- Email: [email protected]
Pediatric sleep disorders: How can sleep-medicine make a difference?
Sleep Medicine Reviews (2009) 13, 107e110
www.elsevier.com/locate/smrv
GUEST EDITORIAL
Pediatric sleep disorders: How can sleep-medicine make a difference? Sleep problems in children are brought up regularly by parents to pediatricians. Many children are now referred for evaluation of sleep-related disorders, particularly obstructive sleep apnea. As health care providers, our focus should be on doing a better job of defining obstructive sleep apnea syndrome and recognizing sleep-related disorders in this pediatric group. Spicuzza and colleagues emphasized the importance of distinguishing between two groups; obese children with sleep-disordered breathing (SDB) and normal weight children with SDB. Both groups present differently and have differing clinical syndromes. This is an important differentiation, especially when considering metabolic and immunological changes that are present in obese children with SDB, as obesity induces health changes that are independent from an isolated upper airway problem. In children with predominant central obesity, many factors are in play and the upper airway problem is likely a consequence of obesity itself. Obese children may suffer from chest bellows inducing symptoms of SDB, particularly seen during rapid eye movement (REM) sleep with muscle atonia. Pulmonary function testing on obese children during wakefulness in supine position may be helpful to see if abdominal obesity is a contributing factor to abnormal breathing during sleep. Obese children have abnormal adipocyte activity, and the dysregulation of these cells leads to abnormal metabolic and immunological responses. Such abnormal responses are not associated with upper airway problems during sleep in normal weight children. Considering the obesity epidemic, it is important to understand the role of adipocytes, their circadian regulation and interaction between sleep and the secretions of various peptides from these cells. The distinction between
the obese child with SDB and co-morbidities from a normal weight child with SDB is therefore, a crucial one. Appropriate treatment options for sleep-related disorders in children are areas in need of further research. A normal weight child with SDB may be more amenable to the type of clinical trials suggested by Kuhle et al. However, little can be concluded from the review performed by these authors, as they failed to differentiate between the two groups clearly outlined by Spicuzza et al. to indicate the validity of trials. The authors indicated that there is a paucity of data on the validity of adeno-tonsillectomy in children with abnormal breathing during sleep. The discussion of the orthodontic literature dating back to the 1980s would have been useful, considering the role of nasal breathing during sleep on maxillo-mandibular growth1e3 and the role that adenoids and tonsils play in decreasing upper airway space. The authors mentioned that randomized treatment studies may be difficult to perform in children. A suggestion is to question how tonsillectomy is performed. As common as adeno-tonsillectomy may be in the otolaryngology practice, this procedure has been performed in several different ways. In our community we have witnessed three different surgical approaches: partial tonsillectomy with retention of the upper third of tonsils, resection of tonsils and fossa wall at the tonsillar interior limit, and emphasis on elimination of all tonsillar tissue followed by suturing lateral walls of the fossa together to avoid pulling of tissue with the advantage of decreasing risk of bleeding, pain and scarring (seen more commonly in second approach). Post-surgical scarring can be a longterm consequence of adeno-tonsillectomy and an unwanted consequence especially in an already
1087-0792/$ - see front matter ª 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.smrv.2008.11.002
