Developing a deep learning model for sleep stage prediction in obstructive sleep apnea cohort using 60 GHz frequency-modulated continuous-wave radar.

Given the significant impact of sleep on overall health, radar technology offers a promising, non-invasive, and cost-effective avenue for the early detection of sleep disorders, even prior to relying on polysomnography (PSG)-based classification. In this study, we employed an attention-based bidirectional long short-term memory (Attention Bi-LSTM) model to accurately predict sleep stages using 60 GHz frequency-modulated continuous-wave (FMCW) radar. Our dataset comprised 78 participants from an ongoing obstructive sleep apnea (OSA) cohort, recruited between July 2021 and November 2022, who underwent overnight polysomnography alongside radar sensor monitoring. The dataset encompasses comprehensive polysomnography recordings, spanning both sleep and wakefulness states. The predictions achieved a Cohen's kappa coefficient of 0.746 and an overall accuracy of 85.2% in classifying wakefulness, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep (N1 + N2 + N3). The results demonstrated that the models incorporating both Radar 1 and Radar 2 data consistently outperformed those using only Radar 1 data, indicating the potential benefits of utilising multiple radars for sleep stage classification. Although the performance of the models tended to decline with increasing OSA severity, the addition of Radar 2 data notably improved the classification accuracy. These findings demonstrate the potential of radar technology as a valuable screening tool for sleep stage classification.

Sleep disturbances in autoimmune encephalitis.

Autoimmune encephalitis is an inflammatory neurological disorder characterized by psychiatric symptoms, cognitive impairment, and focal neurological deficits or seizures. Sleep disturbances are not a major consideration in the diagnosis and treatment of patients with autoimmune encephalitis. Various types of sleep disturbances are frequent, severe, and long-lasting, which can compromise the recovery and quality of life in patients with autoimmune encephalitis. Sleep disorders in patients with autoimmune encephalitis have received limited attention, and the prevalence and pathophysiological mechanisms of sleep disorders remain unclear. Recent studies have suggested that early recognition of specific sleep disturbances may provide clues for diagnosing autoimmune encephalitis. Furthermore, early diagnosis and treatment of sleep disturbances can promote recovery and improve long-term outcomes in patients with autoimmune encephalitis. In this report, we aimed to provide a comprehensive and extensive understanding of the clinical relevance of autoimmune encephalitis and specific related sleep disorders.

Long Sleep Duration and Dissatisfaction with Sleep Quality Are Associated with Ischemic Stroke in Young Patients.

INTRODUCTION: Suboptimal sleep duration and poor sleep quality have been proposed to increase stroke risk. However, their significance in young ischemic stroke is unclear. We aimed to investigate the importance of sleep duration and quality on young ischemic stroke patients. METHODS: A multicenter matched case-control study was performed to evaluate under-recognized risk factors in young (<45 years) ischemic stroke patients in 8 tertiary hospitals in Korea. A total of 225 patients and 225 age- and sex-matched controls were enrolled in the same period. Detailed information about patients' demographics, socioeconomic state, and traditional and nontraditional risk factors including sleep-related factors were obtained using structured questionnaires. Risk of ischemic stroke was estimated using conditional logistic regression analysis. RESULTS: Although average sleep duration was similar in patients and controls, patients were more likely to have long (≥9 h) or extremely short (<5 h) sleep durations. In addition, the proportion of subjects with dissatisfaction with sleep quality was higher in patients than controls (66.2 vs. 49.3%, p < 0.001). In multivariable conditional logistic regression analysis, long sleep duration (OR: 11.076, 95% CI: 1.819-67.446, p = 0.009) and dissatisfaction with sleep quality (OR: 2.116, 95% CI: 1.168-3.833, p = 0.013) were independently associated with risk of ischemic stroke. CONCLUSIONS: Long sleep duration and dissatisfaction with sleep quality may be associated with increased risk of ischemic stroke in young adults. Improving sleep habit or quality could be important for reducing the risk of ischemic stroke.

More extensive white matter disruptions present in untreated obstructive sleep apnea than we thought: A large sample diffusion imaging study.

