In this 74‑minute video, Dr. Joanna Wrede, a pediatric sleep neurologist at Seattle Children’s Hospital, explains how sleep disorders are identified and treated in children with Schaaf-Yang syndrome.
Click below to watch the video. If you're short on time, scroll down for timestamps to find the portions you're most interested in.
Presentation Summary With Timestamps
0:00 Introduction
1:43 Roadmap
- What we will cover
- Types of disorders seen in SYS
- Diagnosis and sleep studies
- Significance of sleep disorders
- Treatment options
- Other disorders of sleep
2:25 Intro
- Schaaf-Yang syndrome is a genetic disorder caused by a variant in the MAGEL2 gene.
- Many shared features with PWS.
- PWS has a high incidence of sleep disorders; it can be helpful to consider these.
3:11 PWS and Sleep
- The vast majority of children with PWS have obstructive sleep apnea.
- This increases the risk of hypoxemia.
- This commonly leads to daytime sleepiness (hypersomnia), narcolepsy, and alterations in sleep patterns.
- Similar effects are likely in people with SYS.
4:54 SYS Clinical Data
- Initial clinical studies summarized data from 28 families; there are now data from over 300 families.
- Cognitive and behavioral characteristics: all children experienced some form of developmental delay; high rates of autism and other behavioral difficulties.
- We examine physical challenges that may set them up for sleep issues.
- Based on initial clinical observations, almost two-thirds experienced obstructive sleep apnea.
- Contributing factors could include hypotonia, excessive weight gain, and scoliosis/kyphosis.
- Autism in most may also lead to sleep issues.
7:24 Polysomnographic Characteristics and Sleep-Disordered Breathing in SYS
- This article in Sleep & Breathing was published in 2020.
- It was based on sleep studies of 22 children from around the world.
8:00 Trends
- Trends identified in these studies included high rate of obstructive sleep apnea, more often moderate or severe, and trends toward fragmented sleep and decreased REM sleep.
8:50 Detailed Findings
- Fragmented sleep: normal versus excessive number of arousals.
- For obstructive sleep apnea, average obstructive index varied over a wide range, but most subjects were moderate to severe.
- Treatment is recommended in this range.
- The average oxygen desaturation index for children studied was high.
- About a quarter of subjects had excessive periodic limb movement.
12:22 Conclusions
- In conclusion, there were high rates of obstructive sleep apnea and high rates of central sleep apnea (about 10%) compared to the general population.
- Children with SYS should have routine sleep studies due to the high risk of sleep disorders.
13:00 Spectrum of Sleep-Related Breathing Disorders
- The spectrum ranges from occasional snoring to severe sleep apnea.
- You can have obstructive sleep apnea without snoring; often sleep study results are worse than expected given the lack of noise.
14:19 Obstructive Sleep Apnea Syndrome
- Also called OSA; it is defined by obstructive events that narrow the airway and cause dips in oxygen levels.
- It can include complete pauses in breathing or shallow breathing.
- In an obstructed airway, the uvula has low tone and can interfere with airflow.
15:53 Sleep Study
- Sleep apnea is diagnosed with sleep studies.
16:07 Polysomnogram
- Polysomnography means multiple sleep measurements. Sensors measure
- Brain waves
- Eye movements
- Muscle activity
- Heart rate and rhythm
- Snoring
- Oxygen and carbon dioxide levels
- Respiratory effort
17:14 Home Sleep Apnea Test
- Home sleep apnea tests monitor some of these but do not include brain wave sensors to determine wakefulness.
- Generally home tests are not for children unless some data gathering is needed in remote locations or before a sleep study time is available.
18:56 Types of Respiratory Events on Sleep Studies
- Usually we can get brain wave, oxygen data, which provide good information.
19:15 Obstructive Apneas
- In obstructive sleep apneas, there is no air detected coming out of the nose or mouth.
- There is still chest and abdominal movement, but no air is getting through.
