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Understanding and Treating Persistent Motion Sickness

Patients with persistent motion sickness represent a subset of patients commonly associated with dizziness and imbalance. While many patients with motion sickness have it in relationship with a condition like migraine, vestibular migraine, or BPPV, there are many patients who just struggle with it on it’s own without a complaint of dizziness.

Motion sickness isn’t an illness where you feel a false sense of motion like vertigo. Motion sickness is a problem that different types of motion or perception of motion will cause you to feel nauseated and sick. The difference between these concepts makes a big difference in how you will need to be treated.

Historically it has been a challenge to diagnose and treat these patients because traditional tests of dizziness and imbalance are going to be negative. Without a strong understanding of motion sickness, it becomes difficult to provide treatments or therapies that have enduring effectiveness, and all you are left with are anti-nausea medications.

Patients with motion sickness can feel ill along a wide variety and intensities of motion. The most common form of motion sickness occurs in people who have difficulty riding in boats or cars. A large portion of the population has experienced motion sickness when riding in a rocking boat or attempting to read in a car.

In it’s more severe forms, patients can feel sick with small amounts of head movement, or when exposed to a busy visual background. The feeling of sickness can cause progressive nausea that can eventually lead to vomiting.

What Drive Motion Sickness

As you can tell, being so sensitive to motion that small head movements or visual stimuli can induce vomiting can feel quite limiting and debilitating for a patient. I personally hate the feeling of nausea more than I hate pain, and it’s common for these patients to avoid social events and gatherings so they can feel safe in the comfort of home.

What happens in the body to generate this terrible feeling?

Most of our understanding of motion sickness stems from our knowledge of nausea and vomiting. Nausea can be driven directly by sensation from the vestibular organ or the gut. Neurological signals from the inner ear and the gut travel to the lower brainstem called the medulla where there are specific neurons dedicated to vomiting.

Diagram showing the inputs to the medulla that activate vomiting.

When these neurons are activated, they activate pathways that increase the production of saliva, take deeper breaths, and initiate contractions of the esophagus and diaphragm. That feeling is also triggering the sympathetic nervous system causing blood flow changes that can lead your hands to get cold and you start to sweat.

Remember that this is a pathway for vomiting. Many patients aren’t going to go through this entire process, but the brain regions associated with this process probably contribute to the levels of nausea people have with motion sensitivity.

Nausea and motion sickness can be driven by different sensory stimuli, but all inputs are likely driving sickness through the medulla.


Based on this knowledge, we have sense that patients with persistent motion sickness and nausea may have problems in these regions which serve as targets for treatment or rehabilitation:

  • Vestibular dysfunction – especially the otolithic organs
  • Gut dysregulation
  • Brain driven sensory sensitivity

Sensory Mismatch and Motion Sickness

The exact mechanisms for how motion sickness triggers the above neurological pathways is currently unknown. The most common theory that I’ve found to have practical treatment implications is called the Sensory Mismatch or Sensory Conflict theory.

The theory suggests that you have 3 systems in your body that help you detect if you are in motion. These are the:

  • Visual System
  • Vestibular System
  • Proprioceptive System

Under most circumstances, your brain takes information from these senses and compares it to the brain’s expectation for motion.

Let’s say that you’re going for a run. Your eyes detect movement of the background while you’re running, your muscles detect motion of your joints, your ears detect the bobbing motion of your head, and your brain knows what it is supposed to feel like to go for a run. When these senses all agree and your brain recognizes how this is supposed to feel , then your brain doesn’t have to resolve any conflict and motion feels perfectly fine.

In patients with motion sickness, the information coming from these senses might be weighted different by the brain. What does that mean? It means that your brain may be more sensitive and prioritize the information that comes from your eyes more than the information that comes from your vestibular system or vice versa.

Now your brain has a problem. Your visual system might be saying that you’re moving a lot while your vestibular and proprioceptive systems aren’t perceiving any motion (Kind of like driving in a car right?). Your senses are conflicting, so your brain has to make the final call.

If your brain doesn’t have good information for how this is supposed to feel, then the sensory mismatch isn’t resolved and the conflict leads to you activating the pathways that drive nausea. The most common expression of this is called vestibular-visual mismatch, and is likely the driving force in nausea and motion sickness in vestibular migraine.

When 2 of your sensory systems are in conflict, it’s up to the brain to reconcile the difference. If it fails, you get dizzy. If it succeeds, you are able to adapt.

How does this help us treat patients with motion sickness?

By understanding the influence that these sensory systems play in motion sickness, we can use a careful examination of these systems to determine where and how to provide different therapies.

In my office, we test eye movements, ocular misalignment, balance, and optokinetic responses to assess the way the brain responds to different sensory conditions.

Once we have an idea of how a patient’s senses might be betraying them, then we can move into a treatment strategy to fix it. First we would try to re-weight their sensory system, then we slowly expose the patient to the offending stimuli.

What does this look like as an example?

The majority of patients we have seen with motion sickness have a high level of visual dependency meaning that they rely too strongly on visual information to maintain balance.

If you have high visual dependency then your brain places too much emphasis on detecting visual motion. If this is the case, you can be watching a movie with a busy action sequence and your brain is going to think that you are moving despite the fact that your vestibular and proprioceptive systems say that you are sitting still.