108 small upper airway. It would be invaluable to have a study comparing the different surgical approaches of tonsillectomy and how each may change treatment outcomes in children with SDB.4 Alves et al. wrote a very useful review on sleep and neuromuscular disorders in children. Treatment of sleep-related disorders in this group decreases frequency of hospitalizations and improves quality of life.5 The use of nasal noninvasive positive pressure ventilation in infancy and young children during wakefulness is still a topic of debate, but the possible contribution to lung development in congenital syndromes is an important topic for future research. From recommendations made by the authors regarding the use of bilevel pressure, one could add further on the pressure differential between inspiratory (IPAP) and expiratory (EPAP) pressures. The authors indicate that neuromuscular weakness plays a role in the loss of coordination between upper airway dilators and effectiveness of positive inspiratory pressure. In this vulnerable group, a large differential between IPAP and EPAP should be avoided due to the variability of upper airway muscle contractions in relation to sleep stages and body position. A large differential may actually lead to partial airway obstruction as shown by the presence of flow limitation at the nose. In our practice we limit the IPAP and EPAP differential to a maximum of 6 cm of H2O in order to avoid iatrogenic induction of some degree of flow limitation. It is important to consider the use of a back-up respiratory rate, taking into account progression of the disease, tolerance by the patient and age. The ‘‘rise-time’’ (the speed at which airflow is delivered from expiration to inspiration) is a function available on bilevel machines and a critical factor to consider as it improves patient comfort and compliance. Finally, evaluation of nasal patency and initiating appropriate nasal treatment if necessary are essential in patient comfort and compliance with noninvasive positive pressure use. Simakajornboon et al. wrote an up-to-date review on RLS/PLMD in children and emphasized the negative impact of this condition on health and quality of life. The familial form of the syndrome seems to occur earlier in life than sporadic cases. Our youngest case was recognized at 6 months of age. Published diagnostic scales are not quite applicable to children and this is a handicap. As mentioned by the authors, dopamine agonists have been a successful treatment option in adults, however there is little information on children. We followed 5 of the 6 children who were placed on pramipexol for PLMs for 26e43 months and did not observe augmentation; they tolerated the drug
Guest editorial and had complete disappearance of PLMs, but had progressive increase of dosage overtime.6 Longterm studies on treatment efficacy for RLS/PLMD in children are lacking, and long-term effects of dopamine agonists should be systematically assessed including hormonal impact at time of puberty. Parasomnias are behavioral problems during sleep that may significantly disturb family life. Kotagal wrote a thorough review on this topic. He mentioned the possibility that parasomnias may be related to a familial form of frontal lobe seizure (and, rarely, a mesio-temporal focus).7 It is important to rule out a seizure disorder as it does involve about 1% of children presenting with a parasomnia. The most interesting development in the investigation of parasomnias has been the discovery that several sleep-related disorders are associated with NREM sleep parasomnias,8e10 and that treatment of the underlying sleep disorder may eliminate the parasomnias.9 When performing quantified electroencephalographic (EEG) analyses of each sleep cycle during the night, EEG recordings during sleep have shown that chronic sleepwalking and sleep-terrors were associated with an abnormal distribution of the delta power during total nocturnal sleep.11,12 These changes were correlated with the cyclic alternating pattern (CAP) analyses, demonstrating the usefulness of this sleep scoring system.13 There is an abnormal intrusion of CAP phase B interrupting the continuity of slow delta activity.14 Whether the abnormal CAP is an indication of the presence of another sleep-related disorder, or is a necessary element for recurrence of the parasomnia is a question that requires further investigation. It is worth pointing out that sleep enuresis (considered a parasomnia), has been eliminated when a child undergoes orthodontic treatment for SDB with rapid maxillary expansion (RME).15,16 RME expands the naso-maxillary complex and has been shown to be a successful treatment option for SDB in children.17 Recently, two different groups have questioned if bruxism is actually a ‘‘protective’’ mechanism developed in those with SDB in an effort to open the upper airway.18,19 Epidemiological studies have shown that SDB is the most common association with bruxism.20 Clearly, the investigation of the interaction between parasomnias and other nocturnal sleep disturbances needs to be pursued. Nevsimalova emphasized that there is an underdiagnosis of narcolepsy in the pediatric population. We would add that narcolepsy is often misdiagnosed. In our practice we see many
