Cardiorespiratory findings in epilepsy: A recent review on outcomes and pathophysiology

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

A polysomnographic study of slow-wave sleep loss in elderly patients with epilepsy

Objective

The primary objective is to explore what causes slow-wave sleep loss in elderly patients with epilepsy. The secondary objective is to identify the PSG characteristics in elderly patients with epilepsy. The clinical demographics, sleep architecture, sleep-related events, and interictal epileptiform discharges are to be evaluated in the objectives.

Methods

The video electroencephalography (VEEG) and polysomnogram (PSG) data from 44 elderly patients with epilepsy and 52 elderly patients with sleep disorders but without definite central nervous system diseases were analysed. This was a case-control study. The differences in the PSG sleep architecture parameters (total sleep time (TST), sleep efficiency, wake after sleep onset, etc.) and sleep-related events (apnea hypopnea index, oxygen desaturation index (ODI), periodic limb movement index, etc.) between the epilepsy and control groups. As Additionally, these parameters were assessed within the elderly patients with epilepsy, comparing the slow-wave sleep existence and slow-wave sleep loss groups, using VEEG and PSG.

Results

The epileptic group exhibited significantly lower TST (343.477 ± 96.3046min vs 389.115 ± 61.5727min, p < 0.05), rapid eye movement (%) (13.011 ± 7.5384 vs 16.992 ± 6.7025, p < 0.05), non-rapid eye movement stage 3 (%) (1.35[0,7.225] vs 3.65[0.425,13.75], p < 0.05), and sleep efficiency (%) (69.482 ± 14.1771% vs 77.242 ± 10.6171%, p < 0.05). Conversely, the ODI (25.6[9.825,51.775] events/hour vs 16.85[5.3,30.425] events/hour, p < 0.05) and spontaneous arousal index (4.0455[2.1805,6.9609] events/hour vs 2.9709[1.4747,5.0554] events/hour, p < 0.05) were significantly higher in elderly patients with epilepsy. The prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) was significantly higher in the slow-wave sleep loss group than in the slow-wave sleep existence group (100% vs 77.8%, p < 0.05). The incidence of slow-wave sleep loss was lower in patients with epilepsy aged between 75 and 85 years compared to those aged between 65 and 75 years.

Conclusion

Elderly patients with epilepsy exhibit higher levels of ODI and spontaneous arousal index. Our findings indicate that OSAHS could be a contributing factor to slow-wave sleep loss in this population. The incidence of slow-wave sleep loss was lower in patients aged above 75 years among elderly patients with epilepsy.

Population Pharmacokinetics and Exposure-Safety of Lipophilic Conjugates Prodrug DP-VPA in Healthy Chinese Subjects for Dose Regime Exploring

Phospholipid-valproic acid (DP-VPA)is a prodrug for treating epilepsy. The present study explored the pharmacokinetics (PK) and exposure safety of DP-VPA to provide a basis for future studies exploring the safe dosage and therapeutic strategies for epilepsy. The study included a randomized placebo-controlled dose-escalation tolerance evaluation trial and a randomized triple crossover food-effect trial in healthy Chinese volunteers. A population pharmacokinetic (PopPK) model was established to analyze the PK of DP-VPA and active metabolite VPA. The exposure safety was assessed with the adverse drug reaction (ADR) in CNS. The PopPK of DP-VPA and metabolite VPA fitted a two-compartment model coupling one-compartment with Michaelis-Menten metabolite kinetics and first-order elimination. The absorption processes after single oral administration of DP-VPA tablet demonstrated nonlinear characteristics, including 0-order kinetic phase and time-dependent phase fitting Weibull distribution. The final model indicated that the DP-VPA PK was significantly affected by dosage and food. The exposure-safety relationship demonstrated a generalized linear regression; mild/moderate ADRs occurred in some subjects with 600 mg and all subjects with 1500 mg of DP-VPA, and no severe ADRs were reported up to 2400 mg. In conclusion, the study established a PopPK model describing the processing of DP-VPA and VPA in healthy Chinese subjects. DP-VPA showed good tolerance after a single dose of 600-2400 mg with nonlinear PK and was affected by dosage and food. Based on the association between neurological ADRs and higher exposure to DP-VPA by exposure-safety analysis, 900-1200 mg was recommended for subsequent study of safety and clinical effectiveness.

