Therapeutic Drug Monitoring of 6 New-Generation Antiseizure Medications Using a Mass Spectrometry Method: Analysis of 2-Year Experience in a Large Cohort of Korean Epilepsy Patients

CONTEXT.—

New-generation antiseizure medications (ASMs) are increasingly prescribed, and therapeutic drug monitoring (TDM) has been proposed to improve clinical outcome. However, clinical TDM data on new-generation ASMs are scarce.

OBJECTIVE.—

To develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for therapeutic drug monitoring (TDM) of 6 new-generation ASMs in serum and analyze the clinical TDM data from a large cohort of Korean patients with epilepsy.

DESIGN.—

Stable isotope-labeled internal standards were added to protein precipitations of serum. One microliter of sample was separated on Agilent Poroshell EC-C18 column, and lacosamide, perampanel, gabapentin, pregabalin, vigabatrin, and rufinamide were simultaneously quantified by Agilent 6460 triple-quad mass spectrometer in multiple-reaction monitoring mode. Linearity, sensitivity, precision, accuracy, specificity, carryover, extraction recovery, and matrix effect were evaluated. TDM data of 458 samples from 363 Korean epilepsy patients were analyzed.

RESULTS.—

The method was linear with limit of detection less than 0.05 μg/mL in all analytes. Intraassay and interassay imprecisions were less than 5% coefficient of variation. Accuracy was within ±15% bias. Extraction recovery ranged from 85.9% to 98.8%. A total of 88% (403 of 458) were on polypharmacy, with 29% (118 of 403) using concomitant enzyme inducers. Only 38% (175 of 458) of the concentrations were therapeutic, with 53% (244 of 458) being subtherapeutic. Drug concentration and concentration-to-dose ratio were highly variable among individuals in all 6 ASMs.

CONCLUSIONS.—

A simple and rapid LC-MS/MS method for TDM of 6 ASMs was developed and successfully applied to clinical practice. This large-scale TDM data could help establish an effective monitoring strategy for these drugs.

The effect of cognitive behavioral therapy on depression of people with epilepsy

BACKGROUND

Depression, a common mental problem frequently detected in people with epilepsy (PWE), is a major factor that decreases the quality of life of PWE. The cognitive behavioral therapy (CBT) is the most commonly used non-pharmacological treatment for depressive disorders. The CBT for PWE with depression has not yet been studied in Korea. This study aimed to evaluate the effects of the CBT on depression in PWE in Korea.

METHOD

This study included 16 PWE with depression who received CBT and 30 control PWE with depression who did not receive CBT. The mean number of CBT sessions per patient was 7.2 in the CBT group. The Beck Depression Inventory-II (BDI-II) and Patient Health Questionnaire-9 (PHQ-9) were administered before and after CBT sessions in the CBT group, whereas PHQ-9 was performed at baseline and follow-up in the control group. The difference in PHQ-9 and BDI-II scores were analyzed between the pre- and post-CBT periods in the CBT group. The difference between baseline and follow-up PHQ-9 scores was compared in the control group.

RESULTS

There was no significant difference in baseline variables between the CBT and control groups. The PHQ-9 score significantly decreased after the CBT sessions in the CBT group (pre-CBT PHQ-9 = 13.56 vs. post-CBT PHQ-9 = 8.56) but it did not change in the control group (Baseline PHQ-9 = 13.83 vs. follow-up PHQ-9 = 14.67). Twelve PWE had undergone four or more CBT sessions with pre-CBT and post-CBT BDI-II. The BDI-II score significantly decreased after CBT sessions (pre-CBT BDI-II = 30.75 vs. post-CBT BDI-II = 21.5). The CBT decreased the sub-field scores of cognitive and physical-emotional factors as well as suicidal ideation, but the score of sleep problems did not significantly improve. The CBT did not significantly change the seizure frequency.

CONCLUSION

The CBT significantly improved depression in Korean PWE. Therefore, it can be considered a treatment tool for depression in PWE. However, a study with more patients and a fixed number of CBT sessions is recommended to generalize this effect.

Identifying important factors for successful surgery in patients with lateral temporal lobe epilepsy

OBJECTIVE

Lateral temporal lobe epilepsy (LTLE) has been diagnosed in only a small number of patients; therefore, its surgical outcome is not as well-known as that of mesial temporal lobe epilepsy. We aimed to evaluate the long-term (5 years) and short-term (2 years) surgical outcomes and identify possible prognostic factors in patients with LTLE.

METHODS

This retrospective cohort study was conducted between January 1995 and December 2018 among patients who underwent resective surgery in a university-affiliated hospital. Patients were classified as LTLE if ictal onset zone was in lateral temporal area. Surgical outcomes were evaluated at 2 and 5 years. We subdivided based on outcomes and compared clinical and neuroimaging data including cortical thickness between two groups.

RESULTS

Sixty-four patients were included in the study. The mean follow-up duration after the surgery was 8.4 years. Five years after surgery, 45 of the 63 (71.4%) patients achieved seizure freedom. Clinically and statistically significant prognostic factors for postsurgical outcomes were the duration of epilepsy before surgery and focal cortical dysplasia on postoperative histopathology at the 5-year follow-up. Optimal cut-off point for epilepsy duration was eight years after the seizure onset (odds ratio 4.375, p-value = 0.0214). Furthermore, we propose a model for predicting seizure outcomes 5 years after surgery using the receiver operating characteristic curve and nomogram (area under the curve = 0.733; 95% confidence interval, 0.588-0.879). Cortical thinning was observed in ipsilateral cingulate gyrus and contralateral parietal lobe in poor surgical group compared to good surgical group (p-value < 0.01, uncorrected).

CONCLUSIONS

The identified predictors of unfavorable surgical outcomes may help in selecting optimal candidates and identifying the optimal timing for surgery among patients with LTLE. Additionally, cortical thinning was more extensive in the poor surgical group.

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.

Prediction of the Responsiveness to Vagus-Nerve Stimulation in Patients with Drug-Resistant Epilepsy via Directed-Transfer-Function Analysis of Their Perioperative Scalp EEGs

This study aims to compare directed transfer function (DTF), which is an effective connectivity analysis, derived from scalp EEGs between responder and nonresponder groups implanted with vagus-nerve stimulation (VNS). Twelve patients with drug-resistant epilepsy (six responders and six nonresponders) and ten controls were recruited. A good response to VNS was defined as a reduction of ≥50% in seizure frequency compared with the presurgical baseline. DTF was calculated in five frequency bands (delta, theta, alpha, beta, and broadband) and seven grouped electrode regions (left and right frontal, temporal, parieto-occipital, and midline) in three different states (presurgical, stimulation-on, and stimulation-off states). Responders showed presurgical nodal strength close to the control group in both inflow and outflow, whereas nonresponders exhibited increased inward and outward connectivity measures. Nonresponders also had increased inward and outward connectivity measures in the various brain regions and various frequency bands assessed compared with the control group when the stimulation was on or off. Our study demonstrated that the presurgical DTF profiles of responders were different from those of nonresponders. Moreover, a presurgical normal DTF profile may predict good responsiveness to VNS.

