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Sleep-related disorders in neurologic disease during childhood
Review Article
Sleep-Related Disorders in Neurologic Disease During Childhood Michael H. Kohrman, MD* and Paul R. Carney, MD† Sleep disorders commonly are associated with neurologic disorders in childhood. This review discusses primary sleep disorders that affect children with primary neurologic diseases. Primary sleep disorders are discussed as they relate to the primary neurologic disease. In addition, sleep disorders secondary to neurologic disorders commonly seen in the practice of pediatric neurology are reviewed. A useful sleep history to improve diagnostic and therapeutic interventions is outlined. Kohrman MH, Carney PR. Sleep-related disorders in neurologic disease during childhood. Pediatr Neurol 2000; 23:107-113.
Introduction Disorders of sleep have an impact on daily living for both patients and caregivers. Sleep disturbance and lack of restful sleep can masquerade as myriad of clinical problems, including inattention, depression, headache, and seizures. Although most neurologic disorders are well characterized during the waking state, descriptions of signs and disabilities are frequently poorly described during rapid eye movement (REM) and non–rapid eye movement (NREM) sleep. Physiologic changes associated with sleep can cause an alteration of signs and function during both REM and NREM sleep. These changes may include alterations in muscle tone, central control of autonomic functions, and changes in cortical neurotransmitter system interaction and balance. This review is limited to the topics outlined in Table 1. These topics were chosen because they represent a group of problems seen by the practicing pediatric neurologist. We have intentionally avoided a discussion of sleep pathophysiology and primary sleep disorders (narcolepsy, circadian rhythm disturbances, and sleep apnea syn-
From the *Department of Pediatrics; Section of Neurology; University of Chicago Pritzker School of Medicine; Chicago, Illinois and † Department of Pediatrics; Division of Neurology; University of Florida College of Medicine; Gainesville, Florida.
© 2000 by Elsevier Science Inc. All rights reserved. PII S0887-8994(00)00174-0 ● 0887-8994/00/$20.00
dromes), except as they relate to primary neurologic disease.
Insufficient Sleep Syndrome The most common cause of excessive daytime sleepiness in children and adults is most likely insufficient sleep syndrome. The child does not obtain sufficient nocturnal sleep to maintain daytime alertness [1]. It is most often overlooked when assessing the child with school problems. Pre-adolescents sleep approximately 9-10 hours per night [2]. Their daytime alertness, as measured by the multiple sleep latency test, yields average sleep latencies that are greater than 19 minutes [2]. During adolescence, the total sleep time remains constant, with total REM time increasing by approximately 5% [3]. Sleep latency, as measured by the multiple sleep latency test, decreases by 30%. Multiple sleep latency tests recorded from college students demonstrated mean sleep latency times of less than 6 minutes [3]. Daily sleep habits change between the pre-adolescent and adolescent period. The pre-adolescent sleeps on average 1 hour more on school nights than on non-school nights, and the adolescent tends to sleep more on non-school nights than on school nights. This behavior change produces a “sleep debt” created during the school week. The child attempts to compensate for the lack of sleep by increasing sleep on non-school nights. By late adolescence, this 2-3 hours of extra sleep each non-school/ work night is the equivalent of an extra night of sleep for the adolescent or adult each weekend. Increasing the daily nocturnal sleep improves daytime alertness and is therapeutic. Sleep logs usually confirm less than 7 hours of sleep at night. In conjunction with increased sleep on weekends, decreased sleep latency and an absence of significant arousals are highly suggestive of insufficient sleep syndrome [3]. Intrinsic disorders of sleep, affective disorders, and psychophysiologic insomnia should be excluded if behavioral modification is not successful.
Communications should be addressed to: Dr. Kohrman; 5841 S. Maryland Ave; MC 3055; Chicago, IL 60637. Received July 12, 1999; accepted March 13, 2000.
