Vagus nerve stimulation in pregnant rats and effects on inflammatory markers in the brainstem of neonates

Transauricular vagal nerve stimulation suppresses inflammatory responses in the gut and brain in an inflammatory bowel disease model

Inflammatory bowel disease (IBD) encompasses Crohn's disease (CD) and ulcerative colitis (UC), is a major health problem on a global scale and its treatment is unsatisfactory. We aimed to investigate the effects of transauricular vagal nerve stimulation (tVNS) on inflammation in rats with IBD induced by trinitrobenzene sulfonic acid (TNBS). A total of 36 adult female Sprague-Dawley rats were given TNBS, or vehicle, and tVNS, or sham, every other day for 30 min for 10 days. Postmortem macroscopic and microscopic colon morphology were evaluated by histological staining. Additionally, IL-1β, IL-6, IL-10, and TNF-α cytokine levels in the colon and the brain were evaluated by immunohistochemistry and western blotting analysis. TNBS induced epithelial damage, inflammation, ulceration, and thickened mucosal layer in the colonic tissues. Administration of tVNS significantly ameliorated the severity of TNBS-induced tissue damage and inflammatory response. TNBS also alters pro-inflammatory and anti-inflammatory balance in the brain tissue. TVNS application significantly suppressed the protein levels of pro-inflammatory cytokines, namely IL-1β, IL-6, and TNF- α while augmenting the level of anti-inflammatory cytokine IL-10 in the colonic and the brain tissue. We have shown that TNBS-mediated colonic inflammation and tissue damage are associated with neuroinflammatory responses in the brain tissue. Also demonstrated for the first time that neuroinflammatory response in the gut-brain axis is suppressed by tVNS in the IBD model. Non-invasive tVNS stands out as a new potential treatment option for types of IBD.

Pregnancy Outcomes in Refractory Epilepsy Patients with Vagus Nerve Stimulation: Long-Term Single-Center Experience

BACKGROUND AND STUDY AIMS

 Vagus nerve stimulation (VNS) has been employed worldwide as an adjunctive therapy in drug-resistant epilepsy patients. However, the mechanisms of VNS action potentially increase the risk of obstetric complications. The study presents the long-term single-center experience with pregnancies and childbirth in women with VNS for refractory epilepsy based on prospectively collected epileptologic data and a retrospective analysis of pregnancy, childbirth, and data about long-term child development.

MATERIAL AND METHODS

 From a group of patients with VNS implanted for refractory epilepsy between October 1999 and January 2018, all the women of childbearing age (younger than 40 years) were identified. After checking their hospital records for data about any pregnancies, the women with confirmed childbirth during active VNS stimulation and their general practitioners were interviewed based on a prepared questionnaire regarding their gynecologic history, the course of pregnancy and childbirth, gestational week, birth weight and length, any congenital anomalies of the child, and the child's psychomotor development, school performance, and somatic health problems.

RESULTS

 From the group of 257 patients implanted with VNS for refractory epilepsy, 4 women (1.5%) became pregnant and gave birth (all on polypharmacotherapy). The mean interval from VNS implantation to birth was 44.3 months. Slight seizure worsening during the last trimester was reported in one woman. In one patient, acute caesarean section was required due to placental separation. Planned birth induction and caesarean section were used in the other two women because of their seizure disorder. No malfunction of the stimulation system was detected during pregnancy or after birth. No congenital malformations were observed. The two children who were of school age at the time of this study require special schooling.

CONCLUSIONS

 The study results confirmed a high rate of obstetric interventions in patients with VNS. Although no teratogenic effect of VNS has been proven, the higher incidence of children exposed to VNS needing special education requires attention.

Vagus nerve stimulation ameliorates L-NAME-induced preeclampsia-like symptoms in rats through inhibition of the inflammatory response

Background

Preeclampsia is characterized by an excessive inflammatory response. Recent studies have shown that vagus nerve stimulation (VNS) has anti-inflammatory properties in vivo. This study aims to investigate whether VNS is safe for use during pregnancy and to explore the therapeutic potential and underlying mechanisms of VNS in PE.

Methods

Pregnant Sprague-Dawley rats were randomly chosen to receive N-nitro-L-arginine methyl ester (L-NAME)-containing water (preeclampsia-like mouse model) or saline (normal pregnancy control) daily at gestational days 14.5–20.5. VNS and the α7nAChR antagonist methyllycaconitine citrate (MLA, 1 mg/kg/d) were given daily at the same time.

Results

VNS decreased the high systolic blood pressure and urinary protein observed in the PE rats. In addition, VNS mitigated abnormal pregnancy outcomes. Moreover, VNS alleviated the inflammatory response by decreasing the levels of inflammatory cytokines. VNS significantly increased the expression of α7nAChR and attenuated the activation of NF-κB p65 in the placenta.

