Clin Auton Res. 2024 Oct 14. doi: 10.1007/s10286-024-01074-9. Online ahead of print.

ABSTRACT

PURPOSE: The aim of this paper is to investigate the acute effects of short-term transcutaneous vagus nerve stimulation (tVNS) on cardio-vagal baroreflex gain and heart rate variability in patients with chronic heart failure (CHF).

METHODS: A total of 16 adults with CHF and left ventricular ejection fraction (LVEF) < 50% in sinus rhythm were enrolled (65 ± 8 years, 63% men, LVEF 40 ± 5%, 88% on beta-blockers, 50% on quadruple CHF therapy). Over a single experimental session, after a 10-min baseline recording, each patient underwent two trials of 10-min tVNS (Parasym Device, 200 µs, 30 Hz, 1 mA below discomfort threshold) at either the right or left tragus in a randomized order, separated by a 10-min recovery.

RESULTS: Compared with baseline, tVNS did not affect heart rate, blood pressure, and respiratory rate (p > 0.05), and no patients complained of discomfort or any adverse effect. Right-sided tVNS was associated with a significant increase in cardio-vagal baroreflex gain (from 5.6 ± 3.1 to 7.5 ± 3.8 ms/mmHg, ∆ 1.9 ± 1.6 ms/mmHg, p < 0.001), while no change was observed with left-sided tVNS (∆ 0.5 ± 2.0 ms/mmHg, p = 0.914). These findings were independent of stimulation-side order (excluding any carry-over effect) and consistent across sex, LVEF category, and HF etiology subgroups (p-value for interaction > 0.05).

CONCLUSIONS: Acute right-sided tVNS increases cardio-vagal baroreflex gain in patients with CHF and LVEF < 50%, with no tolerability concerns.

PMID:39402309 | DOI:10.1007/s10286-024-01074-9

FEBS Open Bio. 2024 Oct 14. doi: 10.1002/2211-5463.13889. Online ahead of print.

ABSTRACT

Autism is a neurodevelopmental disorder with limited treatment alternatives and which incidence is increasing. Some research suggests that vagus nerve simulation might lead to the reduction of certain symptom. Therefore, we aimed to examine the effect of bilateral transcutaneous auricular vagus nerve stimulation (tVNS) on the inflammatory response in an adult valproic acid (VPA) induced mouse (C57BL6) model of autism for the first time. The autism model was induced by oral VPA administration (600 mg·kg^-1) to C57BL/6 pregnant mice on E12.5 days. The study included three groups: the VPA Transcutaneous Auricular Stimulation Group (VPA + tVNS), the VPA Control Group (VPA + sham), and the Healthy Control Group (Control + sham). Each group included 16 mice (8 M/8 F). Our results show that serum IL-1β and IL-6 levels were significantly higher in male VPA-exposed mice than controls. However, IL-1β was significantly lower, and IL-6, TNF- α, and IL-22 were not different in female VPA-exposed mice compared to the control group. Brain NLRP3 levels were significantly higher in both sexes in the VPA autism model (P < 0.05). tVNS application increased brain NLRP3 levels in both sexes and reduced serum IL-1β levels in male mice. We conclude that cytokine dysregulation is associated with the VPA-induced adult autism model, and the inflammatory response is more pronounced in male mice. tVNS application altered the inflammatory response and increased brain NLPR3 levels in both sexes. Further studies are needed to understand the beneficial or detrimental role of the inflammatory response in autism and its sexual dimorphism.

PMID:39401991 | DOI:10.1002/2211-5463.13889

BMC Anesthesiol. 2024 Aug 3;24(1):269. doi: 10.1186/s12871-024-02612-8.

ABSTRACT

BACKGROUND: Different approach ultrasound-guided superior laryngeal nerve block was used to aid awake intubation, but little is known which approach was superior. We aimed to compare the parasagittal and transverse approaches for ultrasound-guided superior laryngeal nerve block in adult patients undergoing awake intubation.

METHODS: Fifty patients with awake orotracheal intubation were randomized to receive either a parasagittal or transverse ultrasound-guided superior laryngeal nerve block. The primary outcome was patient’s quality of airway anesthesia grade during insertion of the tube into the trachea. The patients’ tube tolerance score after intubation, total procedure time, mean arterial pressure, heart rate, Ramsay sedation score at each time point, incidence of sore throat both 1 h and 24 h after extubation, and hoarseness before intubation, 1 h and 24 h after extubation were documented.