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Table 1. Sleep-related disorders in neurologic disease during childhood Insufficent sleep syndrome Sleep and epilepsy Electrical status epilepticus of sleep Frontal lobe epilepsy/nocturnal paroxysmal dystonia Benign rolandic epilepsy Rett syndrome Benign sleep myclonus Muscle disease and sleep Congenital myopathies Duchene’s dystropy Myotonic dystrophy Myasthenia gravis Depression Attention-deficit–hyperactivity disorder Tourette’s syndrome Insomnia Psychophysiologic insomnia Sleep state misperception Sleep-related breathing disorders Achondroplasia Chiari malformation Down syndrome Prader-Willi syndrome Blindness Irregular sleep-wake cycle Non–24-hour sleep-wake cycle Headache Cluster Tension Migraine
Sleep-Related Epilepsy Sleep-related epilepsy accounts for 30% of seizure disorders in children. In generalized seizure disorders, Janz [4] determined that 34% of seizures occurred from arousal, 45% only in sleep, and 21% both diurnally and nocturnally. Interictal activation is observed primarily in NREM sleep. Focal discharges during REM sleep were evident in approximately 25% of children with epilepsy who underwent nocturnal recordings. These discharges did not correlate with seizure semiology, seizure frequency, therapeutic agents, or patient age [5]. Frequent nocturnal seizures can fragment sleep, leading to impairment of daytime function. Antiepileptic agents are also believed to improve sleep abnormalities [6]. Children with epilepsy underperform in achievement testing compared with age and intelligence quotient–matched control groups. It is hypothesized that underachievement in some children may in part be secondary to poor daytime alertness resulting from sleep fragmentation [7]. The interactions between seizures, antiepileptic agents, and sleep require further study. Electrical Status Epilepticus of Sleep Subclinical electrical status epilepticus of sleep is associated with continuous bilateral spike-and-wave discharges occurring during 85% or more of NREM sleep. A
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prolonged duration of months to years is not uncommon and produces profound loss of intellectual function [1]. Most patients have previously demonstrated other seizure semiology. The syndrome is often refractory to therapy. Intellectual function may not improve after normalization of the electroencephalographic (EEG) recordings. Valproic acid is the drug of choice. The response to therapy is often poor. Multiple antiepileptic regimens, including steroids, have been used. Lamotrigine and topiramate should also be considered in monotherapy or polytherapy. Nocturnal Frontal Lobe Epilepsy Nocturnal frontal lobe epilepsy remains a diagnostic challenge. The episodes have been labeled as parasomnias, nocturnal episodic dystonia, and normal sleep movements. Seizures are often bizarre in character. Detection with surface EEG recordings is often difficult. Patients demonstrate several minimal (e.g., scratching or rubbing the nose and the head) and minor (e.g., pelvic thrusting or swinging with dystonic component) attacks. One half present with major episodes (e.g., sudden elevation of the head and trunk from the bed with complex behaviors) that occur mainly during NREM sleep. Motor attacks were characterized by stereotypy, sudden onset, short duration, and repetitiveness [8]. In 80%, epileptiform abnormalities were evident. An autosomal-dominant form has been described, with an average age at seizure onset of 8 years [9,10]. This mutation is associated with an alteration of a central nicotinic acetylcholine receptor. Nocturnal Events That May Mimic Epilepsy The parasomnias are often confused with seizure manifestations. Rarely, sleep walking can mimic partial complex seizures. Polysomnography often demonstrates events occurring during delta sleep. Extended EEG montages should be used to confirm nocturnal seizures. Sleep walking tends to occur during the first half of the night. If events occur during the early morning hours, a diagnosis of REM behavior disorder should be excluded. Confusional arousals and night terrors may also mimic nocturnal seizures. Rhythmic movement disorders consist of a group of rhythmic movements involving the head and neck. Head turning, head banging, and body rocking are observed, usually at sleep onset and may persist into light sleep [1]. They are often quite stereotyped and can be confused with partial seizures. Gastroesophageal reflux may result in pulmonary aspiration and exacerbate asthma. The syndrome may mimic central and obstructive apnea or seizure disorders. Events are temporally associated with feeding, and the diagnosis is confirmed by upper gastrointestinal studies or recording esophageal pH during sleep. Normal pH studies in children with frank clinical aspiration secondary to gastroesophageal reflux have been observed in children made NPO for the study.
