The vagus nerve is one of 12 cranial nerves, exiting the skull rather than through the vertebral column. The vagus nerve is the tenth cranial nerve. This nerve supplies motor nerve impulses to the muscles of the voice box and tongue, receiving sensory impulses from the throat, ear and the organs of the chest and abdomen, and supplying visceral nerve impulses to the glands of the throat, chest and abdominal organs.
Diabetes can cause neuropathy, or nerve damage, to a number of different areas of the body. A prolonged increase in blood sugar associated with diabetes can alter nerve chemistry, and damage the blood vessels that support the nerves.
In cases where diabetes has damaged the vagus nerve, it can cause gastroparesis, a condition wherein the muscles of the stomach and intestine are not able to efficiently move food through the gastrointestinal system. Gastroparesis manifests in symptoms such as nausea, vomiting, heartburn, constipation, abdominal bloat, stomach spasms and decreased appetite.
Chronic alcohol abuse is known to cause damage to nerves, a condition referred to as alcoholic neuropathy. Alcohol abuse has a dose-related toxic effect on the autonomic nervous system, of which the vagus nerve is a part. Abstaining from alcohol can reverse the damage to the vagus nerve.
Infection and Surgical Complications
Vagus nerve damage can occur following upper respiratory viral infections. These infections initially involved symptoms such as cough, nasal congestion and runny noses. Symptoms that persisted in patients identified as having post viral vagal neuropathy, or PVVN, included cough, throat clearing, difficulty speaking and vocal fatigue.
The vagus nerve can sometimes be damaged during surgery to the stomach or small intestine. A procedure called laparoscopic hemifundoplication, used to treat gastric reflux, has been associated with vagus nerve damage.