Enlightening the mechanism of ferroptosis in epileptic heart

Epilepsy is a chronic neurological degenerative disease with a high incidence, affecting all age groups. Refractory Epilepsy (RE) occurs in approximately 30-40% of cases with a higher risk of sudden unexpected death in epilepsy (SUDEP). Recent studies have shown that spontaneous seizures developed in epilepsy can be related to an increase in oxidative stress and reactive oxygen derivatives (ROS) production. Increasing ROS concentration causes lipid peroxidation, protein oxidation, destruction of nuclear genetic material, enzyme inhibition, and cell death by a mechanism known as "ferroptosis" (Fts). Inactivation of glutathione peroxidase 4 (GPX4) induces Fts, while oxidative stress is linked with increased intracellular free iron (Fe+2) concentration. Fts is also a non-apoptotic programmed cell death mechanism, where a hypoxia-inducible factor 1 alpha (HIF-141) dependent hypoxic stress-like condition appears to occur with accumulation of iron and cytotoxic ROS in affected cells. Assuming convulsive crises as hypoxic stress, repetitive convulsive/hypoxic stress can be an effective inducer of the "epileptic heart" (EH), which is characterized by altered autonomic function and a high risk of malignant or fatal bradycardia. We previously reported that experimental recurrent seizures induce cardiomyocyte Fts associated with SUDEP. Furthermore, several genes related to Fts and hypoxia have recently been identified in acute myocardial infarction. An emerging theme from recent studies indicates that inhibition of GPX4 through modulating expression or activities of the xCT antiporter system (SLC7A11) governs cell sensitivity to oxidative stress from ferroptosis. Furthermore, during hypoxia, an increased expression of stress transcriptional factor ATF3 can promote Fts induced by erastin in a HIF-141-dependent manner. We propose that inhibition of Fts with ROS scavengers, iron chelators, antioxidants, and transaminase inhibitors could provide a therapeutic effect in epilepsy and improve the prognosis of SUDEP risk by protecting the heart from ferroptosis.

Analysis of forensic autopsy cases associated with epilepsy: Comparison between sudden unexpected death in epilepsy (SUDEP) and not-SUDEP groups

Background and aims

Epilepsy is a common and chronic neurological disorder characterized by seizures that increase the risk of mortality. SUDEP is the most common seizure-related category of death. The study aimed to evaluate the key characteristics between SUDEP and not-SUDEP death cases.

Methods

A retrospective study of forensic autopsy cases from 2002 to 2021, performed by the Academy of Forensic Science (Ministry of Justice, China), identified a total of 31 deaths associated with epilepsy. We compared the different characteristics between individuals who died of SUDEP (SUDEP group) and individuals with epilepsy died suddenly due to unrelated causes (not-SUDEP group).

Results and conclusions

13 cases met the general accepted definition of SUDEP; and 18 cases were classified as not-SUDEP. The mean age of the not-SUDEP group was significantly higher than that of the SUDEP groups (p < 0.05) and there were more cases without a clear cause of epilepsy in the SUDEP group than in the not-SUDEP group (p < 0.05). Death position differed significantly between the two groups, with more cases dying in the prone position in the SUDEP group (p < 0.05). Complete autopsies were performed in 24 of the 31 cases. There were no significant differences in heart, lungs and brain weights, or in ventricular thickness (p > 0.05) between the SUDEP and not-SUDEP groups. In addition, compared to the not-SUDEP group, the SUDEP group featured a significantly more cases with coronary lesions (grades 1-3, p < 0.05). Neuropathological lesions were identified in 12 of the 13 SUDEP cases (92.3%), cardiac lesions were present in 10 cases (76.9%) and pulmonary edema and pulmonary congestion were present in all cases. The primary cause of death in 13 of the 31 cases was seizure disorder or epilepsy. The primary mechanism of death in SUDEP group was mainly asphyxia while that in the not-SUDEP group was cardiopulmonary failure (p < 0.05). Patients in the prone position had a significantly higher risk of asphyxia than those who were not. Here, we investigated the key characteristics between SUDEP and not-SUDEP death cases, which may help to facilitate forensic diagnosis in presumed SUDEP cases.

Medical Technology: A Systematic Review on Medical Devices Utilized for Epilepsy Prediction and Management

BACKGROUND

Epilepsy is a devastating neurological disorder that affects nearly 70 million people worldwide. Epilepsy causes uncontrollable, unprovoked and unpredictable seizures that reduce the quality of life of those afflicted, with 1-9 epileptic patient deaths per 1000 patients occurring annually due to sudden unexpected death in epilepsy (SUDEP). Predicting the onset of seizures and managing them may help patients from harming themselves and may improve their well-being. For a long time, electroencephalography (EEG) devices have been the mainstay for seizure detection and monitoring. This systematic review aimed to elucidate and critically evaluate the latest advancements in medical devices, besides EEG, that have been proposed for the management and prediction of epileptic seizures. A literature search was performed on three databases, PubMed, Scopus and EMBASE.

