Is vagal-nerve stimulation safe during pregnancy? A mini review

Efficacy of bright light therapy for perinatal depression: A meta-analysis of a randomized controlled trial

BACKGROUND

Pharmacological treatments are commonly used in individuals experiencing perinatal depression (PPD); however, a debate regarding the reproductive safety of antidepressants is ongoing. Many pregnant women opt to discontinue antidepressant out of concern about potential negative effects on the developing fetus, while slow and ineffective antidepressant medications hinder improved outcomes in women with PPD. In recent years, bright light therapy (BLT) has gained traction as a treatment option for PPD; however, clinical trials findings examining the efficacy of BLT in this population have been inconclusive.

AIM

To validate the feasibility and safety of BLT for the treatment of PPD.

METHODS

We performed a meta-analysis of randomized controlled trials of patients with PPD treated with BLT vs placebo following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. We searched PubMed, Embase, the Cochrane Library, and Web of Science for randomized controlled studies published up to December 2023. The results were evaluated using the standardized mean difference of improvement for depression scores and odds ratios (ORs) for remission rate, response rate, incidence of adverse events, and dropout rate.

RESULTS

The BLT group had higher PPD response rate [50.68% vs 33.08%; OR = 2.05; 95% confidence interval (CI): 1.25-3.35; P = 0.004; I^² = 35%] and remission rate (54.10% vs 18.52%; OR = 5.00; 95%CI: 2.09-11.99; P = 0.0003; I^² = 0%) than the placebo group. Improvements in depression scores were higher in the BLT group than the placebo group for the overall efficacy (standardized mean difference = -0.47; 95%CI: -0.80 to -0.13; P = 0.007). No significant differences between the two groups in drop-outs (21.84% vs 29.63%; OR = 0.63; 95%CI: 0.31-1.29; P = 0.21; I^² = 0%) or adverse events (17.89% vs 9.68%; OR = 2.01; 95%CI: 0.95-4.25; P = 0.07; I^² = 0%) were observed.

CONCLUSION

BLT can potentially treat PPD, showing better results than the control group in this study. BLT is effective and safe and could increase the available therapeutic options for PPD.

An update on the pharmacotherapy of postpartum depression

Extensive research has been conducted on postpartum depression (PPD) over the past century, and yet no definitive answer regarding its etiopathogenesis, risk factors, genetic predilection, and treatment has been found. The few preclinical and clinical studies propose that maternal brain adaptations to the endocrinological, immunological, and behavioral changes and external sociodemographic risk factors in the perinatal period make women more vulnerable to anxiety and depression. Irrespective of the cause, a dilemma exists regarding the type of help to provide postpartum mothers. With very few treatment options at our disposal, deciding between psychotherapy, pharmacological, and non-pharmacological therapy on a case-by-case basis is unproductive because in developing countries infrastructure is limited and the availability of medications, especially for psychiatric illnesses, is still evolving. Hence, regardless of psychotherapy, antidepressants remain the first line of treatment with selective serotonin reuptake inhibitors (SSRIs); sertraline has the best efficacy and safety profile in breastfeeding women. As endocrine factors play a significant role in etiopathogenesis, hormonal therapy with oxytocin has been shown to be efficacious, and studies investigating the role of testosterone in treating PPD are also under way. In 2019, the US Food and Drug Administration (FDA) approved the first and only drug for the sole purpose of treating PPD, brexanolone. Zuranolone, a drug recently approved by the FDA, has a similar mechanism of action to brexanolone. For breastfeeding mothers reluctant to use pharmacotherapy, somatic therapy has been studied, including bright light therapy, vagal nerve stimulation, and newer noninvasive interventions. This article encompasses a short note on PPD, including its etiopathogenesis and clinical characteristics, and recapitulates the various available and evolving pharmacological and nonpharmacological therapies.

Update on Neuromodulation for Migraine and Other Primary Headache Disorders: Recent Advances and New Indications

PURPOSE OF REVIEW

Neuromodulation techniques currently available for headache management are reviewed in this article, with a focus on recent advances in non-invasive devices for migraine and trigeminal autonomic cephalalgias.

