Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

Neural Regen Res. 2025 Apr 1;20(4):917-935. doi: 10.4103/NRR.NRR-D-23-01444. Epub 2024 Apr 3.

ABSTRACT

Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients’ clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.

PMID:38989927 | DOI:10.4103/NRR.NRR-D-23-01444

Gut microbiota-astrocyte axis: new insights into age-related cognitive decline

Neural Regen Res. 2025 Apr 1;20(4):990-1008. doi: 10.4103/NRR.NRR-D-23-01776. Epub 2024 Apr 16.

ABSTRACT

With the rapidly aging human population, age-related cognitive decline and dementia are becoming increasingly prevalent worldwide. Aging is considered the main risk factor for cognitive decline and acts through alterations in the composition of the gut microbiota, microbial metabolites, and the functions of astrocytes. The microbiota-gut-brain axis has been the focus of multiple studies and is closely associated with cognitive function. This article provides a comprehensive review of the specific changes that occur in the composition of the gut microbiota and microbial metabolites in older individuals and discusses how the aging of astrocytes and reactive astrocytosis are closely related to age-related cognitive decline and neurodegenerative diseases. This article also summarizes the gut microbiota components that affect astrocyte function, mainly through the vagus nerve, immune responses, circadian rhythms, and microbial metabolites. Finally, this article summarizes the mechanism by which the gut microbiota-astrocyte axis plays a role in Alzheimer’s and Parkinson’s diseases. Our findings have revealed the critical role of the microbiota-astrocyte axis in age-related cognitive decline, aiding in a deeper understanding of potential gut microbiome-based adjuvant therapy strategies for this condition.

PMID:38989933 | DOI:10.4103/NRR.NRR-D-23-01776

Research Progress of Vagal Nerve Regulation Mechanism in Acupuncture Treatment of Atrial Fibrillation

Chin J Integr Med. 2024 Jul 11. doi: 10.1007/s11655-024-3660-5. Online ahead of print.

ABSTRACT

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. It has a high prevalence and poor prognosis. The application of antiarrhythmic drugs and even surgery cannot completely treat the disease, and there are many sequelae. AF can be classified into the category of “palpitation” in Chinese medicine according to its symptoms. Acupuncture has a significant effect on AF. The authors find that an important mechanism of acupuncture in AF treatment is to regulate the cardiac vagus nerve. Therefore, this article intends to review the distribution and function of vagus nerve in the heart, the application and the regulatroy effect for the treatment of AF.

PMID:38990478 | DOI:10.1007/s11655-024-3660-5

Atrial fibrillation radiofrequency ablation in a patient with vagus nerve stimulation

Neurophysiol Clin. 2024 Jul 10;54(5):102996. doi: 10.1016/j.neucli.2024.102996. Online ahead of print.

ABSTRACT

Vagus nerve stimulation (VNS) is an effective neuromodulatory treatment for patients with drug resistant epilepsy who cannot undergo curative surgical resection. Safety information states that the use of radiofrequency ablation devices may damage the VNS generator and leads. However, documented cases are scarce. This 62-year-old patient with bitemporal lobe epilepsy treated with VNS underwent radiofrequency ablation of an atrial fibrillation without any perioperative or postoperative complications.

PMID:38991469 | DOI:10.1016/j.neucli.2024.102996

Crosstalk between gut-brain axis: unveiling the mysteries of gut ROS in progression of Parkinson’s disease

Inflammopharmacology. 2024 Jul 11. doi: 10.1007/s10787-024-01510-2. Online ahead of print.

ABSTRACT

“Path to a good mood lies through the gut.” This statement seems to imply that it has long been believed that the gut is connected with the brain. Research has shown that eating food activates the reward system and releases dopamine (DA), establishing a link between the peripheral and central nervous system. At the same time, researchers also trust that the gut is involved in the onset of many diseases, including Parkinson’s disease (PD), in which gastrointestinal dysfunction is considered a prevalent symptom. Reports suggest that PD starts from the gut and reaches the brain via the vagus nerve. Recent studies have revealed an intriguing interaction between the gut and brain, which links gut dysbiosis to the etiology of PD. This review aims to explore the mechanistic pathway how reactive oxygen species (ROS) generation in the gut affects the makeup and operation of the dopamine circuitry in the brain. Our primary concern is ROS generation in the gut, which disrupts the gut microbiome (GM), causing α-synuclein accumulation and inflammation. This trio contributes to the loss of DA neurons in the brain, resulting in PD development. This review also compiles pre-clinical and clinical studies on antioxidants, demonstrating that antioxidants reduce ROS and increase DA levels. Collectively, the study highlights the necessity of comprehending the gut-brain axis for unraveling the riddles of PD pathogenesis and considering new therapeutic approaches.