METHODS

Following title/abstract screening by two independent reviewers, 27 articles were selected for critical analysis in this review.

RESULTS

These articles revealed ambulatory, non-invasive and wearable medical devices, such as the in-ear EEG devices; the accelerometer-based devices and the subcutaneous implanted EEG devices might be more acceptable than traditional EEG systems. In addition, extracerebral signalbased devices may be more efficient than EEG-based systems, especially when combined with an intervention trigger. Although further studies may still be required to improve and validate these proposed systems before commercialization, these findings may give hope to epileptic patients, particularly those with refractory epilepsy, to predict and manage their seizures.

CONCLUSION

The use of medical devices for epilepsy may improve patients' independence and quality of life and possibly prevent sudden unexpected death in epilepsy (SUDEP).

Heart Rate Variability Analysis for Seizure Detection in Neonatal Intensive Care Units

In Neonatal Intensive Care Units (NICUs), the early detection of neonatal seizures is of utmost importance for a timely clinical intervention. Over the years, several neonatal seizure detection systems were proposed to detect neonatal seizures automatically and speed up seizure diagnosis, most based on the EEG signal analysis. Recently, research has focused on other possible seizure markers, such as electrocardiography (ECG). This work proposes an ECG-based NSD system to investigate the usefulness of heart rate variability (HRV) analysis to detect neonatal seizures in the NICUs. HRV analysis is performed considering time-domain, frequency-domain, entropy and multiscale entropy features. The performance is evaluated on a dataset of ECG signals from 51 full-term babies, 29 seizure-free. The proposed system gives results comparable to those reported in the literature: Area Under the Receiver Operating Characteristic Curve = 62%, Sensitivity = 47%, Specificity = 67%. Moreover, the system’s performance is evaluated in a real clinical environment, inevitably affected by several artefacts. To the best of our knowledge, our study proposes for the first time a multi-feature ECG-based NSD system that also offers a comparative analysis between babies suffering from seizures and seizure-free ones.

Envisioning the role of inwardly rectifying potassium (Kir) channel in epilepsy

Epilepsy is a devastating neurological disorder characterized by recurrent seizures attributed to the disruption of the dynamic excitatory and inhibitory balance in the brain. Epilepsy has emerged as a global health concern affecting about 70 million people worldwide. Despite recent advances in pre-clinical and clinical research, its etiopathogenesis remains obscure, and there are still no treatment strategies modifying disease progression. Although the precise molecular mechanisms underlying epileptogenesis have not been clarified yet, the role of ion channels as regulators of cellular excitability has increasingly gained attention. In this regard, emerging evidence highlights the potential implication of inwardly rectifying potassium (Kir) channels in epileptogenesis. Kir channels consist of seven different subfamilies (Kir1-Kir7), and they are highly expressed in both neuronal and glial cells in the central nervous system. These channels control the cell volume and excitability. In this review, we discuss preclinical and clinical evidence on the role of the several subfamilies of Kir channels in epileptogenesis, aiming to shed more light on the pathogenesis of this disorder and pave the way for future novel therapeutic approaches.

Exploring factors associated with interictal heart rate variability in patients with medically controlled focal epilepsy

PURPOSE

Heart rate variability (HRV) reflects the balance between the functional outputs of the sympathetic and parasympathetic nervous systems. It is lower in patients with epilepsy than in the healthy controls. However, HRV has been inadequately studied in different patient subgroups with medically controlled epilepsy. Hence, this study aimed to investigate factors associated with interictal HRV in patients with medically controlled epilepsy.

METHODS

This retrospective cohort study included 54 patients (24 males and 30 females) with medically controlled focal epilepsy who only received monotherapy to eliminate the confounding effect of different antiseizure medications (ASMs). Patients with major systemic or psychiatric disorder comorbidities were excluded. For HRV analysis, electroencephalography and 5-minute well-qualified electrocardiogram segment recording were conducted during stage N1 or N2 sleep. In addition, the association between age, gender, seizure onset type, ASMs, and the time domain and frequency-domain HRV measures was analyzed.

RESULTS

HRV negatively correlated with advanced age. Patients with focal to bilateral tonic-clonic seizure (FBTCS) had a significantly lower HRV than focal impaired awareness seizures (FIAS). HRV was not associated with any gender and ASMs.

CONCLUSIONS

HRV negatively correlated with age, and patients with FBTCS had a decreased HRV. Thus, these patients may have a declining autonomic function. Therefore, different seizure types may carry different risks of autonomic dysfunction in patients with medically controlled focal epilepsy.