RECENT FINDINGS

The currently available FDA-cleared non-invasive devices for migraine include transcutaneous supraorbital and supratrochlear nerve stimulation, single-pulse transcranial magnetic stimulation (sTMS), external concurrent occipital and trigeminal neurostimulation (eCOT-NS), remote electrical neuromodulation (REN), and non-invasive vagal nerve stimulation (nVNS) with indications for migraine and trigeminal autonomic cephalalgias. Emerging non-invasive techniques being explored for use in migraine include transcranial direct current stimulation (tDCS), kinetic oscillation stimulation (KOS), and auricular transcutaneous vagal nerve stimulation (at-VNS). In addition to primary headache, non-invasive neuromodulation is being investigated for comorbid conditions such as depression. Non-invasive neuromodulation devices remain a safe, well-tolerated, and effective therapy for patients with primarily migraine and trigeminal autonomic cephalalgias. Ongoing research is needed to determine efficacy in other headache disorders and comorbid conditions.

Neuromodulation for Headache Management in Pregnancy

PURPOSE OF REVIEW

Management of primary headache disorders during pregnancy is limited due to known teratogenicity or unknown safety of many currently available pharmaceutical therapies. Here, we explore the safety and efficacy of non-invasive neuromodulatory devices as another treatment modality for pregnant patients.

RECENT FINDINGS

There are six FDA-cleared, non-invasive neuromodulatory devices currently available for the management of headache that include remote electrical neuromodulation (REN), noninvasive vagal nerve stimulation (nVNS), external trigeminal nerve stimulation (eTNS), single-pulse transcranial magnetic stimulation (sTMS), and external concurrent occipital and trigeminal neurostimulation (eCOT-NS). Neuromodulatory devices are a safe, effective, and well tolerated non-pharmacological option for migraine and other primary headache disorders. Although evidence of safety and tolerability use in pregnancy is limited, they may serve as a therapeutic alternative or adjunct to improve the care of our pregnant patients.

Vagus nerve stimulation: a physical therapy with promising potential for central nervous system disorders

The diseases of the central nervous system (CNS) often cause irreversible damage to the human body and have a poor prognosis, posing a significant threat to human health. They have brought enormous burdens to society and healthcare systems. However, due to the complexity of their causes and mechanisms, effective treatment methods are still lacking. Vagus nerve stimulation (VNS), as a physical therapy, has been utilized in the treatment of various diseases. VNS has shown promising outcomes in some CNS diseases and has been approved by the Food and Drug Administration (FDA) in the United States for epilepsy and depression. Moreover, it has demonstrated significant potential in the treatment of stroke, consciousness disorders, and Alzheimer's disease. Nevertheless, the exact efficacy of VNS, its beneficiaries, and its mechanisms of action remain unclear. This article discusses the current clinical evidence supporting the efficacy of VNS in CNS diseases, providing updates on the progress, potential, and potential mechanisms of action of VNS in producing effects on CNS diseases.

Modulation of vagal activity may help reduce neurodevelopmental damage in the offspring of mothers with pre-eclampsia

Maternal Immune Activation (MIA) has been linked to the pathogenesis of pre-eclampsia and adverse neurodevelopmental outcomes in the offspring, such as cognitive deficits, behavioral abnormalities, and mental disorders. Pre-eclampsia is associated with an activation of the immune system characterized by persistently elevated levels of proinflammatory cytokines, as well as a decrease in immunoregulatory factors. The Cholinergic Anti-inflammatory Pathway (CAP) may play a relevant role in regulating the maternal inflammatory response during pre-eclampsia and protecting the developing fetus from inflammation-induced damage. Dysregulation in the CAP has been associated with the clinical evolution of pre-eclampsia. Some studies suggest that therapeutic stimulation of this pathway may improve maternal and fetal outcomes in preclinical models of pre-eclampsia. Modulation of vagal activity influences the CAP, improving maternal hemodynamics, limiting the inflammatory response, and promoting the growth of new neurons, which enhances synaptic plasticity and improves fetal neurodevelopment. Therefore, we postulate that modulation of vagal activity may improve maternal and fetal outcomes in pre-eclampsia by targeting underlying immune dysregulation and promoting better fetal neurodevelopment. In this perspective, we explore the clinical and experimental evidence of electrical, pharmacological, physical, and biological stimulation mechanisms capable of inducing therapeutical CAP, which may be applied in pre-eclampsia to improve the mother's and offspring's quality of life.