Pediatric sleep disorders teenagers who have already been placed on stimulants such as modafinil or amphetamine-based compounds, and most of the time the decision is based on limited information. As mentioned, sleep paralysis and hypnagogic hallucinations are also seen in the normal population and with any syndrome that causes daytime sleepiness. The diagnosis of cataplexy may be difficult if the event is not witnessed by a specialist familiar with the symptoms. Clinicians should be cautious when labeling a cataplectic event in the setting of ‘‘partial muscle weakness’’ lasting for more than 5 min and not triggered by obvious stimuli particularly laughter. Even though the HLA DQB1*0602 is a useful marker, it is important to keep in mind that a significant number of the population are positive for this haplotype without any evidence of narcolepsy. We frequently receive consultations on teenagers presenting with a history of great difficulty getting out of bed in the morning, having excessive daytime sleepiness, and showing two or more sleep-onset REM periods (SOREMP) on multiple sleep latency testing (MSLT). In these patients, we have found that a good clinical evaluation often reveals a narrow upper airway associated with a narrow naso-maxillary complex, and/ or a small mandible. The MSLT does show 2 or 3 SOREMP and mean sleep latency of 5e8 min. However, nocturnal polysomnogram (PSG) shows abnormalities that unfortunately have not been included in scoring recommendations from the Atlas of the American Academy of Sleep Medicine. On PSG there is intermittent snoring, and the nasal flow pressure transducer shows ‘‘flattening’’ of the peak of the flow wave contour for an extended period of time particularly during NREM sleep, signifying persistent airflow limitation. During REM sleep there are even greater disturbances with abnormal breathing. Considering the hemoglobine oxyhemoglobin dissociation curve, it is clear that the presence of a significant breathing disturbance is necessary before an oxygen desaturation of 3e 4% will take place in children with otherwise normal lungs, and therefore such oxygen desaturations are typically not present. This is misleading and results in inappropriate diagnoses (i.e., normal study) and recommendations, particularly if a sleep laboratory transmits raw data to a clinician who may not necessarily have experience in treating SDB in children. A common presentation in these pediatric cases is the complaint of morning fatigue leading to ‘‘sleeping in’’ on mornings particularly on weekends. This behavior is exaggerated with the onset of puberty. In two of our clinical cases where saliva was collected
109 every 90 min from 19:00 to 07:00 h, the peak of melatonin secretion was found to be between 05:00 and 06:00 h, which was clearly delayed compared to peers. Appropriate treatment of SDB resolved daytime sleepiness and eliminated SOREMP on MSLT. On the other hand, if facing an uncommon presentation it is wise to question a possible diagnosis of narcolepsy. For example, a female teenager whose only complaint was chronic insomnia, had been unresponsive to hypnotics for 2e3 years, and had difficulty with sleep initiation and maintenance despite the fact that she would feel sleepy by 20:00. She took short naps but still experienced daytime fatigue and gave much effort to school attendance. An MSLT can be somewhat helpful even if not a gold-standard diagnostic test as it may indicate abnormal sleepiness. However, keep in mind that the presence of 2 or 3 SOREMP is not a strong diagnostic criterion.21,22 As mentioned by the author, cerebrospinal fluid hypocretin measurement is a much better marker and the most definitive tool we have today for narcolepsy, and one should consider it when in doubt of the diagnosis. In summary, pediatric sleep disorders cover a very important aspect of pediatric medicine. It is vital that we give value to night and daytime symptoms, are able to recognize underlying causes and initiate appropriate treatment, as sleeprelated disorders in the pediatric population have been shown to have serious social and healthrelated consequences now and later on in life.