Rett Syndrome
Sleep-Disordered Breathing
Although 67% of patients with Rett syndrome have hyperventilation and apnea while awake, sleep apnea is rare. During sleep, Marcus et al. [11] observed no difference in the duration of periodic breathing, number of episodes of central apnea with desaturation, or number of episodes of obstructive apnea or end-tidal carbon dioxide tension between patients with Rett syndrome and control patients. However, low sleep efficiency, long sleep-onset latency, and short and fragmented total sleep time are observed. A therapeutic trial of melatonin was effective in decreasing sleep-onset latency during 3 weeks of treatment [12]. Percy et al. [13] observed that naltrexone modified some of the respiratory disturbance in Rett syndrome. However, motor function loss and more rapid progression of the disorder suggested a deleterious effect of naltrexone [13]. Bromocriptine therapy demonstrated improvements in communication and relaxation in some of the patients; a more regular sleep pattern was observed in four, hyperpnea disappeared in five, and teeth grinding in three of 12 patients and a reduction in stereotypic hand activities occurred in five and signs of improved motor abilities in three patients [14].
Central and obstructive apneas are common complications for patients with muscle disease. Normal breathing requires the action of the diaphragm, intercostal muscles, and bulbar musculature. Obstruction can occur at the pharyngeal level because of primary bulbar weakness or because of the inability of the diaphragm and intercostal muscles to overcome the normal change in airway resistance produced by progression from waking to NREM sleep to REM sleep. This problem is intensified by the natural loss of intercostal muscle tone accompanying REM sleep [21]. Muscle fatigue producing hypoventilation occurs primarily in the early morning hours during REM sleep [22]. Diaphragmatic paralysis may result from birth trauma, surgical injury, myelopathies, poliomyelitis, syringomyelia, myopathies, and neuropathies. Hypoventilation and central apnea during REM sleep can be observed in patients with diaphragmatic paralysis, despite normal waking respiratory function. Therapy with diaphragmatic pacing or nocturnal ventilation may be necessary. Nocturnal oxygen supplementation may be of benefit if the carbondioxide drive is normal. Weakness of the diaphragm or intercostal muscles (or both) is often observed in patients with muscular dystrophy. The use of polysomnography to assess cardiorespiratory status and respiratory muscle fatigue in patients with Duchenne’s dystrophy demonstrates that the first sign of respiratory weakness is obstructive apnea during REM sleep in these patients [22]. The central control of respiration in patients with Duchenne’s dystrophy is normal. In contrast, patients with myotonic dystrophy have greater variability in waking tidal volumes and respiratory cycle times than normal and almost exclusively periodic breathing in light sleep (stage 1 and 2) [23]. Broughton et al. [24] demonstrated neuropsychologic abnormalities beyond those expected from daytime sleepiness in patients with myotonic dystrophy.
Benign Neonatal Sleep Myoclonus Synchronous myoclonic jerks of the arms and legs during quiet sleep are the hallmark of benign sleep myoclonus [1]. Asymmetry may be present, and myoclonus is not associated with EEG changes. Administration of diazepam exacerbates myoclonus [15]. The pathophysiologic mechanism of benign neonatal sleep myoclonus may be similar to the rat pup seizure model described by Moshe [16], in which exacerbation of seizures occurs in the rat pup with administration of diazepam, but the seizures were responsive to baclofen. In this example, benzodiazepine receptors in the brainstem change specificity as the rat matures, with expected seizure control in the adult rat with benzodiazepine administration [16]. Early in the course of infantile spasms, the EEG is often normal and may be confused with neonatal sleep myoclonus. Muscle Disease and Sleep Congenital Myopathies Hypoventilation is common in children with congenital myopathies, with desaturation at less than 90% for 49% of the total sleep time present in eight children in one study [17]. Respiratory abnormalities in nemaline myopathy were first observed in REM sleep [18]. Obstructive apnea has been reported in association with mitochondrial encephalomyopathy [19]. Chronic hypoventilation has been associated with increased brainstem gliosis. It is hypothesized that gliosis may play a role in the loss of central respiratory control in these patients [20].