Effects of Vagus Nerve Stimulation on Sleep-Disordered Breathing, Daytime Sleepiness, and Sleep Quality in Patients With Drug-Resistant Epilepsy

Background and Purpose

This study aimed to determine the long-term effects of vagus nerve stimulation (VNS) on sleep-disordered breathing (SDB), daytime sleepiness, and sleep quality in patients with drug-resistant epilepsy (DRE). It also investigated the relationships among these main effects, clinical characteristics, and VNS parameters.

Methods

Twenty-four patients were recruited. Paired t-tests and multiple linear regression analyses were performed to determine how the demographic and clinical characteristics of the patients influenced the variables that changed significantly after VNS treatment.

Results

After VNS, the patients showed significant increases in the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), apnea index, hypopnea index, and oxygen desaturation index (ODI), as well as a significant decrease in the lowest arterial oxygen saturation (SaO₂ nadir) (p<0.05). The multiple linear regression analyses demonstrated that the predictor of larger increases in AHI and RDI was being older at baseline, and that the predictor of a larger increase in apnea index was a longer epilepsy duration. The strongest predictor of a larger increase in ODI was a higher frequency of aura episodes at baseline, followed by a longer epilepsy duration. The strongest predictor of a larger decrease in SaO₂ nadir was a higher frequency of aura episodes at baseline, followed by a longer epilepsy duration.

Conclusions

This study has confirmed that VNS improves seizure control in patients with DRE, whereas it increases obstructive sleep apnea (OSA). Furthermore, the increase in OSA is affected by age and the duration of epilepsy. Therefore, careful observation and monitoring of SDB is recommended in patients who undergo VNS.

Association between Self-Perceived Periodic Limb Movement during Sleep and Excessive Daytime Sleepiness Depend on Restless Leg Symptoms in Korean Adolescents

Although periodic limb movement during sleep (PLMS) and restless legs syndrome (RLS) are common in children and adolescents, they are relatively overlooked as a target of treatment. PLMS has been evaluated as having a lower clinical significance than RLS. This study examined the relationship of socio-behavioral factors of PLMS in Korean adolescents and checked whether PLMS is associated with excessive daytime sleepiness (EDS), depending on whether restless legs symptoms accompany it. In a cross-sectional study, 25,789 adolescents between 12 and 18 years of age (15.76 ± 1.73 years; female 51.49%) were evaluated using an online survey. Various self-report questionnaires were used to assess PLMS and RLS symptoms, EDS, sleep habits, and various socio-behavioral factors. The prevalence of self-perceived PLMS and restless legs symptoms were 903 (3.50%) and 1311 (5.08%), respectively. Of the 1311 participants, 399 had self-perceived PLMS. The odds ratios (ORs) for self-perceived PLMS in participants with restless legs symptoms were: males (OR = 1.528; 95% CI: 1.145–2.040), usually/always experienced apnea apnea (OR, 3.006; 95% CI, 1.954–4.624), increased proneness to Internet addiction (OR = 1.013; 95% CI: 1.001–1.025), sometimes/often consuming coffee (OR = 1.312; 95% CI: 1.015–1.695), EDS (OR = 0.826; 95% CI: 0.488–1.398), and perceived insufficient sleep (OR = 1.143; 95% CI: 0.835–1.565). The male gender, witness apnea, consuming coffee, and being prone to Internet addiction were identified as factors significantly associated with self-perceived PLMS in participants with restless legs symptoms. However, EDS and insufficient sleep were associated with self-perceived PLMS in the absence of restless legs symptoms.

ENIGMA-Sleep: Challenges, opportunities, and the road map

Neuroimaging and genetics studies have advanced our understanding of the neurobiology of sleep and its disorders. However, individual studies usually have limitations to identifying consistent and reproducible effects, including modest sample sizes, heterogeneous clinical characteristics and varied methodologies. These issues call for a large-scale multi-centre effort in sleep research, in order to increase the number of samples, and harmonize the methods of data collection, preprocessing and analysis using pre-registered well-established protocols. The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) consortium provides a powerful collaborative framework for combining datasets across individual sites. Recently, we have launched the ENIGMA-Sleep working group with the collaboration of several institutes from 15 countries to perform large-scale worldwide neuroimaging and genetics studies for better understanding the neurobiology of impaired sleep quality in population-based healthy individuals, the neural consequences of sleep deprivation, pathophysiology of sleep disorders, as well as neural correlates of sleep disturbances across various neuropsychiatric disorders. In this introductory review, we describe the details of our currently available datasets and our ongoing projects in the ENIGMA-Sleep group, and discuss both the potential challenges and opportunities of a collaborative initiative in sleep medicine.

Levetiracetam Therapeutic Drug Monitoring in a Large Cohort of Korean Epileptic Patients

Levetiracetam is a new antiepileptic drug (AED) used for treating and preventing partial or generalized seizures. The usefulness of levetiracetam therapeutic drug monitoring (TDM) is related to inter- or intra-individual pharmacokinetic variability, drug interactions, and patient noncompliance. We aimed to investigate the levetiracetam TDM status in Korean epilepsy patients. Serum trough levetiracetam concentrations were measured using liquid chromatography–tandem mass spectrometry in 710 samples from 550 patients. The median (range) daily and weight-adjusted levetiracetam doses were 1500 (20–5000) mg and 25.5 (3.03–133.0) mg/kg, respectively. Patients on levetiracetam monotherapy constituted only 19.5% of the population, while 30.1% were on co-medication with valproate and 56.0% with enzyme-inducing AEDs (EIAEDs). Observed levetiracetam concentrations were widely distributed, ranging 0.8–95 mg/L, with a median of 17.3 mg/L. Levetiracetam concentrations were therapeutic, supra-therapeutic, and sub-therapeutic in 58.5% (n = 393), 11.6% (n = 78), and 29.9% (n = 201) of samples, respectively. There was a strong correlation between weight-adjusted levetiracetam dosage and concentrations (ρ = 0.6896, p < 0.0001). In this large-scale clinical study, a large inter-individual difference in levetiracetam pharmacokinetics was observed, and levetiracetam concentrations were influenced by EIAEDs. For individual dose adjustments and monitoring compliance, routine levetiracetam TDM is needed in epilepsy patients.

Association between eveningness preference, socio-behavioral factors, and insomnia symptoms in Korean adolescents

OBJECTIVE/BACKGROUND

Studies focusing on insomnia in adolescents are relatively scarce compared to those on excessive daytime sleepiness. We aimed to investigate the prevalence of insomnia symptoms and associated factors in Korean high school students.

PATIENTS/METHODS

A total of 8565 students (girls: 4104) were investigated nationwide, across 15 South Korean districts using an online self-report questionnaire. Insomnia symptoms were evaluated using the Global Sleep Assessment Questionnaire. The participants' mean age was 16.77 ± 0.85 years.

RESULTS

The prevalence of insomnia symptoms was 39.43% (n = 3377). Logistic regression was used to estimate the odds ratio (OR) of insomnia symptoms associated with sleep characteristics and social behaviors after adjusting for the relevant covariates. Evening preference (OR, 2.51, 95% CI, 2.20-2.86), perception of insufficient sleep (OR, 3.55, 95% CI, 3.11-4.06), snoring usually/always (OR, 1.25; 95% CI, 1.00-1.55), witnessed sleep apnea usually/always (OR, 1.70; 95% CI, 1.17-2.46), increased internet addiction (OR, 1.02; 95% CI, 1.02-1.03), bad sleep environment (OR, 1.77; 95% CI, 1.50-2.10), ≥3 private extra classes (OR, 1.23; 95% CI, 1.01-1.49), often coffee consumption (OR, 1.31; 95% CI, 1.10-1.56), and often nocturnal eating (OR, 1.24; 95% CI, 1.06-1.45) were associated with insomnia symptoms. Evening preference (OR, 3.48; 95% CI, 2.52-4.82) was also associated with insomnia symptoms in the perceived sufficient sleep subgroup.