Obstructive sleep apnea (OSA) may lead to white mater (WM) disruptions and cognitive deficits. However, no studies have investigated the full extent of the brain WM, and its associations with cognitive deficits in OSA remain unclear. We thus applied diffusion tensor imaging (DTI) tractography with multi-fiber models and used atlas-based bundle-specific approach to investigate the WM abnormalities for various tracts of the cerebral cortex, thalamus, brainstem, and cerebellum in patients with untreated OSA. We enrolled 100 OSA patients and 63 healthy controls. Fractional anisotropy (FA) and mean diffusivity (MD) values mapped on 33 regions of interest including WM tracts of cortex, thalamus, brainstem, and cerebellum were obtained from tractography-based reconstructions. We compared FA/MD values between groups and correlated FA/MD with clinical data in the OSA group after controlling for age and body mass index. OSA patients showed significantly lower FA values in multiple WM fibers including corpus callosum, inferior fronto-occipital fasciculus, middle/superior longitudinal fasciculi, thalamic radiations, and uncinate (FDR <0.05). Higher FA values were found in medial lemniscus of patients compared to controls (FDR <0.05). Lower FA values of rostrum of corpus callosum correlated with lower visual memory performance in OSA group (p < .005). Our quantitative DTI analysis demonstrated that untreated OSA could negatively impact the integrity of pathways more broadly, including brainstem structures such as medial lemniscus, in comparison to previous findings. Fiber tract abnormalities of the rostral corpus callosum were associated with impaired visual memory in untreated OSA may provide insights into the related pathomechanism.

Sleep quality of patients with papillary thyroid carcinoma: a prospective longitudinal study with 5-year follow-up.

We evaluated the pre- and postoperative sleep quality of patients with newly diagnosed papillary thyroid carcinoma (PTC) who underwent thyroid surgery, and investigated the factors associated with persistent poor sleep quality. The Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale, and Stanford sleepiness scale were used to estimate sleep quality and daytime sleepiness. Face-to-face surveys were conducted preoperatively, and 1, 4, and 10 months after thyroid surgery. The PSQI was administered during a telephone interview about after 5 years after surgery. Forty-six patients (mean age 47.3 ± 10.1 years) with PTC (11 males, 35 females) were included in this study. Twenty-one participants underwent lobectomy and 25 underwent total thyroidectomy. Preoperatively, 35 (76.1%) patients showed poor sleep quality. PSQI scores at postoperative 1, 4, and 10 months were significantly lower than preoperative scores (p < 0.001). Postoperative 5-year PSQI scores decreased significantly compared to the preoperative scores (p < 0.001). Patients newly diagnosed with PTC suffered from sleep disturbance before and after surgery for at least 10 months, recovering to a comparable rate of sleep disturbance with the general population by 5 years after surgery. Higher preoperative PSQI score was at risk for prolonged poor sleep quality in patients with PTC.

Automated Detection of Sleep Apnea-Hypopnea Events Based on 60 GHz Frequency-Modulated Continuous-Wave Radar Using Convolutional Recurrent Neural Networks: A Preliminary Report of a Prospective Cohort Study.

Radar is a promising non-contact sensor for overnight polysomnography (PSG), the gold standard for diagnosing obstructive sleep apnea (OSA). This preliminary study aimed to demonstrate the feasibility of the automated detection of apnea-hypopnea events for OSA diagnosis based on 60 GHz frequency-modulated continuous-wave radar using convolutional recurrent neural networks. The dataset comprised 44 participants from an ongoing OSA cohort, recruited from July 2021 to April 2022, who underwent overnight PSG with a radar sensor. All PSG recordings, including sleep and wakefulness, were included in the dataset. Model development and evaluation were based on a five-fold cross-validation. The area under the receiver operating characteristic curve for the classification of 1-min segments ranged from 0.796 to 0.859. Depending on OSA severity, the sensitivities for apnea-hypopnea events were 49.0-67.6%, and the number of false-positive detections per participant was 23.4-52.8. The estimated apnea-hypopnea index showed strong correlations (Pearson correlation coefficient = 0.805-0.949) and good to excellent agreement (intraclass correlation coefficient = 0.776-0.929) with the ground truth. There was substantial agreement between the estimated and ground truth OSA severity (kappa statistics = 0.648-0.736). The results demonstrate the potential of radar as a standalone screening tool for OSA.

A Case of Perampanel Overdose Presenting with Respiratory Failure.

Perampanel is a novel antiepileptic drug that has been used as an adjunctive treatment for focal-onset seizures. No reports to date have documented respiratory suppression as a side effect of perampanel in adults. Herein, we report a 51-year-old man with focal epilepsy presented with type 2 respiratory failure after accidently consuming of 66 mg of perampanel. Clinicians should consider the possibility of respiratory compromise whenever a high dose of perampanel needs to be administered to patients.

Ictal Swearing as a Lateralizing Value for the Dominant Hemisphere in Temporal Lobe Epilepsy.

