Prevalence and Characterization of NOTCH2NLC GGC Repeat Expansions in Koreans: From a Hospital Cohort Analysis to a Population-Wide Study

Background and Objectives

GGC repeat expansions in the NOTCH2NLC gene are associated with a broad spectrum of progressive neurologic disorders, notably, neuronal intranuclear inclusion disease (NIID). We aimed to investigate the population-wide prevalence and clinical manifestations of NOTCH2NLC-related disorders in Koreans.

Methods

We conducted a study using 2 different cohorts from the Korean population. Patients with available brain MRI scans from Seoul National University Hospital (SNUH) were thoroughly reviewed, and NIID-suspected patients presenting the zigzag edging signs underwent genetic evaluation for NOTCH2NLC repeats by Cas9-mediated nanopore sequencing. In addition, we analyzed whole-genome sequencing data from 3,887 individuals in the Korea Biobank cohort to estimate the distribution of the repeat counts in Koreans and to identify putative patients with expanded alleles and neurologic phenotypes.

Results

In the SNUH cohort, among 90 adult-onset leukoencephalopathy patients with unknown etiologies, we found 20 patients with zigzag edging signs. Except for 2 diagnosed with fragile X-associated tremor/ataxia syndrome and 2 with unavailable samples, all 16 patients (17.8%) were diagnosed with NIID (repeat range: 87-217). By analyzing the Korea Biobank cohort, we estimated the distribution of repeat counts and threshold (>64) for Koreans, identifying 6 potential patients with NIID. Furthermore, long-read sequencing enabled the elucidation of transmission and epigenetic patterns of NOTCH2NLC repeats within a family affected by pediatric-onset NIID.

Discussion

This study presents the population-wide distribution of NOTCH2NLC repeats and the estimated prevalence of NIID in Koreans, providing valuable insights into the association between repeat counts and disease manifestations in diverse neurologic disorders.

Long-term effects of adjunctive eslicarbazepine acetate in adult Asian patients with refractory focal seizures: Post hoc analysis of a phase III trial

A post hoc analysis of data from Asian patients included in the study BIA-2093-304 was conducted to evaluate the long-term safety/tolerability and efficacy of adjunctive eslicarbazepine acetate (ESL) in adult Asian patients with refractory focal seizures. Part I was a randomized controlled trial, in which patients received ESL (800 or 1200 mg once daily [QD]) or placebo, assessed over a 12-week maintenance period. Patients completing Part I could enter two open-label extension periods (Part II, 1 year; Part III, ≥2 years), during which all received ESL (400-1600 mg QD). Safety/tolerability was assessed by evaluating treatment-emergent adverse events (TEAEs). Efficacy assessments included responder and seizure freedom rates. The safety population included 125, 92, and 23 Asian patients in Parts I, II, and III, respectively. Incidence of ESL-related TEAEs was 61.3%, 45.7%, and 17.4% during Parts I, II, and III, respectively. ESL-related TEAEs (most commonly, dizziness, somnolence, and headache) were consistent with ESL's known safety profile. During Part I, responder rates were higher with ESL 800 (41.7%) and 1200 mg QD (44.4%) versus placebo (32.6%), although not statistically significant. Seizure freedom rates with ESL 800 (5.5%) and 1200 mg QD (11.1%) were also higher versus placebo (0%) (p < 0.05 for ESL 1200 mg QD versus placebo). At the end of Part II, responder and seizure freedom rates were 60.3% and 14.7%, respectively. In summary, adult Asian patients with refractory focal seizures were responsive to treatment with ESL as adjunctive therapy and generally showed treatment tolerance well for up to 3 years. No new/unexpected safety findings were observed.

Long-term efficacy and safety of adjunctive perampanel in patients from the Asia-Pacific region with refractory focal-onset seizures in Study 335 open-label extension

OBJECTIVE

To evaluate the long-term efficacy, safety, and tolerability of adjunctive perampanel for the treatment of patients with refractory focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS), from the Asia-Pacific region.

METHODS

Study 335 (NCT01618695) was a randomized, double-blind, placebo-controlled, Phase III study. Patients aged ≥12 years with refractory FOS who completed the Core Study could enter an open-label extension (OLEx) Phase (6-week Conversion and ≥46-week Maintenance Period). Endpoints included median percent reduction in seizure frequency per 28 days, 50% responder and seizure-freedom rates, and treatment-emergent adverse events (TEAEs).

RESULTS

The Intent-to-Treat Analysis Set included 704 patients (529 received perampanel and 175 received placebo during the Core Study; all patients received perampanel during OLEx). The median percent reduction in seizure frequency and 50% responder rates in patients who received perampanel during the Core Study were maintained throughout the OLEx Phase (Week 64-75: 55.9% and 54.3%, respectively). Seizure freedom for ≥12 consecutive months at any time during perampanel treatment was achieved by 4.1% of patients with FOS and 14.2% of patients with FBTCS. Among patients treated with perampanel 4 mg/day (n = 83), median reduction in seizure frequency was lower in those who received concomitant enzyme-inducing anti-seizure medications (EIASMs) than those who received non-EIASMs. The most common TEAE was dizziness (n = 318; 46.8%); 141 (20.8%) patients had TEAEs that led to study/drug withdrawal.

SIGNIFICANCE

Overall, long-term seizure control was achieved with adjunctive perampanel in patients with refractory FOS, with or without FBTCS, in an Asia-Pacific population.

Chronic social stress in early life can predispose mice to antisocial maltreating behavior

Purpose

In our previous study, we developed an assay system to evaluate antisocial maltreating behavior of conspecific mice using a perpetrator-victim paradigm. We also generated a mouse model for the maltreating behavior by mimicking child maltreatment or abuse. Here, we further investigate the antisocial behavior using anti-aggressive and antipsychotic drugs.

Methods

Model mice sequentially subjected to maternal separation (MS), social defeat (SD), and social isolation (SI) in that order (MS/SD/SI model) were subjected to a maltreating behavioral task. The MS/SD/SI mice were treated with oxytocin (OXY), clozapine (CLZ), haloperidol (HAL), and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Western blotting and enzyme-linked immunosorbent assay were used for protein analysis.

Results

A substantial portion of the MS/SD/SI model mice (46% of males and 40% of females) showed a higher number of nose pokes than the control. OXY or 8-OH-DPAT treatment reduced the high number of nose pokes by the MS/SD/SI mice, whereas HAL increased it. CLZ did not affect the number of nose pokes by the MS/SD/SI mice. Interestingly, although the OXY level in the MS/SD/SI mice was similar to that in the control, the amount of OXY receptor was lower in the MS/SD/SI mice. The amount of 5-HT1A receptor was also decreased in the MS/SD/SI mice.

Conclusion

Chronic social stress in childhood might predispose a mouse to antisocial behavior. Our maltreating behavior assay system, including the MS/SD/SI model, is a good animal system for research on and drug screening for brain disorders associated with antisocial or psychotic behavior.

Treatment compliance, treatment patterns, and healthcare utilization in epilepsy patients with first add-on antiepileptic drugs: A nationwide cohort study

Objective

This study aimed to assess the treatment compliance, patterns, healthcare resource utilization (HCRU), and costs of anti-epilepsy drugs (AEDs) as the first add-on therapy in patients with epilepsy.

