Sleep Study: The Results

I met with the sleep study doctor Ajayi (MD, FCCP, FAASM, D, ABSM... to be exact) yesterday. He said the same thing that all doctors say about Jett: "He is the most (fill in the blank) of any child with DS I have seen in my career." In this case, it was "the best sleep study results" he'd ever seen in a person with DS. To understand why I requested the sleep study, see Jett's Sleep Study: Mommy's Nightmare.

General Sleep Info:

During sleep, we pass through five phases of sleep: stages 1, 2, 3, 4, and REM sleep. NREM Stage 1 is very light sleep; NREM Stage 2 has special brain waves called sleep spindles and K complexes; NREM Stages 3 and 4 show increasingly more high-voltage slow waves. In NREM Stage 4, it is extremely hard to be awakened by external stimuli. The amount of time spent in the deepest stages of NREM (Stages 3 and 4) change from childhood through adulthood. In fact, this change is prominent during adolescence, when about 40 percent of this activity is lost and replaced by Stage 2 NREM sleep. In addition to these changes, the percentage of time spent in REM sleep also changes during development. Adults spend almost 50 percent of their total sleep time in stage 2 sleep, about 20 percent in REM sleep, and the remaining 30 percent in the other stages. Infants, by contrast, spend about half of their sleep time in REM sleep. According to the chart below, a child Jett's age would spend 30% in REM sleep on average.




Sleep in DS:

Although obstructive sleep apnea is seen in only 0.7 to 2 percent of all children, a previous study based on 53 children and adults with Down syndrome between the ages of four weeks and 51 years old (an average of seven years old), found an incidence of sleep abnormalities as high as 100 percent in some cases. George Capone, MD and Director of the Down Syndrome Clinic at Kennedy‐Krieger Institute said in a talk that perhaps poor sleep effects the prefrontal cortex which effects emotions and mental health. 94% of adults with DS had abnormal sleep. 70% had severe OSA (AHI>30/hour) with below 90% oxygen in sleep. 

In untreated people with DS, the REM sleep is greatly diminished. Their REM may be in the 2% range. Subjects with DS show a significant reduction in percentage of REM sleep, a marked delay in first REM latency and a statistically significant decrease in high-frequency rapid eye movements during REM sleep. The percentage of REM sleep in humans can be considered as an index of brain "plasticity" and the high-frequency REMs can represent an index of the brain ability to organize information, which is vital for learning and memory.

Also, children with DS show a clearly decreased peak amplitude of growth hormone during sleep; this causes the poor physical development in these subjects and might be related to the occurrence of sleep apnea. Obstructive sleep apnea has also been repeatedly reported in these children; however, if obvious risk factors are absent, children with DS tend to show the presence of central sleep apnea which is caused by a probable dysfunction of autonomic control at a brainstem level.

In people with DS a significant occurance of central, as opposed to obstructive, sleep apneas was found which also showed a significant age-related increase. Central apneas were mostly preceded by sighs, occurred more frequently during sleep stages 1 and REM, and were often organized in long sequences of periodic breathing. Sleep structure was not significantly modified by apneas and oxygen desaturation. It is hypothesized that the increase in central sleep apneas is related to a dysfunction of central respiratory control at the brainstem level in DS (Ferri et al., 1997).

The presence of central sleep apnea induced a further significant increase in low-frequency and very-low-frequency components of heart rate variability, similarly to the effects of the presence of OSA already described in the literature (Schiomi, Guilleminault, Sasanabe, Hirota, Maekawa, et al., 1996).

This final study is additional evidence for impaired brainstem function in DS which is demonstrated by abnormalities in brainstem auditory evoked potentials, abnormal presence of central sleep apnea and impaired balance between sympathetic and vagal control of heart rate variability during sleep.

Finally, the altered balance between the sympathetic and vagal systems can be viewed also in psychophysiological terms, following the ideas of the so-called "Polyvagal Theory" (Porges, 1995) which states that the vagal system does not represent a unitary dimension and is formed by two distinct motor systems. The first one is the "vegetative status" originating in the dorsal motor nucleus, associated with passive automatic regulation of visceral subdiaphragmatic functions, the second is the "smart vagus", originating in the nucleus ambiguus (NA), associated with the active processes of attention, motion, emotion, and communication, with supradiaphragmatic target organs. Thus, the changes reported in the autonomic function of subjects with Down syndrome, together with the already reported changes in central control of respiration (Ferri et al., 1997), might be physiopathologically connected with the basic mechanisms of their developmental psychomotor problems.