19:37 Central Apneas
- With central apneas, no air is coming out, but there are also no breathing movements.
- A certain amount can be normal, particularly following a deep breath.
- During a pause in breathing, if oxygen level dips or lasts long enough, we have to count it.
20:44 Mixed Apneas
- Mixed apneas are a combination of the other types.
20:59 Hypopneas
- These involve shallow breathing; our criterion is a 30% drop in airflow.
- Sometimes we see changes that don’t meet the criteria.
- Flow limitations mean that airflow tracings on the polysomnogram flatten out.
- Oxygen level dips of 3% or more count as hypopneas.
22:01 Formula to Determine
- If you put all of these breathing events together, add them up and divide by the hours of sleep, it yields the apnea hypopnea index.
- With children, the obstructive apnea hypopnea index (oAHI) is used; this excludes central apneas.
22:40 Obstructive Apnea Hypopnea Index
- Approximate severity
- oAHI < 1 = normal
- oAHI 1-5 = mild
- oAHI 5-10 = moderate
- oAHI > 10 = severe
- Interpretation is important; other factors can contribute to severity.
- Even with fewer events per hour, kids are more affected by these events than adults.
24:00 Polysomnogram: Normal Breathing, N3 Sleep
- With normal breathing, every breath looks nearly the same on a polysomnogram.
- Most calm breathing occurs in deep sleep.
24:57 17-Year-Old with Down Syndrome, AHI 104
- This is an extreme example featuring many airflow stoppages with chest and abdominal movement.
- With every stoppage of breath, the oxygen level dips and the brain wakes up.
- It becomes exhausting because the heart rate and blood pressure also increase at these times.
26:11 Sleep Apnea Worse Than Numbers (AHI) Suggest
- Sometimes disorganized breathing occurs without countable hypopneas based on oxygen and brain wave measures.
- Interpretation is important in these cases.
26:04 Sleep-Disordered Breathing: Contributing Factors
- Part of the problem is structural and can include tonsils or large adenoid tissues.
- Craniofacial differences can play a role.
- Obesity can be a factor; fat deposits around organs and even around the airway can obstruct breathing.
- Lung capacity, upper airway narrowing, and abnormal muscular tone are other factors.
- Genetic and hormonal factors can also contribute. Growth hormone therapy may be a factor in some cases.
20:17 SYS and PWS Risk Factors
- Hypotonia
- Scoliosis
- Small airway
- Obesity
- Growth hormone therapy?
30:45 Special Considerations
- Growth hormone therapy in PWS improves many physical and possibly cognitive outcomes.
- One study of growth hormone therapy in SYS shows similar improvements.
- However, there are concerns it may worsen obstructive sleep apnea due to lymphoid tissue enlargement, increased BMR, and increased symptoms of laryngomalacia.
- General recommendations for PWS are to have a sleep study within the first year of life and before starting growth hormone therapy.
- If GH therapy is begun in the NICU, sleep study would have to be done there; not all institutions have that capability, however.
- Pre- and post-GH therapy sleep studies can reveal whether GH is having a negative impact on sleep disorders.
34:35 At Risk for Other Types of Sleep-Disordered Breathing
- Hypoxemia and hypoventilation are risks with restrictive lung diseases.
- This can lead to elevated blood carbon dioxide levels.
- Regarding central sleep apnea, a certain amount can be normal, but an excess can reduce brain arousal to decreased oxygen and high carbon dioxide levels.
37:26 Why Does Sleep Apnea Matter in Adults?
- In adults, untreated sleep apnea can lead to increased risk for high blood pressure, strokes, and heart attacks.
- Disordered sleep can increase the risk of weight gain and type 2 diabetes.
- It also can magnify the negative effects of existing health conditions.
39:20 Why Does Sleep Apnea Matter in Children?
- Parents often bring their children to the sleep clinic because of behavioral problems: ADHD symptoms, impulsive behaviors, moodiness, risk taking, and declining school performance.