CONCLUSION

Insomnia symptoms were common in Korean high school students. Evening preference was the major factor associated with insomnia symptoms. Various socio-behavioral factors were also associated with insomnia symptoms.

Asian accreditation of sleep medicine physicians and technologists: practice guidelines by the Asian Society of Sleep Medicine

Due to the rapid growth in sleep medicine's professional content, several countries have recognized sleep medicine as an independent specialty. The practice of sleep medicine and the demand for this service in Asian countries are expanding. At this point of growth, the accreditation of sleep medicine specialists is paramount to patient care and the training of physicians and technologists. The Asian Society of Sleep Medicine (ASSM) mandated a taskforce committee for the accreditation of sleep medicine practice. This taskforce developed Asian accreditation practice guidelines for sleep medicine physicians and technologists. This paper presents the newly approved Asian accreditation practice guidelines for sleep medicine physicians and technologists by the ASSM.

Regional Ictal Hyperperfusion in the Contralateral Occipital Area May Be a Poor Prognostic Marker of Anterior Temporal Lobectomy: A SISCOM Analysis of MTLE Cases

BACKGROUND AND OBJECTIVE

Subtraction of ictal SPECT coregistered to MRI (SISCOM) provides complementary information for detecting the ictal onset zone, especially in patients with MRI-negative focal epilepsy, and provides additional useful information for predicting long-term postresection outcomes. This study sought to investigate the relationship between surgical failure and increased cerebral blood flow (CBF) pattern using SPECT in patients with mesial temporal lobe epilepsy with unilateral hippocampal sclerosis (MTLE-HS).

METHODS

Among 42 subjects who underwent anterior temporal lobectomy with amygdalohippocampectomy (ATL-AH) for MTLE-HS, 29 (69.0%) were seizure-free (SF group). Hyperperfusion was compared in 14 ipsilateral and contralateral brain regions in SISCOM images between the two groups.

RESULTS

The pattern of ictal hyperperfusion in temporal regions did not vary significantly between the SF and non-seizure-free (NSF) groups. However, CBF increases in the contralateral occipital area was more frequent in the NSF group than in the SF group. Furthermore, ictal hyperperfusion of the ipsilateral occipital and contralateral parietal areas tended to be more frequent in the NSF group.

CONCLUSION

The results indicate that poor ATL-AH surgical outcome is associated with a tendency of ictal hyperperfusion of the contralateral occipital cortex based on SISCOM analysis. The pattern of early ictal CBF changes implicating the propagation from temporal to occipital cortices can be considered a marker of poor surgical outcomes of ATL-AH in MTLE-HS patients.

Effect of Long-Term Treatment with Vagus Nerve Stimulation on Mood and Quality of Life in Korean Patients with Drug-Resistant Epilepsy

BACKGROUND AND PURPOSE

This study aimed to determine the long-term effects of vagus nerve stimulation (VNS) treatment on suicidality, mood-related symptoms, and quality of life (QOL) in patients with drug-resistant epilepsy (DRE). We also investigated the relationships among these main effects, clinical characteristics, and VNS parameters.

METHODS

Among 35 epilepsy patients who underwent VNS implantation consecutively in our epilepsy center, 25 patients were recruited to this study for assessing the effects of VNS on suicidality, mood-related symptoms, and QOL. The differences in these variables between before and after VNS treatment were analyzed statistically using paired t-tests. Multiple linear regression analyses were also performed to determine how the patients' demographic and clinical characteristics influenced the variables that showed statistically significant changes after long-term VNS treatment.

RESULTS

After VNS, our patients showed significant improvements not only in the mean seizure frequency but also in suicidality, depression, and QOL. The reduction in depression was associated with the improvement in QOL and more-severe depression at baseline. The reduction in suicidality was associated with higher suicidality at baseline, smaller changes in depression, and less-severe depression at baseline. Improved QOL was associated with lower suicidality at baseline.

CONCLUSIONS

This study found that VNS decreased the mean seizure frequency in patients with DRE, and also improved their depression, suicidality, and QOL. These results provide further evidence for therapeutic effect of VNS on psychological comorbidities of patients with DRE.

Safety, tolerability, and efficacy of brivaracetam as adjunctive therapy in patients with focal seizures, generalized onset seizures, or Unverricht-Lundborg disease: An open-label, long-term follow-up trial

This long-term open-label extension (OLE) trial was conducted to evaluate the long-term safety and tolerability of brivaracetam (BRV) at individualized doses in patients with epilepsy and focal (partial-onset) or generalized onset seizures, or Unverricht-Lundborg disease (ULD). A secondary objective was to evaluate efficacy of BRV in the subgroups of patients with focal or generalized onset seizures. Patients with epilepsy were eligible to enroll in this OLE (N01125; NCT00175916) and were analyzed if they had completed a previous double-blind BRV trial (N01114 [NCT00175929], N01252 [NCT00490035], N01254 [NCT00504881], N01187 [NCT00357669], and N01236 [NCT00368251]), and were expected to obtain a reasonable benefit from long-term BRV treatment. Patients entered the OLE at the BRV dose recommended at the end of the previous trial, with dose adjustments of BRV and concomitant antiseizure medications permitted. Safety variables included treatment-emergent adverse events (TEAEs). Efficacy variables in patients with focal seizures were percent reduction in focal seizure frequency, 50 % responder rates, and 6- and 12-month seizure-freedom. Eight hundred and fifty-three patients (729 [85.5 %] with focal seizures, 30 [3.5 %] with generalized onset seizures, and 94 [11.0 %] with ULD) were enrolled and included in the Safety Set. Overall, 619 (72.6 %) patients discontinued the trial, mainly due to lack of efficacy (354 [41.5 %]), adverse events (100 [11.7 %]), and patient choice (98 [11.5 %]). During the OLE, 588 (68.9 %) patients received BRV for ≥12 months, 403 (47.2 %) for ≥36 months, and 223 (26.1 %) for ≥96 months. The most common modal dose of BRV was 150 mg/day (415 [48.7 %] patients). In the ULD subgroup, the most common modal BRV dose was 100 mg/day (44/94 [46.8 %] patients), and 37/94 (39.4 %) patients had ≥96 months of BRV exposure. Overall, 720/853 (84.4 %) patients reported TEAEs, 451 (52.9 %) had a drug-related TEAE, and 95 (11.1 %) discontinued BRV due to a TEAE. In the ULD subgroup, 87/94 (92.6 %) patients reported TEAEs, 60 (63.8 %) had a drug-related TEAE, and 16 (17.0 %) discontinued due to a TEAE. In patients with focal seizures, the median reduction in focal seizure frequency from Baseline was 43.1 % (n = 728), the 50 % responder rate was 43.6 % (n = 729), and 6- and 12-month seizure freedom rates were 22.2 % and 15.8 %, respectively (n = 595). Overall, BRV was well-tolerated as long-term adjunctive therapy in patients with focal seizures, generalized onset seizures, or Unverricht-Lundborg disease, with improvements in focal seizure frequency maintained over time.

