Our solution to optimise the vagus nerve

 

Decoding stress

Stress is a word that we hear all the time but many people don’t recognise the full extent of the impact that it has on us. Our bodies react to it through a series of physiological changes caused by the release of stress hormones, in particular, cortisol. These are commonly used as biological markers to assess our response and recovery but are not easy to obtain. 

Chronic stress can result in imbalances in our autonomic nervous system (ANS), where the sympathetic “flight or fright” response is over activated through continued exposure to stressors, resulting in health problems ranging from heart failure, inflammatory bowel disease and chronic pain syndrome. It can also lead to a clinical diagnosis of anxiety and depression.

So how do we find a simpler way to de-code and measure stress so we can intervene earlier and personalise treatment?  MindSpire’s expertise lies in unravelling stress, using non-invasive biomarkers from heart rate, in particular Heart Rate Variability (HRV) and brain wave patterns  collected from an ear piece in non-clinical settings. These are used to personalise treatments and monitor their effectiveness.

 The ANS influences the function of organs through the activity of the sympathetic (SNS) and parasympathetic nervous system (PNS). A major component of the PNS is the vagus nerve, the 10th cranial nerve, which acts as an "information superhighway" between our brain, thorax, lungs, heart and abdomen, heart and gut to help maintain homeostasis through the “rest and relax”  or “tend-and-befriend” responses.  

 

Harnessing the vagus nerve communication system

In its role as the “great wandering protector” of the body, the vagus nerve relays information back to the brain via afferent fibres, which make up 80% of the nerve.  It also plays a key role in the gut-brain axis, responsible for 2-way information and allowing a route for neurotransmitters produced by gut based microflora to communicate directly with the brain.  On the flip side, to maintain homeostasis, the sympathetic nervous system drives the “fight-or-flight” response. Ideally, within the autonomic nervous system, the tug of war between these two polar opposite mechanisms creates a "yin-yang" type of harmony marked by homeostatic balance.

 In 1921, Nobel Prize-winning physiologist, Otto Loewi discovered that stimulating the vagus nerve caused a reduction in heart rate by triggering the release of a substance he coined Vagusstoff (German for “vagus substance”). This substance was later identified as acetylcholine and became the first neurotransmitter ever identified by scientists. 

Today non-invasive vagus nerve stimulation with small electrical pulses is already approved for treatment in patients with epilepsy, depression, chronic pain and cluster migraines.  fMRI studies have revealed that stimulation sends electrical signals through to the brainstem, ending in the nucleus of the solitary tract, which in turn signals several other forebrain, limbic and brainstem sites, including the amygdala and nucleus accumbens, (thought to influence the pathogenesis of depression) and the locus coereleus.

 To date there has been no real data-driven insight into how stress affects an individual’s health. It is however possible to predict levels of stress with over 80% accuracy using a combination of data derived from  electrocardiogram (ECG) and brain wave electroencephalograms (EEG) patterns data using neural network models. 

Building an personalised model is key and can be supplemented with qualitative and behavioural data to establish a baseline and clear patterns between stress with the environment and activity. 

With an established baseline we can personalise vagus nerve stimulation, either on its own or possibly overlaid with other treatments.  This is starting with a straightforward open loop stimulation without any adjustment of the parameters whilst we finish building and testing our algorithms to drive a closed loop stimulation with instantaneous biofeedback. This is our goal; to respond to the therapeutic needs and actual physiological state of the body. 

And as we learn and share more about the insights into the effectiveness of interventions in the treatment of chronic stress,  the levels of stress in specific populations and the opportunity for increasing human flourishing.

 

Introducing our wearable bioelectronic earpiece