This issue will address Sleep Disordered Breathing, especially
Obstructive Sleep Apnea Syndrome (OSAS), which may be the most
harmful of all the sleep disorders to children and adults’ health,
cognition, learning, behaviors, and safety according to the research
findings. However, the good news is that SDB, including the most
severe OSAS, is usually correctable or treatable. Additionally, some
studies report improvements in children’s cognition, learning,
and/or behaviors post-treatment.
What is Sleep Disordered Breathing and
Obstructive Sleep Apnea Syndrome?
Sleep-Disordered Breathing (SDB) represents a broad range of
nighttime breathing problems ranging from primary snoring (PS) at
the mildest end of the spectrum to Obstructive Sleep Apnea Syndrome
(OSAS) at the severe end. There are two types of snoring that can
occur: (1) primary snoring (PS), which sleep specialists thought was
benign until recent research began to shed doubt on that premise,
and (2) snoring associated with OSAS, which sleep specialists and
research findings now associate with many health, neurocognitive,
learning, and/or behavior problems. Upper-Airway Resistance
Syndrome (UARS) falls within the mid-range on the spectrum of SDB
and consists of mild airway resistance (sometimes attributed to
asthma or allergies at night), but not complete airway blockage
stopping breathing found in more severe OSAS.
More
research has been conducted on Obstructive Sleep Apnea Syndrome (OSAS)
[frequently abbreviated to Obstructive Sleep Apnea (OSA) or Sleep
Apnea (SA)] than any other sleep disorder. This extensive research
has been undertaken on adults with OSAS because it is considered the
most dangerous and damaging form of all sleep disorders, especially
if it goes undetected for many years (Carroll & Loughlin, 1995).
Until the mid-to late 1990’s, most physicians believed that OSAS
only occurred in older adults, primarily older obese adults. Due to
decades of incorrect beliefs, little research was conducted on
pediatric OSAS until recently. This is why many pediatric
professionals have limited information on OSAS and its’ negative
impact on children.
OSAS
in children is most often caused by a breathing obstruction due to
enlarged tonsils and/or adenoids, which causes raspy breathing or
light snoring in young children and loud snoring in adolescents
(Carroll & Loughlin, 1992). This obstruction can result in
belabored breathing or an absence (cessation) of breathing during
sleep for a minimum of five seconds per apnea event up to 60+
seconds. These apnea events can be mild and occur 1-2 times per
hour, or they can occur up to 50-60+ times per hour in very severe
cases. This difficulty in breathing may result in waking the child
from sleep and/or result in an oxygen deficit to the brain and
arterial blood flow, as well as a dangerous drop in carbon dioxide
levels in more severe cases.
Although there is a need for more and better prevalence studies of
SDB, OSAS, and all pediatric sleep disorders, an initial prevalence
study of OSAS in children under eight years of age estimated the
rate to be approximately 2.5% (Marcus, 2001). It may be as high as
6% in adolescents (Johnson & Roth, 2006), although this initial
study reporting adolescent OSAS estimates was done in a
questionnaire format that is subject to reporter bias, and no actual
overnight sleep studies were conducted to confirm a diagnosis of
OSAS. Approximately sixty-seven percent of children with Downs
Syndrome have OSAS (Marcus et al., 1991). Two studies indicated
that African-American (A-A) children and A-A men under 25 years of
age have a two-fold greater risk of having OSAS than Caucasians of
the same ages (Johnson & Roth, 2006; Redline et al., 1997). Rosen’s
(1999) findings suggest that African-American children are three
times more likely to have OSAS than Caucasian or Hispanic-American
children.
Initial research findings suggest that untreated OSAS may be
associated with, or possibly result in, developmental delays
(Carroll & Loughlin, 1992), lower cognitive scores on some subtests
of intellectual measures (Friedman, Hendeles-Amitai, & Kozminsky,
2003; Montgomery-Downs et al., 2005); lower academic performance or
lower grade point averages (Gozal, 1998; Johnson & Roth, 2006;
Luginbuehl, 2004; Taras & Potts-Datema, 2005; Urschitz et al.,
2003), and some behavior or emotional problems, more specifically
ADHD and depressive symptoms (Beebe et al., 2004; Chervin et al.,
2002; Crabtree, Varni, & Gozal, 2004; Harvey et al., 1999; Johnson
& Roth, 2006).
