Periodic Limb Movement Disorder

[s54]

I've been suffering from very severe day-time sleepiness for years and doctors have not been able to figure out why. I currently take stimulants (adderall and Vyvanse) because that is the only thing that can keep me awake. If I do not take those meds, I sleep for about 15-20 hours per day. I had a polysomnogram and multiple sleep latency study one year ago (which didn't provide any definitive answers about the severe sleepiness) and I recently began looking over the results of the study to see if anything was over-looked the first time around. I have a few general questions that I hope you can answer for me.
What would be considered a high 'spontaneous arousal index', and what would be considered a low or mild 'spontaneous arousal index'? Also, what would be considered high and low for the 'leg movement arousal index'?
Is it normal for everyone to have arousals during their sleep, or do people with no sleep disorders have generally no arousals at all?
The other thing I wanted to know is what the diagnostic criteria is for Periodic Limb Movement Disorder. Is there a certain number of periodic limb movements that has to happen during sleep? Does the PLM index have to be higher than a certain number?

[Steven Y Park, MD]

An arousal index of up to 15 or lower is considered "normal" but it may be higher as you get older. What's more important is the number of times an arousal occurred from a respiratory event. These are called RERAs (respiratory event related arousal).

For PLMD, an index of 5 or less per hour is considered normal. Sometimes they'll report an arousal index as well. PLMs occur more often in non-REM sleep.

Both of these numbers are just approximations. We don't really know what "normal" is.

There's a concept of deep sleep instability where subcortical arousals occur, but don't show up on the surface EEGs. This can also occur due to micro-obstructions and arousals.

It sounds like you may ultimately be given a diagnosis of "idiopathic hypersomnia" if they can't find anything to explain your chronic fatigue.

If you prefer not to sleep on your back, then it sounds like you may still have an anatomic, sleep-breathing disorder called upper airway resistance syndrome (UARS). Take a look at my article on UARS.

[KatEyes]

I used to have occasional episodes of waking up coughing, choking, trying to get my breath. Turned out to be obstructive sleep apnea. Also have PLMD.

Sleepdeprived02 - I don't know how low your oxygen went, but are you aware of the risks involved?  If that was recorded with little sleep, it might be even worse in a regular night. By the way, I've been wearing one of those silly masks you mentioned for 3 years. Too bad my brain was already peppered with microvascular ischemic lesions (from the low oxygen) and my thinking and memory could not fully recover. At least now they are no longer increasing in number and size. May not be the shining star I once was, but I'm much better than Ibefore CPAP. Do some reading about what sleep apnea does to a person. My CPAP is now my security blanket. Takes some getting used to, but it really is a lifesaver.

[sleepdeprived02]

OMG!!!  I have the 'choking in my sleep' thing too!!!  I have had this episode about 6 times in my entire life and I am now in my mid 40's.  It seems like the last few times I had episodes have been here recently.

Mine  TOO is like the "swallowing something and it getting in my windpipe" kind of choking as well!! It wakes me up sometimes, and I'm gasping for breath followed by profuse coughing.  I thought it was asthma all this time!

And, I ALSO am extremely fatigued, especially in the mornings!!!  I had a sleep study and they said it was for the most part inconclusive, cause I didnt sleep much that night.  But for the time I DID sleep, they said I had LOW oxygen levels and "sleep arousals."  

They suggested I come back and be tested with one of those ridiculous looking Ninja Turtle face masks.  Which I havent yet been back.  I just aint gonna wear one of those silly things!  

[s54]

Thank you for responding to my questions.

From what I've read about PLMD, it seems to be more common in older people, but I am only 20 years old right now. Even when I was really young, my parents said that I used to kick a lot in my sleep. Whenever I wake up, my sheets are almost always kicked off the bed. I've been having chronic fatigue and sleepiness issues since I was 16. I feel like I've missed out on so much in my life because I can't keep myself awake. I have to take multiple naps during the day (which are usually more than 2 hours long).

My RERA index was only 0.2 per hour. The hypopnea arousal index was 0.2 per hour and I had 0 apnea arousals. All of my respiratory arousals occured in supine position.
My PLM was 5.9 per hour, and I was diagnosed with mild PLMD because of that.
The spontaneous arousal index was 26.3 per hour. What are spontaneous arousals? Are they arousals that are from an unknown cause?

When I first went to the sleep clinic, they thought I had narcolepsy because I get waves of sleepiness that hit me so suddenly, and when I fall asleep for a few minutes, I have dreams, which means I go right into REM sleep. But during the Multiple Sleep Latency Test, I didn't even fall asleep during the scheduled naps, so they ruled out narcolepsy just because of that.

Just recently, I woke up feeling like I was choking. I was sleeping on my back (which I normally don't do). It wasn't the type of "choking" where I felt like I wasn't getting enough air, it was the type of choking where I felt like I was drinking something and it "went down the wrong tube" and I proceeded to have a coughing fit trying to breathe again. For two days after that, my lungs (or maybe it was my trachea?) were really sore.
That has happened only 2 times before.
Could that be related to the breathing disorder you mentioned? UARS? Where could I find your article about it?

Thank you again for responding to my questions. If you have any more information or suggestions for me, I would really appreciate it. I have seen multiple doctors over the years and they can't figure out why I'm so tired all the time and I just don't know what to do anymore.