Jett's Results:

Sleep summary

The total time in bed was 411.5 minutes. With a total sleep time of 306.5 minutes. Sleep onset latency was 59.5 minutes (The normal time he goes to sleep was an hour after lights out.) with a sleep efficiency of 74.5% (nl>85%). The percentage of sleep time spent in stage N1, N2, N3, and REM was 15.7, 39, 23, and 22.3% respectively with an REM latency of 87 minutes (nl 75-120 minutes). The patient had an arousal index of 10.8 (nl<12) with an arousal awakening index of 10.8 (nl<15). The number of REM awakenings was 0.

Cardiac summary

The average heart rate asleep was 102 bpm. EKG showed normal sinus rhythm.

Respiratory summary

The baseline oxyhemoglobin saturation was 96% with the lowest being 93%. The percentage of sleep time with oxygen saturations between 90-100% was 100%. The apnea index was .4 (nl<1) while the apnea/hypopna index was .4 (nl<1). There were a total of zero central apneas, 0 obstructive hypopneas, 2 obstructive apneas and 0 mixed apneas recorded. Sleepiness scale was 11. (Maybe because he falls asleep in the car and because he may fall asleep if you lay him down in the afternoon?) Toddler/DS snore scale was 4.

Apnea index .4
Apnea/hypopna index .4
Lowest respiratory oxyhemogloblin desaturation 93% with obstructive apnea
Arousal awakening index 10.8

Movement summary
The plm (periodic leg movement) index was 2 (nl<5) The plm arousal index was .4 (nl<5)

Interpretation:
This was a normal study the patient has primary snoring with sleep fragmentation.

Suggestions:
Followup with sleep clinic for further evaluation and management at age 3.

Dr. Ajayi said that he woke up 11 times an hour (sleep fragmentation) when 10 times is normal for a child his age so it's nothing to be concerned about. He said he had adequate NREM for the growth hormone to be released and the highest REM of any DS child he had ever seen (in 11 years).
As for snoring, Jett doesn't snore. He did a little that night because he had been crying for an hour and therefore had some congestion..
Would have liked the REM to be 30%, but I can't complain about 22.3%!

For more info on REM sleep and Ginkgo and how it connects to Down syndrome, see Teresa Cody's blog post: http://changingmindsaboutdownsyndrome.blogspot.com/2011/02/can-sleep-be-as-easy-as-gb.html

Sources

http://science.education.nih.gov/supplements/nih3/sleep/guide/info-sleep.htm
http://changingmindsaboutdownsyndrome.blogspot.com/2011/02/can-sleep-be-as-easy-as-gb.html
http://faculty.washington.edu/chudler/sleep.html 
http://www.odec.ca/projects/2004/rich4a0/public_html/information.htm

Related Posts

Jett's Sleep Study: Mommy's Nightmare
Ginkgo: The Hows and Whys for Down Syndrome
Vitamin D3 and Sleep 
Link Between Sleep Deprivation & Alzheimer's Risk 
Stimulating Growth
DMAE (Dimethylaminoethanol)
Keeping Nasal Passages Clear and Mouths Closed
Ashwagandha
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Jett's Sleep Study: Mommy's Nightmare

March 17, 2011

During REM sleep, your brain takes daily information from your short term memory and stores it in your long term memory. But, because of chemical imbalances, people with DS have much less REM than a typical person, which contributes to impaired memory. If you can't build upon what you learned that day, you have to start all over again the next day. It's very difficult to get from A to Z when you don't remember A.

That's partly why Jett takes ginkgo throughout the day and at night since it's proven to help restore REM in mice with DS. For more info on REM sleep and Ginkgo and how it connects to Down syndrome, see Teresa Cody's blog post: http://changingmindsaboutdownsyndrome.blogspot.com/2011/02/can-sleep-be-as-easy-as-gb.html
So, I needed a sleep study to see how Jett's REM compared to that of a untreated person with DS and to a typical person. Does he need more ginkgo overall? Does he need an extra dose in the middle of the night? (Gingko has a half life of 7 hours, while the biloba part, most importantly, has a half life of only 3 hours.) Do I need to teach him to swallow a time-release capsule ASAP? Is it having any effect on his REM at all? (I'm working the assumption that, prior to using ginkgo, Jett's REM would be similar to that of an untreated child with DS.)

