One of the cranial nerves, the vagus nerve controls many parts of the body, like digestion and the larynx. Learn about the different types of vagus nerve disorders and problems, and what happens when there is vagus nerve damage.
The tenth cranial nerve, the vagus nerve “controls the movement of food from the stomach through the digestive tract," as well as the larynx and other parts of the face, according to the National Digestive Diseases Information Clearinghouse (NDDIC). The Stritch School of Medicine adds that the vagus nerve is the longest cranial nerve, which travels “from the brain stem though the organs in the neck, thorax and abdomen." The vagus nerve also has two sensory ganglia: the superior vagal ganglia and the inferior vagal ganglia. When damage occurs to the vagus nerve, the patient can have problems with swallowing, speaking, and controlling her bowels.
One of the vagus nerve disorders is gastroparesis, in which the patient's stomach takes longer than normal to empty. The muscles in the stomach and intestines malfunction, causing food to move slowly or not at all through the digestive tract. The NDDIC states that symptoms of gastroparesis include heartburn, spasm in the stomach area, pain in the upper abdomen, gastroesophageal reflex, lack of appetite, vomiting undigested food, abdominal bloating, weight loss, early fullness and abnormal blood glucose levels.
Locked-in syndrome occurs when there is paralysis to the vagus nerve or other lower cranial nerves. The Merck Manual Professional Edition states that the patient has problems with movement, specifically in the lower face and limbs. The patient cannot move her eyes laterally, but vertical movement is not affected. The vagus nerve damage or other cranial nerve damage prevents the patient from chewing, speaking, swallowing, or breathing on her own. However, cognitive functions remain intact.
When a patient has aphonia, she can have a partial or complete vocal loss from damage to the larynx, one of the structures the vagus nerve controls. The Beth Israel Deaconess Medical Center states that the patient has physical or psychological paralysis of the vocal cords and spasms of the vocal cords. Other symptoms of aphonia include problems swallowing, throat pain, hoarseness and being unable to speak.
Another one of the vagus nerve disorders, dysphagia affects the patient's ability to swallow. Through vagus nerve damage, the muscles cannot start the swallowing reflex. The patient can also have pain when swallowing. The National Institute on Deafness and Other Communication Disorders (NIDCD) notes that a patient with dysphagia may not be able to eat enough to maintain a healthy weight, and can develop aspiration pneumonia, which is an inflammation of the lungs from inhaled bacteria.