Correlations between interictal extratemporal spikes and clinical features, imaging characteristics, and surgical outcomes in patients with mesial temporal lobe epilepsy

PURPOSE

The significance of interictal epileptiform discharges (IEDs) observed in the extratemporal lobe has not been fully evaluated in patients with mesial temporal lobe epilepsy (MTLE). This study aimed to evaluate the surgical outcomes, clinical features, and functional neuroimaging characteristics of patients in relation to the presence or absence of extratemporal IED in MTLE with hippocampal sclerosis (HS).

METHODS

A total of 165 patients with HS-induced MTLE who had undergone anterior temporal lobectomy were enrolled and stratified into the extratemporal interictal epileptiform discharges (ETD) and the temporal lobe discharges (TD) groups. We analyzed the differentiating features of pre- and postsurgical evaluation data between the two groups. For outcome assessment, only patients with a follow-up of at least 2 years were enrolled, and the outcomes were classified based on Engel classification.

RESULTS

The ETD group showed extensive glucose hypometabolism involving the temporal lobe and extratemporal regions (p < 0.001), and IEDs were observed bilaterally or contralateral to the ictal focus (p = 0.02). However, there was no difference in the surgical outcomes between the two groups. On multivariate analysis, statistically significant variables related to ETD occurrence including seizure onset age were not identified nevertheless.

CONCLUSION

Our results indicate that ETD had a surgical outcome comparable to that of TD. Therefore, a surgical intervention need not be delayed even if extratemporal IED may be found in presurgical long-term scalp EEG monitoring.

Association between morningness-eveningness, sleep duration, weekend catch-up sleep and depression among Korean high-school students

The present study aimed to examine the association between morningness-eveningness preferences, sleep duration, weekend catch-up sleep duration and depression among Korean high-school students. A total of 8,655 high-school students participated from 15 districts in South Korea and completed an online self-report questionnaire. The following sleep characteristics were assessed: weekday and weekend sleep duration, weekend catch-up sleep duration, morningness-eveningness preference, perceived sufficiency of sleep, self-reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, gender, body mass index, number of private classes, proneness to internet addiction, and depressive mood were also evaluated. A logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates. Eveningness preference was a significant predictor of depressive mood (adjusted OR, 1.71; 95% CI, 1.47-1.99). Weekend CUS durations that were ≥2 hr and enrollment in numerous private classes were associated with a lower risk for depression (0.68, 0.55-0.85; 0.76, 0.60-0.95; respectively). Female gender, underweight and obese body weight, short weekday sleep durations, excessive daytime sleepiness, perceived excessiveness and insufficiency of sleep, self-reported snoring and sleep apnea, proneness to internet addiction and a non-optimal sleep environment were associated with an increased risk for depression. Eveningness preference and insufficient weekday sleep duration were associated with an increased risk for depression. Weekend CUS duration ≥2 hr reduced the risk for depression. Diverse aspects, including sleeping habits and sleep-related environmental factors, should be considered to reduce depressive symptoms in late adolescents.

Defining the optimal target for anterior thalamic deep brain stimulation in patients with drug-refractory epilepsy

OBJECTIVE

The anterior thalamic nucleus (ATN) is a common target for deep brain stimulation (DBS) for the treatment of drug-refractory epilepsy. However, no atlas-based optimal DBS (active contacts) target within the ATN has been definitively identified. The object of this retrospective study was to analyze the relationship between the active contact location and seizure reduction to establish an atlas-based optimal target for ATN DBS.

METHODS

From among 25 patients who had undergone ATN DBS surgery for drug-resistant epilepsy between 2016 and 2018, those who had follow-up evaluations for more than 1 year were eligible for study inclusion. After an initial stimulation period of 6 months, patients were classified as responsive (≥ 50% median decrease in seizure frequency) or nonresponsive (< 50% median decrease in seizure frequency) to treatment. Stimulation parameters and/or active contact positions were adjusted in nonresponsive patients, and their responsiveness was monitored for at least 1 year. Postoperative CT scans were coregistered nonlinearly with preoperative MR images to determine the center coordinate and atlas-based anatomical localizations of all active contacts in the Montreal Neurological Institute (MNI) 152 space.

RESULTS

Nineteen patients with drug-resistant epilepsy were followed up for at least a year following bilateral DBS electrode implantation targeting the ATN. Active contacts located more adjacent to the center of gravity of the anterior half of the ATN volume, defined as the anterior center (AC), were associated with greater seizure reduction than those not in this location. Intriguingly, the initially nonresponsive patients could end up with much improved seizure reduction by adjusting the active contacts closer to the AC at the final postoperative follow-up.

CONCLUSIONS

Patients with stimulation targeting the AC may have a favorable seizure reduction. Moreover, the authors were able to obtain additional good outcomes after electrode repositioning in the initially nonresponsive patients. Purposeful and strategic trajectory planning to target this optimal region may predict favorable outcomes of ATN DBS.

Efficacy, safety, and tolerability of perampanel in Asian and non-Asian patients with epilepsy

People of different ethnic or racial backgrounds may experience variations in pharmacokinetic and pharmacodynamic responses to drug therapies. Our post hoc analysis evaluated the efficacy, safety, and tolerability of perampanel in Asian and non-Asian populations with refractory focal seizures with or without focal to bilateral tonic-clonic (FBTC) seizures. This analysis pooled data from 4 randomized, placebo-controlled, phase-3 studies involving patients aged ≥12 years who have focal seizures with or without FBTC seizures. Patients were receiving 2, 4, 8, or 12 mg perampanel (or placebo) by the end of a 6-week titration period and for a further 13 weeks during the maintenance phase. Efficacy endpoints included median percent change in seizure frequency per 28 days, and 50% and seizure-freedom responder rates relative to baseline. The median percent change in seizure frequency per 28 days from baseline was significantly greater than placebo for perampanel 8 and 12 mg (-31.1% and -38.1% change, respectively; each P < 0.0001) in the Asian population, and for perampanel 4, 8, and 12 mg (-21.1% [P = 0.0001], -26.3% [P < 0.0001], and -27.7% [P = 0.0001] change, respectively) in the non-Asian population. The 50% responder rate relative to baseline was significantly greater than placebo for perampanel 8 and 12 mg (40.1% and 43.8%, respectively; each P < 0.0001) in the Asian population, and for perampanel 4, 8, and 12 mg (29.4% [P = 0.0002], 32.8% [P < 0.0001] and 34.5% [P = 0.0001]), respectively, in the non-Asian population. Seizure-freedom rate among all patients was 4.9%-11.7% for perampanel 2, 4, 8, and 12 mg. The most frequently reported treatment-emergent adverse events (TEAEs) across both populations were dizziness, somnolence, irritability, headache, and fatigue. The most common psychiatric TEAEs were aggression and irritability. Perampanel demonstrated a favorable and similar risk-benefit profile in both Asian and non-Asian populations with refractory focal seizures.