References 1. Linder-Aronson S. Dimensions of face and palate in nose breathers and habitual mouth breathers. Odont Rev 1969; 14:187e200. 2. Hershey HG, Stewart BL, Warren DW. Changes in nasal airway resistance associated with rapid maxillary expansion. Am J Orthod 1976;69:274e84. 3. Zettergreen L, Linder-Aronson S, Norlander B, Agren K, Svanborg E. Longitudinal effect on facial growth after tonsillectomy in children with obstructive sleep apnea. World J Orthod 2002;3:67e72. 4. Guilleminault C, Li KK, Khramtsov A, Pelayo R, Martinez S. Sleep-disordered breathing: surgical outcomes in prepubertal children. Laryngoscope 2004;114:132e7. 5. Robert D, Argaud L. Noninvasive positive ventilation in the treatment of sleep-related breathing disorders. Sleep Med 2007;8:441e52. 6. Martinez S, Guilleminault C. Periodic leg movements in prepubertal children with sleep disturbances. Dev Med Child Neurol 2004;46:765e70. 7. Pedley TA, Guilleminault C. Episodic nocturnal wanderings responsive to anticonvulsant drug therapy. Ann Neurol 1977;2:30e5. 8. Ohayon M, Guilleminault C, Priest R. How frequent are night terrors, sleep walking and confusional arousals in the
110
9.
10.
11.
12.
13.
14.
15.
16.
general population, their relationship to other sleep and mental disorders. J Clin Psychiatry 1999;60:268e76. Guilleminault C, Palombini L, Pelayo R, Chervin RD. Sleepwalking and night terrors in prepubertal children: what triggers them? Pediatrics 2003;111:e17e25. Goodwin JL, Kaeming KL, Fregosi RF, Rosen GM, Morgan WJ, Smith T, et al. Parasomnias and sleep-disordered breathing in Caucasian and Hispanic children e the Tucson children’s assessment of sleep apnea study. BMC Med 2004:2e 14.www.biomedical.com/1741-7015/2/14. Gaudreau H, Joncas S, Zadra A, Montplaisir J. Dynamics of slow-wave activity during NREM sleep of sleepwalkers and control subjects. Sleep 2000;23:755e60. Guilleminault C, Poyares D, Abat F, Palombini L. Sleep and wakefulness in somnambulism, a spectral analysis study. J Psychosom Res 2001;51:411e6. Zucconi M, Oldani A, Ferini-Strambi L, Smirne S. Arousal fluctuation in non-rapid eye movement parasomnia: the role of the cyclic alternating pattern as a measure of sleep instability. J Clin Neurophysiol 1995;12:147e54. Bruni O, Ferri R, Novelli L, Finotti E, Miano S, Guilleminault C. NREM sleep instability in children with sleep terrors: the role of slow-wave-activity interruptions. Clin Neurophysiol 2008;119:985e92. Kurol J, Modin H, Bjerkhoel A. Orthodontic maxillary expansion and its effect on nocturnal enuresis. Angle Orthod 1998;68:225e32. Timms DJ. Rapid maxillary expansion in the treatment of nocturnal enuresis. Angle Orthod 1990;60:229e34.
Guest editorial 17. Pirelli P, Saponara M, Guilleminault C. Rapid maxillary expansion in children with obstructive sleep apnea. Sleep 2004;27:761e6. 18. Khoury S, Rouleau GA, Rompre ´ PH, Mayer P, Montplaisir JY, Lavigne GJ. A significant increase in breathing amplitude precedes sleep bruxism. Chest 2008;134:332e7. 19. Simmons JH, Prehn RS. Nocturnal bruxism as a protective mechanism against obstructive breathing during sleep. Sleep 2008;31(Suppl. 1):A199. 20. Ohayon MM, Li KK, Guilleminault C. Risk factors for sleep bruxism in the general population. Chest 2001;119:53e61. 21. Bishop C, Rosenthal L, Roerhrs T, Roth T. The frequency of multiple sleep-onset REM periods among subjects with no excessive daytime sleepiness. Sleep 1996;19:727e30. 22. Mignot E, Lin L, Finn L, Lopes C, Pluff K, Sundstrom ML, et al. Correlates of sleep-onset REM periods during the multiple sleep latency tests in community adults. Brain 2006;129:1609e23.