Ictal swearing, as an epileptic manifestation, has rarely been reported. Despite its poor localization value and unclear mechanism, several previous studies have reported that it frequently originates from the temporal lobe and more often from the non-dominant hemisphere. Herein, we report a case of a 41-year-old right-handed man with a history of stereotypical manifestation of ictal swearing with a left (dominant) hemisphere origin, confirmed by video electroencephalography monitoring. Reasonable suspicion that repetitive swearing could be a manifestation of seizures is important for clinicians not to misdiagnose the disease.

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.

Effects of zonisamide monotherapy on bone health in drug-naive epileptic patients.

OBJECTIVE: Alteration of bone strength is an adverse effect of antiepileptic drug treatment. We investigated the effects of zonisamide (ZNS) monotherapy on bone mineral density (BMD) and biomarkers of bone metabolism after 13 months of treatment in drug-naive epileptic patients. METHODS: Fifty-nine patients with new onset drug-naive epilepsy were enrolled (29 women, 30 men; mean age = 31.5 ± 11.5 years). The BMD and T scores were measured at the lumbar spine and femoral neck by using dual-energy X-ray absorptiometry. Biomarkers specific for bone metabolism (bone-specific alkaline phosphatase, parathyroid hormone, osteocalcin, insulinlike growth factor-1, C-telopeptide, and vitamin D3 levels) were measured before and after long-term ZNS monotherapy. Analysis of covariance (ANCOVA) was used to estimate BMD and biomarkers of bone metabolism before and after ZNS therapy. Age, sex, treatment duration, and ZNS dosage were included as covariates for adjustment in the ANCOVA model. Furthermore, subgroup analyses were performed for each sex, and the effect size was calculated. RESULTS: After 13 months of ZNS treatment, the BMD and T scores at the lumbar spine (L1-L4 level) and femoral neck were not significantly different. Moreover, the biochemical markers showed no significant differences after ZNS monotherapy. Women showed significantly decreased baseline BMD at the femoral neck compared to men (P = .026), although the mean age and body mass index were not significantly different between the sexes. No significant changes in BMD or biomarkers of bone metabolism were seen in either sex after 13 months of ZNS treatment. SIGNIFICANCE: The results suggest that long-term ZNS monotherapy does not affect bone health in drug-naive patients with epilepsy negatively.

Sleep duration rather than sleep timing is associated with obesity in adolescents.

OBJECTIVE: In this study, we investigated differences in sleep patterns between obese and non-obese adolescents, and determined which sleep-related parameters were associated with a risk of adolescent obesity. METHODS: In this cross-sectional study, we evaluated 22,906 adolescents between 12 and 18 years of age (mean 15.2 ± 1.7 years; male 50.9%). Self-report questionnaires were used to assess body mass index (BMI) and sleep habits. Obesity was defined as a BMI-for-age ≥ 95th percentile. Weekend catch-up sleep (CUS) duration was calculated as the sleep duration on free days minus sleep duration on school days. We estimated mid-sleep time on free days corrected for oversleep on free days (MSFsc) and social jet lag. Then, we performed multivariate analysis for adolescent obesity and BMI, respectively. RESULTS: The prevalence of obesity was 6.0%. The average sleep duration (P = 0.017) and weekend CUS duration (P < 0.001) of obese adolescents were shorter than those of non-obese adolescents. However, there was no significant difference in MSFsc or social jet lag by the obesity status. After adjustment, obesity was significantly associated with short average sleep duration (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.86-0.96) and short weekend CUS duration (OR 0.92, 95% CI 0.89-0.95). Similarly, BMI was inversely correlated with average sleep duration (B = -0.15, 95% CI -0.19 to -0.11) and weekend CUS duration (B = -0.09, 95% CI -0.11 to -0.06). CONCLUSIONS: Our observations suggest that short sleep duration, rather than late MSFsc or social jet lag, was associated with adolescent obesity.

Moderate to severe obstructive sleep apnea during REM sleep as a predictor of metabolic syndrome in a Korean population.

PURPOSE: Metabolic syndrome is a cluster of metabolic abnormalities including obesity, hypertension, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hyperglycemia. Obstructive sleep apnea (OSA) is known to be associated with metabolic syndrome. However, it remains uncertain which sleep parameters of OSA are associated with metabolic syndrome. We aimed to clarify the relationship between sleep variables and the presence of metabolic syndrome in patients with OSA. METHODS: We prospectively recruited patients who visited the institute for the evaluation of sleep-disordered breathing. All patients underwent overnight polysomnography and sleep questionnaires. They were diagnosed with metabolic syndrome according to the 2007 consensus definition by the International Diabetes Federation. We applied multivariate logistic regression models to predict the presence of metabolic syndrome with variables related to sleep parameters. RESULTS: A total of 85 patients (43 men) were enrolled. The mean age (± standard deviation) was 52.0 ± 14.3 years. Metabolic syndrome was diagnosed in 39 (46%) patients. Patients with metabolic syndrome had a significantly higher apnea-hypopnea index (AHI) compared with patients without metabolic syndrome. An AHI greater than 15/h during REM sleep was a significant independent predictor of metabolic syndrome (adjusted OR, 7.08; 95% CI, 1.60-31.41; p = 0.010) after adjusting for age, body mass index, and non-REM AHI ≥ 15/h. In partial correlation analysis, REM AHI was significantly associated with the presence of metabolic syndrome after adjusting for age and BMI (r = 0.229, p = 0.042). CONCLUSION: Korean patients with OSA frequently had comorbid metabolic syndrome. Moderate to severe OSA during REM sleep may be a predictor of metabolic syndrome.