Myasthenia Gravis Central and obstructive sleep apnea are the result of muscle weakness in myasthenia. Little has been published on sleep and children with myasthenia. In adults, 60% of patients have apnea and hypopnea during REM sleep. Cognitive testing demonstrates normal vigilance but decreased memory in myasthenic patients with sleep apnea [25]. The duration of illness also correlated with the severity of the apnea [26]. We prefer bi-level positive airway pressure (BiPAP) therapy with a constant rate to tracheostomy in severely affected children. Attention-Deficit–Hyperactivity Disorder Although the etiology of attention-deficit– hyperactivity disorder is multifactorial, sleep problems in this group of
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children are common. The behavioral effects of sleep fragmentation are different in children and adults. Most adults and older, usually obese, adolescents complain of excessive daytime sleepiness. This finding is thought to be secondary to the frequent arousals. The behavioral response of children is often one of paradoxical hyperactivity as they increase motor activity to stay awake. Emotional liability may also be observed [27]. Children tend to have obstructive hypopnea with relatively few complete apneic events. They tend to have less arousals and shorter arousals than adults with obstructive apnea. Severe obstructive sleep apnea can impair cognition in children [28]. Periodic leg movements can also produce sleep fragmentation. Frank symptoms of restless leg syndrome can also prolong sleep latency [29]. Picchetti et al. [29] recorded more than five periodic limb movements per hour in 18 of 27 patients with attention-deficit– hyperactivity disorder. Restless leg syndrome was clinically evident in eight of 18 patients. Tourette’s Syndrome The movements of Tourette’s syndrome can persist during sleep. Sleep complaints are commonly reported. Drake et al. [30] in a study of Tourette’s syndrome observed that patients had increased nocturnal awakenings and movements when tics persisted to sleep. The prevalence of sleep fragmentation and loss of slow-wave sleep was greatest in patients with Tourette’s syndrome and attention-deficit– hyperactivity disorder. Those patients with Tourette’s syndrome and obsessive-compulsive signs demonstrated increased sleep latency, decreased REM sleep, and decreased REM sleep latency [30]. Allen et al. [31] also demonstrated a similar correlation in male children with Tourette’s syndrome and attention-deficit– hyperactivity disorder using a sleep questionnaire. Most sleep problems identified by the questionnaire were arousal related. Insomnia
Sleep State Misperception Patients, who actually sleep normally, will misperceive the time spent asleep, resulting in the misperception of inadequate sleep [1]. Children often have little recollection of sleep events and an increased frequency of parasomnias; however, this sleep state misperception is a rare cause of insomnia in childhood. Both the sleep latency and total sleep times are normal [1]. Treatment is aimed at reassurance; hypnotics should be avoided.
Sleep-Related Breathing Disorders Chiari Malformation Breathing problems in Chiari malformations are variable. Rebreathing hyperoxic hypercapnic ventilatory and arousal responses are frequently blunted in older children with myelomeningocele and Chiari malformation type 2; isocapnic hypoxic rebreathing ventilatory responses are only rarely affected. The hypoxic ventilatory response is usually preserved in children with myelomeningocele and Chiari malformation type 2 [32]. In a recent polysomnographic study of 83 patients, 37% had no abnormalities, 42% had mild abnormalities, and 20% had moderate or severe abnormalities. Central apnea predominated in 12 of 17 patients in the moderate/severe group. Obstruction was observed in five of 17. Adenotonsillectomy did not improve obstruction in three of five patients, suggesting other abnormalities in pharyngeal muscle control were present. Thoracic or thoracolumbar myelomeningocele, previous posterior fossa decompression, and pulmonary function abnormalities were associated with an increased risk of sleep-disordered breathing [33]. The intracranial pressure may rise up to 50 cm H2O after the onset of obstruction in patients with myelomeningocele, hydrocephalus, Chiari malformation, or syringomyelia. Adenotonsillectomy resolves the pressure changes and airway obstruction. It is hypothesized that these pressure swings may contribute to syrinx formation in these patients [34].
Psychophysiologic Insomnia Psychologic stressors that hinder sleep onset may produce psychophysiologic insomnia [1]. Other than prolonged sleep latency, sleep is normal. Patients with psychophysiologic insomnia often sleep better away from home or when on vacation. Falling asleep while reading or watching television is common for these patients because they have difficulty falling asleep in bed. Patients develop an association of bed with their daily life stressors. Disassociating stress from the sleep environment, through relaxation techniques, self-hypnosis, and creating a “worry time” several hours before bedtime in which patients sit down and contemplate their problems, should be the first approach to therapy. Prolonged use of sedative/hypnotics is not recommended.