Michelle Cao Christian Guilleminault* Stanford Sleep Medicine Program, Stanford University Medical School, Stanford, CA, USA *Corresponding author. E-mail address: [email protected] (C. Guilleminault)
www.elsevier.com/locate/smrv
GUEST EDITORIAL
Pediatric sleep disorders: How can sleep-medicine make a difference? Sleep problems in children are brought up regularly by parents to pediatricians. Many children are now referred for evaluation of sleep-related disorders, particularly obstructive sleep apnea. As health care providers, our focus should be on doing a better job of defining obstructive sleep apnea syndrome and recognizing sleep-related disorders in this pediatric group. Spicuzza and colleagues emphasized the importance of distinguishing between two groups; obese children with sleep-disordered breathing (SDB) and normal weight children with SDB. Both groups present differently and have differing clinical syndromes. This is an important differentiation, especially when considering metabolic and immunological changes that are present in obese children with SDB, as obesity induces health changes that are independent from an isolated upper airway problem. In children with predominant central obesity, many factors are in play and the upper airway problem is likely a consequence of obesity itself. Obese children may suffer from chest bellows inducing symptoms of SDB, particularly seen during rapid eye movement (REM) sleep with muscle atonia. Pulmonary function testing on obese children during wakefulness in supine position may be helpful to see if abdominal obesity is a contributing factor to abnormal breathing during sleep. Obese children have abnormal adipocyte activity, and the dysregulation of these cells leads to abnormal metabolic and immunological responses. Such abnormal responses are not associated with upper airway problems during sleep in normal weight children. Considering the obesity epidemic, it is important to understand the role of adipocytes, their circadian regulation and interaction between sleep and the secretions of various peptides from these cells. The distinction between
the obese child with SDB and co-morbidities from a normal weight child with SDB is therefore, a crucial one. Appropriate treatment options for sleep-related disorders in children are areas in need of further research. A normal weight child with SDB may be more amenable to the type of clinical trials suggested by Kuhle et al. However, little can be concluded from the review performed by these authors, as they failed to differentiate between the two groups clearly outlined by Spicuzza et al. to indicate the validity of trials. The authors indicated that there is a paucity of data on the validity of adeno-tonsillectomy in children with abnormal breathing during sleep. The discussion of the orthodontic literature dating back to the 1980s would have been useful, considering the role of nasal breathing during sleep on maxillo-mandibular growth1e3 and the role that adenoids and tonsils play in decreasing upper airway space. The authors mentioned that randomized treatment studies may be difficult to perform in children. A suggestion is to question how tonsillectomy is performed. As common as adeno-tonsillectomy may be in the otolaryngology practice, this procedure has been performed in several different ways. In our community we have witnessed three different surgical approaches: partial tonsillectomy with retention of the upper third of tonsils, resection of tonsils and fossa wall at the tonsillar interior limit, and emphasis on elimination of all tonsillar tissue followed by suturing lateral walls of the fossa together to avoid pulling of tissue with the advantage of decreasing risk of bleeding, pain and scarring (seen more commonly in second approach). Post-surgical scarring can be a longterm consequence of adeno-tonsillectomy and an unwanted consequence especially in an already
1087-0792/$ - see front matter ª 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.smrv.2008.11.002
