Lyme disease has the power to affect the body in various ways. When the borrelia bacteria, which causes Lyme disease, makes its way into the bloodstream from the bite of an infected tick, it travels throughout the body, settling in tissues, joints, the heart, and throughout the nervous system.
Because the bacteria can easily go undetected, Lyme disease is often hard to treat and can leave lasting symptoms. In the worst cases, the infection can lead to permanent damage to the joints and other areas of the body. Recent research has investigated chronic Lyme and the vagus nerve to see if there is any connection. But what is the vagus nerve, and can it actually be affected by Lyme disease?
What is the vagus nerve?
The vagus nerve is one of 12 cranial nerves that help the brain communicate with the rest of the body. The 12 nerves are responsible for different things such as sensory information that helps with sight, smell, taste, and sound processing. Others control muscle movement and the function of specific glands throughout the body. In some cases, a nerve can be responsible for sending both sensory information and participating in the function of motor skills. The vagus nerve, the longest of all cranial nerves, is one that does both.
Also known as the pneumogastric nerve, the vagus nerve plays a role in various bodily processes such as digestion, heart rate, breathing, cardiovascular activity, and reflex actions including sneezing, swallowing, and coughing.
It is a key player in managing unconscious actions that are controlled by the autonomic nervous system. Recent research surrounding the vagus nerve has also found that it is a part of the gut-brain axis – the connection between the gut and the brain that has an effect on both digestive and mental health.
What diseases affect the vagus nerve?
Issues can arise when a person has a condition that can damage the vagus nerve. Some examples of diseases or health conditions that can lead to problems with the function of the vagus nerve include:
- Surgery to the stomach or small intestine
- Chronic stress
- Nerve damage
Other conditions have also been shown to have close ties with the function of the vagus nerve. However, it’s not clear whether the vagus nerve causes these conditions or just malfunctions in people who have them. Some examples include:
- Vasovagal syncope
- Heart disease
- Metabolic disease
What happens when the vagus nerve is irritated?
The vagus nerve acts as a stimulator to help with various sensory and motor functions. It can become irritated by various health conditions, pain, fear, or high levels of stress. Other things that can cause an overstimulation of the vagus nerve include:
- Seeing blood or getting blood drawn
- Illness of the gastrointestinal tract
- Bowel movements
- Excessive heat
- Standing up quickly
- Standing for a long period of time
The vagus nerve plays such a significant role in the body that when it becomes irritated, unwanted symptoms (often referred to as a vagal response) may occur. These symptoms can include:
- Ringing in the ears
- Excessive sweating
- Pale skin
- Blurry vision
- Tunnel vision
- Cold and/or clammy skin
Can Lyme affect the vagus nerve?
While the connection between Lyme disease and the vagus nerve is still being investigated, research over the last decade has found that some patients with chronic Lyme disease are affected by vagus nerve irritation. This can lead to vasovagal syncope, which is a type of fainting driven by the overstimulation of the vagus nerve.
It is thought that the bacteria that causes Lyme disease can make its way into the autonomic nervous system and wreak havoc on how the vagus nerve functions. Researchers also associate the onset of vasovagal symptoms with Lyme disease because of the evidence that the modulation of the cardiac vagal tone is affected by the borrelia bacteria. To put it simply: the vagus nerve is designed to help regulate heart rate and activity, but has a more difficult time doing so in people with Lyme disease.
Lyme disease has also been known to cause nerve damage, but more recent evidence has found that some of this nerve damage can occur to the cranial nerves, including the vagus. When the vagus nerve is damaged, it malfunctions.
While research surrounding the vagus nerve and its connection to Lyme disease is still ongoing, recent years have produced studies showing clinical evidence that Lyme disease is a much more serious condition than people may think. When it comes to the vagus nerve and its vital role in many autonomic bodily functions, it’s safe to say that Lyme disease can compromise that system.