Additionally, Jett's growth is not up to par and since growth occurs in deep sleep, I was also curious to see just how much of all the other stages of sleep he was getting. Perhaps his lack of growth is because of too little deep sleep; or perhaps another chemical imbalance is causing the growth hormone improper production, release or utilization. Either way, I have to rule out each thing until I can find the cause. I need an exact problem before I can find a solution.

And now for the sleep study...

We showed up at 8pm with a suitcase full of toys, books, food -- anything I thought we might need in a nine hour period. The very-patient-lab-tech, Brian was very patient. He had a lot of patience. That must be the number one quality in a children sleep study technician.... Patience and perseverance....

When Brian walked in, I was cleaning out Jett's nose. Jett held up his little nostrils so I could more easily put in the nose drops, use the Nose Frida, etc.

Brain was impressed with his cooperation. "I applaud the fact that you're cleaning his nose, but later on, when he's crying, it'll all start all over again and you really won't be able to keep him totally clear."

"Oh," I said, "but Jett doesn't cry. Unless he's in dire pain, or something." Brain nodded his head, hopeful, but not he least bit convinced as I assured him of Jett's angelic nature.

Next, I had to distract Jett while Brian taped, wrapped, braided and glued 25 wires -- that's twenty five wires -- to Jett's wiggly, bobbing head, face, neck, back, waist and foot. This procedure took 45 minutes.

Brain was quite impressed with Jett. He said that he's done this to a thousand children and Jett was definitely one of the easiest. (He also remarked on his amazing cognition and motor skills as he busily played with the inflated hospital glove and flipped through the pages in his book.)

That turned out to be the easy part.

(Sorry for the blurry pictures!)

Once the bed was all prepared (allergy-free sheets, etc.), Brain said, "Okay, now I have to put on the last wires. (HUH?) This one in particular is the most annoying, but one of the most important. It touches his nose and hangs over his lip. (HUH?) It monitors the respiration and lip movement, etc. So before breastfeeding, you'll have to lift it up, very carefully, like this... (HUH? In the dark??) I've put extra strong tape on it to make it'll stay put. You can lay in the bed with him until he's asleep, but then you need to leave him and only come back when he wakes up -- not moves or moans, but wakes up."

I'd spent the last year developing the habit of attending to Jett's every little breath, whimper and sigh, around the clock... "Okay," I said, "Sure, I can do that."

After what felt like an hour and 15 minutes of rocking, singing and back patting, Jett finally fell asleep. As he was drifting off, I could hear children from other rooms crying. I slipped out of his (super noisy, plastic sheet lined) bed, ate a sandwich, checked my email and settled into the twin bed nearby. I was excited about the prospect of sleeping without him kicking me for one night.

I laid on the pillow and sighed deeply. Then Jett woke up -- rolled over -- with head up looking around, touching the bed clothes in search for me. It took about 20 minutes to get him back down. Back out of his (super noisy) bed, 20 minutes later he's awake again... This time screaming and crying all wrapped up in the wires... I couldn't see anything so I had to turn the light up a little bit to get the wires untangled. He was crying and crying and crying and crying and crying. I don't know how long it took me to get him asleep... An hour? He finally fell asleep on me and I carefully slid him off on his own again. I was ready to call the whole thing off. He woke two more times shortly after. Screaming, crying.

It was that stupid nose wire that was driving him crazy! He telepathically insisted that I take it off. So I did -- Brian wasn't kidding about the strength of the tape! After three rips, I got it off. Jett screamed bloody murder! But he finally settled down, rolled on his stomach and I got back into my bed.

Jett woke again at 5:30 am. Brian came in and said that he got enough data and we could leave. Yea!!!!! He said that it actually went very well and many kids never do fall asleep and have piercing blood curdling cries. He said Jett did great. I couldn't imagine that they'd get good data from it, but, at that point, I didn't care one single bit. I just wanted to LEAVE.

Even though I ripped off the tape and wires surrounding his nose and mouth, Brian said he still got a good reading because when Jett turned over onto his stomach, the mouth and nose sensors were in the correct position!

That traumatic night lowered Jett's immune system enough that Jett now has his first cold in his life. I sure hope the data we get was worth it!

UPDATE: Jett does not in fact have a cold. He's teething! He was up all last night and well, so were we.

Related Posts

Jett's Sleep Study: The Results
Ginkgo: The Hows and Whys for Down Syndrome
Stimulating Growth
Nontoxic Bedding

Laura's blog post with her experience as well as tips for surviving a sleep study: http://downsyndromeupupupandaway.blogspot.com/2011/05/surviving-sleep-study.html