Vagus nerve stimulation for treating developmental and epileptic encephalopathy in young children

Objective

To investigate the clinical variables that might predict the outcome of developmental and epileptic encephalopathy (DEE) after vagus nerve stimulation (VNS) therapy and identify the risk factors for poor long-term outcome.

Patients and methods

We retrospectively studied 32 consecutive children with drug-resistant DEE who had undergone VNS surgery from April 2019 to July 2021, which were not suitable for corpus callosotomy. In spite of combining valproic acid, levetiracetam, lamotrigine, topiramate, etc. (standard anti-seizure medicine available in China) it has not been possible to effectively reduce seizures in the population we investigate (Cannabidiol and brivaracetam were not available in China). A responder was defined as a frequency reduction decrease > 50%. Seizure freedom was defined as freedom from seizures for at least 6 months. Sex, electroencephalograph (EEG) group, neurodevelopment, time lag, gene mutation, magnetic resonance imaging (MRI), and epilepsy syndrome were analyzed with Fisher's exact test, The age at onset and age at VNS therapy were analyzed with Kruskal-Wallis test, statistical significance was defined as p < 0.05. And used the effect size to correction.

Results

Among the 32 patients, the median age at VNS implantation was 4.7 years (range: 1-12 years). At the most recent follow-up, five children (15.6%) were seizure-free and 22 (68.8%) were responders. Univariate analysis demonstrated that the responders were significantly associated with mild development delay/intellectual disability (p = 0.044; phi coefficient = 0.357) and a multifocal EEG pattern (p = 0.022; phi coefficient = -0.405). Kaplan-Meier survival analyses demonstrated that a multifocal EEG pattern (p = 0.049) and DEE without epileptic spasm (ES) (p = 0.012) were statistically significant (p = 0.030). Multivariate analysis demonstrated that DEE with ES had significant predictive value for poor long-term outcome (p = 0.014, hazard ratio = 5.433, confidence interval = 1.402-21.058).

Conclusions

Our study suggested that VNS was a generally effective adjunct treatment for DEE. Although the predictive factors for VNS efficacy remain unclear, it should be emphasized that patients with ES are not suitable candidates for epilepsy surgery. Further investigations are needed to validate the present results.

Gastric electrical stimulation is safe during pregnancy and delivery: Results from a French cohort

BACKGROUND

Gastric electrical stimulation (GES) is an effective therapy in medically refractory chronic nausea and vomiting. GES is assumed to be a contraindication for pregnancy. We examined the safety of GES during pregnancy and its clinical impact on vomiting symptoms.

METHODS

A retrospective study was performed in two tertiary centers including all female patients of childbearing age implanted with GES. Patients without pregnancy while on GES were asked about their desire and concerns about pregnancy. Patients who were pregnant while on GES therapy were interviewed about the course of the pregnancy and labor, as well as the health of the children.

KEY RESULTS

Among 91 patients implanted at childbearing age, 54 patients without pregnancy answered the questionnaire. Nine patients (16.7%) reported a desire for pregnancy and five patients (7.4%) reported worries about the safety of GES during pregnancy. Sixteen pregnancies were reported in 10 patients. All pregnancies ended in a live birth with premature birth in 12 pregnancies (75.0%). No health concern was currently noted in these children. No severe GES-related complications occurred during pregnancy with only pain at the implantation site reported during 3 pregnancies (18.8%). The severity and frequency of nausea and vomiting significantly increased during the first trimester (p = 0.04 and p = 0.005, respectively) and decreased after the delivery, becoming lower than before the pregnancy (p = 0.044 and p = 0.011, respectively).

CONCLUSION & INFERENCES

Patients are concerned regarding pregnancy while being treated with GES. No serious maternal or fetal complications related to GES were noted in our cohort.

