–1.369) 0.539

Conclusion

The mortality reduction capability of statin was more prominent in the STEMI group compared with the NSTEMI group.

P5494Impact of the gender difference on long-term clinical outcomes in dyslipidemic South Korean AMI patients who underwent PCI with new-generation DES

Background

There are limited comparative data concerning long-term major clinical outcomes between male and female in dyslipidemic AMI patients after PCI with new-generation DES.

Purpose

We thought to investigate the impact of gender difference on the 2-year clinical outcomes.

Methods

Finally, a total of 2403 eligible dyslipidemic AMI patients who underwent PCI with new-generation DES were enrolled and they were separated into two groups; the male group (n=1800) and the female group (n=603). The primary endpoint was major adverse cardiac events (MACE) defined as all-cause death, recurrent myocardial infarction (re-MI), target lesion revascularization (TLR), and target vessel revascularization (TVR). The secondary endpoints were the incidence of the individual components of MACE and target vessel failure (TVF), a composite of death related to the target vessel, re-MI, or clinically driven TVR

Results

Two propensity score-matched (PSM) groups (422 pairs, n=844, C-statistic = 0.850) were generated. In the total study population, the cumulative incidences of MACE, all-cause death, re-MI, and TVF were significantly higher in the female group compared with the male group. However, after propensity score-matched (PSM) analysis, the cumulative incidences of MACE (HR, 0.971; 95% CI, 0.628–1.501; p=0.895), all-cause death (HR, 1.061; 95% CI, 0.536–2.100; p=0.865), re-MI (HR, 1.212; 95% CI, 0.433–2.907; p=0.813), and TVF (HR, 0.764; 95% CI, 0.474–1.229; p=0.267) were similar between the two groups. In addition, the cumulative incidences of cardiac death, TLR, TVR were not significantly different between the two groups (Table 1).

Outcomes Cumulative Events at 2-year (%) Hazard Ratio (95% CI) p value Male Female Log-rank Propensity score matched patients MACE 41 (10.4) 40 (10.3) 0.895 0.971 (0.628–1.501) 0.895 All-cause death 16 (4.0) 17 (4.2) 0.865 1.061 (0.536–2.100) 0.865 Cardiac death 13 (3.3) 9 (2.2) 0.391 0.691 (0.295–1.616) 0.393 Re-MI 8 (2.0) 9 (2.4) 0.813 1.212 (0.433–2.907) 0.813 TLR 7 (1.8) 6 (1.6) 0.781 0.857 (0.298–2.550) 0.781 TVR 16 (4.3) 10 (2.7) 0.236 0.623 (0.283–1.373) 0.241 TVF 39 (10.2) 30 (7.8) 0.265 0.764 (0.474–1.229) 0.267

Conclusion

The gender difference was not apparent in these dyslipidemic South Korean AMI patients who underwent PCI with new-generation DES during 2-year follow-up period.

Hypoxia improves hair inductivity of dermal papilla cells via nuclear NADPH oxidase 4-mediated reactive oxygen species generation'

BACKGROUND

Dermal papilla cells (DPCs) play a key role in hair regeneration and morphogenesis. Therefore, tremendous efforts have been made to promote DPC hair inductivity.

OBJECTIVES

The aim of this study was to investigate the mitogenic and hair inductive effects of hypoxia on DPCs and examine the underlying mechanism of hypoxia-induced stimulation of DPCs.

METHODS

DPCs' hair inductivity was examined under normoxia (20% O₂ ) and hypoxia (2% O₂ ).

RESULTS

Hypoxia significantly increased the proliferation and delayed senescence of DPCs via Akt phosphorylation and downstream pathways. Hypoxia upregulated growth factor secretion of DPCs through the mitogen-activated protein kinase pathway. Hypoxia-preconditioned DPCs induced the telogen-to-anagen transition in C₃ H mice, and also enhanced hair neogenesis in a hair reconstitution assay. Injected green fluorescent protein-labelled DPCs migrated to the outer root sheath of the hair follicle, and hypoxia-preconditioning increased survival and migration of DPCs in vivo. Conditioned medium obtained from hypoxia increased the hair length of mouse vibrissa follicles via upregulation of alkaline phosphatase, vascular endothelial growth factor, and glial cell line-derived neurotrophic factor. We examined the mechanism of this hypoxia-induced stimulation, and found that reactive oxygen species (ROS) play a key role. For example, inhibition of ROS generation by N-acetylcysteine or diphenyleneiodonium treatment attenuated DPCs' hypoxia-induced stimulation, but treatment with ROS donors induced mitogenic effects and anagen transition. NADPH oxidase 4 is highly expressed in the DPC nuclear region, and NOX4 knockout by CRISPR-Cas9 attenuated the hypoxia-induced stimulation of DPCs.

CONCLUSIONS

Our results suggest that DPC culture under hypoxia has great advantages over normoxia, and is a novel solution for producing DPCs for cell therapy. What's already known about this topic? Dermal papilla cells (DPCs) play a key role in hair regeneration and morphogenesis, but they are difficult to isolate and expand for use in cell therapy. Tremendous efforts have been made to increase proliferation of DPCs and promote their hair formation ability. What does this study add? Hypoxia (2% O₂ ) culture of DPCs increases proliferation, delays senescence and enhances hair inductivity of DPCs. Reactive oxygen species play a key role in hypoxia-induced stimulation of DPC. What is the translational message? Preconditioning DPCs under hypoxia improves their hair regenerative potential, and is a novel solution for producing DPCs for cell therapy to treat hair loss.