108 small upper airway. It would be invaluable to have a study comparing the different surgical approaches of tonsillectomy and how each may change treatment outcomes in children with SDB.4 Alves et al. wrote a very useful review on sleep and neuromuscular disorders in children. Treatment of sleep-related disorders in this group decreases frequency of hospitalizations and improves quality of life.5 The use of nasal noninvasive positive pressure ventilation in infancy and young children during wakefulness is still a topic of debate, but the possible contribution to lung development in congenital syndromes is an important topic for future research. From recommendations made by the authors regarding the use of bilevel pressure, one could add further on the pressure differential between inspiratory (IPAP) and expiratory (EPAP) pressures. The authors indicate that neuromuscular weakness plays a role in the loss of coordination between upper airway dilators and effectiveness of positive inspiratory pressure. In this vulnerable group, a large differential between IPAP and EPAP should be avoided due to the variability of upper airway muscle contractions in relation to sleep stages and body position. A large differential may actually lead to partial airway obstruction as shown by the presence of flow limitation at the nose. In our practice we limit the IPAP and EPAP differential to a maximum of 6 cm of H2O in order to avoid iatrogenic induction of some degree of flow limitation. It is important to consider the use of a back-up respiratory rate, taking into account progression of the disease, tolerance by the patient and age. The ‘‘rise-time’’ (the speed at which airflow is delivered from expiration to inspiration) is a function available on bilevel machines and a critical factor to consider as it improves patient comfort and compliance. Finally, evaluation of nasal patency and initiating appropriate nasal treatment if necessary are essential in patient comfort and compliance with noninvasive positive pressure use. Simakajornboon et al. wrote an up-to-date review on RLS/PLMD in children and emphasized the negative impact of this condition on health and quality of life. The familial form of the syndrome seems to occur earlier in life than sporadic cases. Our youngest case was recognized at 6 months of age. Published diagnostic scales are not quite applicable to children and this is a handicap. As mentioned by the authors, dopamine agonists have been a successful treatment option in adults, however there is little information on children. We followed 5 of the 6 children who were placed on pramipexol for PLMs for 26e43 months and did not observe augmentation; they tolerated the drug
Guest editorial and had complete disappearance of PLMs, but had progressive increase of dosage overtime.6 Longterm studies on treatment efficacy for RLS/PLMD in children are lacking, and long-term effects of dopamine agonists should be systematically assessed including hormonal impact at time of puberty. Parasomnias are behavioral problems during sleep that may significantly disturb family life. Kotagal wrote a thorough review on this topic. He mentioned the possibility that parasomnias may be related to a familial form of frontal lobe seizure (and, rarely, a mesio-temporal focus).7 It is important to rule out a seizure disorder as it does involve about 1% of children presenting with a parasomnia. The most interesting development in the investigation of parasomnias has been the discovery that several sleep-related disorders are associated with NREM sleep parasomnias,8e10 and that treatment of the underlying sleep disorder may eliminate the parasomnias.9 When performing quantified electroencephalographic (EEG) analyses of each sleep cycle during the night, EEG recordings during sleep have shown that chronic sleepwalking and sleep-terrors were associated with an abnormal distribution of the delta power during total nocturnal sleep.11,12 These changes were correlated with the cyclic alternating pattern (CAP) analyses, demonstrating the usefulness of this sleep scoring system.13 There is an abnormal intrusion of CAP phase B interrupting the continuity of slow delta activity.14 Whether the abnormal CAP is an indication of the presence of another sleep-related disorder, or is a necessary element for recurrence of the parasomnia is a question that requires further investigation. It is worth pointing out that sleep enuresis (considered a parasomnia), has been eliminated when a child undergoes orthodontic treatment for SDB with rapid maxillary expansion (RME).15,16 RME expands the naso-maxillary complex and has been shown to be a successful treatment option for SDB in children.17 Recently, two different groups have questioned if bruxism is actually a ‘‘protective’’ mechanism developed in those with SDB in an effort to open the upper airway.18,19 Epidemiological studies have shown that SDB is the most common association with bruxism.20 Clearly, the investigation of the interaction between parasomnias and other nocturnal sleep disturbances needs to be pursued. Nevsimalova emphasized that there is an underdiagnosis of narcolepsy in the pediatric population. We would add that narcolepsy is often misdiagnosed. In our practice we see many