In
this issue, we will present the results of some of the first studies
conducted between 1966 and 2001 on the impact of SDB or OSAS on
cognition, learning, and behaviors to provide an historical
perspective, as well as two new studies. In an upcoming Fall issue,
we will review this topic in more depth based on the research
conducted between 2002 and 2008.
Welcome to “Wake Up America’s” issue on Sleep Disordered Breathing
and OSAS.
Marsha Luginbuehl, PhD, NCSP
Editor, Wake Up America!
~~~~~~~~~~~~~~~~~~
The Impact of Sleep-disordered Breathing on Cognition
and Behavior in Children:
A Review and Meta-synthesis of the Literature
Research conducted by Charles S. Ebert, Jr., MD, MPH, and Amelia F.
Drake, MD, Chapel Hill, NC.
A meta-synthesis was conducted with 206 studies that explored the
impact of sleep-disordered breathing (SDB) on cognition and
behaviors between 1966 and 2001. However, 189 of these studies were
discarded due to small sample size or other methodological errors.
Seventeen of the studies on 5312 patients between 2 and 18 years
were retained to review the impact of SDB on cognition and
behaviors. Although 15 of these 17 studies had some mild
methodological errors, these errors were not believed to have
notable impact on the outcome of results. The results suggest that
sleep-disordered breathing may have a significant impact on
cognition and/or behaviors in children.
Sleep-disordered breathing (SDB) represents a broad range of
nighttime breathing problems ranging from primary snoring (PS) at
the mildest end of the spectrum to obstructive sleep apnea syndrome
(OSAS) at the severe end. OSAS is partial or complete obstruction of
the airways occurring two or more times per hour during sleep for
children. If it occurs multiple times per hour, it reduces the
child’s level of oxygen entering the brain and blood stream and the
carbon dioxide level may drop to unacceptable levels. These apnea
events may also fragment or awaken the child from sleep throughout
the night. Upper-airway resistance syndrome (UARS) falls within the
mid-range on the spectrum of SDB and consists of mild airway
resistance, but not complete airway blockage like OSAS. Due to
concerns about the effects of SDB on children’s cognition, learning,
and behaviors, sleep specialists began researching these issues in
the 1960’s. The following is a brief summary of 17 studies
conducted between 1966 and 2001 that do not exhibit significant
design or methodological problems:
Studies Reporting Neurocognitive Deficits and More Behavior Problems
in SDB Children & Adolescents than Those without Sleep Problems
Weissbluth et al. (1983) had parents complete sleep and daytime
behavior questionnaires on 71 children with primary snoring (PS) and
355 controls with no sleep problems. The PS children exhibited more
daytime behavior problems than controls.
Ali et al. (1993) questioned 66 parents of children with PS and 66
parents of controls without PS about snoring, sleep, breathing
disorders, and behaviors. A modified sleep study was also
conducted. Parents of the children who snored or who had more
serious sleep disturbances reported more behavior problems in their
children than did the parents of children in the control group.
Ali et al. (1994) questioned 507 parents of children with PS and
found that these parents reported a higher occurrence of sleepiness,
hyperactivity, and restless sleep in PS children than children who
did not snore.
Rhodes et al. (1995) did an overnight sleep study (polysomnography)
on 14 obese students and found that seven of them had obstructive
sleep apnea syndrome (OSAS). The students with OSAS had deficits in
learning, memory, and vocabulary compared to the seven students
without OSAS who did not have these problems.
Chervin et al. (1997) had 143 parents complete questionnaires (no
sleep study) assessing snoring, sleepiness, and restless legs at
night. Parents of 27 students reported PS in their children and
also indicated that they exhibited more inattention and
hyperactivity than the 116 without PS or other sleep problems.