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Achondroplasia Three groups of children with achondroplasia have been identified: group 1, obstructive apnea produced by a relative adenotonsillar hypertrophy as a result of midfacial hypoplasia; group 2, obstructive apnea associated with muscle weakness, a small foramen magnum, and hydrocephalus; and group 3, severe respiratory problems, including cor pulmonale, resulting in death resulting from cardiorespiratory failure. Tasker et al. [35] proposed that the etiology of these abnormalities is consistent with localized alteration of chondrocranial development and is rostral, intermediary, and caudal in groups 1, 2, and 3, respectively.
Down Syndrome
Blindness
Although obstructive apnea is commonly observed secondary to airway hypotonia in patients with Down syndrome, central apnea is also observed in those with Down syndrome who have normal airway anatomy. These apneas are associated with significant desaturation [36]. Obstructive apnea in Down syndrome is not associated with obesity, age, or congenital heart disease [37]. Aggressive correction of airway abnormalities and follow-up polysomnography in any patient with changes in mental status is recommended [38]. Lefaivre et al. [39] have advocated uvulopalatopharyngoplasty in children with Down syndrome. However, this procedure may serve only as a temporary correction of the airway obstruction. In our experience, regrowth of the pharyngeal tissues in such children is not uncommon [39].
The mammalian circadian pacemaker, the suprachiasmatic nuclei [44], functions to entrain the 24-hour day/ night cycle and coordinates the activity of other pacemakers with external light stimuli. Light sensed by the retina is encoded by the suprachiasmatic nuclei by way of the retinal hypothalamic tract. Without external cues (zeitgeber), humans have a free running sleep-wake cycle of approximately 25 hours. The alteration of external cues or the inability to synchronize one’s internal clock with the external environmental clock results in circadian sleep disorders. Clinically, blindness causes a loss of entrainment, leading to an irregular sleep-wake pattern or the non–24-hour sleep-wake disorder. With an irregular sleepwake pattern a total disorganization of sleep and waking is present, although the total sleep time during the 24-hour period remains normal. The major sleep period and episodes of sleep and waking occur intermittently throughout the day [1]. This pattern is similar to normal infant sleep, but the sleep periods are shorter. The syndrome also occurs in patients with diffuse brain injury from trauma or perinatal insults [45]. Melatonin administration to mimic physiologic melatonin secretion may be of benefit in patients with severe brain injury [46]. Blindness is the most common cause of the non–24-hour sleep-wake disorder. Blind patients continually have a 1-2– hour daily delay in their sleep phase [1]. Evening melatonin administration in this group of patients is an effective method to synchronize the circadian rhythm of these individuals with external cues [47].
Prader-Willi Syndrome Obesity, hyperphagia, and developmental delay are the most common manifestations of Prader-Willi syndrome. The genetics of this disorder remain of great interest, with clinical manifestations of Prader-Willi syndrome present when a paternally derived deletion of chromosome 15q11q13 or maternal uniparental heterodisomy in this chromosomal region occurs. If the maternal deletion is inherited, these children manifest Angelman’s syndrome. Obesity can lead to obstructive sleep apnea in these patients; however, respiratory abnormalities may be present before obesity. These abnormalities include an increased frequency of apneas, a decreased nadir of oxygen saturation, an increased maximum heart rate, and a blunted respiratory response to hypercapnia during NREM sleep [40]. The sleep architecture is altered in patients with PraderWilli syndrome. Increased sleep time and slow-wave sleep during both daytime and nighttime testing are observed. Those patients with excessive daytime sleepiness or shortened nocturnal REM latencies demonstrate an increased number of REM periods and a decreased average REM interval between REM periods compared with patients with Prader-Willi syndrome and nonshortened nocturnal REM latencies and control groups, which consisted of narcoleptic patients and obese patients [41]. In other studies, adults and children with Prader-Willi syndrome demonstrated little or no sleep apnea, but REM-related oxygen desaturation was quite common, with its severity significantly correlating with increased obesity. The results of these studies suggest that these patients have upper airway resistance syndrome, resulting in REM fragmentation and excessive daytime sleepiness, rather than frank apnea [42]. Sleep disturbances are not consistently associated with specific chromosomal abnormalities. Excessive daytime sleepiness and sleep-onset REM periods may be more common in patients with paternal deletions than in those with maternal uniparental heterodisomy [43].