Pediatric sleep disorders teenagers who have already been placed on stimulants such as modafinil or amphetamine-based compounds, and most of the time the decision is based on limited information. As mentioned, sleep paralysis and hypnagogic hallucinations are also seen in the normal population and with any syndrome that causes daytime sleepiness. The diagnosis of cataplexy may be difficult if the event is not witnessed by a specialist familiar with the symptoms. Clinicians should be cautious when labeling a cataplectic event in the setting of ‘‘partial muscle weakness’’ lasting for more than 5 min and not triggered by obvious stimuli particularly laughter. Even though the HLA DQB1*0602 is a useful marker, it is important to keep in mind that a significant number of the population are positive for this haplotype without any evidence of narcolepsy. We frequently receive consultations on teenagers presenting with a history of great difficulty getting out of bed in the morning, having excessive daytime sleepiness, and showing two or more sleep-onset REM periods (SOREMP) on multiple sleep latency testing (MSLT). In these patients, we have found that a good clinical evaluation often reveals a narrow upper airway associated with a narrow naso-maxillary complex, and/ or a small mandible. The MSLT does show 2 or 3 SOREMP and mean sleep latency of 5e8 min. However, nocturnal polysomnogram (PSG) shows abnormalities that unfortunately have not been included in scoring recommendations from the Atlas of the American Academy of Sleep Medicine. On PSG there is intermittent snoring, and the nasal flow pressure transducer shows ‘‘flattening’’ of the peak of the flow wave contour for an extended period of time particularly during NREM sleep, signifying persistent airflow limitation. During REM sleep there are even greater disturbances with abnormal breathing. Considering the hemoglobine oxyhemoglobin dissociation curve, it is clear that the presence of a significant breathing disturbance is necessary before an oxygen desaturation of 3e 4% will take place in children with otherwise normal lungs, and therefore such oxygen desaturations are typically not present. This is misleading and results in inappropriate diagnoses (i.e., normal study) and recommendations, particularly if a sleep laboratory transmits raw data to a clinician who may not necessarily have experience in treating SDB in children. A common presentation in these pediatric cases is the complaint of morning fatigue leading to ‘‘sleeping in’’ on mornings particularly on weekends. This behavior is exaggerated with the onset of puberty. In two of our clinical cases where saliva was collected
109 every 90 min from 19:00 to 07:00 h, the peak of melatonin secretion was found to be between 05:00 and 06:00 h, which was clearly delayed compared to peers. Appropriate treatment of SDB resolved daytime sleepiness and eliminated SOREMP on MSLT. On the other hand, if facing an uncommon presentation it is wise to question a possible diagnosis of narcolepsy. For example, a female teenager whose only complaint was chronic insomnia, had been unresponsive to hypnotics for 2e3 years, and had difficulty with sleep initiation and maintenance despite the fact that she would feel sleepy by 20:00. She took short naps but still experienced daytime fatigue and gave much effort to school attendance. An MSLT can be somewhat helpful even if not a gold-standard diagnostic test as it may indicate abnormal sleepiness. However, keep in mind that the presence of 2 or 3 SOREMP is not a strong diagnostic criterion.21,22 As mentioned by the author, cerebrospinal fluid hypocretin measurement is a much better marker and the most definitive tool we have today for narcolepsy, and one should consider it when in doubt of the diagnosis. In summary, pediatric sleep disorders cover a very important aspect of pediatric medicine. It is vital that we give value to night and daytime symptoms, are able to recognize underlying causes and initiate appropriate treatment, as sleeprelated disorders in the pediatric population have been shown to have serious social and healthrelated consequences now and later on in life.