PMID:38992324 | DOI:10.1007/s10787-024-01510-2

The latest reports and treatment methods on polycystic ovary syndrome

Ann Med. 2024 Dec;56(1):2357737. doi: 10.1080/07853890.2024.2357737. Epub 2024 Jul 4.

ABSTRACT

Polycystic ovary syndrome (PCOS) is an increasingly recognized endocrine disorder. The pathogenesis is not fully known. Polycystic ovary syndrome is still difficult to diagnose correctly, despite simple diagnostic criteria. The aim of the study is to review the current knowledge about PCOS and treatment options for patients with the disease. To explore this topic, publications were reviewed and conclusions drawn from them. The incidence of hyperandrogenism in a patient with PCOS may be as high as 60-80%. Increased androgen levels affect ovulation and menstruation, and also result in hirsutism and acne. Additionally, patients have problems with proper glucose tolerance (insulin resistance), type 2 diabetes, hypertension, cardiovascular diseases and metabolic syndrome. PCOS results in various symptoms in patients.

The latest treatment methods were analysed. A standard review of publications in the field of diagnosis and treatment of PCOS, IR and hyperandrogenism was used.

Lifestyle, especially diet, deserves special attention due to its ease of use. Sleep quality, physical activity and stress reduction are also important. Diet should be the treatment of first choice. Only if dietary intervention does not bring results, the doctor considers pharmacotherapy. Recently, acupuncture and herbal medicine, vagus nerve stimulation have been used in the treatment of PCOS and regulation of hormone levels. Patients are given supplementation to improve the quality of functioning, but it must be remembered that inappropriate doses or too long use may result in a toxic effect opposite to the therapeutic one.

Appropriate diet, physical activity – lifestyle changes are crucial in the treatment of PCOS. Supplementation and pharmaceuticals support treatment. It is mandatory to examine these environmental and lifestyle factors as they not only contribute to the occurrence of the disease but also influence its progression.

PMID:38965663 | DOI:10.1080/07853890.2024.2357737

Electrical stimulation of the vagus nerve ameliorates inflammation and disease activity in a rat EAE model of multiple sclerosis

Proc Natl Acad Sci U S A. 2024 Jul 9;121(28):e2322577121. doi: 10.1073/pnas.2322577121. Epub 2024 Jul 5.

ABSTRACT

Multiple sclerosis (MS) is a demyelinating central nervous system (CNS) disorder that is associated with functional impairment and accruing disability. There are multiple U.S. Food and Drug Administration (FDA)-approved drugs that effectively dampen inflammation and slow disability progression. However, these agents do not work well for all patients and are associated with side effects that may limit their use. The vagus nerve (VN) provides a direct communication conduit between the CNS and the periphery, and modulation of the inflammatory reflex via electrical stimulation of the VN (VNS) shows efficacy in ameliorating pathology in several CNS and autoimmune disorders. We therefore investigated the impact of VNS in a rat experimental autoimmune encephalomyelitis (EAE) model of MS. In this study, VNS-mediated neuroimmune modulation is demonstrated to effectively decrease EAE disease severity and duration, infiltration of neutrophils and pathogenic lymphocytes, myelin damage, blood-brain barrier disruption, fibrinogen deposition, and proinflammatory microglial activation. VNS modulates expression of genes that are implicated in MS pathogenesis, as well as those encoding myelin proteins and transcription factors regulating new myelin synthesis. Together, these data indicate that neuroimmune modulation via VNS may be a promising approach to treat MS, that not only ameliorates symptoms but potentially also promotes myelin repair (remyelination).

PMID:38968104 | DOI:10.1073/pnas.2322577121

Vagal predominance correlates with mood state changes of winter-over expeditioners during prolonged Antarctic residence

PLoS One. 2024 Jul 5;19(7):e0298751. doi: 10.1371/journal.pone.0298751. eCollection 2024.

ABSTRACT

OBJECTIVE: Winter-over expeditioners in Antarctica are challenged by various environmental and psycho-social stress factors, which may induce psychophysiological changes. The autonomic nervous system (ANS) plays a crucial role in the adaptation process under stress. However, the relationship between ANS activity and the mood states of expeditioners remains largely unexplored. This study aims to uncover the pattern of ANS adjustment under extreme Antarctic environments and provide new insights into the correlations between ANS activity and mood state changes, which may provide scientific data for medical interventions.