RESULTS: Patients’ quality of airway anesthesia was significantly better in the parasagittal group than in the transverse group (median grade[IQR], 0 [0-1] vs. 1 [0-1], P = 0.036). Patients in the parasagittal approach group had better tube tolerance scores (median score [IQR],1[1-1] vs. 1 [1-1.5], P = 0.042) and shorter total procedure time (median time [IQR], 113 s [98.5-125.5] vs. 188 s [149.5-260], P < 0.001) than those in the transverse approach group. The incidence of sore throat 24 h after extubation was lower in the parasagittal group (8% vs. 36%, P = 0.041). Hoarseness occurred in more than half of the patients in parasagittal group before intubation (72% vs. 40%, P = 0.023).

CONCLUSIONS: Compared to the transverse approach, the ultrasound-guided parasagittal approach showed improved efficacy in terms of the quality of airway topical anesthesia and shorter total procedure time for superior laryngeal nerve block.

TRIAL REGISTRATION: This prospective, randomized controlled trial was approved by the Ethics Committee of Nanjing First Hospital (KY20220425-014) and registered in the Chinese Clinical Trial Registry (19/6/2022, ChiCTR2200061287) prior to patient enrollment. Written informed consent was obtained from all participants in this trial.

PMID:39097713 | DOI:10.1186/s12871-024-02612-8

Epilepsy Behav. 2024 Aug 2;159:109948. doi: 10.1016/j.yebeh.2024.109948. Online ahead of print.

ABSTRACT

PURPOSE: Drug-resistant epilepsy (DRE) affects one-third of patients with focal epilepsy. A large portion of patients are not candidates for epilepsy surgery, thus alternative options, such as vagus nerve stimulation (VNS), are proposed. Our objective is to study the effect of vagus nerve stimulation on lesional versus non-lesional epilepsies.

METHODS: This is a retrospective cohort study in a single center in London, Ontario, which includes patients with DRE implanted with VNS, implanted between 1997-2018 and the date of analysis is December 2023.

PARTICIPANTS: Patients implanted with VNS were classified by lesional (VNS-L) and non-lesional (VNS-NL) based on their MRI head findings. We further subdivided the VNS groups into patients with VNS alone versus those who also had additional epilepsy surgeries.

RESULTS: A total of 29 patients were enrolled in the VNS-L, compared to 29 in the VNS-NL. The median age of the patients in the study was 31.8 years, 29.31 % were men (N = 17). 41.4 % (n = 12) of the patients were VNS responders (≥50 % seizure reduction) in the VNS-L group compared to 62.0 % (n = 18) in the VNS-NL group (p = 0.03). When other epilepsy surgeries were combined with VNS in the VNS-L group, the median rate of seizure reduction was greater (72.4 (IQR 97.17-45.88) than the VNS-NL group 53.9 (IQR 92.22-27.92); p = 0.27).

CONCLUSIONS: VNS is a therapeutic option for patients with lesional epilepsy, with slightly inferior results compared to patients with non-lesional epilepsy. Patients implanted with VNS showed higher seizure reduction rates if they had previous epilepsy surgeries. This study demonstrates that VNS in lesional epilepsies can be an effective treatment.

PMID:39096795 | DOI:10.1016/j.yebeh.2024.109948

Front Neurosci. 2024 Jul 18;18:1368754. doi: 10.3389/fnins.2024.1368754. eCollection 2024.

ABSTRACT

OBJECTIVE: Recent studies have shown that transcutaneous vagal nerve stimulation (tVNS) holds promise as a treatment for neurological or psychiatric disease through the ability to modulate neural activity in some brain regions without an invasive procedure. The objective of this study was to identify the neural correlates underlying the effects of tVNS.

METHODS: Twenty right-handed healthy subjects with normal hearing participated in this study. An auricle-applied tVNS device (Soricle, Neurive Co., Ltd., Gyeongsangnam-do, Republic of Korea) was used to administer tVNS stimulation. A session consisted of 14 blocks, including 7 blocks of tVNS stimulation or sham stimulation and 7 blocks of rest, and lasted approximately 7 min (1 block = 30 s). Functional magnetic resonance imaging (fMRI) was performed during the stimulation.

RESULTS: No activated regions were observed in the fMRI scans following both sham stimulation and tVNS after the first session. After the second session, tVNS activated two clusters of brain regions in the right frontal gyrus. A comparison of the activated regions after the second session of each stimulation revealed that the fMRI following tVNS exhibited four surviving clusters. Additionally, four clusters were activated in the overall stimulated area during both the first and second sessions. When comparing the fMRI results after each type of stimulation, the fMRI following tVNS showed four surviving clusters compared to the fMRI after sham stimulation.

CONCLUSION: tVNS could stimulate some brain regions, including the fronto-parietal network. Stimulating these regions for treating neurological or psychiatric disease might require applying tVNS for at least 3.5 min.

PMID:39091347 | PMC:PMC11292796 | DOI:10.3389/fnins.2024.1368754

IEEE Trans Biomed Eng. 2024 Aug 2;PP. doi: 10.1109/TBME.2024.3436649. Online ahead of print.