Methods

We conducted a retrospective population-based cohort study using Korean National Health Insurance claims data from 2016 to 2020. Patients with epilepsy who newly received AED add-on therapy were identified and followed for up to 12 months to evaluate persistence, adherence, treatment patterns, HCRU, and costs.

Results

Among 6,746 patients who initiated AED add-on therapy, 65.5% were persistent on their index AED add-on from the index date until the end of the follow-up period, and the mean persistent time on the index add-on was 307.3 ± 92.3 days. A total of 76.8% patients were adherent, with a medication possession ratio (MPR) ≥80%, and the mean MPR was 88.9 ± 25.4%. Persistence and adherence to the index AED add-on were relatively higher among patients prescribed lamotrigine, levetiracetam, oxcarbazepine, and perampanel than those prescribed carbamazepine, topiramate, or valproate. A total of 41.0% of the patients changed their index AED add-on during the follow-up period. The carbamazepine, topiramate, and valproate groups had higher rates of change than the other AED groups. HCRU and costs tended to be lower in the lamotrigine, levetiracetam, oxcarbazepine, and perampanel groups. Furthermore, perampanel showed the lowest HCRU and costs for all-cause cases as well as the lowest length of stay and outpatient visits for epilepsy-related cases.

Conclusion

In this population-based study, the use of lamotrigine, levetiracetam, oxcarbazepine, or perampanel as the first add-on therapy in patients with epilepsy contributed to better treatment compliance and lower HCRU and costs than that of carbamazepine, topiramate, or valproate.

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.

Regional variations in retinopathy of prematurity incidence for preterm infants <32 weeks' gestation in China

OBJECTIVES

National-level data on the incidence of retinopathy of prematurity (ROP) in different regions of China is insufficient. This study aimed to compare ROP incidences and care practices in different regions of China and their relationship with regional gross domestic product (GDP) per capita.

STUDY DESIGN

Retrospective cohort study.

METHODS

All infants born at <32 weeks gestational age (GA) and admitted to 70 neonatal intensive care units (NICUs) from January 1, 2019, to December 31, 2020, were enrolled. Hospitals were categorised into three regional groups according to geographical locations and GDP per capita from high to low: Eastern, Central, and Western China. The incidence of death or ROP, and care practices were compared among the groups.

RESULTS

A total of 18,579 infants were enrolled. Median GA was 29.9 (interquartile range 28.4-31.0) weeks and birth weight was 1318.1 (317.2) g. The percentage of GA <28 weeks, complete administration of antenatal steroids, and weight gain velocity during NICU stay were highest in Eastern China and lowest in Western China (all P < 0.01). In Eastern, Central, and Western China, the rates of death or any stage of ROP were 33.3%, 38.5%, and 39.2%, respectively (P < 0.01).

CONCLUSIONS

There were considerable regional disparities in ROP incidence in preterm infants with GA <32 weeks in China. The incidence of death or ROP ranged from high to low in Western, Central, and Eastern China.

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.

Using spectral and temporal filters with EEG signal to predict the temporal lobe epilepsy outcome after antiseizure medication via machine learning

Epilepsy is a neurological disorder in which the brain is transiently altered. Predicting outcomes in epilepsy is essential for providing feedback that can foster improved outcomes in the future. This study aimed to investigate whether applying spectral and temporal filters to resting-state electroencephalography (EEG) signals could improve the prediction of outcomes for patients taking antiseizure medication to treat temporal lobe epilepsy (TLE). We collected EEG data from a total of 46 patients (divided into a seizure-free group (SF, n = 22) and a non-seizure-free group (NSF, n = 24)) with TLE and retrospectively reviewed their clinical data. We segmented spectral and temporal ranges with various time-domain features (Hjorth parameters, statistical parameters, energy, zero-crossing rate, inter-channel correlation, inter-channel phase locking value and spectral information derived from Fourier transform, Stockwell transform, and wavelet transform) and compared their performance by applying an optimal frequency strategy, an optimal duration strategy, and a combination strategy. For all time-domain features, the optimal frequency and time combination strategy showed the highest performance in distinguishing SF patients from NSF patients (area under the curve (AUC) = 0.790 ± 0.159). Furthermore, optimal performance was achieved by utilizing a feature vector derived from statistical parameters within the 39- to 41-Hz frequency band with a window length of 210 s, as evidenced by an AUC of 0.748. By identifying the optimal parameters, we improved the performance of the prediction model. These parameters can serve as standard parameters for predicting outcomes based on resting-state EEG signals.

Is the 'safe zone' identified in preoperative computed tomography helpful for choosing optimal implant for fixation of radial head fracture?

The purpose of this study is to assess the clinical significance of the radiologic safe zone based on computed tomography and to compare the outcomes of three different implants for fixation of isolated radial head fractures. We retrospectively reviewed 367 patients who underwent internal fixation for isolated radial head fractures. We newly defined two subtypes of Mason type II fractures associated with the radiographic safe zone (IIA, two-part fracture allowing for safe fixation of plate; IIB, two-part fracture not allowing for safe fixation). 170 patients (CCS group, n = 82; HCS group, n = 31; plate group, n = 57) were investigated with no significant differences in demographics. The range of pronation and supination at 1 month postoperatively (P = 0.04 and P = 0.04) and the range of supination at 6 and 12 months postoperatively (P = 0.03 and P = 0.03) were significantly smaller in the plate group. In Mason type IIB fractures, the average MEPS was higher in the CCS and HSC groups than in the plate group (P = 0.01 and P = 0.02). And the average DASH score was lower in the CCS and HCS groups (P < 0.01 and P < 0.01). Evaluation of the radiologic safe zone is potentially helpful in selecting better surgical fixation option. For type III fractures, 2.3-mm cortical screws would be a better option than Acutrak screws. Plates would not be suitable for type IIB radial head fractures.

Issues of Women with Epilepsy and Suitable Antiseizure Drugs

Seizure aggravation in women with epilepsy (WWE) tends to occur at two specific times during the menstrual cycle: the perimenstrual phase and the ovulation period. Antiseizure drugs (ASDs), especially those that induce enzymes, can accelerate the metabolism of hormones in oral contraceptives, rendering them less effective. Estrogen in contraceptive pills increases the metabolism of lamotrigine. Physiological changes during pregnancy can significantly impact the pharmacokinetics of ASDs, potentially necessitating adjustments in dosage for women with epilepsy to maintain seizure control. The use of valproate in pregnant women is associated with the highest risk of major congenital malformations among ASDs. Risks of major congenital malformations associated with lamotrigine, levetiracetam, and oxcarbazepine were within the range reported in the general population. Exposure to valproate can lead to lower IQ in offspring. Reduced folic acid levels are linked to orofacial clefts, cardiovascular malformations, and urogenital and limb anomalies in WWE. Decreased folate levels are expected with the use of enzyme-inducing ASDs. However, a high dose of folate was associated with an increased risk of cancer in children of mothers with epilepsy. Most ASDs are generally considered safe for breastfeeding and should be encouraged. However, no single ASD is considered ideal for childbearing WWE. Lamotrigine and levetiracetam are relatively more suitable options for this situation.

Who are the Better Candidates for Epilepsy Surgery?

