Non-invasive vagus nerve stimulation can combat fatigue, new research claims

In today’s busy world, humans have devised endless strategies to reduce fatigue. Whether it’s strong industrial coffee, energy drinks in extraordinary shades, or complex sleep habits, everyone has their own way to stay alert. Researchers now argue that new technologies to combat fatigue may have emerged in the form of non-invasive electrical stimulation of the brain.

The study published by scientists in Air Force Research Laboratory And Pentagon providers InfoCitex Co., Ltd., I used a nervous system stimulation therapy called cervical vagus nerve stimulation (VNS).

On the other hand the study Transcranial direct current stimulation (tDCS), an electrical stimulation technique that applies current to the scalp, has been shown to have the potential to improve cognitive performance under fatigue, but other brain stimulation techniques have not yet been investigated. Hmm.

Team including the first author Lindsey K. McIntyre, VNS hypothesized that it could be even more effective than tDCS. This is because both techniques target a region of the brain stem called the locus coeruleus (LC) that secretes the wakefulness hormone norepinephrine.

The tDCS signal must pass through the skin, skull, and the rest of the brain to reach the LC, but VNS technology stimulates the vagus nerve, the central nerve of the parasympathetic nervous system. The device gammaCore Sapphire used in this study is applied to the skin of the neck to stimulate nerves. The author wanted this to be a faster route to activate LC. In addition, VNS is self-administering and takes only 6 minutes instead of the 30 minutes required for tDCS, making it a more attractive option for fatigue reduction.

To test their theory, the team used 40 volunteers, all staff at Wright-Patterson Air Force Base near Dayton, Ohio. Participants were awake for a total of 34 hours. After 12 hours, the skin was given a round or fake stimulus to the VNS using a specific device that vibrates and clicks like a real one, without any electrical stimulus. The group was then given four sets of cognitive tasks to assess alertness.

The results were mixed. No significant impact of VNS was observed on the two tasks. The first was a continuous attention test. McWorth Clock Test The other is called a memory test. N-back test..

In the other two tasks, VNS-stimulated participants performed significantly better at two time points, approximately 12 and 15 hours after stimulation. The task is Psychomotor alert task (PVT) and Air Force-Multi-attribute task battery (AF-MATB). The improvement in AF-MATB performance was driven by tasks that required visual attention. PVT is also a very visual task, and the authors suggest that the obvious benefits of VNS devices stem from improved execution control. How to adapt to the demands of new or changing tasks. “

The outcomes of the behavioral tasks were mixed, but the subjective reports from the volunteers were more robust. Significant differences were observed 21 to 31 hours after stimulation because the increase in fatigue reported by the VNS group was much smaller.

Will VNS devices be used immediately to combat fatigue outside the lab? The authors have confirmed their data by other laboratories using more diverse labs in terms of gender and age. It points out that it is necessary. In addition, note that the particular type of VNS technique used in the study, cervical VNS, has only been tested in the clinical population. Such devices are medically approved for the treatment of cluster headaches. Keep the coffee grinder within reach until further research is done.

reference:

McIntyre, LK, McKinley, RA, Goodyear, C and others Cervical percutaneous vagus nerve stimulation (ctVNS) improves human cognitive performance under sleep deprivation stress. Communication biology. 2021; 4 (634). Doi: 10.1038 / s42003-021-02145-7