ABSTRACT

A fast-growing field of neuroscience and medicine is the treatment of disease via electrical stimulation of the peripheral nervous system. Peripheral nerve stimulation delivers stimulation to nerves of the periphery where the target nerve can and is often located deep within the abdomen. Long-term preclinical animal models that demonstrate the safety and/or efficacy of electrical stimulation have predominantly used a skull mount to connect to neural interfaces. When targeting nerves of the extremities and abdomen, this mount location is less favourable due to its distance to the implant causing complications in surgery and to the longevity of the device in vivo.

OBJECTIVE: Here we aimed to develop and validate a chronic magnetic percutaneous connector designed for placement on the dorsal-lumbar aspect of the spine of awake, freely moving rats.

METHODS: A pedestal and external connector was developed, bench tested to assess for continuity, durability and disconnection forces, and validated in awake rats chronically implanted with an abdominal vagus nerve electrode array. The implanted pedestal and external connector were designed with custom PCBs, spring-loaded pins, magnets and biocompatible 3D printed housing.

RESULTS: The magnetic coupling mechanism allowed disconnection with minimal force, was highly reliable in maintaining electrical connection in awake rats and allowed recording of electrically evoked compound action potentials after chronic implantation.

CONCLUSION: In conclusion, this percutaneous connector is a useful research tool for peripheral nerve stimulation studies.

SIGNIFICANCE: The connector described will allow investigation into the safety and efficacy of emerging neuromodulation therapies for the treatment of disease.

PMID:39093683 | DOI:10.1109/TBME.2024.3436649

Int J Surg. 2024 Aug 2. doi: 10.1097/JS9.0000000000001984. Online ahead of print.

NO ABSTRACT

PMID:39093860 | DOI:10.1097/JS9.0000000000001984

Am J Med. 2024 Jul 30:S0002-9343(24)00468-6. doi: 10.1016/j.amjmed.2024.07.007. Online ahead of print.

ABSTRACT

Alongside the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, the number of patients with persistent symptoms following acute infection with SARS-CoV-2 is of concern. It is estimated that at least 65 million people worldwide meet criteria for what the World Health Organization (WHO) defines as “post-COVID-19 condition” – a multisystem disease comprising a wide range of symptoms. Effective treatments are lacking. In the present review, we aim to summarize the current evidence for the effectiveness of non-invasive or minimally invasive brain stimulation techniques in reducing symptoms of post-COVID-19. A total of nineteen studies were identified, one using transcutaneous vagus nerve stimulation (tVNS), another using transorbital alternating current stimulation (toACS), six studies on transcranial magnetic stimulation (TMS) and eleven studies on transcranial direct current stimulation (tDCS) for the treatment of post-COVID-19 symptoms. Existing studies report first promising results, illustrating improvement in clinical outcome parameters. Yet, the mechanistic understanding of post-COVID-19 and how brain stimulation techniques may be benefitial are limited. Directions for future research in the field are discussed.

PMID:39089436 | DOI:10.1016/j.amjmed.2024.07.007

Turk Neurosurg. 2024 Mar 13. doi: 10.5137/1019-5149.JTN.46250-24.2. Online ahead of print.

ABSTRACT

Background：Vagus nerve schwannoma is an infrequently occurring schwannoma, in which a distinct subtype exists wherein the tumor is confined to the cerebellomedullary cistern without invading the jugular foramen. This unique tumor is called purely intracranial vagal schwannoma. Clinical Presentation：In this report, we present a case of purely intracranial vagal schwannoma in its asymptomatic early phase, incidentally discovered during surgery performed on a patient with hemifacial spasm. Because of the small size of the tumor, we definitively recognized that it originated from the second rootlet on the caudal side. The tumor was totally resected uneventfully and a favorable prognosis was achieved. Furthermore, we conducted a comprehensive literature review to summarize the classification, origin, and surgical complications associated with this rare tumor type. Conclusions：To the best of our knowledge, this is the first case report of an asymptomatic purely intracranial vagal schwannoma. Based on our literature review, we propose that: 1) the origin of tumor is related to the time of onset of symptoms, 2) nearly all purely intracranial vagal schwannomas can be entirely resected and favorable prognosis can be achieved, and 3) surgeons should be aware of potential cardiovascular complications during surgical procedures.

PMID:39087301 | DOI:10.5137/1019-5149.JTN.46250-24.2

Front Neurol. 2024 Jul 16;15:1440696. doi: 10.3389/fneur.2024.1440696. eCollection 2024.

NO ABSTRACT

PMID:39087014 | PMC:PMC11289522 | DOI:10.3389/fneur.2024.1440696