Chervin et al. reported that children with ADHD symptoms are 5.17
times more likely to snore than children from the general pediatric
population.
Owens et al. (1998) performed PSG studies and diagnosed 100 children
with OSAS and 52 with a behavioral sleep disorder (BSD). These
parents completed questionnaires assessing sleep and behaviors. The
OSAS diagnosed children had more externalizing behaviors
(aggression, hyperactivity, and conduct problems) than the children
with a BSD diagnosis (there was no control group).
Ferreirra et al. (2000) administered questionnaires to 960 parents
assessing sleep and behaviors. Eighty-four parents reported that
their children exhibited PS as well as increased daytime sleepiness,
irritability, and more daytime behavioral disturbances compared to
those without sleep problems.
Blunden et al. (2000) did overnight PSG studies and compared 16
students with PS or OSAS to 16 students without these sleep
problems. The OSAS-PS group exhibited poorer attention, memory, and
lower intelligence test scores than the controls without OSAS-PS.
Brunetti et al. (2001) studied 895 students and did an overnight PSG
on the 44 students whose parents had rated them as being habitual
snorers. Brunetti reported that 12 of the 44 students met the
criteria for OSAS. The parents of the OSAS students rated their
children on questionnaires as having poor school performance.
Gozal
et al. (2001) issued questionnaires to parents of 797 adolescents
with PS and 791 adolescents without PS. He found that adolescents
with lower academic performance were 2.79 times more likely to have
snored (PS) during early childhood than their better-performing
classmates.
Studies Reporting Neurocognitive Functioning and Behavioral
Changes Pre- and Post-Treatment of SDB
Guilleminault et al. (1982) did surgical intervention (adenotonsillectomyà T & A) on 25 students with PS and
possible OSAS and corrected the sleep problems. These students had
deficits in addition speed tests before treatment compared to 25
students without sleep problems. Their addition speed improved
significantly post-treatment. Twelve out of 14 of these students
who were school age were in special education pre-treatment, but
Guilleminault et al. reported that eight students could be
mainstreamed into general education post-treatment due to their
improvements. Teachers also reported that many of the students’
behaviors improved after surgery, although this was not documented
by behavior rating scales, but by teachers’ observations and
comments.
Postic et al. (1986) identified 100 children with PS and 50 children
without sleep problems using parent questionnaires. After correcting
the PS with a T & A, parents indicated that their children’s mouth
breathing and behaviors improved significantly.
Stradling et al. (1990) did a modified sleep study and parental
questionnaires on 61 preschool children with OSAS or PS and 31
children without these sleep problems that needed a T & A for other
reasons. After T & A, parents of the OSAS or PS groups reported
decreases in daytime sleepiness, hyperactivity, restless sleep, and
learning problems while there was no change in the controls after T
& A.
Ali
et al. (1996) did a modified sleep study and parental questionnaires
on 12 elementary-aged children with OSAS, 11 with PS, and 10
controls. The OSAS and PS groups exhibited more aggression,
inattention, and hyperactivity than the controls pre-treatment.
After T & A surgery, the OSAS and PS groups showed a reduction in
those behaviors and there was no significant difference on
behavioral questionnaires between the three groups post-surgery.
Gozal
(1998) did a modified sleep study on 307 first graders in urban New
York who were in the lowest 10% of their classes. He found that
20.8% of this group had some form of SDB, 66 had PS, and 177 did not
have any of these sleep problems and became the control group.
After T & A surgery was completed on 34 children who had OSAS, their
mean grades improved after surgery compared to no grade improvement
for the other students with OSAS or PS who did not undergo surgery.
Richards et al. (2000) conducted telephone interviews with parents
and performed overnight sleep studies (PSG) on 45 students in first
grade who had OSAS. There were no controls. Parents and PSG
results indicated that snoring, disturbed sleep, and daytime
sleepiness improved after surgery.
Goldstein et al. (2000) issued questionnaires pre- and post-surgery
to parents of 36 preschoolers who had OSAS and found that their
attention problems, thought problems, withdrawal, and anxious
behaviors improved post-surgery.
