Effects of intranasal kinetic oscillation stimulation on heart rate variability

Achieving symptom relief in patients with myalgic encephalomyelitis by targeting the neuro-immune interface and optimizing disease tolerance

Myalgic encephalomyelitis (ME) previously also known as chronic fatigue syndrome is a heterogeneous, debilitating syndrome of unknown etiology responsible for long-lasting disability in millions of patients worldwide. The most well-known symptom of ME is post-exertional malaise, but many patients also experience autonomic dysregulation, cranial nerve dysfunction and signs of immune system activation. Many patients also report a sudden onset of disease following an infection. The brainstem is a suspected focal point in ME pathogenesis and patients with structural impairment to the brainstem often show ME-like symptoms. The brainstem is also where the vagus nerve originates, a critical neuro-immune interface and mediator of the inflammatory reflex which regulate systemic inflammation. Here, we report the results of a randomized, placebo-controlled trial using intranasal mechanical stimulation targeting nerve endings in the nasal cavity, likely from the trigeminal nerve, possibly activating additional centers in the brainstem of ME patients and correlating with a ∼30% reduction in overall symptom scores after 8 weeks of treatment. By performing longitudinal, systems-level monitoring of the blood immune system in these patients, we uncover signs of chronic immune activation in ME, as well as immunological correlates of improvement that center around gut-homing immune cells and reduced inflammation. The mechanisms of symptom relief remain to be determined, but transcriptional analyses suggest an upregulation of disease tolerance mechanisms. We believe that these results are suggestive of ME as a condition explained by a maladaptive disease tolerance response following infection.

Prenatal and recent methylmercury exposure and heart rate variability in young adults: the Seychelles Child Development Study

Epidemiologic evidence of an adverse association between exposure to methylmercury (MeHg) from consuming fish and heart rate variability (HRV) is inconclusive. We aimed to evaluate MeHg exposure in relation to HRV parameters in a large cohort of young adults from a high fish consuming population in the Republic of Seychelles. Main Cohort participants in the Seychelles Child Development Study were evaluated at a mean age of 19 years. Prenatal MeHg exposure was determined in maternal hair growing during pregnancy and recent exposure in participant's hair taken at the evaluation. The evaluation consisted of short (~2 h) and long (overnight) Holter recordings obtained in 514 and 203 participants, respectively. Multivariable analyses examined the association of prenatal and recent MeHg exposure (in separate models) with time-domain and frequency-domain HRV parameters in different physiologic circumstances: supine position, standing position, mental stress when undergoing a mathematics test, sleep, and long recording. Prenatal MeHg exposure was not associated with any of the 23 HRV parameters studied after adjustment for multiplicity. The recent MeHg showed a trend toward significance only for few variables in the primary model. However, after additional adjustment for activity levels, polyunsaturated fatty acids, and multiplicity none were significant after a Bonferroni adjustment. In conclusion, prenatal and recent MeHg exposure had no consistent pattern of associations to support the hypothesis that they are adversely associated with heart rate variability in this study population that consumes large amounts of fish.

Effects of intranasal kinetic oscillation stimulation on heart rate variability

Background

Kinetic oscillation stimulation in the nasal cavity (KOS) has been shown to have positive symptomatic effects in subjects with non‐allergic rhinitis and in patients with migraine.

Methods

To evaluate the effect of KOS on autonomic function, we assessed heart rate variability (HRV) in this small exploratory study in 12 healthy subjects. KOS treatment was performed using a minimally invasive system with a single‐use catheter inserted into the nasal cavity. During treatment, the tip was inflated and oscillated with a mean pressure of 95 millibar and amplitude of the oscillations of 100 millibar at a frequency of 68 Hz. Treatment was given for 15 minutes sequentially on each side. Heart rate variability was assessed during five 30‐minutes periods before, during and immediately after KOS treatment and 3.5 hours thereafter. KOS resulted in a substantial reduction of HRV.

Results

As compared to baseline recorded during 30 minutes preceding treatment, VLF was reduced by 65%, LF by 55%, the ratio LF/HF by 44%, with somewhat smaller observed effects in the time domain; SDNN and RMSDD were reduced by of 36% and 18%, respectively. Heart rate remained stable during treatment with minimal mean changes from 68 ± 7 bpm before to 68 ± 9 and 69 ± 9 bpm during and after treatment. Reduction of HRV parameters was consistently seen in all subjects, with rapid onset and return towards baseline values during post‐treatment observation periods.

Conclusions

KOS has an effect on the autonomic balance with pronounced heart‐rate independent reduction on HRV.