References 1. Linder-Aronson S. Dimensions of face and palate in nose breathers and habitual mouth breathers. Odont Rev 1969; 14:187e200. 2. Hershey HG, Stewart BL, Warren DW. Changes in nasal airway resistance associated with rapid maxillary expansion. Am J Orthod 1976;69:274e84. 3. Zettergreen L, Linder-Aronson S, Norlander B, Agren K, Svanborg E. Longitudinal effect on facial growth after tonsillectomy in children with obstructive sleep apnea. World J Orthod 2002;3:67e72. 4. Guilleminault C, Li KK, Khramtsov A, Pelayo R, Martinez S. Sleep-disordered breathing: surgical outcomes in prepubertal children. Laryngoscope 2004;114:132e7. 5. Robert D, Argaud L. Noninvasive positive ventilation in the treatment of sleep-related breathing disorders. Sleep Med 2007;8:441e52. 6. Martinez S, Guilleminault C. Periodic leg movements in prepubertal children with sleep disturbances. Dev Med Child Neurol 2004;46:765e70. 7. Pedley TA, Guilleminault C. Episodic nocturnal wanderings responsive to anticonvulsant drug therapy. Ann Neurol 1977;2:30e5. 8. Ohayon M, Guilleminault C, Priest R. How frequent are night terrors, sleep walking and confusional arousals in the
110
9.
10.
11.
12.
13.
14.
15.
16.
general population, their relationship to other sleep and mental disorders. J Clin Psychiatry 1999;60:268e76. Guilleminault C, Palombini L, Pelayo R, Chervin RD. Sleepwalking and night terrors in prepubertal children: what triggers them? Pediatrics 2003;111:e17e25. Goodwin JL, Kaeming KL, Fregosi RF, Rosen GM, Morgan WJ, Smith T, et al. Parasomnias and sleep-disordered breathing in Caucasian and Hispanic children e the Tucson children’s assessment of sleep apnea study. BMC Med 2004:2e 14.www.biomedical.com/1741-7015/2/14. Gaudreau H, Joncas S, Zadra A, Montplaisir J. Dynamics of slow-wave activity during NREM sleep of sleepwalkers and control subjects. Sleep 2000;23:755e60. Guilleminault C, Poyares D, Abat F, Palombini L. Sleep and wakefulness in somnambulism, a spectral analysis study. J Psychosom Res 2001;51:411e6. Zucconi M, Oldani A, Ferini-Strambi L, Smirne S. Arousal fluctuation in non-rapid eye movement parasomnia: the role of the cyclic alternating pattern as a measure of sleep instability. J Clin Neurophysiol 1995;12:147e54. Bruni O, Ferri R, Novelli L, Finotti E, Miano S, Guilleminault C. NREM sleep instability in children with sleep terrors: the role of slow-wave-activity interruptions. Clin Neurophysiol 2008;119:985e92. Kurol J, Modin H, Bjerkhoel A. Orthodontic maxillary expansion and its effect on nocturnal enuresis. Angle Orthod 1998;68:225e32. Timms DJ. Rapid maxillary expansion in the treatment of nocturnal enuresis. Angle Orthod 1990;60:229e34.
Guest editorial 17. Pirelli P, Saponara M, Guilleminault C. Rapid maxillary expansion in children with obstructive sleep apnea. Sleep 2004;27:761e6. 18. Khoury S, Rouleau GA, Rompre ´ PH, Mayer P, Montplaisir JY, Lavigne GJ. A significant increase in breathing amplitude precedes sleep bruxism. Chest 2008;134:332e7. 19. Simmons JH, Prehn RS. Nocturnal bruxism as a protective mechanism against obstructive breathing during sleep. Sleep 2008;31(Suppl. 1):A199. 20. Ohayon MM, Li KK, Guilleminault C. Risk factors for sleep bruxism in the general population. Chest 2001;119:53e61. 21. Bishop C, Rosenthal L, Roerhrs T, Roth T. The frequency of multiple sleep-onset REM periods among subjects with no excessive daytime sleepiness. Sleep 1996;19:727e30. 22. Mignot E, Lin L, Finn L, Lopes C, Pluff K, Sundstrom ML, et al. Correlates of sleep-onset REM periods during the multiple sleep latency tests in community adults. Brain 2006;129:1609e23.
Michelle Cao Christian Guilleminault* Stanford Sleep Medicine Program, Stanford University Medical School, Stanford, CA, USA *Corresponding author. E-mail address: [email protected] (C. Guilleminault)