So if we know that the patient is way too visually dependent, then we would have the patients perform exercises to increase their ability to rely on vestibular and proprioceptive senses. That means we might do a lot of their exercises or therapies with their eyes closed initially and gradually progress them to doing exercises with eyes open. As they can tolerate these motions better, then we might slowly start to expose them to the busy visual environments that would normally induce dizziness.

It can be complicated and nerve racking to confront motion sickness because patients with this problem have spent so much time designing their life to avoid these nauseating activities.

But at the end of the day if we are really going to give people their lives back, then we need to have the courage to confront the things that have kept us in the prison of our perceived broken bodies.

Dizziness: Misdiagnosed and Mistreated

Dizziness: Misdiagnosed and Mistreated

 

Dizziness is Hard to Diagnose

When people have dizziness as a complaint, it can be one of the most commonly misdiagnosed and mistreated conditions around. The challenge is that dizziness is a symptom that can be associated with lots of different conditions. Here’s a short list of conditions associated with dizziness:

Primary dizziness: Dizziness as a primary disease entity

  • Positional vertigo (BPPV)
  • Meniere’s disease

Secondary dizziness: Dizziness as a result of another problem

  • Stroke
  • Migraine
  • Concussion
  • Tumors
  • Medications

On top of that, dizziness means something different to different people. Does your dizziness feel like spinning? Rocking? Feeling off balance? Light headedness? Sometimes the feeling of dizziness can be hard to describe because you just feel disoriented and lost in space.

All of these factors are important to help a doctor get the right diagnosis.

It means that a doctor has to take a good health history, perform the right bedside tests, and order the appropriate diagnostic testing to find out the cause of your dizziness. Without knowing what’s causing this feeling, then administering the right treatment can be a lucky guess at best, or make you more dizzy at worst.

It’s no wonder that people who have chronic vertigo and other balance issues often see their primary care doctor, neurologist, ENT, physical therapist, acupuncturist, and more looking for answers on how to get their world to stop moving.

Dizziness is Even Harder to Treat

Another challenge with dizziness patients is that medications don’t really do a good job of making the world stop moving. Many patients with chronic dizziness are placed on anti-depressants, anti-anxiety meds, and drugs for nausea. The problem with that is that the patient may not be as nauseated, but their brains are not responding to their environment appropriately.

Dizziness after spinning on a bat is easy to explain, but what if the world is spinning when you're standing still?

Dizziness after spinning on a bat is easy to explain, but what if the world is spinning when you’re standing still?

 Dizziness can also be treated by positional maneuvers like the Epley maneuver and head shaking exercises like gaze stability. Both are extremely effective when they are used appropriately, but can be useless if it’s performed on the wrong patient with the wrong diagnosis.

That’s why it’s so important to know what’s really going on with a patient. Many clinics will take any person with dizziness and just do some of these maneuvers even though the maneuvers may not be appropriate for the patient’s specific condition. In order to help a patient recover, we have to examine them closely to make sure that we have the right information to begin care.

Case Study: 

Recently we had a patient come in with dizziness and had been seeing an ENT for treatment. She was having problems feeling off balance for a while and it was made with head turning sometimes. She wasn’t experiencing a spinning type sensation, but just a sense of feeling out of sorts.

The doctor diagnosed her with benign paroxysmal positional vertigo or BPPV. It’s arguably the most common form of vertigo and is usually easily treated with a positional maneuver called the Epley maneuver. The doctor performed Epley and gave her some alternative maneuvers that she could do at home whenever she felt dizzy.

The problem was that the maneuver wasn’t changing anything. She tried doing the maneuvers for several weeks with no change. When she followed up with the doctor, the doctor told her there wasn’t anything else he could do and that some cases don’t respond.

Fortunately the patient found her way to our office through a referral from one of our patients who got really great results with balance problems

BPPV usually causes a spinning sensation that is really short lived. In many cases, doctors can diagnose BPPV with a test called the Dix-Halpike maneuver. You can look at this test below. If you have BPPV your eyes will start moving making a fast oscillating movement called nystagmus.

It’s this nystagmus when the inner ear moves the eyes that creates a feeling of spinning.

When this patient came in, we did a thorough history and found out that her “vertigo” didn’t have any spinning at all. She just felt disoriented and off balance. We performed the Dix-Halpike test and she had her eyes stayed solid.

So now we knew that she probably didn’t have BPPV, and that’s why the Epley maneuver didn’t work that well for her. It was time to figure out what other anatomy might be causing her problem.

We did a test called the smooth pursuit neck torsion test. It’s a test developed from patients who had dizziness after whiplash. It’s an indicator that the neck might be causing the eyes to move abnormally. You can see that test here below. In patients with neck problems, the eyes will start jumping instead of staying smooth.

Now that we knew the neck could be a problem, we started addressing the neck using the NUCCA procedure for structural correction.

Within 2 visits, the patient’s dizziness was about 80% gone. We have more work to do to help the neck heal, but with some time I think this patient will get back to normal.

Find the Cause, Deliver the Solution

So this isn’t an indictment on another professional. Lots of ENTs keep their focus on infections of the ear, nose, and throat. An ENT with a neurology background would probably have found the same thing and recommended physical therapy or chiropractic care.

The lesson here is that dizziness is complicated, and one treatment won’t solve all forms of dizziness. For any condition, we have to spend time with our patient, listen to their history, examine them thoroughly, and we can find a game plan to help them get back to normal.

Talk to Dr. Chung