The resective epilepsy surgery can be the effective procedure to get seizure-free outcome in these drug resistant epilepsy (DRE) patients. Class I evidence firmly establishes the superiority of epilepsy surgery over medical treatments in both seizure control and quality of life for DRE patients. For the effective identification of optimal surgical candidates, it's essential to understand the prognostic factors of epilepsy surgery based on the surgical methods employed. Established positive prognostic indicators for temporal resection include the presence of hippocampal sclerosis on magnetic resonance imaging (MRI), focal lesions on MRI, unilateral temporal spikes, concordant ictal electroencephalography (EEG), and a history of prolonged febrile convulsion. Potential negative predictors encompass preoperative secondary generalized tonic-clonic seizures, a normal MRI, postoperative EEG spikes, and age at the time of surgery. For neocortical epilepsy, the prognostic factors identified through multivariate analysis were the presence of a discrete lesion, localized hypometabolism on Fluorodeoxyglucose positron emission tomography (FDG-PET), and localized ictal EEG. A significant correlation was found between achieving a seizure-free outcome in no visible lesion on MRI (MR-negative) epilepsy patients and having concordance in two or more presurgical evaluations, specifically in interictal EEG, ictal EEG, FDG-PET, and ictal single-photon emission computed tomography. There was a marked improvement in the seizure-free outcome in MR-negative temporal lobe epilepsy (TLE) by the application of this strategy. The better surgical candidates for epilepsy surgery are the followings: patients displaying a discrete lesion on MRI with concordant video-EEG monitoring (VEM) results, patients diagnosed with unilateral hippocampal sclerosis who have concordant VEM results, patients with unilateral hippocampal sclerosis but discordant VEM results, patients with focal cortical dysplasia and concordant VEM results, and patients diagnosed with MR-negative TLE who exhibit two or more consistent results from presurgical evaluations.

Identification of bacterial pathogens in brain abscesses by metagenomic approach using nanopore 16S amplicon sequencing

Brain abscess is medically challenging. In this study, we applied nanopore sequencing for 16S rRNA analysis and investigated its efficacy and diagnostic value for patients with brain abscesses. Genomic DNA was extracted from the pus samples (n = 27) of brain abscess, and 16S rRNA genes were amplified by PCR. Sequencing libraries were generated using a rapid barcoding kit, and the generated reads were analyzed using the EPI2ME16S workflow. A conventional culture study was performed. More sensitive identification of pathogens was made by 16S sequencing, faster than the culture study. The proportion of anaerobic bacteria identified by 16S sequencing was higher (75%) than that obtained by culturing (32%). Polymicrobial infections were identified in 10 cases (40%) by 16S sequencing, while the culture study identified multiple bacteria in only 2 cases (8%). 16S sequencing was useful for identifying the composition of polymicrobial infections, including rare pathogens, and for the initial diagnosis of space-occupying lesions.

Midline catheters in the operating room

Backgrounds

Among various vascular access devices, midline catheters (MCs) are commonly used in emergency departments, but rarely in operating rooms.

Aims

To evaluate the feasibility and safety of MCs in the operating room.

Materials and Methods

This was a retrospective study. The medical records of patients who underwent MC placement in the operating room from October 2020 to July 2022 were reviewed. The rates of successful catheter insertion as well as major and minor complications were assessed.

Results

Successful catheter insertions were achieved in 149 of 161 patients (92.5%). The median dwell time of midlines was eight days (IQR: 6-10 days). A major or minor complication occurred in 6.7% of the midlines. The rates of major complications of occlusion, upper extremity deep vein thrombosis (DVT), and catheter-related bloodstream infection were 1.3%, 0.7%, and 0%, respectively.

Conclusions

Placement of MCs in the operating room was feasible and safe. Also, the procedure provides an acceptable alternative for replacing central line catheters and peripherally inserted central catheters.

Five-Year Retention of Perampanel and Polytherapy Patterns: 328 Patients From a Single Center in South Korea

BACKGROUND AND PURPOSE

Perampanel (PER) is an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonist used to treat focal and generalized epilepsy. Comprehensive data from real-world settings with long-term follow-ups are still scarce. This study aimed to determine the factors related to PER retention and the polytherapy pattern with PER.

METHODS

We reviewed all patients with epilepsy with a history of PER prescription during 2008-2017 and over a follow-up of >3 years. PER usage patterns and associated factors were analyzed.

RESULTS

Among the 2,655 patients in the cohort, 328 (150 females, 178 males) were enrolled. The ages at onset and diagnosis were 21.1±14.7 years and 25.6±16.1 years (mean±standard deviation), respectively. The age at the first visit to our center was 31.8±13.8 years. Seizure types were focal, generalized, and unknown onset in 83.8%, 15.9%, and 0.3% of patients, respectively. The most common etiology was structural (n=109, 33.2%). The maintenance duration of PER was 22.6±19.2 months (range=1-66 months). The initial number of concomitant antiseizure medications was 2.4±1.4 (range=0-9). The most common regimen was PER plus levetiracetam (n=41, 12.5%). The median number of 1-year seizures before PER usage was 8 (range=0-1,400). A seizure reduction of >50% was recorded in 34.7% of patients (52.0% and 29.2% in generalized and focal seizures, respectively). The 1-, 2-, 3-, 4-, and 5-year retention rates for PER were 65.3%, 50.4%, 40.4%, 35.3%, and 21.5%, respectively. A multivariate analysis indicated that lower age at onset was associated with longer retention (p=0.01).

CONCLUSIONS

PER was safely used in patients with diverse characteristics and was maintained for a long time in a real-world setting, especially in patients with a lower age at onset.

Myelin oligodendrocyte glycoprotein antibody-associated encephalitis after severe acute respiratory syndrome coronavirus 2 infection: a case report and retrospective case reviews

Several cases of myelin oligodendrocyte glycoprotein (MOG) antibody-associated encephalitis have been reported after coronavirus disease 2019 (COVID-19). In this case, the patient presented with focal status epilepticus with impaired awareness, auditory hallucinations, and incoherent speech after COVID-19. Brain magnetic resonance imaging revealed no specific findings. Cerebrospinal fluid results showed pleocytosis and MOG antibody testing confirmed anti-MOG antibody with live cell-based fluorescence-activated cell sorting assay. The patient was diagnosed with MOG antibody-associated autoimmune encephalitis and treated with intravenous immunoglobulin, rituximab, and tocilizumab. This case occurred presumably due to auto-antibody production following COVID-19.

Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110  MeV/c^{2} and 210-240  MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

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.

MOG antibody-associated encephalitis in adult: clinical phenotypes and outcomes

BACKGROUND

We investigated the clinical characteristics and outcomes of myelin oligodendrocyte glycoprotein (MOG) antibody-associated autoimmune encephalitis (MOGAE) in adult patients.

METHODS

From an institutional cohort, we analysed adult patients with MOGAE followed-up for more than 1 year. Disease severity was assessed using the modified Rankin scale (mRS) and Clinical Assessment Scale in Autoimmune Encephalitis scores. Immunotherapy profiles, outcomes and disease relapses were evaluated along with serial brain MRI data.