METHODS: Fourteen expeditioners at Zhongshan Station participated in this study. The study was conducted during four representative periods: pre-Antarctica, Antarctica-1 (pre-winter), Antarctica-2 (winter), and Antarctica-3 (summer). The heart rate variability (HRV) of the expeditioners was continuously measured for 24 hours to evaluate ANS activity. Plasma levels of catecholamines were tested by ELISA. Mood states were assessed by the Profile of Mood States (POMS) scale.

RESULTS: HRV analysis showed a disturbance of ANS during winter and summer periods. For frequency domain parameters, very low frequency (VLF), low frequency (LF), high frequency (HF), and total power (TP) significantly increased during the second half of the mission. Especially, LF/HF ratio decreased during summer, indicating the predominance of vagal tone. Results of the time domain analysis showed increased heart rate variability during the austral winter and summer. Plasma epinephrine (E) significantly increased during residence in Antarctica. Compared with pre-Antarctica, the vigor, depression, and anger scores of the expeditioners decreased significantly during the austral summer. Notably, the depression score showed a moderate positive correlation with LF/HF, while weak negative correlations with other HRV indicators, including TP, VLF, and LF. Anger score showed a moderate positive correlation with LF/HF and weak negative correlations with the average normal-to-normal (NN) interval, and the root mean square of differences between adjacent RR intervals (RMSSD). Plasma E level weakly correlated with the average NN interval.

CONCLUSION: Prolonged residence in Antarctica increased the ANS activities and shifted the cardiac autonomic modulation towards vagal predominance. The alteration of HRV correlated with mood states and plasma epinephrine levels.

PMID:38968274 | PMC:PMC11226091 | DOI:10.1371/journal.pone.0298751

Blood Pressure Variability After Non-invasive Low-level Tragus Stimulation in Acute Heart Failure

J Cardiovasc Transl Res. 2024 Jul 5. doi: 10.1007/s12265-024-10544-4. Online ahead of print.

ABSTRACT

Higher blood pressure (BP) variability (BPV) was shown to be strong predictors of poor cardiovascular outcomes in heart failure (HF). It is currently unknown if low-level tragus stimulation (LLTS) would lead to improvement in BPV in acute HF (AHF). The 22 patients with AHF (median 80 yrs, males 60%) were randomly assigned to active or sham group using an ear clip attached to the tragus (active group) or the earlobe (sham group) for 1 h daily over 5 days. In the active group, standard deviation (SD), coefficient of variation (CV) and δ in SBP were significantly decreased after LLTS (all p < 0.05). All the changes in SD, CV and δ in SBP before and after stimulation were also significantly different between active and sham groups (all p < 0.05). This proof-of-concept study demonstrates the beneficial effects of LLTS on BPV in AHF.

PMID:38969912 | DOI:10.1007/s12265-024-10544-4

A multi-channel stimulator with an active electrode array implant for vagal-cardiac neuromodulation studies

Bioelectron Med. 2024 Jul 6;10(1):16. doi: 10.1186/s42234-024-00148-3.

ABSTRACT

BACKGROUND: Implantable vagus nerve stimulation is a promising approach for restoring autonomic cardiovascular functions after heart transplantation. For successful treatment a system should have multiple electrodes to deliver precise stimulation and complex neuromodulation patterns.

METHODS: This paper presents an implantable multi-channel stimulation system for vagal-cardiac neuromodulation studies in swine species. The system comprises an active electrode array implant percutaneously connected to an external wearable controller. The active electrode array implant has an integrated stimulator ASIC mounted on a ceramic substrate connected to an intraneural electrode array via micro-rivet bonding. The implant is silicone encapsulated for biocompatibility and implanted lifetime. The stimulation parameters are remotely transmitted via a Bluetooth telemetry link.

RESULTS: The size of the encapsulated active electrode array implant is 8 mm × 10 mm × 3 mm. The stimulator ASIC has 10-bit current amplitude resolution and 16 independent output channels, each capable of delivering up to 550 µA stimulus current and a maximum voltage of 20 V. The active electrode array implant was subjected to in vitro accelerated lifetime testing at 70 °C for 7 days with no degradation in performance. After over 2 h continuous stimulation, the surface temperature change of the implant was less than 0.5 °C. In addition, in vivo testing on the sciatic nerve of a male Göttingen minipig demonstrated that the implant could effectively elicit an EMG response that grew progressively stronger on increasing the amplitude of the stimulation.

CONCLUSIONS: The multi-channel stimulator is suitable for long term implantation. It shows potential as a useful tool in vagal-cardiac neuromodulation studies in animal models for restoring autonomic cardiovascular functions after heart transplantation.

PMID:38970083 | DOI:10.1186/s42234-024-00148-3