Giselle Carnaby, PhD, professor at The University of Texas Health Science Center at San Antonio (UT Health San Antonio), talks about relearning how to swallow after being diagnosed with dysphagia.
Interview conducted by Ivanhoe Broadcast News in 2023.
Once the condition starts, what’s the progression of that in someone who does not have a comorbid disease?
Carnaby: You can get swallowing issues just from getting old. As we age, one of the things that occurs is our muscles get weaker and just like your muscles of arms and legs, the swallowing muscles are made of skeletal muscle. In fact, to swallow, you use 26 to 30 muscles and nine cranial nerves, so it’s one of the most neurocomplex movements that the body can do. Swallowing also has to coordinate with breathing. When you swallow, you don’t breathe. When you breathe, you don’t swallow. Those two reciprocal systems have to be coordinated in a very finely timed agenda, if that makes sense.
Is that the first symptom that people get? Because the breathing and swallowing starts to go first and they’ll inhale food?
Carnaby: I think one of the early symptoms that you can get is needing to clear your throat a lot. It might be a voice change, needing to clear your throat, coughing on particular foods or fluids, or just feeling uncomfortable with them and starting to avoid them. We know that a good 40 percent of the general elderly population will experience some of these difficulties. For example, difficulties taking the medication. Having trouble getting pills down. Pills are an abnormal swallowing behavior. It’s something we have to be taught, it’s not something that is normal to the body system, so your body recognizes a pill as foreign. We teach our children when they’re young to swallow pills with water. In fact, that’s probably one of the worst things you can do and actually, you’re better off putting a pill in some more pudding-like material. The body then will recognize it as food and not as foreign substance, so that’s an example
Is that seeing or feeling the pill because it’s a foreign shape?
Carnaby: Our body identified a pill as a foreign body, not just because of the shape but through the sensation of consistency and its movement through the system.
How does this progress? It can start with clearing your throat, but where does it go after that?
Carnaby: It really just depends on what type of swallowing problem the person is suffering and how the person responds and what they’re doing, in particular, how they’re eating or drinking. People can start to avoid certain food / fluid materials, not going out as much, not wanting to sound weird when eating in front of people (due to coughing or clearing) and can start underutilizing the muscles of the swallowing system. Those people will start to see muscular weakness occur very slowly over time. As the muscular weakness in the upper end (pharynx) of the swallow starts, they start to squeeze less with their swallowing muscles, push less, move less, and it becomes cyclical, and you get what’s called a disuse atrophy. Or another term for it in the elderly is dynapenia or sarcopenia.
The bottom part relies on the stomach, or the biome does this?
Carnaby: Yes. There’s also a concept called the oral microbiome as well. We know that in patients that don’t swallow as frequently, either not spontaneously or don’t swallow as frequently because of disease or weakness, will actually get a change in the microenvironment of the oral cavity and of the throat. These changes can go on to affect health and even relate to the microenvironment of the gut. There are researchers actively investigating these relationships and how they impact health.
The question before about spreading throughout the body, now we know that this starts with muscle weakness and then what happens as that progresses, if anything?
Carnaby: You start to lose weight unintentionally. Generally, unintentional weight loss is one of the early symptoms. It can be an early symptom of disease as well. Then as you lose weight, it can become cyclic, the muscles get weaker, you lose more weight, you eat less, you get less from your food because you’re taking smaller amounts, you can become fatigued easier. For example, someone who only eats a little “tea and toast.” You eat less, you become less mobile, you become more fragile, you’re then more susceptible to diseases because you don’t have a healthy immune system. An immuno-change can occur as a result of this whole cascade that just began with having some weakness in your swallow.
The tea and toast make sense, you said, put the pills in pudding. What are the textures of food that they might normally gravitate to?
Carnaby: Well, it’s really interesting. One of the hardest things to swallow because it moves so rapidly is thin fluid. Any kind of water, drinks, thin fluids like those. Yet quite often when someone’s having a problem with their swallowing, they’ll try to flush food (or pills) down with fluid. I know it sounds counterintuitive, but sometimes when you do that, you’ll actually push material down into your airway, which you don’t want to do. That action can create pneumonia, or a chest infection. We call that action, “aspiration” and you can get aspiration pneumonia from that. Aspiration can result in a lung infection and more serious side effects including death. One of the things that we focus on a lot in our treatment program is building or loading the swallow muscular system to build it rather than unloading the system. So, we use foods and fluids like barbells in the gym to help load the weight on the muscle system and teach people ways to swallow things like pills, or teach ways to deal with any difficulty they are having moving food or fluid (termed “a bolus”) through the system. In some cases, we will use a bolus to move a bolus, so using different food materials to help move other food materials through the system rather than flushing with liquids like water.
You’ve done a nice little analogy a minute ago. It’s lifting bolus to make that stronger. What can people do themselves to make that muscle work better?
Carnaby: Well, it’s really something you need to consult with a swallowing specialist about because you can also do the wrong thing or actions in swallowing, so you have to bear that in mind. But one of the things we’ve been working on in this program is really trying to fine tune, if you like, a ladder of actions/ movements to do when you swallow or what we call physiological strengthening along with motor control so that we get the resistive load and the timing right in the swallowing tasks. Remember, I talked about the timing. It’s important to get the timing right, as well as use the right level and diversity of “barbells” so that the swallow mechanism can start to build strength. It’s a complex combination of that offered at different points in the program. But if we apply the correct design of tasks, it works well and we’ve had a lot of success in being able to build those muscles to improve swallowing function and reduce the risk of negative events.