Headache Headache has been reported to coexist with primary sleep disorders and after sleep deprivation. A cluster headache typically occurs during the first REM period. Patients frequently report waking 1-2 hours after sleep onset with a headache. Episodic clusters usually last 2 weeks to 3 months. They are circannual and circadian in nature. Cluster periods are usually more frequent at the times of maximum and minimum daylight (i.e., 2 weeks after the summer and winter solstices). Several investigators have documented cluster headaches in patients with obstructive sleep apnea syndrome [48,49]. Anecdotal reports have suggested that treating the obstructive sleep apnea may prevent or lessen the incidence of cluster headaches. In adults, prospective studies have revealed a significant incidence of primary sleep disorders in patients with chronic headaches [50]. Identified sleep disorders have included obstructive sleep apnea syndrome, periodic leg movements, psychophysiologic insomnia, and fibromyalgia. All those with sleep disorders described disrupted sleep. Seventy percent of those with sleep disorders had been prescribed hypnotics because of complaints of poor sleep. Headache improved in all patients who were
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Table 2.
Components of sleep history
Bedtime Associated routines and rituals? When is lights-out time? How long does it take to fall asleep? Sleep-onset—sudden awakening? Are there hypnogogic hallucinations? Are there uncomfortable sensations? Are there uncontrolled movements? Nighttime behavior Are there arousals? When do arousals occur? How frequently do arousals occur? Are there behaviors associated with arousals? Does the child have difficulty falling asleep? Are there abnormal movements or sounds during the night? Does the child snore or have apnea? Is there enuresis or encorpresis? Does the child bite the tongue or is there blood on the bedclothes? In what position does the child sleep? Is the child restless? Morning awakening When does the child awaken? How long does it take for the child to be alert? Is the child refreshed? Is there sleep paralysis? Are there abnormal movements at arousal? Is there early morning headache, nausea, or vomiting? Daytime behavior Is the child sleepy during the day? When does this sleepiness manifest? Does the child nap during the daytime? How long is the nap? What is the length of time to fall alseep? Does the nap refresh? What is the child’s behavior on awakening? General concerns What is the duration of the problem? Is the source of concern related to the problem; the child, parent, or school, or a combination? Is there family or personal stress? Is there drug or alcohol use? Is there excessive caffeine use? Is the child depressed?
treated for their sleep disorder and not for their headache [50]. Headaches that occur mostly on waking have been observed in high association with sleep disorders [51]. In a cohort of 304 adult patients who completed a sleep questionnaire before undergoing polysomnography, 18% diagnosed with obstructive sleep apnea reported frequent morning headaches, 21% with other sleep disorders reported morning headaches, and 38% with no identifiable sleep disorder reported frequent morning headaches. Chronic headaches in one third of such patients may improve after treatment of obstructive sleep apnea [52]. Nocturnal sleep recordings with cassette EEG in patients with chronic headaches demonstrated reduced sleep time, sleep efficiency, decreased sleep latency, frequent awakenings, and reduced delta sleep [53]. Although patients with migraine exhibit increased REM sleep and REM latency, subjects with tension headaches have reduced
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REM sleep. Thus patients with an identifiable sleep disorder will present with a chief complaint of headache. The headaches will usually improve after the diagnosis and treatment of the sleep disorder. Future studies will help to identify patients with headache at risk of sleep disorders and the pathophysiology and treatment. In conclusion, sleep disorders are commonly observed in patients referred for neurologic problems. These problems are often not identified. Use of a careful sleep history will improve the diagnostic yield of the clinician. Table 2 provides a general outline for taking a sleep history in clinical practice [54]. The identification and treatment of a primary sleep disorder in many cases will improve the daytime functioning of these patients.