The
results of the meta-synthesis concluded that 17 acceptable studies
conducted between 1966 and 2001 seem to indicate that there is an
association between Sleep Disordered Breathing (such as PS and OSAS)
and problems with cognition, learning, and behaviors in children and
adolescents. Although some of these 17 studies did not clearly
separate PS from OSAS, but combined them, possibly confounding the
effects of these sleep problems, the studies that did do overnight
polysomnography to positively identify PS and OSAS reported that
even milder PS appears to have some impact on students’ performance
or behaviors. These studies suggested that PS and OSAS may impact a
variety of cognitive abilities and behaviors ranging from memory,
attention, activity level, externalizing behaviors, anxiety, daytime
alertness, vocabulary, irritability, and possibly overall school
performance and intellectual level. The seven studies that looked at
changes in cognition or behaviors post-treatment (T & A surgery)
reported measurable or significant improvements in cognition,
nighttime sleeping, academics, or behaviors.
Some
of the medical research (to be reviewed in a later E-Newsletter
issue) suggests that milder forms of SDB like primary snoring (PS)
may evolve into more serious SDB and OSAS. Even if it does not, 12
of these 17 studies reported that PS alone may have a negative
impact on cognitive functioning and behaviors. Sleep specialists
have reported that approximately 80-85% of PS or OSAS pediatric
cases can be corrected or improved with adenotonsillectomy surgery.
Therefore, in April, 2002, the American Academy of Pediatrics
recommended that physicians screen all children for snoring and
determine risk for OSAS. Given that there have been documented
improvements in cognition, learning, and behaviors post-surgery of
SDB, early screening by many pediatric professionals, such as
pediatricians, school nurses at Kindergarten screenings, school
psychologists conducting psychoeducational evaluations, and
professionals providing Well Child Clinic Check-ups and Child Find
screenings would be a pro-active method to identify more of these
health problems and hopefully correct them. This might reduce some
of the negative impact sleep disordered breathing (SDB) might have
on behaviors and/or school performance if the problems are corrected
early. At the present time, only about 2-3% of all children with
sleep problems like SDB are being screened and identified.
Article summary by Marsha Luginbuehl, PhD, NCSP, President Child
Uplift, Inc.
References
Main Article:
Ebert, Jr., C.S. & Drake, A.F. (2004).
The impact of sleep-disordered breathing on cognition and behavior
in children: A review and meta-synthesis of the literature.
Otolaryngology—Head and Neck Surgery,
814-826.
Other References Cited:
Ali, N.J., Pitson, D., & Stradling, J.R. (1996). Sleep disordered
breathing: Effects of adenotonsillectomy
on behavior & psychologic function. European Journal
of Pediatrics, 155: 56-62.
Ali, N.J., Pitson, D., & Stradling, J.R. (1994). Natural history of
snoring and related behavior problems
between ages of 4 and 7. Arch. Dis. Child, 71:
74-76.
Ali, N.J., Pitson, D., & Stradling, J.R. (1993). Snoring, sleep
disturbance, and behavior in 4-5 year olds.
Arch. Dis. Child, 68: 360-366.
Blunden, S., Lushington, K., Kennedy, D., et al., (2000).
Behavior and neurocognitive performance in
children 5-10 years who snore compared to controls.
Journal of Clinical and Experimental
Neuropsychology, 22(5): 554-568.
Brunetti, L., Rana, S., Lospalluti, M.L., et al. (2001). Prevalence
of obstructive sleep apnea syndrome in
a cohort of 1,207 children in southern Italy. Chest,
120, 1930-1935.
Chervin, R.D., Dillon, J.E., Bassetti, C., et al. (1997). Symptoms
of sleep disorders, inattention, and
hyperactivity in children. Sleep, 20(2),
1185-1192.
Ferreira, A.M., Clemente, V., Gozal, D., et al. (2000). Snoring in
Portuguese primary school children.
Pediatrics, 106(5),
64-69.
Goldstein, N.A., Post, C., Rosenfeld, R.M., et al. (2000). Impact of
tonsillectomy and adenoidectomy
on child behavior. Archives of
Otolaryngology—Head and Neck Surgery,126,
494-498.