RESULTS

A total of 40 patients were enrolled and categorised into cortical encephalitis (18 patients), limbic encephalitis (LE, 5 patients) and acute disseminated encephalomyelitis (ADEM, 17 patients). 80.0% of patients achieved good clinical outcomes (mRS 0‒2) and 40.0% relapsed. The LE subtype was associated with an older onset age (p=0.004) and poor clinical outcomes (p=0.014) than the other subtypes but with a low rate of relapse (0.0%). 21/25 (84.0%) relapse attacks were associated with an absence or short (≤6 months) immunotherapy maintenance. On MRI, the development of either diffuse cerebral or medial temporal atrophy within the first 6 month was correlated with poor outcomes. MOG-antibody (MOG-Ab) was copresent with anti-N-methyl-D-aspartate receptor (NMDAR)-antibody in 13 patients, in whom atypical clinical presentation (cortical encephalitis or ADEM, p<0.001) and disease relapse (46.2% vs 0.0%, p<0.001) were more frequent compared with conventional NMDAR encephalitis without MOG-Ab.

CONCLUSIONS

Outcomes are different according to the three phenotypes in MOGAE. Short immunotherapy maintenance is associated with relapse, and brain atrophy was associated with poor outcomes. Patients with dual antibodies of NMDAR and MOG have a high relapse rate.

Comparing the efficacy of different methods of faecal microbiota transplantation via oral capsule, oesophagogastroduodenoscopy, colonoscopy, or gastric tube

BACKGROUND

The increasing prevalence of multidrug-resistant organism (MDRO) carriage poses major challenges to medicine as healthcare costs increase. Recently, faecal microbiota transplantation (FMT) has been discussed as a novel and effective method for decolonizing MDRO.

AIM

To compare the efficacy of different FMT methods to optimize the success rate of decolonization in patients with MDRO carriage.

METHODS

This prospective cohort study enrolled patients with MDRO carriages from 2018 to 2021. Patients underwent FMT via one of the following methods: oral capsule, oesophagogastroduodenoscopy (EGD), colonoscopy, or gastric tube.

FINDINGS

A total of 57 patients underwent FMT for MDRO decolonization. The colonoscopy group required the shortest time for decolonization, whereas the EGD group required the longest (24.9 vs 190.4 days, P = 0.022). The decolonization rate in the oral capsule group was comparable to that in the EGD group (84.6% vs 85.7%, P = 0.730). An important clinical factor associated with decolonization failure was antibiotic use after FMT (odds ratio = 6.810, P = 0.008). All four groups showed reduced proportions of MDRO species in microbiome analysis after FMT.

CONCLUSION

Compared to other conventional methods, the oral capsule is an effective FMT method for patients who can tolerate an oral diet. The discontinuation of antibiotics after FMT is a key factor in the success of decolonization.

Lesion Detection Through MRI Postprocessing in Pathology-Proven Focal Cortical Dysplasia: Experience at a Single Institution in the Republic of Korea

BACKGROUND AND PURPOSE

Focal cortical dysplasia (FCD) is one of the most common causes of drug-resistant epilepsy, and necessitates a multimodal evaluation to ensure optimal surgical treatment. This study aimed to determine the supportive value of the morphometric analysis program (MAP) in detecting FCD using data from a single institution in Korea.

METHODS

To develop a standard reference for the MAP, normal-looking MRIs by two scanners that are frequently used in this center were chosen. Patients with drug-resistant epilepsy and FCD after surgery were candidates for the analysis. The three-dimensional T1-weighted MRI scans of the patients were analyzed as test cases using the MAP.

RESULTS

The MRI scans of 87 patients were included in the analysis. The radiologist detected abnormal findings correlated with FCD (RAD positive [RAD(+)]) in 34 cases (39.1%), while the MAP could detect FCD in 25.3% of cases. A combination of the MAP (MAP[+] cases) with interpretations by the radiologist increased the detection to 42.5% (37 cases). The lesion detection rate was not different according to the type of reference scanners except in one case. MAP(+)/RAD(-) presented in three cases, all of which had FCD type IIa. The detection rate was slightly higher using the same kind of scanner as a reference, but not significantly (35.0% vs. 22.4% p=0.26).

CONCLUSIONS

The results of postprocessing in the MAP for detecting FCD did not depend on the type of reference scanner, and the MAP was the strongest in detecting FCD IIa. We suggested that the MAP could be widely utilized without developing institutional standards and could become an effective tool for detecting FCD lesions.

Seronegative autoimmune encephalitis: clinical characteristics and factors associated with outcomes

Seronegative autoimmune encephalitis is autoimmune encephalitis without any identifiable pathogenic antibody. Although it is a major subtype of autoimmune encephalitis, many unmet clinical needs exist in terms of clinical characteristics, treatments and prognosis. In this institutional cohort study, patients diagnosed with seronegative autoimmune encephalitis with available 2-year outcomes were analysed for the disease course, 2-year outcome prediction system, effect of immunotherapy, necessity of further immunotherapy at 6 or 12 months and pattern of brain atrophy. Seronegative autoimmune encephalitis was subcategorized into antibody-negative probable autoimmune encephalitis, autoimmune limbic encephalitis and acute disseminated encephalomyelitis. Poor 2-year outcome was defined by modified Rankin scale scores 3-6, and the 2-year serial data of Clinical Assessment Scales in Autoimmune Encephalitis score was used for longitudinal data analyses. A total of 147 patients were included. The frequency of achieving a good 2-year outcome (modified Rankin scale 0-2) was 56.5%. The antibody-negative probable autoimmune encephalitis subtype exhibited the poorest outcomes, although the baseline severity was similar among the subtypes. The RAPID score, consisting of five early usable clinical factors, refractory status epilepticus, age of onset ≥60 years, probable autoimmune encephalitis (antibody-negative probable autoimmune encephalitis subtype), infratentorial involvement and delay of immunotherapy ≥1 month, was associated with poorer 2-year outcomes. Any immunotherapy was associated with clinical improvement in the patients with low risk for poor 2-year outcomes (RAPID scores 0-1), and the combination immunotherapy of steroid, immunoglobulin, rituximab and tocilizumab was associated with better outcomes in the patients with high risk for poor 2-year outcomes (RAPID scores 2-5). In patients with persistent disease at 6 months, continuing immunotherapy was associated with more improvement, while the effect of continuing immunotherapy for more than 12 months was unclear. In the longitudinal analysis of MRI, the development of cerebellar atrophy indicated poor outcomes, while the absence of diffuse cerebral atrophy or medial temporal atrophy indicated the possibility of a good outcome. This study provides information about the clinical characteristics and courses, the effect of immunotherapy and its duration, and prognostic factors in seronegative autoimmune encephalitis.

Exploration of shared features of B cell receptor and T cell receptor repertoires reveals distinct clonotype clusters

Although B cells and T cells are integral players of the adaptive immune system and act in co-dependent ways to orchestrate immune responses, existing methods to study the immune repertoire have largely focused on separate analyses of B cell receptor (BCR) and T cell receptor (TCR) repertoires. Based on our hypothesis that the shared history of immune exposures and the shared cellular machinery for recombination result in similarities between BCR and TCR repertoires in an individual, we examine any commonalities and interrelationships between BCR and TCR repertoires. We find that the BCR and TCR repertoires have covarying clonal architecture and diversity, and that the pattern of correlations appears to be altered in immune-mediated diseases. Furthermore, hierarchical clustering of public B and T cell clonotypes in both health and disease based on correlation of clonal proportion revealed distinct clusters of B and T cell clonotypes that exhibit increased sequence similarity, share motifs, and have distinct amino acid characteristics. Our findings point to common principles governing memory formation, recombination, and clonal expansion to antigens in B and T cells within an individual. A significant proportion of public BCR and TCR repertoire can be clustered into nonoverlapping and correlated clusters, suggesting a novel way of grouping B and T cell clonotypes.

