Yet One More Question From Dr. Park

[Steven Y Park, MD]

How many of you have any or all of the following:

Chronic cough,
Hoarseness
post-nasal drip,
mucous
throat clearing
lump sensation
tightening
throat pain
difficulty swallowing
or burning?

[Quixotic1]

Someone a while ago told us about a study showing that a huge number of patients with MS meet the definition of sleep apnea and that 50% of them were obstructive.  So both types are seen in MS.  I'll see if I can rustle up that study.

With regard to what you would expect, I suggest that, while there would be plenty of reason to have central apnea, the muscular effects of MS can lead to an obstructive pattern in several ways.  We have upper airway and chest spasms which are often tonic and sustained.  We also have loss of motor function seen as weakness or flaccidity.  Both of these processes are seen in the breathing and swallowing symptoms we report.

On a more personal note, I have an extraordinarily small jaw due to congenital deficiency of 13 permanent teeth.  They have to use a pediatric tray to get impressions.  My TMJ lost all it's cartilage by the time I was mid-30's, and is permanently subluxed.  My jaw excursion is about 25mm.  I wonder what kind of sleep I would have if I slept lying down instead of propped up so far. (I'm the one sleeping 12-14 hours a day in about 5 hitches.)

Again, I thank you for a fascinating new look at one of our worst problems - fatigue and cognitive difficulty.

Quix

[Steven Y Park, MD]

Before I answer your questions and spill the beans, I think it's safe to say the most of the people who gave answers on this post has a majority of the symptoms that I asked about. These symptoms are the classic findings in laryngopharyngeal reflux disease. This is when acid comes up into the pharynx, causing inflammation and irritation, leading to some or all of the above symptoms. It's thought to be due to a dysfunction of the upper esophageal sphincter, as opposed to a dysfunction of the lower esophageal sphincter that's seen in GERD.

The problem is that you only need microscopic amounts of stomach juices in your throat to cause these symptoms. For the double-probe pH studies, there's a certain number of reflux episodes at a certain pH to meet the criteria for LPRD. Using esophageal manometry, UARS patients (see next paragraph) have been shown to have significant negative pressure in the chest during an episode. You also have to realize that it's not only acid coming up, but sometimes bile, digestive enzymes and even bacteria. Studies have shown finding H. pylori and pepsin in middle ear, sinus and lung washings.

Upper airway resistance syndrome (UARS) is a variation/precursor to obstructive sleep apnea (OSA), where you don't officially meet the criteria for obstructive sleep apnea. You need at least 5 apneas or hypopneas every hour on average to say you have sleep apnea. Each episode has to last at least 10 seconds. But it you stop breathing 25 times every hour and wake up after 1-9 seconds, then your total score is 0.

UARS patients have a typical upper airway anatomy, where due to smaller jaw structures (with dental crowding) the tongue naturally sits higher and further back. Normally when on their backs, the tongue falls back somewhat due to gravity. But in UARS patients, there isn't too much space, so there's very little space behind the tongue. When in deep sleep, due to muscle relaxation, you stop breathing and wake up quickly, then turn over. Most people with UARS learn to sleep only on their sides or stomachs.

Dr. Guilleminault, a pioneer in sleep medicine that first described UARS, stated that OSA patients have underactive nervous systems, whereas UARS patients have a normal or hyperactive nervous systems (that's why they wake up too quickly into light sleep). As I've mentioned before, chronic long-term deep sleep deprivation can lead to a low-grade physiologic stress response. This can heighten not only your nervous system, but your immune system as well. Robert Sapolsky, in his very interesting book, Why Zebras Don't get Ulcers, makes the suggestion that repeated low-grade stresses ratchet up your immune system so that it stays hyperactivated for too long. This is in contrast to one big stress that ends, and the initially heightened immune system then drops to below normal, and then back to baseline. This is why many people get sick AFTER a very stressful event.


To be honest, before I started to participate on the MS forum, my understanding of MS was identical to yours. When Laura (LGK54) posted a question about sleep and MS, I was fascinated by what she had to say about the high incidence of sleep problems and the fact that a number of the members were on CPAP for sleep apnea. As I started reading through the MS forum, many of the symptoms sounded remarkably like what I seen in my patients with upper airway resistance syndrome. Symptoms include chronic fatigue, unrefreshing sleep, not being able to sleep on their backs, various cysts and nodules throughout the body, cold hands and feet, various GI issues, GERD, LPRD, depression or anxiety, hypothyroidism, low blood pressure when younger (and later on sometimes turning into high blood pressure), headaches, migraines, sinus problems, TMJ, lightheadedness, and one parent that snores heavily.

Many patients with UARS progress later on in life to obstructive sleep apnea, especially if they gain weight. Many people with UARS have a parent that has OSA.

Frankly, I was very surprised to see that the vast majority of respondents had each of the three other questions that I asked (sleep position, cold extremities, parental snoring, and now laryngopharyngeal reflux disease). Maybe it's more due to selection—only people with these conditions are replying.

Here are my conclusions about MS and UARS:

1. The similarities in symptoms are total coincidence and to be taken with a grain of salt, or
2. There is a link or a connection, but there may be a common point of branching higher up in the "cascade," or
3. both conditions have symptoms that overlap, although they are from two different origins, or
4. one may directly or indirectly cause or aggravate the other.

I think it's a toss up amongst all four options. One thing I'm much more appreciative of now is how prevalent sleep issues are in patients with MS (thanks, Laura). With the incidence of OSA to be up to 24% in men and 11% in women, and much higher if you include UARS, it may be worthwhile to at least screen for it anyway, even if you don't have MS. So what I'm seeing may be the natural incidence of sleep-breathing issues in the normal population (who just also happen to have MS).

I think the next step for me is to examine the upper airway anatomy to see if MS patients have the typical appearance that I see in UARS: the voice box and the tongue collapses severely when lying on the back, restricting the upper airway breathing passageways.

I'm in no way suggesting that MS is caused by a sleep-breathing disorder. I'm just very fascinated by the similarities between the two, and so I think it's worthwhile investigating it a little further.

Quixotic1,

You have some great questions. I have some very speculative thoughts on this, but I don't think this is good time or place to address them, unless I have more data or evidence to back it up. One thing about MS and breathing is that you would think breathing problems would be more of a central component, since the lesions are in the brain. I'm not sure if people with both MS and OSA have more obstructive or central.

[Karen99]

Occasional hoarseness only.  

[HVAC]

post-nasal drip,
mucous
throat clearing
lump sensation
tightening
throat pain
difficulty swallowing
or burning?

[doublevision1]

* occasional hoarseness

* occasional difficulty swallowing: food is slower going down and sometimes feels stuck; also, I can acutely feel food and liquid as it moves down my throat, like how ice water feels going down on a hot day.  Don't know if that makes any sense!

[Lulu54]

DJ, thanks for sharing that info with everyone here.  I often wonder how often this tendency toward spasm develops into something much more serious, or life-threatening in your case.  

Lulu