Gozal, D. (1998). Sleep disordered breathing and school performance
in children. Pediatrics, 102(3):
616-620.
Gozal, D. & Pope, D.W. (2001). Snoring during early childhood and
academic performance at ages
thirteen to fourteen years. Pediatrics, 107(6),
1394-1399.
Guilleminault, C., Winkle, R., Korobkin, R., et al.
(1982). Children and nocturnal snoring: Evaluation of the
effects of sleep related respiratory resistive load and
daytime functioning. European Journal of
Pediatrics, 139,
165-171.
Owens, J., Opipari, L., Nobile, C. (1998). Sleep and daytime
behavior in children with obstructive sleep
apnea and behavioral sleep disorders. Pediatrics,
102: 1178-1184.
Postic, S., Pasquariello, P., & Barank, C. (1986). Relief of upper
airway obstruction by
adenotonsillectomy. Otolaryngology-Head and Neck
Surgery, 94, 476-480.
Rhodes, S.K., Shimoda, K.C., Waid, L.R., et al. (1995).
Neurocognitive deficits in morbidly obese children
with obstructive sleep apnea. Journal of Pediatrics,
127, 741-744.
Richards, W. & Ferdman, R.M., (2000). Prolonged morbidity due to
delays in the diagnosis and treatment
of obstructive sleep apnea in children. Clinical
Pediatrics, 103-108.
Stradling, J.R., Thomas, G., Warley, A.R., et al. (1990). Effect of
adenotonsillectomy on nocturnal
hypoxemia, sleep disturbance, and symptoms in snoring
children. Lancet,335,249-253.
Weissbluth, M., Davis, A., & Poncher, J. (1983). Signs of airway
obstruction during sleep and behavior
development, and academic problems. Journal of
Development & Behavioral Pediatrics, 4, 119-121.
~~~~~~~~~~~~~~~~~~
Sleep Apnea and Learning in Adults
Research conducted by Clete Kushida, MD, PhD, RPSGT, Stanford Sleep
Disorders Clinic
Associate Professor of Psychiatry & Behavioral Sciences – Stanford
University
Is cognitive function affected by sleep interruption, as seen in
obstructive sleep apnea patients? Or is the decline in mental
functioning due to the decrease in oxygen during respiratory
obstruction, resulting in a loss of brain cells? Dr. Clete Kushida
of Stanford University believes that both are contributing
factors. Consistently, patients with obstructive sleep apnea perform
poorer on cognitive tasks in comparison to those without obstructive
sleep apnea. However, the more cognitive reserves (higher
intelligence, rapid mental processing, and capacity for memory
recall) a person has, the more insult the brain may be able to
withstand, mediating the effects on attention and learning. In sum,
the more neural pathways initially established for the processing of
information, the less a deficit, or even loss of brain cells, is
noticed.
For optimal health and mental restoration, we must experience
periods of consolidated sleep time (Beebe & Gozal, 2002). This
allows the brain to cycle through five consecutive stages of sleep,
generally lasting between 60-90 minutes to complete all sleep
stages. With each interruption in the sleep cycle due to respiratory
obstruction or otherwise, the brain cycles again from wake to stage
1 to stage 2, etc. This consistently interrupted cycle could
potentially prevent the brain from entering the 5th stage of sleep.
This last stage of sleep is REM sleep and is thought to support the
functions of cognitive processing, memory, and learning.
Article summarized by Margaret Papadakis, RPSGT, University of North
Carolina
Main Article:
Kushida, et al. (2006). The Apnea Positive Pressure Long-term
Efficacy Study (APPLES): Rationale, design, methods, and
procedures. Journal of Clinical Sleep Medicine, 2(3),
288-300.
More reading:
Beebe, D.W. & Gozal, D. (2002). Obstructive sleep apnea and the
prefrontal cortex: towards a comprehensive model linking
noctural upper airway obstruction to daytime cognitive
and behavioral deficits. Journal of Sleep Research, 11, 1-16.