A five-year longitudinal study reveals progressive cortical thinning in narcolepsy and faster cortical thinning in relation to early-onset

Narcolepsy with cataplexy is characterized by excessive daytime sleepiness, cataplexy, and other REM sleep phenomena. Previous MRI studies were cross-sectional in design and could not adequately address if disease progression leads the brain structural abnormalities in narcolepsy. Our analysis in patients using longitudinally collected brain MRIs (n = 17; 2 scans per patient; scan interval: 4.7 ± 1.9 years) revealed widespread progressive cortical thinning in bilateral dorsolateral frontal and fusiform cortices, right anterior cingulate (corrected p < 0.05). Cross-sectional analyses showed faster progressive cortical thinning in patients than controls (n = 83, one scan per subject available), which we confirmed significant in the analysis of a small-set of longitudinal control data (n = 10). The pattern of progressive thinning in patients was overlapped well with those found in structural and functional studies of narcolepsy. We also found a faster progression of cortical thinning and worse disease severity (decreased sleep efficiency, increased sleep latency and arousal index) over time in a subgroup of patients with earlier disease onset (n = 9, onset age: 15.9 ± 2.5 years old) compared to later disease onset (n = 8, 25.3 ± 4.9). The faster progressive cortical thinning and worse disease severity over time in the patients with early-onset suggest compelling evidence of disease progression existing in this phenotype of narcolepsy syndrome. Our result based on a small dataset, however, demands a more careful investigation of the underlying mechanism.

Preoperative N stage evaluation in advanced gastric cancer patients using multidetector CT: can the sum of the diameters of metastatic LNs be used for N stage evaluation?

AIM

To compare the diagnostic performance of total counts of metastatic lymph nodes (LN-sum) and conventional multidetector (MD) computed tomography (CT) staging in the nodal evaluation of advanced gastric cancer (AGC) patients.

MATERIALS AND METHODS

In total, 127 consecutive patients who underwent preoperative MDCT and gastrectomy for AGC were identified. Metastatic LNs on MDCT were defined as LNs with a short axis ≥8 mm, marked or heterogeneous enhancement, and morphological features (central necrosis, round shape, clustering). The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the N-stage using LN-sum and conventional MDCT staging were generated and compared. In addition, metastatic LN counts between the MDCT and the histopathological examinations and correlation between LN-sum and histopathological nodal status were analysed.

RESULTS

The total counts of metastatic LNs on MDCT was significantly smaller than those detected in histopathological assessments (p<0.0001). LN-sum showed significant correlation with the pathological N stage and the number of metastatic LNs (rho=0.69, 0.73, p<0.0001). The areas under the receiver operating characteristic curve were 0.896, and 0.835, for N stage ≥N2 and N3, with cut-off values of 12.5 and 23.5 mm, respectively. LN-sum provided better diagnostic performance than conventional MDCT staging for discriminating N0-2 versus N3; sensitivity, accuracy, PPV and NPV of LN-sum were significantly higher (80.4 versus 52.2%, 81.1 versus 68.5%, 71.2 versus 57.1%, and 88 versus 74.1%).

CONCLUSION

LN-sum may be sufficiently useful in assessing the N3 stage of AGC and may help to plan appropriate therapy for AGC patients.

High Frequency Oscillations in Epilepsy: Detection Methods and Considerations in Clinical Application

High frequency oscillations (HFOs) is a brain activity observed in electroencephalography (EEG) in frequency ranges between 80–500 Hz. HFOs can be classified into ripples (80–200 Hz) and fast ripples (200–500 Hz) by their distinctive characteristics. Recent studies reported that both ripples and fast fipples can be regarded as a new biomarker of epileptogenesis and ictogenesis. Previous studies verified that HFOs are clinically important both in patients with mesial temporal lobe epilepsy and neocortical epilepsy. Also, in epilepsy surgery, patients with higher resection ratio of brain regions with HFOs showed better outcome than a group with lower resection ratio. For clinical application of HFOs, it is important to delineate HFOs accurately and discriminate them from artifacts. There have been technical improvements in detecting HFOs by developing various detection algorithms. Still, there is a difficult issue on discriminating clinically important HFOs among detected HFOs, where both quantitative and subjective approaches are suggested. This paper is a review on published HFO studies focused on clinical findings and detection techniques of HFOs as well as tips for clinical applications.

Sleep and libido in men with obstructive sleep apnea syndrome

OBJECTIVES

The objectives of this study were to investigate the relationship between a low libido and objective sleep parameters as well as mood disturbances in patients with obstructive sleep apnea syndrome (OSA).

METHODS

We enrolled 436 untreated patients who were newly diagnosed with OSA (all male, mean age 42.8 years). Patients completed the Symptom checklist-90-Revised (SCL-90-R), Epworth Sleepiness Scale (ESS), Beck Depression Inventory-II (BDI), and Beck Anxiety Inventory (BAI). Patients were divided into low-libido and normal-libido groups according to their response to the statement "Loss of sexual interest or pleasure" on the SCL-90-R.

RESULTS

Approximately 23% of patients reported a low libido. Patients with a low libido were older (47.5 ± 9.0 vs. 41.4 ± 11.1 years; p < 0.001), had more nocturia (33.3% vs. 16.6%; p < 0.001), higher BDI (9.0 (5.0-14.0) vs. 5.0 (2.0-9.0); p < 0.001) and BAI score (11.0 (6.3-16.8) vs. 5.0 (2.0-10.0); p < 0.001). These patients had a lower non-REM sleep stage 3 (N3) % (0.1 (0-4.0) vs. 2.3 (0.1-7.9); p < 0.001). Multivariate analysis revealed that older age and higher BDI score were independent factors associated with a low libido.

CONCLUSIONS

Men with untreated OSA suffered from a low libido. Older age and depressed mood were the most important factors of low libido in middle-aged men with OSA.

Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene

The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little.

Past climate changes in Greenland ice were accompanied by large aerosol concentration changes. Here, the authors show that by correcting for transport effects, reliable source changes for biogenic aerosol from North America, sea salt aerosol from the North Atlantic, and dust from East Asian deserts can be derived.

SPECT perfusion changes during ictal automatisms with preserved responsiveness in patients with right temporal lobe epilepsy

Ictal automatism with preserved responsiveness (APR) has been reported, particularly in nondominant temporal lobe epilepsy (TLE), but its pathophysiology remains poorly understood. This study sought to investigate the relationship between APRs and increased cerebral blood flow (CBF) using ictal single photon emission computed tomography (SPECT) in TLE. Forty-seven subjects with right mesial TLE (15 with and 32 without APR) were enrolled. Patients with APR (APR+) were subdivided into four groups according to degree of responsiveness during seizures. Cerebral blood flow changes during these seizures were semiquantitatively assessed by subtraction ictal SPECT coregistered to MRI (SISCOM). Hyperperfusion in temporal regions did not vary significantly between the APR+ and APR- groups. Cerebral blood flow changes in the frontal area, insula, cingulum, and occipital area were also nonsignificant. However, hyperperfusion in the ipsilateral parietal areas was more frequent in the APR- group than in the APR+ group. Furthermore, hyperperfusion of the contralateral basal ganglia showed an inclination to be more common in the APR- group, but without statistical significance. The study suggested that the involvement of the parietal association cortex during seizure may play an important role in ictal loss of consciousness in TLE. Further studies will be needed to elucidate the pathophysiology of changes in consciousness during temporal lobe seizures.