Chronic social stress during early development is involved in antisocial maltreatment behavior in mice

Purpose

Early-life stress can cause brain inflammation and affect social behavior in adulthood. In humans, maltreated (abused or neglected) children often exhibit antisocial behavior, including violent and sadistic behavior, in adulthood. However, it is unknown whether maltreatment behavior occurs in rodents. Here, we developed an assay system to evaluate conspecific maltreatment behavior in the mouse.

Methods

To assess maltreatment behavior, we devised a two-chamber apparatus separated by a transparent partition, in which one chamber was provided with a nose-poking hole that would trigger foot shocks onto the other. Lidocaine was used to inhibit neural activity in vivo. Brain oscillations were investigated by electroencephalograph. Enzyme-linked immunosorbent assay was used for protein assay. The mouse model was sequentially subjected to maternal separation (MS), social defeat (SD), and social isolation (SI) in that order (MS/SD/SI model).

Results

Inactivation of the anterior cingulate cortex and medial prefrontal cortex increased the level of nose-poking. Maltreatment behavior provoked changes in oxytocin, corticosterone, and brain-derived neurotrophic factor levels. MS/SD/SI mice exhibited more sustained nose-poking behavior during the experiment, resulting in increased foot shocks to the mouse in the opposite chamber. Abnormal brain oscillations were observed in the MS/SD/SI mice.

Conclusion

The MS/SD/SI model and maltreatment-behavior assay may be useful not only to study the relationship between social stress in childhood and antisocial behavior in adulthood, but also for study of etiology, pathology, or treatment for brain disorders, such as psychopathy.

Multidimensional Early Prediction Score for Drug-Resistant Epilepsy

Background and Purpose

Achieving favorable postoperative outcomes in patients with drug-resistant epilepsy (DRE) requires early referrals for preoperative examinations. The purpose of this study was to investigate the possibility of a user-friendly early DRE prediction model that is easy for nonexperts to utilize.

Methods

A two-step genotype analysis was performed, by applying 1) whole-exome sequencing (WES) to the initial test set (n=243) and 2) target sequencing to the validation set (n=311). Based on a multicenter case–control study design using the WES data set, 11 genetic and 2 clinical predictors were selected to develop the DRE risk prediction model. The early prediction scores for DRE (EPS-DRE) was calculated for each group of the selected genetic predictors (EPS-DRE_gen), clinical predictors (EPS-DRE_cln), and two types of predictor mix (EPS-DRE_mix) in both the initial test set and the validation set.

Results

The multidimensional EPS-DRE_mix of the predictor mix group provided a better match to the outcome data than did the unidimensional EPS-DRE_gen or EPS-DRE_cln. Unlike previous studies, the EPS-DRE_mix model was developed using only 11 genetic and 2 clinical predictors, but it exhibited good discrimination ability in distinguishing DRE from drug-responsive epilepsy. These results were verified using an unrelated validation set.

Conclusions

Our results suggest that EPS-DRE_mix has good performance in early DRE prediction and is a user-friendly tool that is easy to apply in real clinical trials, especially by nonexperts who do not have detailed knowledge or equipment for assessing DRE. Further studies are needed to improve the performance of the EPS-DRE_mix model.

Association of Nucleus Basalis of Meynert Functional Connectivity and Cognition in Idiopathic Rapid-Eye-Movement Sleep Behavior Disorder

Background and Purpose

Cognitive impairments are common in isolated rapid-eye-movement sleep behavior disorder (iRBD), in which the cholinergic system may play an important role. This study aimed to characterize the cortical cholinergic activity using resting-state functional connectivity (FC) of the nucleus basalis of Meynert (NBM) according to the cognitive status of iRBD patients.

Methods

In this cross-sectional study, 33 patients with polysomnography-confirmed iRBD and 20 controls underwent neuropsychological evaluations and resting-state functional magnetic resonance imaging. Thirteen of the iRBD patients had mild cognitive impairment (iRBD-MCI), and the others were age-matched patients with normal cognition (iRBD-NC). The seed-to-voxel NBM–cortical FC was compared among the patients with iRBD-MCI, patients with iRBD-NC, and controls. Correlations between average values of significant clusters and cognitive function scores were calculated in the patients with iRBD.

Results

There were group differences in the FC of the NBM with the left lateral occipital cortex and lingual gyrus (adjusted for age, sex, and education level). The strength of FC was lower in the iRBD-MCI group than in the iRBD-NC and control groups (each post-hoc p<0.001). The average NBM–lateral occipital cortex FC was positively correlated with the memory-domain score in iRBD patients.

Conclusions

The results obtained in this study support that cortical cholinergic activity is impaired in iRBD patients with MCI. FC between NBM and posterior regions may play a central role in the cognitive function of these patients.

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.

Perampanel as First Add-On Therapy in Patients with Focal-Onset Seizures in the FAME Trial: <i>Post hoc</i> Analyses of Efficacy and Safety Related to Maintenance Dose and Background Antiepileptic Drug Therapy

Background and Purpose: FAME (Fycompa^® as first Add-on to Monotherapy in patients with Epilepsy; NCT02726074), a previously reported single-arm, phase IV study, showed that perampanel improved seizure control as first add-on to failed anti-seizure medication (ASM) monotherapy in 85 South Korean patients aged ≥12 years with focal-onset seizures (FOS) with/without focal to bilateral tonic-clonic seizures. We present results of three <i>post hoc</i> analyses of FAME that further assessed the efficacy and safety of perampanel.Methods: Patients were stratified by low- (4, 6 mg/day) versus high- (8, 10, 12 mg/day) dose maintenance perampanel, perampanel added to first- versus second-line ASM monotherapy, and concomitant background ASM monotherapy and perampanel dose. The primary endpoint was the proportion of patients with a ≥50% reduction in total seizure frequency during the 24-week maintenance period. Safety was assessed by the descriptive incidence of treatment-emergent adverse events (TEAEs).Results: In <i>post hoc</i> analyses, 50% responder rates were significantly higher for low- versus high-dose maintenance perampanel (88.6% vs. 40.0%; <i>p</i><0.001) and when added to first- versus second-line ASM monotherapy (83.5% vs. 33.3%; <i>p</i>=0.013). By concomitant background ASM and perampanel maintenance dose, 50% responder rates were 100% for perampanel 4 mg/day added to carbamazepine, oxcarbazepine, lamotrigine, or valproic acid, and 85% when added to levetiracetam. Add-on perampanel improved 75% and seizure-free responder rates, and median percent changes from baseline seizure frequency per 28 days. Perampanel was well tolerated when added to ASM monotherapy, with dizziness being the most common TEAE.Conclusions: <i>Post hoc</i> analyses of FAME provide supportive data for the use of perampanel as an effective and well-tolerated first add-on treatment to a broad spectrum of ASM monotherapies in patients with FOS.