Safe and effective implantation and use of vagal nerve stimulation in new-onset refractory status epilepticus in early pregnancy: a case report

Introduction

The management of new-onset refractory status epilepticus (NORSE) in pregnancy may be complicated by anti-seizure medication (ASM) polytherapy-associated teratogenicity. We aim to demonstrate the safety and efficacy of vagal nerve stimulation (VNS) in a pregnant patient presenting with NORSE.

Case description

A 30-year old female, at 5-weeks' gestation presented with drug-refractory myoclonic status epilepticus, responsive only to high levels of anesthetic agents. The severity of seizures did not allow extubation, and the patient remained ventilated and sedated. VNS was implanted 26 days after seizure onset. The immediate post-operative output was 0.25 mA, which was rapidly titrated up to 0.5 mA the next morning, and to 0.75 mA that afternoon. This was further increased to 1.0 mA on 3rd day post-operation, and to 1.25 mA 7 days post-op. Myoclonic jerks diminished significantly 7 days post-op, allowing extubation. Twenty days after VNS implantation, no myoclonic jerks were observed. There was also a notable neurological improvement including increased alertness and mobility, and ability to obey commands. Drug overdose was subsequently found to be the most likely etiology of her NORSE. An early pregnancy assessment 17 days after VNS implantation showed a normally sited pregnancy, normal fetal heart activity and crown-rump length. The patient remained seizure free, gained functional independence and delivered a premature but otherwise healthy baby at 33 weeks' gestation.

Conclusion

NORSE is challenging to manage, further compounded in pregnancy due to the teratogenicity of ASMs and ASM polytherapy. This is the first case-study to report the safe implantation and use of VNS during the first trimester of pregnancy for the management of NORSE.

Vagus nerve stimulation for conservative therapy-refractive epilepsy and depression

Numerous studies confirm that the vagus nerve stimulation (VNS) is an efficient, indirect neuromodulatory therapy with electrically induced current for epilepsy that cannot be treated by epilepsy surgery and is therapy-refractory and for drug therapy-refractory depression. VNS is an established, evidence-based and in the long-term cost-effective therapy in an interdisciplinary overall concept.Long-term data on the safety and tolerance of the method are available despite the heterogeneity of the patient populations. Stimulation-related side effects like hoarseness, paresthesia, cough or dyspnea depend on the stimulation strength and often decrease with continuing therapy duration in the following years. Stimulation-related side effects of VNS can be well influenced by modifying the stimulation parameters. Overall, the invasive vagus nerve stimulation may be considered as a safe and well-tolerated therapy option.For invasive and transcutaneous vagus nerve stimulation, antiepileptic and antidepressant as well as positive cognitive effects could be proven. In contrast to drugs, VNS has no negative effect on cognition. In many cases, an improvement of the quality of life is possible.iVNS therapy has a low probability of complete seizure-freedom in cases of focal and genetically generalized epilepsy. It must be considered as palliative therapy, which means that it does not lead to healing and requires the continuation of specific medication. The functional principle is a general reduction of the neuronal excitability. This effect is achieved by a slow increase of the effectiveness sometimes over several years. Responders are those patients who experience a 50% reduction of the seizure incidence. Some studies even reveal seizure-freedom in 20% of the cases. Currently, it is not possible to differentiate between potential responders and non-responders before therapy/implantation.The current technical developments of the iVNS generators of the new generation like closed-loop system (cardiac-based seizure detection, CBSD) reduce also the risk for SUDEP (sudden unexpected death in epilepsy patients), a very rare, lethal complication of epilepsies, beside the seizure severity.iVNS may deteriorate an existing sleep apnea syndrome and therefore requires possible therapy interruption during nighttime (day-night programming or magnet use) beside the close cooperation with sleep physicians.The evaluation of the numerous iVNS trials of the past two decades showed multiple positive effects on other immunological, cardiological, and gastroenterological diseases so that additional therapy indications may be expected depending on future study results. Currently, the vagus nerve stimulation is in the focus of research in the disciplines of psychology, immunology, cardiology as well as pain and plasticity research with the desired potential of future medical application.Beside invasive vagus nerve stimulation with implantation of an IPG and an electrode, also devices for transdermal and thus non-invasive vagus nerve stimulation have been developed during the last years. According to the data that are currently available, they are less effective with regard to the reduction of the seizure severity and duration in cases of therapy-refractory epilepsy and slightly less effective regarding the improvement of depression symptoms. In this context, studies are missing that confirm high evidence of effectiveness. The same is true for the other indications that have been mentioned like tinnitus, cephalgia, gastrointestinal complaints etc. Another disadvantage of transcutaneous vagus nerve stimulation is that the stimulators have to be applied actively by the patients and are not permanently active, in contrast to implanted iVNS therapy systems. So they are only intermittently active; furthermore, the therapy adherence is uncertain.