Intractable Epilepsy with Solitary Cerebral Calcification

Cerebral calcification is a common incidental finding upon brain imaging and its epileptogenicity is often underestimated. Here, we report a case of intractable epilepsy arising in conjunction with a solitary cerebral calcification. A 42-year-old male with intractable epilepsy was admitted to the epilepsy clinic for invasive epilepsy surgery. Brain magnetic resonance imaging revealed a slight high-intensity signal change in the right amygdala and a small, calcified lesion in the right lateral temporal region. The patient underwent invasive monitoring with subdural electrodes. He had five habitual seizures with automatisms and fast activity. These seizures initiated in the right lateral temporal area just above the solitary calcified lesion. Neuropathology of the calcified lesion showed no specific findings apart from a fibrocalcific nodule. Thus, although solitary cerebral calcifications may be an asymptomatic or coincidental finding in some patients, they may also have a highly epileptogenic focus.

Lacosamide and Levetiracetam Have No Effect on Sharp-Wave Ripple Rate

Pathological high-frequency oscillations are a novel marker used to improve the delineation of epileptogenic tissue and, hence, the outcome of epilepsy surgery. Their practical clinical utilization is curtailed by the inability to discriminate them from physiological oscillations due to frequency overlap. Although it is well documented that pathological HFOs are suppressed by antiepileptic drugs (AEDs), the effect of AEDs on normal HFOs is not well known. In this experimental study, we have explored whether physiological HFOs (sharp-wave ripples) of hippocampal origin respond to AED treatment. The results show that application of a single dose of levetiracetam or lacosamide does not reduce the rate of sharp-wave ripples. In addition, it seems that these new generation drugs do not negatively affect the cellular and network mechanisms involved in sharp-wave ripple generation, which may provide a plausible explanation for the absence of significant negative effects on cognitive functions of these drugs, particularly on memory.

Comparison of levetiracetam and oxcarbazepine monotherapy among Korean patients with newly diagnosed focal epilepsy: A long-term, randomized, open-label trial

This open-label, multicenter, randomized phase IV trial (NCT01498822) of noninferiority design compared the long-term effectiveness, safety, and tolerability of levetiracetam (LEV) monotherapy with those of oxcarbazepine (OXC) monotherapy in adults with newly diagnosed focal epilepsy. Korean patients (16-80 years), with ≥2 unprovoked focal seizures in the year preceding the trial, who had not taken any antiepileptic drugs (AEDs) in the last 6 months, were randomized to receive LEV or OXC (1:1). Effectiveness, safety, and tolerability were assessed over a 50-week period. Treatment failure rates (per protocol set) were 15/118 (12.7%) in the LEV-treated group and 30/128 (23.4%) in the OXC-treated group, an absolute difference of -10.7% (95% confidence interval [CI] -20.2, -1.2). Because the upper 95% CI limit was less than the pre-specified noninferiority margin of 15%, LEV was considered noninferior to OXC. Twenty-four-week and 48-week seizure freedom rates were 53.8% and 34.7% for LEV vs. 58.5% and 40.9% for OXC. Both LEV and OXC were well tolerated, with 8.7% and 8.6% of patients reporting serious treatment-emergent adverse events, respectively. By comparing LEV with OXC, another newer AED, LEV can be considered a useful option as initial monotherapy for patients with newly diagnosed focal epilepsy.

Thalamo-cortical network underlying deep brain stimulation of centromedian thalamic nuclei in intractable epilepsy: a multimodal imaging analysis

OBJECTIVE

Deep brain stimulation (DBS) of the centromedian thalamic nucleus (CM) can be an alternative treatment option for intractable epilepsy patients. Since CM may be involved in widespread cortico-subcortical networks, identification of the cortical sub-networks specific to the target stimuli may provide further understanding on the underlying mechanisms of CM DBS. Several brain structures have distinguishing brain connections that may be related to the pivotal propagation and subsequent clinical effect of DBS.

METHODS

To explore core structures and their connections relevant to CM DBS, we applied electroencephalogram (EEG) and diffusion tensor imaging (DTI) to 10 medically intractable patients - three generalized epilepsy (GE) and seven multifocal epilepsy (MFE) patients unsuitable for resective surgery. Spatiotemporal activation pattern was mapped from scalp EEG by delivering low-frequency stimuli (5 Hz). Structural connections between the CM and the cortical activation spots were assessed using DTI.

RESULTS

We confirmed an average 72% seizure reduction after CM DBS and its clinical efficiency remained consistent during the observation period (mean 21 months). EEG data revealed sequential source propagation from the anterior cingulate, followed by the frontotemporal regions bilaterally. In addition, maximal activation was found in the left cingulate gyrus and the right medial frontal cortex during the right and left CM stimulation, respectively. From DTI data, we confirmed concrete structural connections between CM and those maximal activation spots identified from EEG data.

CONCLUSION

These results suggest that the anterior cingulate can be a core cortical structure for the bilateral propagation of CM stimulation. Our DTI findings also indicate that the propagation of CM stimulation may rely upon integrity of structural connections between CM and these key cortical regions. Structures and their connections found in this study may be relevant in the interpretation of the clinical outcomes of CM DBS.

Prevalence of Self-Perceived Snoring and Apnea and Their Association with Daytime Sleepiness in Korean High School Students

Background and Purpose

There has been no nationwide population-based study of the prevalence of self-perceived snoring/apnea in Korean adolescents. The purpose of this study was to estimate prevalence of self-perceived snoring/apnea in Korean high-school students and to evaluate their association with daytime sleepiness.

Methods

An online survey was used to investigate 12,672 students at 75 high schools across the 15 nationwide districts of South Korea. The variables were obtained using a self-reported questionnaire. The students answered questions about self-perceived snoring/apnea during the past 30 days. Daytime sleepiness was measured using a validated Korean version of the Epworth Sleepiness Scale, which was modified for adolescents. Covariates were the sex, school grade, frequency of self-perceived snoring/apnea, body mass index, sleep duration during a school day, and subjective perception of sleep duration.

Results

The prevalence of self-perceived snoring/apnea was 22.8% (26.4% for males vs. 18.8% for females, p<0.001) and 9.2% (10.5% for males vs. 7.7% for females, p<0.001). Obesity was significantly associated with self-perceived snoring [odds ratio (OR)=2.18, 95% confidence interval (CI)=1.94–2.46] and apnea (OR=1.57, 95% CI=1.33–1.86). Multivariate analysis showed that any frequency of self-perceived snoring/apnea was significantly associated with excessive daytime sleepiness (EDS). The OR of EDS increased significantly with the frequency of snoring and apnea. Female, sleep duration of <5 hours during a school day, and subjective perceptions of insufficient and considerable sleep durations were also significantly associated with EDS.

Conclusions

The prevalence of self-perceived snoring/apnea was significantly higher in students who were male and obese. Students with self-perceived snoring/apnea exhibited more significant EDS and an increased risk of EDS as the frequency of snoring and apnea increased.

Accuracy of MEG in localizing irritative zone and seizure onset zone: Quantitative comparison between MEG and intracranial EEG

BACKGROUND

We conducted the study to examine accuracy of the magnetoencephalography (MEG) spike source localization in presurgical evaluation of patients with medically refractory focal epilepsy.