~~~~~~~~~~~~~~~~~~
Sleep Apnea and Learning in Children
Obstructive Sleep Apnea (OSA) compromises brain functioning during
sleep by depriving the brain of sufficient oxygen and by fragmenting
sleep. When breathing is obstructed, the brain often responds by
causing the sleeper to move or change position, trying to open up
the breathing passages. This movement, however, may cause a partial
or complete arousal (awakening) from sleep, thereby interrupting
normal progression through the various sleep stages. The associated
oxygen deprivation and the accompanying sleep fragmentation may have
a long-term impact. Beebe and Gozal (2002) suggested that these
factors may particularly impair the functioning of the prefrontal
cortex, which plays an important role in executive cognition, such
as planning, decision-making, appropriately paying attention, and
controlling your behavior and emotions. When these cognitive
abilities are not functioning optimally, there are likely to be
consequences for academic performance, behavior, thinking, and
emotional control. For example, there is growing evidence that some
children who appear to have ADHD may also have symptoms of OSA or
another sleep disorder. Poor control of attention and behavior
could certainly appear to be symptoms of ADHD.
Another possibility is that OSA may affect behavior and cognition
simply by means of sleepiness. Few adults function optimally when
they are chronically sleepy, and neither do children. Obstructive
Sleep Apnea is classified as a dyssomnia, indicating that it may be
associated with excessive daytime sleepiness.
These behavioral, cognitive, and emotional changes may improve when
treatment of OSA improves sleep quality and blood gas levels. Not
all aspects of cognition, however, seem equally vulnerable to OSA.
It appears that different aspects of cognition are differentially
vulnerable to sleep loss. For example, Beebe and Gozal (2002)
predicted that executive cognition should be more impaired than
basic cognitive tasks such as simple calculation, word recognition,
or paying attention to something highly interesting. Likewise,
complex tasks may be the first to show the impact of poor sleep,
while simple or highly motivating tasks may be more resilient.
Results have been mixed with regard to general intelligence, memory,
and some aspects of executive cognition. As always, however,
caution in interpreting the available literature is called for since
not all studies find an impact of OSA.
The good news is that the negative impact of OSA may be reversible
in some cases. Friedman et al. (2003) used the Kaufman Assessment
Battery for Children to assess cognitive function before and 6-10
months after adenotonsillectomy for OSA. Thirty-nine children (ages
5-9 years) with OSA performed worse than healthy controls on several
subscales and the general scale Mental Processing Composite. Most
of these deficits improved to the level of the control group after
surgery.
Article summary by Jane Gaultney, PhD, Associate Professor of
Psychology, University of North Carolina at Charlotte
More reading:
Beebe, D. W. & Gozal, D. (2002). Obstructive sleep apnea and the
prefrontal cortex: Towards a comprehensive model linking
nocturnal upper airway obstruction to daytime cognitive and
behavioral deficits. Journal of Sleep Research, 11(1), 1-16.
Chervin et al. (2006). Sleep-disordered breathing, behavior, and
cognition in children before and after
adenotonsillectomy.
Pediatrics, 117, 769-778,
CCPL2.
Ebert, Jr., C. S. & Drake, A. F. (2004). The impact of
sleep-disordered breathing on cognition and behavior in children: A
review
and meta-synthesis of the literature. Otolaryngology –
Head and Neck Surgery, 131(6), 814-826.
Friedman, B. C. et al. (2003). Adenotonsillectomy improves
neurocognitive function in chilfen with Obstructive Sleep Apnea
Syndrome. Sleep, 26(8), 999-1005.
~~~~~~~~~~~~~~~~~~
Next Month's Topic
Our next issue of "Wake Up America!" will feature Dr. Amy Wolfson,
Ph.D., professor of psychology from Holy Cross University, who is
one of the leading experts researching and publishing information
on adolescent sleep problems and school starting times. Dr. Wolfson
will review some of the most important research in this area
including some of her own research. We will also provide some
advice on ways to help adolescents improve their sleep habits, which
usually results in better school performance and attendance.