Discussion

Our findings indicate that maternal VNS treatment is safe during pregnancy and has a protective effect in a pregnant rat model of preeclampsia induced by L-NAME.

Managing migraine in pregnancy and breastfeeding

The disproportionate prevalence of migraine among women in their reproductive years underscores the clinical significance of migraine during pregnancy. This paper discusses how migraine evolves during pregnancy, secondary headache disorders presenting in pregnancy and puerperium, and acute and preventive options for migraine management during pregnancy and lactation. Migraine is influenced by rising estrogen levels during pregnancy and their sharp decline in puerperium. Migraine, and migraine aura, can present for the first time during pregnancy and puerperium. There is also a higher risk for the development of preeclampsia and cerebrovascular headache during these periods. New or refractory headache, hypertension, and abnormal neurological signs are important "red flags" to consider. This paper reviews the diagnostic utility of neuroimaging studies and the risks of each during pregnancy. Untreated migraine can itself lead to preterm delivery, preeclampsia, and low birth weight infants. Behavioral interventions and lifestyle modifications are the cornerstone for migraine treatment during pregnancy. In addition, one should consider the risks and efficacy of each treatment during pregnancy on an individual basis. The protective nature of breastfeeding for migraine is debated, but there is no evidence to suggest breastfeeding worsens migraine. Acute and preventive migraine treatment options are available for nursing mothers. Neuromodulation and neurostimulation devices are additional options for treatment during pregnancy and lactation, while the safety of using calcitonin gene-related peptide receptor antagonists during these times remains to be determined.

Experience on the use of Vagus Nerve Stimulation during pregnancy

OBJECTIVE

Vagus Nerve Stimulation (VNS) is a neuromodulation device approved for the treatment of medically refractory epilepsy. Worldwide, only 35 cases of pregnancies that has been described. This study aims to continue to increase the limited knowledge of the use of VNS during pregnancy.

METHODS

We interrogated the database of the Epilepsy program at Western University (1998-2018), and identified those patients who were implanted with VNS and became pregnant.

RESULTS

From 114 patients implanted with VNS in our centre, four patients had a total of seven pregnancies. This is the first report with one woman implanted with VNS having three pregnancies. Three patients had genetic generalized epilepsy and one focal epilepsy due to periventricular nodular heterotopia. The median duration since implantation was 3.17 years (IQR: 1.33-4.33) and the output was 2.75 mA (IQR: 1.5-3.5). No modifications in stimulation settings were made in any patient during pregnancy. Three patients had obstetric complications, requiring c-sections. All babies were healthy, except one with intellectual disabilities of unclear severity.

CONCLUSION

Our small sample suggests VNS could increase the obstetrical complications, but is likely safe for the fetus. However, a larger sample size should be collected to determine safety and potential teratogenicity of VNS.

Unique Populations with Episodic Migraine: Pregnant and Lactating Women

PURPOSE OF REVIEW

Migraine is a disabling and prevalent neurological disease, commonly affecting women during their reproductive years. It is crucial for providers to be able to adequately counsel women who are pregnant, planning pregnancy, or nursing, regarding preventive and abortive treatment options for episodic migraine. This review will discuss (1) the expected course of migraine during pregnancy and the post-partum period, (2) recommended preventive therapies for migraine during pregnancy and lactation, and (3) recommended abortive medications for migraine during pregnancy and lactation.

RECENT FINDINGS

Recent research has indicated safety for triptan use during pregnancy and ibuprofen use during the first trimester of pregnancy. Considerations for use of emerging migraine-preventive treatment, such as non-invasive neurostimulators, are discussed. For clinical decision-making and patient counseling, it is important to understand both the limitations in determining teratogenic effects in humans and the principles affecting medication transmission from mother to breast milk.

A review of vagus nerve stimulation as a therapeutic intervention

In this review, we provide an overview of the US Food and Drug Administration (FDA)-approved clinical uses of vagus nerve stimulation (VNS) as well as information about the ongoing studies and preclinical research to expand the use of VNS to additional applications. VNS is currently FDA approved for therapeutic use in patients aged >12 years with drug-resistant epilepsy and depression. Recent studies of VNS in in vivo systems have shown that it has anti-inflammatory properties which has led to more preclinical research aimed at expanding VNS treatment across a wider range of inflammatory disorders. Although the signaling pathway and mechanism by which VNS affects inflammation remain unknown, VNS has shown promising results in treating chronic inflammatory disorders such as sepsis, lung injury, rheumatoid arthritis (RA), and diabetes. It is also being used to control pain in fibromyalgia and migraines. This new preclinical research shows that VNS bears the promise of being applied to a wider range of therapeutic applications.