Perampanel as First Adjunctive Treatment in Patients with Focal-Onset Seizures in the FAME Study: <i>Post hoc</i> Analyses of Dose-Related Efficacy, Safety and Clinical Factors Associated with Response

Background and Purpose: Perampanel is approved for the adjunctive treatment of focal-onset seizures (FOS) with or without secondary generalized seizures. The FAME (Fycompa^® as first Add-on to Monotherapy in patients with Epilepsy; NCT02726074) study evaluated the efficacy and safety of perampanel added to monotherapy in patients with FOS with or without secondary generalized seizures (SGS). <i>Post hoc</i> analyses of the FAME study assessed potential predictors of response and an in-depth evaluation of the safety and efficacy of perampanel.Methods: Efficacy was assessed by reduction of total seizure frequency by ≥50%, ≥75% or 100%, and safety by incidence of treatment-emergent adverse events (TEAEs) and TEAEs leading to discontinuation. Univariate and multivariate logistic regression analyses for treatment response were performed.Results: Most patients (82/85) received perampanel doses of 4-8 mg/day during maintenance therapy and the highest efficacy rates were achieved with 4 mg/day, irrespective of efficacy outcome. Doses of 4 or 6 mg/day in patients with FOS with SGS (n=16) produced comparable efficacy outcomes. In multivariate analysis, total perampanel dose was predictive of 50% and 75% response rates; longer total perampanel administration period with 50% response; and concomitant non-anti-seizure medication with a 100% response. Patients developed a TEAE more frequently during the 12-week titration period (60.2%) than the 24-week maintenance period (28.4%), including dizziness (45.5% vs. 9.1%), somnolence (10.2% vs. 0%), and headache (4.5% vs. 3.4%).Conclusions: <i>Post hoc</i> analyses show that even low doses of perampanel may be effective and TEAEs are usually self-limited or well-tolerated.

Neuropsychiatric symptoms and seizure related with serum cytokine in epilepsy patients

Neuroinflammation contributes to epileptogenesis and ictogenesis. Various signals of neuroinflammation lead to neuronal hyper-excitability. Since an interplay between epilepsy, psychiatric comorbidities and neuroinflammation has been suggested, we explored psychiatric symptoms in epilepsy patients, and the relationship with neuroinflammation. We screened epilepsy patients who were admitted for video-EEG monitoring between July 2019 and December 2020. Enrolled patients were asked to respond to neuropsychiatric questionnaires (Hospital Anxiety and Depression Scale (HADS) and Neuropsychiatric Inventory-Questionnaire (NPI-Q)) on admission. Serum cytokines (IL-1β, IL-2, IL-6, IFN-γ, CCL2, and CCL5) were measured by ELISA on admission, and within 6 h after a seizure. We enrolled 134 patients, and 32 patients (23.9%) had seizures during monitoring. Cytokine levels did not change after seizures, but IL-2 and IL-6 increased in cases of generalized tonic–clonic seizures. The HADS-A score was lower in Q4 of CCL5 (p-value = 0.016) and anxiety was also less common in Q4 of CCL5 (p-value = 0.042). NPI-Q question 4 (depression) severity was higher in CCL2 (p-value = 0.024). This suggested that psychiatric symptoms may also be related to inflammatory processes in epilepsy patients. Further large, standardized studies are necessary to underpin the inflammatory mechanisms in epilepsy and psychiatric symptoms.

Chronic social stress during early development elicits unique behavioral changes in adulthood

Purpose

Chronic social stress is known to induce inflammation in the brain, and early-life stress affects the brain and social behavior in adulthood. To study the relationship between social stress in childhood development and social behavior in adulthood, we subjected mice to a sequential early-life social stresses and characterized their adult behavioral phenotypes.

Methods

C57BL/6 mice were sequentially subjected to maternal separation (MS), social defeat (SD), and social isolation (SI) in that order. The body weights of the MS/SD/SI mice were measured. Behavioral tasks related to anxiety, depression, locomotion, learning/memory, and repetitive/compulsive-like behavior were conducted. Social behaviors suggesting sociability, social interaction, aggression, and social fear were investigated.

Results

MS/SD/SI mice weighed less than the control mice. At 7 and 8 weeks of age. These mice displayed normal behaviors in anxiety-, depression-, and learning/memory-related tasks, but they exhibited increased locomotor activity and a low level of repetitive/compulsive-like behavior. Notably, they exhibited increased social interaction, impaired empathy-related fear, reduced predator fear, and increased defensive aggressiveness.

Conclusion

Social stress during childhood development resulted in behavioral alterations, and MS/SD/SI mice generated by mimicking child abuse or maltreatment showed unique abnormalities in social behaviors. MS/SD/SI mice might be useful not only to study the relationship between social stress and brain inflammation but also psychosocial behaviors observed in individuals with brain disorders, such as psychopaths.

The safety and efficacy of intravenous immunoglobulin in autoimmune encephalitis

OBJECTIVE

Although intravenous immunoglobulin (IVIG) is the first-line immunotherapy in autoimmune encephalitis, all supporting evidence comes from retrospective case series. Here, we performed a prospective clinical trial of IVIG for functional recovery in autoimmune encephalitis.

METHODS

This single-arm, open-label study assessed the efficacy and safety of 10% intravenous IVIG treatment in newly diagnosed patients with possible autoimmune encephalitis. Patients received IVIG (0.4 g/kg/day) for 5 days. Rescue immunotherapy was permitted when the patient deteriorated before day 8 or showed no improvement at day 8. The primary outcome was the change in the modified Rankin Scale (mRS) score at day 8 and 29. The secondary outcomes were the mRS score improvement and the score changes and improvements on four other clinical scales.

RESULTS

Overall, 23 patients received IVIG (intension-to-treat, ITT), and 18 patients completed the study according to the protocol (per-protocol, PP). mRS improved significantly at days 8 and 29 compared to baseline in both the ITT and PP populations. Other secondary outcomes also improved significantly at day 8, 15, and 29 versus baseline. In the PP population, 6/18 patients achieved favorable outcomes with IVIG alone (mRS = 0~2 at day 8), and 12/18 patients received rescue immunotherapy. Five adverse events were reported in relation to IVIG, all of which were mild.

INTERPRETATION

IVIG improved neurological functional outcomes, and the improvement was evident by day 8. Adverse effects were tolerable. These data provide the prospective evidence regarding the efficacy of IVIG in improving the functional outcomes of 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.

Predicting Parkinson's disease using gradient boosting decision tree models with electroencephalography signals

INTRODUCTION

Parkinson's disease (PD) is a neurodegenerative disorder with only symptomatic treatments currently available. Although correct, early diagnoses of PD are important, the existing diagnostic method based on pathologic examinations only has an accuracy of approximately 80.6%. Although electroencephalography (EEG)-based assistive technology has been introduced, it has been difficult to implement in practice due to the high computational complexity and low accuracy of the analysis methods. This study proposed a fast, accurate PD prediction method using the Hjorth parameter and the gradient boosting decision tree (GBDT) algorithm.

METHOD

We used an open EEG dataset with 41 PD patients and 41 healthy controls (HCs); EEG signals were recorded from participants at the University of New Mexico (PD: 27 vs. HC: 27) and University of Iowa (PD: 14 vs. HC: 14). We explored the analytic time segment and frequency range in which the Hjorth parameter best represents the EEG characteristics of PD patients.

