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?

[s54]

Hi, thank you so much for your response. Well my PLM index was 5.9, so my doctor diagnosed me with mild PLMD. From what I've read about PLMD, it seems more common in older people. I'm only 20 right now, and even when I was really young, my parents said that I kicked a lot in my sleep. My sheets are always kicked off my bed when I wake up, so I'm actually suprised that the PLM index was not higher.

I had a spontaneous arousal index of 26.3. I had a respiratory disturbance index of 1.4. There have been 2 or 3 times in my life where I have woken up suddenly because I felt like I was choking, like I was drinking something that "went down the wrong tube" and I proceeded to have a coughing fit. The few times this has happened, it was when I was sleeping on my back, and during my sleep study, all of the respiratory arousals occured while I was on my back as well.

Thank you for mentioning the problem of PLMD and OSA possibly obscuring each other. That is something that I will have to keep in mind.

I'm actually not sure if all medical issues have been ruled out. Doctors haven't been able to help me with that issue either. I've had MRIs, EEGs, and more blood tests than I can even remember. The results have been abnormal for many of the tests, but the doctors can't give me any answers. I'm only 20 and have been trying to get answers for the last 4 years and I don't know what to do anymore.

Thank you so much for your help, I really appreciate it!!

[KatEyes]

Hopefully someone with more technical knowledge on diagnostic criteria will come along, but I think anything over an average of 5 PLM's per hour is considered mild and over 20 severe. What matters symptomatically more than the count is how many arousals they cause per hour. How many did your study show?

An open discussion with your doctor will let them know you feel there are yet undiagnosed issues and you need them to push further diagnostically rather than treat the symptoms. I would like to suggest you do not accept being put on meds "just in case" the limb movements are the problem. The dopamine meds can be necessary for some, but the side effects merit careful consideration before going that route, and even then are best kept at the lowest possible effective dose, which requires periods of time at each level, and they should never be stopped abruptly. I made that mistake and paid dearly.

Another thing to be aware of is that if you were to happen to have PLMD, it can obscure obstructive sleep apnea during a study. (That can work vice versa too.) It was my 3rd study over several years before my OSA was picked up because during the studies the arousals from the limb movements were so frequent, I didn't sleep long or deep enough for apnea events to occur. It was only after getting the movements somewhat under control yet still being too sleepyheaded that another study showed moderate OSA, and later severe OSA.

Also consider the meds you may have been on at the time of the study, as some can disrupt sleep architecture. So can thyroid issues. I would hope all such medical causes have already been ruled out. Oh, and having a low ferritin level (storage iron) is sometimes associated with limb movments.

Sorry I have no real answers for you, just some things to be aware of as you move forward and insist on some answers.