METHODS

Ten consecutive patients with refractory focal epilepsy who were candidates for two-stage surgery with long-term intracranial electroencephalography (ICEEG) monitoring were enrolled. Interictal MEG recordings with simultaneous scalp EEG were obtained within 7days before the ICEEG electrode implantation. The location of each MEG spike source was quantitatively compared with ICEEG spike foci (focal area of interictal spikes) and ICEEG ictal foci (earliest cortical origin of seizures). Gyral-width concordance and sublobar concordance were also determined for all MEG spike sources. Gyral-width concordance was defined by distance of 15mm or less between MEG spike sources and ICEEG spike foci or ICEEG ictal foci.

RESULTS

Visual analyses of the MEG traces of all 10 patients revealed 292 spikes (29.2±24.0 per patient). Spike yield of the MEG was similar to the simultaneously recorded scalp EEG. MEG spike sources were closely located with ICEEG spike foci (distance: 9.3±10.8mm). Clustered MEG spike sources were even closer to ICEEG spike foci (distance: 7.3±6.4mm). MEG spike sources, even clustered ones, were less concordant with ICEEG ictal foci and had significant longer distance from ICEEG ictal foci (distance: 21.5±15.6mm for all sources, 19.7±13.7mm for clustered sources). Gyral-width concordance rate and sublobar concordance rate were also higher with ICEEG interictal spike foci than with ICEEG ictal foci. On the other hand, 53.4% of interictal spike foci from ICEEG were not detected by interictal MEG recordings.

CONCLUSIONS

MEG spike sources, especially clustered ones, from interictal recording could localize the irritative zone of ICEEG with a high accuracy. However, MEG spike sources have relatively poor correlation with seizure onset zone and lower sensitivity in identifying all irritative zones of ICEEG. This limitation should be considered in the interpretation of MEG results.

Asymmetric Gray Matter Volume Changes Associated with Epilepsy Duration and Seizure Frequency in Temporal-Lobe-Epilepsy Patients with Favorable Surgical Outcome

Background and Purpose

This study aimed to estimate the changes in gray matter volume (GMV) and their hemispheric difference in patients with mesial temporal lobe epilepsy (MTLE) using a voxel-based morphometry (VBM) methodology, and to determine whether GMV changes are correlated with clinical features.

Methods

VBM analysis of brain MRI using statistical parametric mapping 8 (SPM8) was performed for 30 left MTLE (LMTLE) and 30 right MTLE (RMTLE) patients and 30 age- and sex-matched healthy controls. We also analyzed the correlations between GMV changes and clinical features of MTLE patients.

Results

In SPM8-based analyses, MTLE patients showed significant GMV reductions in the hippocampus ipsilateral to the epileptic focus, bilateral thalamus, and contralateral putamen in LMTLE patients. The GMV reductions were more extensive in the ipsilateral hippocampus, thalamus, caudate, putamen, uncus, insula, inferior temporal gyrus, middle occipital gyrus, cerebellum, and paracentral lobule in RMTLE patients. These patients also exhibited notable reductions of GMV in the contralateral hippocampus, thalamus, caudate, putamen, and inferior frontal gyrus. We observed that GMV reduction was positively correlated with several clinical features (epilepsy duration and seizure frequency in RMTLE, and history of febrile seizure in LMTLE) and negatively correlated with seizure onset age in both the RMTLE and LMTLE groups.

Conclusions

Our study revealed GMV decreases in the hippocampus and extrahippocampal regions. Furthermore, the GMV reduction was more extensive in the RMTLE group than in the LMTLE group, since it included the contralateral hemisphere in the former. This difference in the GMV reduction patterns between LMTLE and RMTLE may be related to a longer epilepsy duration and higher seizure frequency in the latter.

Correlation between headaches and affective symptoms in patients with epilepsy

Headaches are a neglected entity in patients with epilepsy (PWE), although PWE have a high chance of suffering from seizure-related as well as seizure-unrelated headaches. We aimed to identify the prevalence and characteristics of headaches and investigate the correlation between headaches and affective symptoms in PWE. Consecutive PWE who visited our tertiary outpatient clinic were interviewed about headaches and epilepsy. Affective symptoms were evaluated using the Korean version of the Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and suicidality portion of the Mini-International Neuropsychiatric Interview. We classified headaches as interictal or seizure-related headaches (SRHs; pre- and postictal). Tension-type headache and migraine were defined based on International Classification of Headache Disorders criteria. From the initial cohort of 177 patients (92 men, mean age: 37.1years), 73 (41.2%) reported suffering from interictal (N=34, 19.2%), preictal (N=3, 1.7%), and postictal (N=48, 27.1%) headaches. Univariate analysis revealed significantly higher BDI and BAI scores in the headache group. Tension-type headaches were the most frequent, and half of the interictal headaches and most of the SRHs were untreated. Spearman's partial correlation analyses showed that headaches overall were significantly related with depression and anxiety. Interictal headaches were correlated with depression only, and postictal headaches were correlated with depression as well as suicidality, separately. These results show that investigating and controlling headaches may relieve affective symptoms and ultimately improve the quality of life of PWE.

The Difference in Heart Rate Change between Temporal and Frontal Lobe Seizures during Peri-ictal Period

BACKGROUND AND PURPOSE

Heart rate (HR) change is easily seen in seizures. Tachycardia is frequently seen in temporal lobe epilepsy (TLE), rather than extra temporal lobe epilepsy (XTLE). We report the difference in the HR pattern between TLE and frontal lobe epilepsy (FLE) during peri-ictal period.

METHODS

The ECG data, collected during EEG monitoring, was used. To compare the HR pattern between FLE and TLE, we investigated the baseline HR, maximum HR, seizure onset to peak HR, HR change, and the time return to baseline.

RESULTS

A total of 198 seizures (FLE was 115, TLE was 83) were included in this study. The baseline HR (in TLE, 74.9 ± 17.2 and in FLE, 70.7 ± 11.5 bpm), there was no difference between two groups. But the mean duration of the increased HR was more prolonged in TLE group (93.8 ± 54.9 seconds) than the FLE group(39.0 ± 21.4 seconds) (p < 0.001), the time to peak HR of the TLE group (135.1 ± 19.1 seconds) was higher than FLE group (119.3 ± 19.7 seconds) (p = 0.027), and the HR change of the TLE group (60.0 ± 26.3 bpm) was more prominent than that of the FLE group (22.8 ± 26.2 seconds) (p < 0.001). Furthermore, a longer duration of HR increase was seen in that of the TLE group than FLE group.

CONCLUSIONS

The HR change of the TLE group was more prominent and prolonged than that of the FLE group. Therefore, the HR change can be a pattern that differentiates TLE from FLE.