White matter tract-specific alterations in male patients with untreated obstructive sleep apnea are associated with worse cognitive function.

STUDY OBJECTIVES: Neurocognitive impairment is one of the daytime symptoms of obstructive sleep apnea (OSA). We proposed to use tract-specific statistical analysis (TSSA) to investigate whether there are fiber tract abnormalities in OSA, which may be undiscovered using voxel-based approaches, and whether such tract-specific disruptions in brain connectivity are associated with neuropsychological deficits in patients with untreated OSA. METHODS: We enrolled 38 patients with OSA diagnosed by overnight polysomnography, and 41 healthy sleepers. Fractional anisotropy (FA) and mean diffusivity (MD) maps were obtained from whole-brain diffusion tensor imaging, and TSSA were used to assess regional deficits of white matter tracts. All participants underwent a battery of neuropsychological tests. To evaluate the association between FA values and clinical, polysomnographic, and neuropsychological parameters in the OSA group, permutation-based tests for correlation were performed preceding cluster-based statistics. RESULTS: Compared to healthy controls, patients with OSA showed decreased values of FA in the left and right anterior thalamic radiations, and right uncinate fasciculus (UNC) (p < 0.001, p = 0.005, and p = 0.008, respectively). A lower score of digit span backward was associated with lower FA values of right UNC in the OSA group (p = 0.023). The Rey Complex Figure Test copy score revealed a positive correlation with FA values in the right UNC (p = 0.010). CONCLUSIONS: The TSSA method indeed identified previously unrevealed tract-specific disruptions in OSA. Furthermore, reduced FA values in the frontal lobe portion of the right UNC which has been known to be involved in working memory function were significantly associated with lower cognitive performance in patients with untreated OSA.

Clinical Usefulness of Intraoperative Motor-Evoked Potential Monitoring during Temporal Lobe Epilepsy Surgery.

BACKGROUND AND PURPOSE: We aimed to determine the effectiveness of intraoperative neurophysiological monitoring focused on the transcranial motor-evoked potential (MEP) in patients with medically refractory temporal lobe epilepsy (TLE). METHODS: We compared postoperative neurological deficits in patients who underwent TLE surgery with or without transcranial MEPs combined with somatosensory evoked potential (SSEP) monitoring between January 1995 and June 2018. Transcranial motor stimulation was performed using subdermal electrodes, and MEP responses were recorded in the four extremity muscles. A decrease of more than 50% in the MEP or the SSEP amplitudes compared with baseline was used as a warning criterion. RESULTS: In the TLE surgery group without MEP monitoring, postoperative permanent motor deficits newly developed in 7 of 613 patients. In contrast, no permanent motor deficit occurred in 279 patients who received transcranial MEP and SSEP monitoring. Ten patients who exhibited decreases of more than 50% in the MEP amplitude recovered completely, although two cases showed transient motor deficits that recovered within 3 months postoperatively. CONCLUSIONS: Intraoperative transcranial MEP monitoring during TLE surgery allowed the prompt detection and appropriate correction of injuries to the motor nervous system or ischemic stroke. Intraoperative transcranial MEP monitoring is a reliable modality for minimizing motor deficits in TLE surgery.

Seizure-like activities in patients with head-up tilt test-induced syncope.