RESULTS

Our best model (CatBoost-based) distinguished PD patients from controls with an accuracy of 89.3%, an area under the receiver operating characteristics curve (AUC) of 0.912, an F-score of 0.903, and an odds ratio of 115.5. These results showed that our models outperformed those of all other previous works and were even superior to previously known pathologic examination-based diagnoses with long-term follow-up (accuracy = 83.9%).

CONCLUSION

The proposed methods are expected to be utilized as an effective method for improving the diagnosis of PD.

Association of Zolpidem With Increased Mortality in Patients With Brain Cancer: A Retrospective Cohort Study Based on the National Health Insurance Service Database

Background and Purpose

Zolpidem is one of the most common hypnotics prescribed to treat insomnia worldwide. However, there are numerous reports of a positive association between zolpidem and mortality, including an association with increased cancer-specific mortality found in a Taiwanese cohort study. This study aimed to determine the association between zolpidem use and brain-cancer-specific mortality in patients with brain cancer.

Methods

This population-based, retrospective cohort study analyzed data in the National Health Insurance Service database. All incident cases of brain cancer at an age of ≥18 years at the time of brain cancer diagnosis over a 15-year period (2003–2017) were included. A multivariate Cox regression analysis after adjustment for covariables was performed to evaluate the associations of zolpidem exposure with brain-cancer-specific and all-cause mortality.

Results

This study identified 38,037 incident cases of brain cancer, among whom 11,823 (31.1%) patients were exposed to zolpidem. In the multivariate Cox regression model, the brain-cancer-specific mortality rate was significantly higher in patients who were prescribed zolpidem than in those with no zolpidem prescription (adjusted hazard ratio [HR]=1.14, 95% confidence interval [CI]=1.08–1.21, p<0.001). Zolpidem exposure was significantly associated with increased brain-cancer-specific mortality after adjustment in younger adults (age 18–64 years; adjusted HR=1.37, 95% CI=1.27–1.49) but not in older adults (age ≥65 years; adjusted HR=0.94, 95% CI=0.86–1.02).

Conclusions

Zolpidem exposure was significantly associated with increased brain-cancer-specific mortality in patients with brain cancer aged 18–64 years. Further prospective studies are warranted to understand the mechanism underlying the effect of zolpidem on mortality in patients with brain cancer.

Association of Plasma Oligomerized Amyloid-β and Cerebral White Matter Lesions in a Health Screening Population

BACKGROUND

Cerebral white matter lesions (WML) are related to a higher risk of vascular and Alzheimer's dementia. Moreover, oligomerized amyloid-β (OAβ) can be measured from blood for dementia screening.

OBJECTIVE

We aimed to investigate the relationship of plasma OAβ levels with clinical and radiological variables in a health screening population.

METHODS

WML, other volumetric parameters of magnetic resonance images, cognitive assessment, and plasma OAβ level were evaluated.

RESULTS

Ninety-two participants were analyzed. The majority of participants' clinical dementia rating was 0 or 0.5 (96.7%). White matter hyperintensities (WMH) increased with age, but OAβ levels did not (r2 = 0.19, p < 0.001, r2 = 0.03, p = 0.10, respectively). No volumetric data, including cortical thickness/hippocampal volume, showed any significant correlation with OAβ. Log-WMH volume was positively correlated with OAβ (r = 0.24, p = 0.02), and this association was significant in the periventricular area. White matter signal abnormalities from 3D-T1 images were also correlated with the OAβ in the periventricular area (p = 0.039). Multivariate linear regression showed that log-WMH values were independently associated with OAβ (B = 0.879 (95% confidence interval 0.098 -1.660, p = 0.028)). Higher tertiles of WMH showed higher OAβ levels than lower tertiles showed (p = 0.044). Using a cutoff of 0.78 ng/mL, the high OAβ group had a larger WMH volume, especially in the periventricular area, than the low OAβ group (p = 0.036).

CONCLUSION

Both WML and plasma OAβ levels can be early markers for neurodegeneration in the healthcare population. The lesions, especially in the periventricular area, might be related to amyloid pathogenesis, which strengthens the importance of WML in the predementia stage.

Evaluation of persistence and healthcare utilization in patients treated with anti-seizure medications as add-on therapy: A nationwide cohort study in South Korea

OBJECTIVE

To compare medication adherence and healthcare utilization among patients who were treated with anti-seizure medications (ASMs) as first add-on to monotherapy for epilepsy using the national health insurance claims data.

METHODS

A retrospective observational cohort study was conducted using the Korean National Health Insurance claims data. Patients who received ASM as first add-on to monotherapy during January 2017 to February 2018 were included. The selected patients were followed up for 12 months to evaluate persistence, adherence, and healthcare resource utilization.

RESULTS

In total, 4277 patients who received ASM as first add-on to monotherapy for epilepsy were enrolled. The mean treatment duration of add-on ASM was 296.6 ± 108.6 days during the 1-year follow-up period and 64.3% of the total population were persistent on the add-on ASM at 365 days from the index date. The mean medication possession ratio (MPR) was 90.3 ± 23.7 and the proportion of adherent patients with ≥80% MPR was 79.3%. Lamotrigine (LTG), levetiracetam (LEV), oxcarbazepine (OXC), and perampanel (PER) groups showed significantly higher persistence and adherence than carbamazepine (CBZ), topiramate (TPM), and valproate (VAL) groups during the 1-year follow-up period. Significant differences in length of stays, total hospitalization cost, outpatient visit cost, and emergency cost were shown between ASM groups and LTG, LEV, OXC, and PER showed relatively low utilization and cost.

CONCLUSIONS

Better adherence was observed in LTG, LEV, OXC, and PER groups than in CBZ, TPM, and VAL groups. Healthcare utilization and related costs showed significant difference between ASM groups.

Clinical significance of Epstein-Barr virus polymerase chain reaction in cerebrospinal fluid

Purpose

Epstein-Barr virus (EBV) is implicated in various neurological conditions. However, the relationship between EBV DNA in cerebrospinal fluid (CSF) and central nervous system (CNS) infection is unclear. We evaluated the clinical manifestation of patients with EBV DNA detected in CSF.

Methods

We reviewed the medical records of patients admitted to Seoul National University Hospital from January 2000 to March 2021 who underwent EBV polymerase chain reaction (PCR) tests in CSF. The subjects were divided into positive and negative groups depending on the presence of EBV DNA, and further clinical information was obtained from positive patients.

Results

CSF EBV PCR tests were performed in 807 patients, and 57 (7.1%) tested positive. Pleocytosis was common (81.1%) in CSF samples with EBV DNA detected, and the proportion was significantly higher than that in samples that were EBV PCR negative (44.5%, p < 0.0001). Among 57 patients with EBV DNA detected in CSF, 51 (89.5%) were diagnosed with CNS infection or inflammatory disorders. Of the 51 patients, 31 (60.8%) had possible etiologies other than EBV. Follow-up evaluation was conducted in 19 of 20 patients, and 63.2% showed a favorable outcome.

Conclusion

Positive EBV PCR in CSF is mostly nonspecific and should be interpreted with caution. A comprehensive workup is needed to identify other etiologies before considering EBV as the sole culprit.