Acoustic Characteristics of Stridor in Multiple System Atrophy

Nocturnal stridor is a breathing disorder prevalent in patients with multiple system atrophy (MSA). An improved understanding of this breathing disorder is essential since nocturnal stridor carries a poor prognosis (an increased risk of sudden death). In this study, we aimed to classify types of stridor by sound analysis and to reveal their clinical significance. Patients who met the criteria for probable MSA and had undergone polysomnography (PSG) were recruited. Patients were then assessed clinically with sleep questionnaires, including the Pittsburgh Sleep Quality Index, and the Hoehn and Yahr scale. Nocturnal stridor and snoring were analyzed with the Multi-Dimensional Voice Program. Nocturnal stridor was recorded in 22 patients and snoring in 18 patients using the PSG. Waveforms of stridors were classified into rhythmic or semirhythmic after analysis of the oscillogram. Formants and harmonics were observed in both types of stridor, but not in snoring. Of the 22 patients diagnosed with stridor during the present study, fifteen have subsequently died, with the time to death after the PSG study being 1.9 ± 1.4 years (range 0.8 to 5.0 years). The rhythmic waveform group presented higher scores on the Hoehn and Yahr scale and the survival outcome of this group was lower compared to the semirhythmic waveform group (p = 0.030, p = 0.014). In the Kaplan Meier's survival curve, the outcome of patients with rhythmic waveform was significantly less favorable than the outcome of patients with semirhythmic waveform (log-rank test, p < 0.001). Stridor in MSA can be classified into rhythmic and semirhythmic types and the rhythmic component signifies a poorer outcome.

Lateralizing Cortical Excitability in Drug Naïve Patients with Generalized or Focal Epilepsy

Background and Purpose:

Numerous transcranial magnetic stimulation (TMS) studies have defined the characteristic features of TMS in epilepsy. TME parameters were expected to classify the epilepsy syndrome or drug responses. However, the results such as cortical silent periods (CSP) are variable according to conditions of patients. Here, we investigate whether specific TMS parameters have localizing or lateralizing values in drug-naïve epilepsy patients.

Methods:

We recruited 148 consecutive untreated patients with epilepsy (idiopathic generalized epilepsy (IGE) 38, focal epilepsy (FE) 110, mean age 31.4 years) and 38 age- and gender-matched normal subjects. We obtained resting motor threshold (RMT), motor-evoked potential (MEP), CSP, short interval intracortical inhibition (SICI, inter-stimuli interval 2–5 ms), and intracortical facilitation (ICF, inter-stimuli interval 10–20 ms). TMS were performed during a seizure-free state of more than 48 h.

Results:

In IGE, no interhemispheric difference in CSP was found (p > 0.05). However, the mean CSP was longer in IGE patients than in normal controls at all stimulus intensities (p < 0.05). The mean CSP in ipsilateral hemisphere (IH) of FE was significantly longer at all stimulus intensities than that in normal controls (p < 0.001). The CSP in IH was longer than that in the contralateral hemisphere of FE. There was no significant difference in CSP between FE and IGE. SICI was significantly reduced only in the IH of FE versus normal subjects. RMT, MEP amplitudes, and ICF did not differ among IGE, FE, and normal controls.

Conclusions:

We found that prolonged CSP and reduced SICI in FE indicate asymmetrically increased cortical inhibition and excitation in the epileptic hemispheres. It suggests that CSP among TMS parameters has a crucial role to lateralize the epileptic hemisphere in FE.

Effects of long-term treatment on brain volume in patients with obstructive sleep apnea syndrome

We assessed structural brain damage in obstructive sleep apnea syndrome (OSA) patients (21 males) and the effects of long-term continuous positive airway pressure (CPAP) treatment (18.2 ± 12.4 months; 8-44 months) on brain structures and investigated the relationship between severity of OSA and effects of treatment. Using deformation-based morphometry to measure local volume changes, we identified widespread neocortical and cerebellar atrophy in untreated patients compared to controls (59 males; Cohen's D = 0.6; FDR < 0.05). Analysis of longitudinally scanned magnetic resonance imaging (MRI) scans both before and after treatment showed increased brain volume following treatment (FDR < 0.05). Volume increase was correlated with longer treatment in the cortical areas that largely overlapped with the initial atrophy. The areas overlying the hippocampal dentate gyrus and the cerebellar dentate nucleus displayed a volume increase after treatment. Patients with very severe OSA (AHI > 64) presented with prefrontal atrophy and displayed an additional volume increase in this area following treatment. Higher impairment of working memory in patients prior to treatment correlated with prefrontal volume increase after treatment. The large overlap between the initial brain damage and the extent of recovery after treatment suggests partial recovery of nonpermanent structural damage. Volume increases in the dentate gyrus and the dentate nucleus possibly likely indicate compensatory neurogenesis in response to diminishing oxidative stress. Such changes in other brain structures may explain gliosis, dendritic volume increase, or inflammation. This study provides neuroimaging evidence that revealed the positive effects of long-term CPAP treatment in patients with OSA.

Prognostic Role of Functional Neuroimaging after Multilobar Resection in Patients with Localization-Related Epilepsy

To investigate the usage of functional neuroimaging as a prognostic tool for seizure recurrence and long-term outcomes in patients with multilobar resection, we recruited 90 patients who received multilobar resections between 1995 and 2013 with at least 1-year follow-up (mean 8.0 years). All patients were monitored using intracranial electroencephalography (EEG) after pre-surgical evaluation. Clinical data (demographics, electrophysiology, and neuroimaging) were reviewed retrospectively. Surgical outcomes were evaluated at 1, 2, 5 years after surgery, and at the end of the study. After 1 year, 56 patients (62.2%) became Engel class I and at the last follow-up, 47 patients (52.2%) remained seizure-free. Furthermore, non-localized 18F-fluorodeoxyglucose positron emission tomography (PET), identifying hypometabolic areas not concordant with ictal onset zones, significantly correlated with seizure recurrence after 1 year. Non-lesional magnetic resonance imaging (MRI) and left-sided resection correlated with poor outcomes. In the last follow-up, non-localized PET and left-sided resection significantly correlated with seizure recurrence. Both localized PET and ictal-interictal SPECT subtraction co-registered to MR (SISCOM) predicted good surgical outcomes in the last follow-up (69.2%, Engel I). This study suggests that PET and SISCOM may predict postoperative outcomes for patients after multilobar epilepsy and shows comparable long-term surgical outcomes after multilobar resection.

Suicidal ideation and insomnia symptoms in subjects with obstructive sleep apnea syndrome

OBJECTIVE

Insomnia symptoms are prevalent in subjects with obstructive sleep apnea syndrome (OSA) and are important risk factors for suicidal ideation (SI). However, the significance of SI has not been clearly demonstrated in persons with both OSA and insomnia. We aimed to investigate the prevalence of SI and its relationship with insomnia symptoms, mood, and other relevant factors.

METHODS

A total of 117 consecutive subjects with untreated OSA (apnea-hypopnea index ≥5/h) participated in the study. They completed questionnaires regarding SI ([BDI-II], item 9), insomnia symptoms (Insomnia Severity Index [ISI]), depressive mood (modified BDI-II [mBDI-II], which excluded items on SI and sleep disturbances), dysfunctional beliefs and attitudes about sleep (DBAS), social support, and quality of life.

RESULTS

The overall prevalence of SI was 20.5% in subjects with OSA. A total of 32 subjects (27.4%) reported significant insomnia symptoms (ISI ≥ 15). Higher SI was associated with higher scores on ISI, DBAS, and mBDI-II and lower scores on social support and quality of life questionnaires. The severity of insomnia was positively correlated with depressive mood. The relationship between SI and insomnia severity was insignificant after adjusting for depressive symptom severity.

CONCLUSION

Patients with OSA may have SI and insomnia symptoms. Collinearity was observed between sleep and mood disturbances. Yet, it is remarkable to find a significant association between OSA and SI, which are additional contributions to insomnia. This study suggests the necessity of integrated approaches to SI and related factors for the comprehensive treatment of OSA.