The purpose of this study was to assess the prevalence and the characteristics of seizure-like activities during head-up tilt test (HUT)-induced syncope, in patients with suspected vasovagal syncope (VVS). We also evaluated the differences in hemodynamic parameters between patients with and without seizure-like activities.A total of 71 patients with suspected VVS, who showed syncope during HUT between October 2010 and May 2013, were analyzed. Electrocardiogram and hemodynamic parameters were continuously monitored during HUT. We also performed video recording of patients during HUT to identify eyeball deviation or seizure-like limb movements.In all, 47 patients (66.2%) showed seizure-like activities at the time of syncope during HUT, 14 patients presented eyeball deviation, without abnormal limb movements, and 33 patients showed abnormal limb movements, such as myoclonic or tonic-clonic activities, as well as eyeball deviation. Upon comparison of the 2 groups with or without seizure-like activities, patients showing seizure-like activities presented a significantly lower heart rate at the time of syncope in HUT (38.51 ±â€Š16.81 vs 49.67 ±â€Š20.12, P < .05). Also, upon comparison within patients showing seizure-like activities, the patients who showed abnormal limb movements with eyeball deviation demonstrated a significantly lower systolic blood pressure and cardiac output at the time of syncope (34.30 ±â€Š12.24 vs 49.00 ±â€Š14.14, P < .05; 0.58 ±â€Š0.40 vs 1.32 ±â€Š0.97, P < .05).Seizure-like activities were observed in high percentage in about 66% of patients during HUT-induced syncope. The occurrence of seizure-like activities was associated with more severe transient hemodynamic changes, such as lower heart rate, systolic blood pressure, and cardiac output at the time of the HUT-induced syncope.

Difference in severity of sleep apnea in patients with rapid eye movement sleep behavior disorder with or without parkinsonism.

OBJECTIVE: Rapid eye movement sleep behavior disorder (RBD) is a common sleep disturbance in patients with neurodegenerative disorders. We aimed to compare sleep parameters among the different types of RBD patients. METHODS: A total of 122 patients with dream enactment behavior were screened. Of these, 92 patients who were diagnosed with RBD by polysomnography were included in this study. Enrolled patients with RBD were classified into four groups based on the following diagnoses: idiopathic RBD (iRBD); RBD with Parkinson disease (PD-RBD); multiple system atrophy (MSA) with RBD (MSA-RBD); and dementia with Lewy bodies (DLB) with RBD (DLB-RBD). Various clinical and polysomnographic parameters were compared. RESULTS: Among the 92 patients with RBD, 35 had iRBD, 25 had PD-RBD, 17 had MSA-RBD, and 15 had DLB-RBD. The mean apnea-hypopnea index of atypical parkinsonism with RBD (AP-RBD) group was 16.2 ± 17.7 events/h (MSA-RBD, 14.0 ± 16.6; DLB-RBD, 18.8 ± 19.1), which was significantly higher than the other groups (p < 0.05). The proportion of patients with 100% supine sleep in the AP-RBD group (44%) was higher than that in the iRBD group (14%; p = 0.030). The proportion of OSA with 100% supine sleep position was significantly higher in the MSA-RBD and DLB-RBD groups than in the iRBD group (p = 0.042 and p = 0.029, respectively). CONCLUSION: Our study demonstrated that patients in the MSA-RBD and DLB-RBD groups had a tendency to sleeping in the supine position and a higher vulnerability to OSA compared to other RBD groups. Further cohort studies are needed to evaluate the influence of these factors on the development of parkinsonism.

Association between periodic limb movements during sleep and cerebral small vessel disease.

OBJECTIVE: Periodic limb movements (PLMs) can increase the risk of cardiovascular disease and mortality. Small vessel disease (SVD) has been considered a precursor to symptomatic stroke. We aimed to investigate the association between PLMs and cerebral SVD. METHODS: We enrolled participants who visited our clinic for the evaluation of sleep disturbance and underwent overnight polysomnography and brain magnetic resonance imaging. The processing steps included rating and analyzing white matter hyperintensities (WMHs), cerebral microbleeds (CMBs), asymptomatic lacunar infarctions (ALIs), perivascular spaces (PVSs), and calculating the total SVD score. Logistic regression and correlation analyses were used to examine the association between PLMs during sleep (PLMS) and SVD. RESULTS: A total of 31 (19 men and 12 women) patients with PLMS index ≥ 15/h were enrolled. The mean age was 61.7 years and the median PLMS index was 46.5/h. A total of 29 controls (16 men and 13 women) with PLMS index < 5/h were also included. PLMS index was positively associated with an increase in WMHs, ALIs, and PVSs (odds ratio [OR] = 1.022, 95% confidence interval [CI] = 1.003-1.040, p = 0.008; OR = 1.024, 95% CI = 1.006-1.043, p = 0.010; OR = 1.029, 95% CI = 1.010-1.049, p = 0.003, respectively). Correlation analyses revealed that total SVD score was significantly correlated with PLMS index (r = 0.504, p < 0.001). CONCLUSIONS: An elevated PLMS index was associated with an increase in WMHs, ALIs, PVSs, and total SVD burden. Our study suggests that PLMS is a marker for SVD, which carries a potential risk for progression to overt stroke or cognitive impairment.