A Rare Case of 3:1 Alpha Variant

Since the first documentation of slow alpha variants in Goodwin et al., there has been a single case report with an actual electroencephalography (EEG). However, any further case has not been reported since then, and neurologists are still unfamiliar with its presence due to its scarcity. Here, we present a rare case of 3:1 subharmonic alpha variant in a hope to acquaint EEG interpretations and speculate upon its benign nature.

Long-term efficacy and safety of perampanel as a first add-on therapy in patients with focal epilepsy: Three-year extension study

PURPOSE

We investigated the long-term efficacy and safety of perampanel as a first add-on therapy in patients with focal epilepsy.

METHODS

This retrospective study represented the 3-year extension phase of a multicenter, open-label, phase 4, prospective study of perampanel as a first add-on therapy in patients with focal epilepsy. Seizure and safety outcomes were assessed annually from the start of the extension study, and the retention rate was calculated from the start of perampanel exposure in the original study.

RESULTS

The 50% responder and seizure freedom rates were 84.8% and 58.7%, respectively, during the third year and 71.7% and 32.6%, respectively, during the entire 3-year period of the extension study. The 1-, 2-, and 3-year retention rates were 62.5%, 53.1%, and 52.1%, respectively. Efficacies were higher in patients that were aged >55 years, male, and receiving ≤4 mg of perampanel. Perampanel was generally well tolerated; 47.3% of patients experienced at least one adverse event during the 3 years of extension (46 adverse events (AEs) in 35 patients). The most common AEs were dizziness (33.8%), somnolence (5.4%), anger (4.1%), and irritability (4.1%). AEs were resolved with perampanel dose reduction or discontinuation in 10 (13.5%) and 12 (16.2%) patients, respectively.

CONCLUSION

Long-term treatment with perampanel as a first add-on therapy did not raise new safety signals in patients with focal epilepsy. Especially at low perampanel doses (≤4 mg/day), sustained improvement in seizure control was achieved, which could potentially avoid adverse drug reactions.

Association of autosomal dominant polycystic kidney disease with cerebral small vessel disease

Cilia dysfunction in autosomal-dominant polycystic kidney disease (ADPKD) may impair the integrity of glymphatic system and be implicated in the progression of cerebral small vessel disease (SVD), although the link between the two diseases has not been investigated. We evaluated the association of ADPKD pathology with SVD pattern and severity. Overall, 304 individuals in an ADPKD (chronic kidney disease stage ≤4 and age ≥50 years) cohort and their age, sex, and estimated glomerular filtration rate (eGFR)-matched controls were retrospectively included. ADPKD severity was classified into 1 A-B, 1 C, and 1 D-E, according to age and height-adjusted total kidney volume. SVD parameters included white-matter hyperintensity (WMH) severity scale, enlarged perivascular space (ePVS) score, and degree of lacunes or cerebral microbleeds (CMBs). After adjustments for age, sex, eGFR, and cerebrovascular risk factor parameters, ADPKD was associated with higher ePVS scores (P < 0.001), but not with the WMH severity or degree of lacunes or CMBs. In the ADPKD subgroup, higher ADPKD severity class was associated with higher ePVS scores (P < 0.001), WMH severity (P = 0.003), and degree of lacunes (P = 0.002). ADPKD associated cilia dysfunction may induce chronic cerebral glymphatic system dysfunction, which may contribute to the specific progression of ePVS compared with other SVD markers.

Adult-onset rapidly worsening progressive myoclonic epilepsy caused by a novel variant in DHDDS

Progressive myoclonic epilepsy (PME) is a heterogeneous neurogenetic disorder manifesting as progressive myoclonus, seizure, and ataxia. We report a case of PME caused by a novel DHDDS variant. Additionally, by reviewing the literature on DHDDS mutations, we compared the phenotype of our patient with previously reported phenotypes. We identified DHDDS (c.638G>A, p. Ser213Asn) as a likely pathogenic variant. The literature review revealed 15 PME patients with DHDDS mutations from 13 unrelated families. According to previous studies, late‐onset patients tend to have a slow‐progressive disease course. Although his myoclonus and ataxia were adult onset, our patient experienced rapid disease aggravation.

Changes in laboratory mice after observation of deceased conspecifics: a pilot suicidality study in animals

PURPOSE

Suicidality can be a serious feature of psychiatric symptoms in encephalitis. Investigating the psychiatric behavior associated with suicidality in animal models of encephalitis is important; thus, determining whether normal laboratory animals are aware of death is necessary.

METHODS

To examine the behavioral and brain activity changes associated with death of conspecifics, laboratory mice were exposed to a cadaveric mouse or an anesthetized mouse. Behavioral tasks associated with anxiety and locomotion were conducted after repeated exposure. Neural activity in the medial prefrontal cortex during the cadaver exploration was investigated using electroencephalographic recordings.

RESULTS

During repeated exposure, mice in the cadaver group showed a gradual decrease in time exploring the cadaver, which was not observed in mice in the anesthesia group. The cadaver group also exhibited increased levels of anxiety in the light/dark transition and elevated plus maze tasks and displayed increased locomotor activity in the open field test. In an electrophysiological study, different brain oscillations were observed when mice were exposed to a cadaveric mouse and an anesthetized mouse. Enhanced delta-band activity and reduced theta- and alpha-band activities were observed during cadaver exploration.

CONCLUSION

The present study results showed that experiences involving dead conspecifics strongly affect mouse behavior and brain activity. These findings may be helpful in treating patients with psychiatric symptoms and aid in understanding the concept of death recognition/awareness in laboratory animals.

Risk factors for scabies treatment resistance: a retrospective cohort study

BACKGROUND

In order to successfully treat scabies and to prevent its spread, it is important to identify the factors that can influence the outcome of scabies treatment.

OBJECTIVES

This study was designed to evaluate the risk factors associated with treatment resistance scabies during use of an effective topical medication.

METHODS

A retrospective cohort study was performed in patients with scabies infestations confirmed by potassium hydroxide (KOH) examinations. Patient characteristics, clinical features and treatment history were collected. The treatment resistance group included patients with persistent scabies infestations for more than 28 days after initiation of antiscabies treatment with 5% permethrin cream.

RESULTS

In total, 138 patients with scabies infestations treated between January 2017 and December 2020 were included in this study. Of these, 100 (72.5%) patients were treated successfully, while 38 (27.5%) patients experienced treatment resistance. In the univariable analysis, risk factors for treatment resistance scabies included impaired cognitive function (OR = 2.66, 95% CI, 1.15-6.14), limited mobility (OR = 2.97, 95% CI, 1.30-6.83), inpatient status (vs. outpatient, OR = 3.3, 95% CI, 1.28-8.54), topical steroid use before diagnosis (OR = 3.52, 95% CI, 1.61-7.81), systemic steroid use before diagnosis (OR = 3.57, 95% CI, 1.26-10.34) and a positive KOH exam after the first treatment (OR = 7.25, 95% CI, 3.24-17.11). In the multivariable analysis, limited mobility (OR = 3.46, 95% CI, 1.02-12.11) and topical steroid use before diagnosis (OR = 3.65, 95% CI, 1.41-9.75) were significant predictive factors for treatment resistance scabies.

CONCLUSIONS

Scabies patients with limited mobility and topical steroid use before diagnosis are at high risk of treatment resistance. Dermatologists should take these findings into consideration when treating patients with scabies infestations.