Sleep Disorders

Absence of Slow Wave Sleep and Xyrem

02/07/2008

Question:

This post is quite similar to a recent post in November but with some notable differences. I`m a 39 year old male recently diagnosed with mild sleep apnea. Bear with me for a brief history.
Three years ago I was a picture of health, 195 lbs, 9% body fat, strength trained 4 times a week, ran 30+ miles a week, life was great. I slept very well, 7 hours per night on average, waking without an alarm. After experiencing a slight sensation of dizziness I went to the doc. Additional symptoms set in and 5 months later I was diagnosed with Hypothyroidism. Despite adequate treatment and normalized T3/T4, dizziness and symptoms of Hypo (which were reduced at first) continued and got worse. New symptoms appeared about 18 months ago and consideration of MS came to the fore. 9 months ago I was diagnosed with Lyme Disease and treated although symptoms persisted. I now present with what appears to be Parkinson`s like symptoms. In the last 18 months, I`ve gone from 205 lbs to 245 lbs. This is mostly from not exercising due to my symptoms (and probably not eating as well too). A sleep study revealed mild sleep apnea. Oxygen mean at 95%, 15 arousals per hour on avgerage. A second study using a cpap did reduce arousals considerably. However, Stage 3/4 was absent in both studies. REM was only 9% in both studies. Oxygen at 95% in the second study as well. The second study did note many arousals which they could not account for. I felt just as rotten after the 2nd study as any other night of sleep. It would seem that the cpap offered no practical benefit except to reduce arousals.
The fatigue I have is considerable. I can sleep 10-15 hours through the night waking unrefreshed. I can then sleep a further 2-5 hours during the day at times. I`m tired all day. I suppose it`s possible that I had Lyme Disease when that dizziness first set in which led to where I am now. I`ve heard that an absence of Stages 3 and 4 can lead to immune suppression so it`s possible that Lyme somehow interferred with these stages and consequently was undiagnosed for that reason.
Any ideas what else might cause an absence of Stage 3/4 sleep? My sleep doc is considering Xyrem for me. Any thoughts on Xyrem?
Many thanks for taking the time to read this post!

Answer:

I would like to apologize for the significant delay we have had in replying to your post. Your question is interesting and has quite a few specifics to which I will gear this answer.
There are many reasons for fatigue and sleepiness. Hypothyroidism, Lyme disease, Multiple Sclerosis, Parkinson's Disease, and Sleep Apnea are a few of the causes and you seem to have been investigated for most of them. It is important to confirm the presence or the lack of each of these conditions, and to treat the existing problems effectively and then reassess your symptoms. Effective treatment for each of these conditions requires careful follow-up, and possibly repeat testing on the part of your physicians.
For example, in treated sleep apnea, there may be significant residual sleepiness that does not improve even with treatment optimal continuous positive airway pressure (CPAP) devices. The persistence of significant arousals on CPAP may indicate high pressure sensitivity (discomfort with high air pressure) or incomplete elimination of respiratory events (pressure is too low). Even though the airway is kept open during a CPAP trial, it's still possible that sub-clinical respiratory events or other conditions such as periodic limb movements can cause arousals. Addressing these issues would be important to get you sleeping and feeling your best.
Sleep stages 3 and 4, also known as slow wave sleep (SWS), are measured differently in research vs clinical arenas. In research, not only SWS is measured, but also all of slow wave activity is calculated usually using computer analysis of the brain wave spectrum. On the other hand, in clinical practice, not all of slow brain activity but only SWS is measured, and this is done using visual analogue methods that may underestimate the activity. So trying to figure out what is normal can be tricky. Nevertheless, it is known that slow wave activity decreases as we grow older. It is not unusual for people in their second decade to have half of the activity that they had as children; and for a healthy 60 year old to have no SWS on a sleep test. Other reasons for SWS reduction include many illnesses, medications, use of certain substances and sleep disturbances. The clinical significance of SWS and slow wave activity is not clear. There does not seem to be noticeable problems that are caused by lack of SWS. The opposite (lack of SWS leading to medical problems) has not been conclusively proven, either.
Reduction in rapid eye movement (REM) sleep has also been seen in people with medical illnesses, medication or substance use, and sleep disturbance. No cause-and-effect relationship has been established. Even though REM sleep is strongly related to memory and learning in mice for example, the findings are not as clear cut in humans.
The use of medications to restore SWS has not been studied in well-done scientific trials so far. Some drugs and medications, such as 5-hydroxytrytophan and Trazodone, have been shown in animal studies to increase the amount of SWS animals may get, but this has not yet been proven in humans. Xyrem (Sodium Oxybate) increases SWS in humans but the clinical significance of artificially increasing the amount of SWS is not clear, in other words, we don't know if it will make you feel more rested. However, this medication seems to be of benefit in patients with narcolepsy. Its mechanism of action is not known but it seems to exert its effect by limiting sleep fragmentation.
As you seem to have significant and disabling sleepiness, I recommend you re-discuss your situation with your Sleep Specialist and with your other physicians. Management of all of your medical problems needs to be optimized before resorting to medications. The use of medications that may improve the amount of SWS is not a proven strategy to treat sleepiness.
If you would like additional information regarding sleep and sleep disorders, you can obtain it on the American Academy of Sleep Medicine website . This website also contains a list of Sleep Centers across the country so you can locate one near you if need it. Good luck, and sleep well.

For more information:

Go to the Sleep Disorders health topic, where you can:

Read articles on this topic
Browse the previously asked questions
Ask your own question.

Response by:

Ziad Shaman, MD
Associate Director, Pulmonary and Critical Care Fellowship Program
Diplomate of the ABIM in Sleep Medicine
Assistant Professor
Division of Pulmonary, Critical Care and Sleep Medicine
MetroHealth Medical Center
School of Medicine
Case Western Reserve University