Up to What Extent Does Dravet Syndrome Benefit From Neurostimulation Techniques?

BACKGROUND

Dravet syndrome (DS) is a refractory developmental and epileptic encephalopathy (EE) with a variety of comorbidities, including cognitive impairment, autism-like behavior, speech dysfunction, and ataxia, which can seriously affect the quality of life of patients and impose a great burden on society and their families. Currently, the pharmacological therapy is patient dependent and may work or not. Neuromodulation techniques, including vagus nerve stimulation (VNS), deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), responsive neurostimulation (RNS), and chronic subthreshold cortical stimulation (CSCS), have become common adjuvant therapies for neurological diseases, but their efficacy in the treatment of DS is unknown.

METHODS

We searched Web of Science, PubMed, and SpringerLink for all published cases related to the neuromodulation techniques of DS until January 15, 2022. The systematic review was supplemented with relevant articles from the references. The results reported by each study were summarized narratively.

RESULTS

The Web of science, PubMed and SpringerLink search yielded 258 items. A total of 16 studies published between 2016 and 2021 met the final inclusion criteria. Overall, 16 articles (109 cases) were included in this study, among which fifteen (107 patients) were involved VNS, and one (2 patients) was involved DBS. After VNS implantation, seizures were reduced to ≥50% in 60 cases (56%), seizure free were found in 8 cases (7.5%). Only two DS patients received DBS treatment, and the initial outcomes of DBS implantation were unsatisfactory. The seizures significantly improved over time for both DBS patients after the addition of antiepileptic drugs.

CONCLUSION

More than half of the DS patients benefited from VNS, and VNS may be effective in the treatment of DS. However, it is important to note that VNS does not guarantee improvement of seizures, and there is a risk of infection and subsequent device failure. Although DBS is a safe and effective strategy for the treatment of refractory epilepsy, the role of DBS in DS needs further study, as the sample size was small. Thus far, there is no strong evidence for the role of DBS in DS.

Women's Issues in Epilepsy

PURPOSE OF REVIEW

Issues pertaining to women with epilepsy have advanced with a better understanding of multidirectional influences among hormones, seizures, and antiseizure medications, as well as pregnancy-related concerns around fertility, seizure destabilization, and antiseizure medication-associated teratogenicity. This article highlights important developments in this field and reviews best practices in the management of women with epilepsy.

RECENT FINDINGS

Important external hormonal influences may impact women with epilepsy particularly in the context of gender-affirming medications, hormonal replacement therapy, and fertility therapies. Fertility for women with epilepsy is influenced by multiple variables; however, in the absence of preexisting fertility issues, epilepsy per se is not associated with significantly impaired fertility. Once women with epilepsy are pregnant, the majority have a stable course. Antiseizure medication use in pregnancy is associated with major congenital malformations 2 to 5 times that of the general population and is highest with high-dose (≥1500 mg or greater total daily) valproate. Carefully considered changes in drug choice and dose may mitigate these risks. Therapeutic drug monitoring plays an important role in pregnancy care, and under expert supervision, women with epilepsy in pregnancy have similar seizure risks as women with epilepsy who are not pregnant. As women with epilepsy age, bone health and menopause may further be impacted by seizures and antiseizure medications.

SUMMARY

The care of women with epilepsy is a multifaceted discipline that recognizes the life-long impact of sex and gender influences on epilepsy care.