Gastrointestinal issues are some of the most common symptoms reported by people with Parkinson’s. And while symptoms like constipation have (deservedly) gotten much attention, others, like gastroparesis, have not.
Gastroparesis, sometimes called delayed gastric emptying, impacts your stomach and, in turn, your overall digestion. It can cause nausea, vomiting, abdominal pain, blood sugar issues, malnutrition, and dehydration. For people with Parkinson’s, gastroparesis can also interfere with the absorption of medications, especially carbidopa/levodopa, which can lead to more OFF times, fewer ON times, and a lower quality of life. Parkinson’s can also increase your risk of developing gastroparesis; so, it’s essential that you know the signs of gastroparesis, how to get an accurate diagnosis, and how to manage the condition if it’s one you experience. In this post, we’ll share information that can help you do just that so you can live well today.
What is gastroparesis?
Gastroparesis is a motility disorder in which food doesn’t move properly from your stomach to your intestines in the absence of an obstruction. (In other words, nothing is blocking the movement of food, but it won’t pass from your stomach to your small intestine as it should.)
When functioning optimally, the movement of muscles in your stomach and other organs in your digestive tract keep food moving along. It’s an automatic process you don’t even have to think about. However, if your autonomic system goes off track — for example, if the nerves and muscles in your stomach and intestines aren’t functioning with their normal strength — the food can’t move through your digestive system as it should. Gastroparesis is an example of a disorder that can arise from this kind of autonomic system dysfunction.
What causes gastroparesis?
Damage to your nerves, including the vagus nerve, can cause gastroparesis. Among its many roles, your vagus nerve is part of the autonomic system that impacts digestion. When functioning correctly, it sends signals to your stomach muscles to contract, and these contractions help push food through your digestive system. If the vagus nerve is damaged, it can’t signal your stomach muscles as it should. As a result, they may not contract properly and push food into the small intestine, and food will remain in your stomach for longer than it should.
Because diabetes is a condition that can impair your vagus nerve, gastroparesis is common among people with diabetes. Parkinson’s can also increase your risk, though the exact science behind this is still being researched. (More on that below.) Gastroparesis can also develop after abdominal surgery or following a viral infection. Amyloidosis, deposits of protein fibers in tissues and organs, and scleroderma, a connective tissue disorder, can also cause the disorder.
Some medications, including certain pain relievers, antidepressants, blood pressure drugs, and allergy medications, can slow gastric emptying and cause symptoms like those associated with gastroparesis. These medications can also worsen gastroparesis for those who have it.
What are the symptoms of gastroparesis?
Not everyone who has gastroparesis experiences symptoms. The most common signs, however, include:
- Vomiting (including vomiting undigested food)
- Abdominal bloating
- Abdominal pain
- Feeling full after eating only a few bites (early satiety)
- Acid reflux
- Changes in blood sugar levels
- Poor appetite
- Weight loss
How is gastroparesis diagnosed?
If you experience these symptoms regularly, your provider can conduct tests to determine if they are caused by gastroparesis.
A standard diagnostic procedure is a gastric emptying scintigraphy test or scan, which allows your physician to watch how food moves through your stomach and gastrointestinal tract. In this procedure, you eat a light meal that contains a tiny and safe dose of radiation that will show up on the scan. Following the small meal, you lie under a machine that projects an image of the food in your stomach, and your provider studies the image to see how long it takes for the food to leave your stomach. If more than half the food remains in your stomach after 60 to 90 minutes, your provider may diagnose you with gastroparesis. (Sometimes, more than one of these procedures is needed for your provider to reach a definitive diagnosis.)
Your provider may perform an upper GI endoscopy to see whether any obstructions are causing the delayed gastric emptying. (An obstruction would rule out gastroparesis.) In this procedure, your provider would insert a long, flexible tube (called an endoscope) into your mouth and throat with a small light and video camera on one end. The clinician then slowly pushes the endoscope through your esophagus, stomach, and the first part of your small intestine, all while studying video images sent from the tube to a computer monitor. This scope allows the clinician to see whether an obstruction is present that may be causing your symptoms or to identify and diagnose gastroparesis or other GI disorders.
Other diagnostic tests your provider might perform include a manometry (which measures the strength of your stomach contractions), an electrogastrogram (a procedure in which electrodes are placed on your stomach to record the electrical activity taking place inside it), or a breath test (when you eat food that contains a substance that your body absorbs and that can be detected in your breath, and your provider monitors the amount of this substance over a period of time to see how quickly your stomach is emptying).
How is gastroparesis linked to Parkinson’s?
Although researchers are exploring possible connections between Parkinson’s and gastroparesis, no definitive conclusions about the underlying disease process or prevalence among people with Parkinson’s have been reached. However, researchers believe gastroparesis is underreported and undertreated in the Parkinson’s community.