Diagnosis of Haemophilus influenzae Pneumonia by Nanopore 16S Amplicon Sequencing of Sputum

We used deep sequencing of the 16S rRNA gene from sputum to identify Haemophilus influenza in a patient with community-acquired pneumonia. This method may be more effective than conventional diagnostic tests in pneumonia patients because of its speed and sensitivity.

Cerebral autoinflammatory disease treated with anakinra

Interest in autoimmune encephalitis has been growing since the discovery of various autoimmune antibodies, such as N‐methyl D‐aspartate receptors antibody and leucine‐rich glioma‐inactivated 1 antibody. However, in contrast to autoimmune encephalitis associated with dysregulated adaptive immunity in the brain, the question of whether innate immunity‐mediated autoinflammatory diseases exist in the brain has drawn much attention. Herein, we report a patient with microglia‐dominant acute autoinflammatory encephalitis successfully treated with anakinra, an including interleukin‐1 receptor blocker. In comparison to systemic autoinflammatory disease, we term this encephalitis cerebral autoinflammatory disease. Cerebral autoinflammatory disease could suggest new conceptual approaches to patients previously diagnosed with an unspecified encephalitis.

LGI1 expression and human brain asymmetry: insights from patients with LGI1-antibody encephalitis

Background

While brain asymmetry has been a fascinating issue in neuroscience, the critical mechanism remains to be elucidated. Based on some index cases with asymmetric 18F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) uptake in leucine-rich glioma-inactivated 1 (LGI1)-antibody encephalitis, we hypothesized LGI1 expression could be asymmetrically distributed in the human brain.

Methods

We enrolled 13 patients who were diagnosed with LGI1-antibody encephalitis between June 2012 and January 2018 at Seoul National University Hospital. Their pretreatment 18F-FDG-PET images were analyzed to find asymmetry between the left and right hemispheres. Guided by these observations, expression of LGI1 in the human hippocampus and the globus pallidus of both cerebral hemispheres was studied in nine post-mortem human brains.

Results

Eleven of the 13 LGI1-antibody encephalitis patients (84.6%) showed asymmetrical FDG high uptake in the hippocampus: nine (81.8%) on the left hippocampus and two (18.2%) on the right. In the basal ganglia, seven patients (53.8%) showed asymmetry: four (57.1%) on the left and three (42.9%) on the right. The asymmetry was not evident in the laterality of faciobrachial dystonic seizures, brain MRI, and EEG. When the expression of LGI1 protein was analyzed in nine post-mortem human brains by western blotting, LGI1 expression was higher on eight left globus pallidus samples (88.89%, P = 0.019) and on four left hippocampal samples (44.44%, P = 0.652), compared to their right hemisphere samples.

Conclusions

Imaging parameters from patients with LGI1-antibody encephalitis and studies of LGI1 protein expression suggest that LGI1 is asymmetrically distributed in the human brain. These observations have implications for our understanding of human brain development.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1314-2) contains supplementary material, which is available to authorized users.

Case of Rickettsia typhi-induced Brain Abscess Mimicking Brain Tumor

Murine typhus is one of the most prevalent rickettsial infections in the world, caused by the bacterial genus Rickettsia. Though the disease manifests a relatively benign clinical course with fever, rash, and headache being the 3 classic symptoms, neurological complications may arise in patients that could become permanent. In this case study, a patient with a brain abscess caused by R typhi infection is described. Based upon the recent reemergence of arthropod-borne disease, the findings in this case are significant; R typhi can cause a brain abscess that mimics a brain tumor, which delays the diagnosis and appropriate management of the disease. Murine typhus should always be considered when performing the differential diagnosis of brain abscesses in South Korea.

Associations of a social network typology with physical and mental health risks among older adults in South Korea

OBJECTIVES

The objectives of this study were to (1) develop an empirical typology of social networks in older Koreans; and (2) examine its effect on physical and mental health.

METHOD

A sample of 6900 community-dwelling older adults in South Korea was drawn from the 2014 Korean National Elderly Survey. Latent profile analysis (LPA) was conducted to derive social network types using eight common social network characteristics (marital status, living arrangement, the number and frequency of contact with close family/relatives, the number and frequency of contact with close friends, frequency of participation in social activities, and frequency of having visitors at home). The identified typologies were then regressed on self-rated health and depressive symptoms to explore the health risks posed by the group membership.

RESULTS

The LPA identified a model with five types of social network as being most optimal (BIC = 153,848.34, entropy = .90). The groups were named diverse/family (enriched networks with more engagement with family), diverse/friend (enriched networks with more engagement with friends), friend-focused (high engagement with friends), distant (structurally disengaged), and restricted (structurally engaged but disengaged in family/friends networks). A series of regression analyses showed that membership in the restricted type was associated with more health and mental health risks than all types of social networks except the distant type.

CONCLUSION

Findings demonstrate the importance of family and friends as a source of social network and call attention to not only structural but also non-structural aspects of social isolation. Findings and implications are discussed in cultural contexts.