How does Parkinson’s disease interact with that?
Carnaby: This participant is part of a study that we’re looking at, involving what we call “swallow fitness,” and it’s a preemptive or preventative design. What we’re trying to do is get in really early and begin working on the swallow muscles and teaching people some of the techniques before there’s overt decline in the system. This lady doesn’t have any major or overt difficulty with swallowing, but she’s starting to do some things that could lead her down that path eventually. So, we change the organization of the swallow now, we change the timing, and we start building strength in the muscles so that as she moves her system along in a more normal manner, in this way we believe we might be able to plateau the decline for longer.
We talked about cancer because that’s pretty obvious, that’s going to impact the swallow if it’s cancer of esophagus or throat. What other diseases go along with them?
Carnaby: There’s a whole slew of diseases that can impact swallowing. Stroke is one of the biggest ones. A lot of swallow therapists will be working with patients who have strokes because when you have a stroke, you often get weakness down one side, and likewise you can get weakness in the throat muscles and in the voice box. Beyond that, there is a wide range of different neurological or other diseases that can affect it. For example, Alzheimer’s disease, ALS, multiple sclerosis, head trauma, or even spinal injury sometimes. You can also see patients who have cervical spine surgery, who post-surgery will have some issues with their swallowing.
What would you advise people that are watching the story that suspect they have swallowing problems? What’s next?
Carnaby: The first thing to do is to reach out. Reaching out to your general physician is probably the first place most people can start. Sometimes your general physician may not be as well versed in who does and who doesn’t treat these issues. In that case, a speech language pathologist may be an option. Speech language pathologists who work with adults often manage swallowing problems quite a lot, so they’re a really good resource. The other people might include ear, nose and throat physicians and gastroenterologists.
Can we talk more about the program you’re doing?
Carnaby: Parkinson’s disease is the second-fastest growing neurodegenerative disease in the US. We don’t really know why that’s the case. In terms of swallowing problems, most Parkinson’s patients will go on to get swallowing problems during the course of their disease. As the disease progresses, a lot of patients with Parkinson’s will have trouble clearing their saliva and can have trouble eating a regular meal. Many will actually go on to receive alternate feeding in the later stages. At the moment, we have very few treatments that are effective in combating that in terms of swallowing and swallowing treatment options. There’s a bunch of researchers all around the US who are looking for different options that might either reverse it or stave it off. This particular program is looking to stave it off, so it is preventative. So let me talk about swallowing a little. Your esophagus (or food pipe) is normally closed. It only opens when you swallow. When it does open, it can expand to let the food through. If you swallow something large, it is very stretchy; it can expand to meet that need. The opening to the esophagus is also a muscle (the cricopharyngeus), and it is kidney shaped. Alternatively, your windpipe (airway) is always open, but it has an area on top of it called the larynx where you find your true vocal folds. These allow us to make voice, and they offer a layer of protection to the lungs when we swallow. When you’re ready to swallow, the larynx (or voice box) raises up and forward, and the vocal cords close offering protection to your airway. At the same time your tongue moves back, to help push the food down the upper throat, and these actions help expand the opening to the esophagus to allow the food to pass through efficiently. The muscle at the opening of the esophagus is not just passively controlled; it’s actually actively controlled by nerves all coordinating in an action that takes approximately eight-hundredths of a second to complete! So… all of those things happen in a sequence in the right amount of time. Sometimes when patients have a swallowing problem, all of the food won’t go through this sequence in a timely manner and the cricopharyngeus muscle or opening to the esophagus will shut closed too soon and there’ll be food hanging about near the top of the voice box. Hence folks may feel the need to clear their throat or cough when this occurs. It’s complicated. It’s hard to describe because there’s so many actions happening so quickly, as I said, 26 to 30 muscles and nine cranial nerves are all involved in a tightly coordinated sequence to make a smooth, safe swallow.
But not everyone gets a swallowing problem?
Carnaby: Correct. Some of us go through life never ever having to think about this. In fact, I would say a large majority do. As we get older, however, the likelihood of a swallowing problem goes up.
In the world of Parkinson’s patients, what is the age where you start to see this in Parkinson’s, like an early onset or later onset?
Carnaby: It really depends on the type of Parkinson’s. Now, Parkinson’s is a big word that covers a lot of subtypes. It really depends on the initial presentation of the patient and the specific type. Some people will have late onset Parkinson’s, some will have early onset Parkinson’s. The earlier the onset group tends to have some of these issues more quickly.
In this case, what is the situation?
Carnaby: These are late onset Parkinson’s patients.
That makes it trickier to fix, so to speak?
Carnaby: No, not really. It’s actually tricky to fix when the problem is more severe. Early onset can sometimes be trickier because the disease can be more aggressive, in general.
Is it trickier? It’s got longer to do something wrong.
Carnaby: If we treat someone who has had the problem for longer, they can have learnt movements that are abnormal to compensate for the swallow issues and this can make it “trickier” to modify but improvements can still be made.
END OF INTERVIEW
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