Some research into the pathophysiology of delayed gastric emptying shows an association with mechanisms caused by neuromuscular dysfunction and suggests that gastroparesis in Parkinson’s is caused by disturbances in either the vagus nerve or in the myenteric plexus, which is part of the enteric nervous system (ENS). Researchers continue to explore the pathophysiology of digestive complications in Parkinson’s, looking especially at the role of alpha-synuclein deposits in the ENS and how these may spread through the vagus nerve, which interacts with the substantia nigra. (The loss of neurons in the substantia nigra leads to dopamine deficiency, the neuropathological hallmark of Parkinson’s.)
Other research suggests that some Parkinson’s medications, including anticholinergic medications and levodopa, may delay gastric emptying, which may help explain why it is more common among people who have been living with Parkinson’s for many years and why it often worsens as Parkinson’s progresses.
What are possible complications of gastroparesis?
As mentioned earlier, gastroparesis can cause complications that impact your quality of life in several ways, especially when you’re living with Parkinson’s. In addition to the frustrating symptoms of nausea and vomiting, it can lead to:
- Malnutrition and dehydration. Frequent vomiting can result in dehydration and malnutrition, which keeps your body from absorbing the nutrients and liquids needed to function correctly. Other symptoms of gastroparesis, such as feeling full after eating just a few bites of food, can prevent you from eating enough to get the energy your body needs.
- Food fermentation. If food stays in your stomach too long, it can ferment, leading to bacterial growth.
- Bezoar development. Food in your stomach can harden into a solid mass called a bezoar. These masses can not only cause nausea and vomiting but can form obstructions that block food from passing into your small intestine.
- Diabetes complications. If you are living with diabetes and gastroparesis, you might have difficulty keeping stable blood sugar levels due to the slowed or erratic movements of food from your stomach to your small intestine.
- Undermanaged Parkinson’s symptoms. Gastroparesis can significantly impact both motor and non-motor Parkinson’s symptoms because it can interfere with the absorption of carbidopa/levodopa. Levodopa, the gold-standard Parkinson’s medication, is absorbed in the small intestine. If the contents of your stomach (including your levodopa pill) are delayed from moving into your small intestine, the effects of your levodopa on your symptoms will also be delayed. Gastroparesis and its impacts on levodopa absorption can also cause less predictable ON/OFF times. Finally, if gastroparesis symptoms cause you to eat and drink less than your body needs, you may lack the energy you need to exercise, stay socially active, and do the many other things that can help you live well with Parkinson’s
What treatment options are available?
Although there is no cure for gastroparesis, there are several options you can explore to help manage the condition.
- Dietary changes. Minor adjustments to your way of eating can lead to significant improvements in gastroparesis symptoms. Eat smaller but more frequent meals, so your stomach has less food to digest at one time. Drink ample water daily and, as we explain below, always take your carbidopa/levodopa with water! Try to limit foods high in fat and those with indigestible fibers, as these take longer to break down in your stomach. Consider working with a registered nutritionist who can help tailor your eating plan to your needs.
- Medication adjustments. Although several medications are commonly prescribed to manage gastroparesis, many interact negatively with Parkinson’s medications, so be sure to talk with your physician about any adjustments. (Commonly prescribed gastroparesis medications include prochlorperazine or chlorpromazine, but both are contraindicated as they can worsen Parkinson’s progression by impacting the central nervous system.) If you don’t already, one crucial medication adjustment you can make is to take your carbidopa/levodopa on an empty stomach with a full glass of water. This helps it move as quickly as possible from your stomach to your small intestine, where it is absorbed.
- Acupuncture. Acupuncture, a complementary therapy used by many people in the Parkinson’s community, is beneficial in managing symptoms of gastroparesis.
- Surgical procedures. One type of surgery for gastroparesis is gastric electrical stimulation. A gastric stimulator is a small device with two leads attached to your stomach and provides mild electric shocks that can help control vomiting. Gastric bypass is another surgical option, and it can be especially beneficial for someone living with gastroparesis, diabetes, and obesity.
- Enteral feeding. Depending on your symptoms and their impacts on your nutrition and overall quality of life, your provider may recommend a feeding tube (or jejunostomy tube) to help you stay hydrated and nourished. Feeding tubes are typically only used temporarily if your symptoms are severe or your blood sugar levels can’t be controlled by any other method. In some severe cases, you may need an IV (parenteral) feeding tube, which allows nutrients to enter your bloodstream directly through a catheter placed into a vein in your chest.
- Gastric venting tube. A gastric venting tube removes the air and drains fluids from your stomach, which can help manage nausea, vomiting, and/or bloating.
- Endoscopic procedures. A newer treatment for gastroparesis, called per oral pyloromyotomy, is a non-surgical procedure that involves inserting an endoscope into your mouth and down to your stomach. Your provider then cuts the pylorus, the valve that empties your stomach, which allows food to move more easily from your stomach to your small intestine. Another treatment currently being investigated involves placing a small tube, or stent, where your stomach connects to your small intestine that can keep this connection open for food to pass through. Your physician can advise you about these procedures and whether they may be good options to treat your symptoms.
Like other gastrointestinal complications, gastroparesis can significantly impact your well-being. As you can see, however, there are several actions you can take to identify and manage the condition. Talk to your care team about any symptoms you experience, and explore treatment options that may work for you so you can live well with Parkinson’s today.
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