40:00 Bottom Line
- Inadequate breathing is bad for the brain and body.
- Treatment decisions involve weighing risks against benefits for young children.
40:26 Treatment Options
- Primary treatments are surgery and PAP.
- Sleeping position and allergy management can be supportive therapy.
- Oral, nasal, and other devices are seldom used for children.
41:23 Surgery
- Tonsil and adenoid removal are typically day surgeries except in severe cases or with comorbid conditions.
- There may be other surgical targets; drug-induced sleep endoscopy can be used to look for other airway obstructions, which may lead to other interventions.
43:37 PAP
- PAP is positive airway pressure. It is used to ensure continuous airflow throughout the night.
- There are various types of PAP devices, including CPAP, APAP, BiPAP, and ASV.
44:38 Mask Options
- There are many different PAP mask types and sizes available.
- There are somewhat fewer options for young children, but if one type doesn’t work, others are available.
46:00 Allergy Control
- No problem trying medications before obtaining a sleep study.
- If you opt for a nasal spray, Flonase Sensimist is recommended.
- Administer at least 15 minutes before bedtime.
- Give it four to five weeks to see if it is helping.
- If there are dust mite allergies, special pillow and mattress covers and frequent laundering can help.
47:59 Other Treatment Options
- Weight loss
- Positional therapy (there are low-tech options)
- Supplemental oxygen (although this does not address the cause of obstructions)
- Palate expansion
- Hypoglossal nerve stimulation (implanted device)
51:29 Other Sleep Disorders in PWS (and SYS- not yet clear)
- Excessive daytime sleepiness: In addition to sleep apnea or insufficient sleep hours, hypothalamic dysfunction can cause this.
- Too much sleepiness is called hypersomnia, and past a certain point it is called narcolepsy, which includes progressing into REM sleep inappropriately.
- Narcolepsy is generally considered an autoimmune condition associated with low levels of orexin; in PWS orexin levels are not exceptionally low.
- There can be cataplexy (sudden loss of muscle tone). Children sometimes exhibit cataplexy when excited.
- It is important to distinguish cataplexy from sleepiness or micro sleep because medical treatments differ.
54:11 Other Common Sleep Issues in Pediatrics
- Insufficient sleep hours
- Insomnia
- Restless leg syndrome
- Circadian misalignment
- Inadequate sleep hygiene
54:34 Sleep Duration Recommendations
- 10 hours at age 10; younger children need more, older ones a little less.
- Teens need 8 to 10 hours of sleep.
55:40 Insomnia
- Can be trouble falling asleep, staying asleep, or waking early.
- Insomnia is more common in PWS than in the general population.
- Insomnia has many possible causes, and many behavioral techniques can be used to help children fall asleep independently.
- Psychophysiologic insomnia is difficulty falling asleep despite trying.
- Medical conditions can also lead to insomnia.
- A number of medications are available to treat insomnia.
57:20 Circadian Misalignment
- Having consistent bedtimes and waking times can help address circadian misalignment.
- Avoid bright lights or screens before bed; expose children to light at morning wake time.
- Don’t sleep in on weekends.
- Melatonin can be useful; start with the lowest effective dose. Some people develop resistance over time and need higher doses, but a washout period can help correct this.
58:50 Circadian Rhythm Disorders in SYS
- Many SYS parents report disrupted sleep patterns.
- There may be a molecular basis for this involving the effects of MAGEL2 on a circadian rhythm protein.
59:42 Restless Leg Syndrome
- An urge to move prevents children from falling asleep.
- This often runs in families.
- It most often relates to low iron levels.
1:02:01 Sleep Hygiene
- Have consistent bedtime routines.
- Allow children to fall asleep independently.
- Keep bedrooms cool, dark, and quiet.
- Soothing sounds can be helpful.
- Some children may benefit from sensory stimulation such as weighted blankets or massage.
1:02:42 Recap
1:03:07 Q&A