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SA, Stefanini MC. Respiratory patterns during sleep in Down’s syndrome: Importance of central apnoeas. J Sleep Res 1997;6:134-6. [37] Marcus CL, Keens TG, Bautista DB, von Pechmann WS, Ward SL. Obstructive sleep apnea in children with Down syndrome. Pediatrics 1991;88:132-9. [38] Jacobs IN, Gray RF, Todd NW. Upper airway obstruction in children with Down syndrome. Arch Otolaryngol Head Neck Surg 1996;122:945-50. [39] Lefaivre JF, Cohen SR, Burstein FD, et al. Down syndrome: Identification and surgical management of obstructive sleep apnea. Plast Reconstr Surg 1997;99:629-37. [40] Schluter B, Buschatz D, Trowitzsch E, Aksu F, Andler W. Respiratory control in children with Prader-Willi syndrome. Eur J Pediatr 1997;156:65-8. [41] Vgontzas AN, Bixler EO, Kales A, et al. Daytime sleepiness and REM abnormalities in Prader-Willi syndrome: Evidence of generalized hypoarousal. Int J Neurosci 1996;87:127-39. [42] Hertz G, Cataletto M, Feinsilver SH, Angulo M. Sleep and breathing patterns in patients with Prader Willi syndrome (PWS). Sleep 1993;16:366-71. [43] Vgontzas AN, Kales A, Seip J, et al. Relationship of sleep abnormalities to patient genotypes in Prader-Willi syndrome. Am J Med Genet 1996;67:478-82. [44] Mistlberger R, Rusak B. Mechanisms and models of the circadian timekeeping system. In: Kryger MH, Roth T, Dement WC, eds. Principles and practice of sleep medicine. Philadelphia: WB Saunders, 1989:141-52. [45] Ferber R. The sleeplessness in the child. In: Kryger MH, Roth T, Dement WC, eds. Principles and practice of sleep medicine. Philadelphia: WB Saunders, 1989:633-9. [46] Lewy A, Ahmed S, Jackson J, Sak R. Melatonin shifts circadian rhythms according to a phase response curve. Chronobiol Int 1992;9: 380-92. [47] Sack R, Lewy A, Blood M, Stevenson J, Keith D. Melatonin administration to blind people: Phase advances and entrainment. J Biol Rhythms 1991;6:249-61. [48] Kudrow L, McGinty DJ, Phillips ER, Stevenson M. Sleep apnea in cluster headache. Cephalgia 1984;4:33-8. [49] Buckle P, Kerr P, Dryger M. Nocturnal cluster headache associated with sleep apnea: A case report. Sleep 1993;16:487-9. [50] Pavia T, Farinha A, Martins A, Batista A, Guilleminault C. Chronic headaches and sleep disorders. Arch Intern Med 1997;157: 1701-5. [51] Aldrich MS, Chauncey JB. Are morning headaches part of obstructive sleep apnea syndrome? Arch Intern Med 1990;150:1265-7. [52] Poceta JS, Dalessio DJ. Identification and treatment of sleep apnea in patients with chronic headache. Headache 1995;35:586-9. [53] Drake ME, Pakalnis A, Andrews JM, Bogner JE. Nocturnal sleep recording with cassette EEG in chronic headache. Headache 1990;30:600-3. [54] Kohrman MH. Pediatric sleep disorders. In: Swaiman K, Ashwal S, eds. Pediatric neurology: Principles and practice, 3rd ed. St. Louis: Mosby, 1999:773-86.
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Sleep-Related Disorders in Neurologic Disease During Childhood Michael H. Kohrman, MD* and Paul R. Carney, MD† Sleep disorders commonly are associated with neurologic disorders in childhood. This review discusses primary sleep disorders that affect children with primary neurologic diseases. Primary sleep disorders are discussed as they relate to the primary neurologic disease. In addition, sleep disorders secondary to neurologic disorders commonly seen in the practice of pediatric neurology are reviewed. A useful sleep history to improve diagnostic and therapeutic interventions is outlined. Kohrman MH, Carney PR. Sleep-related disorders in neurologic disease during childhood. Pediatr Neurol 2000; 23:107-113.
Introduction Disorders of sleep have an impact on daily living for both patients and caregivers. Sleep disturbance and lack of restful sleep can masquerade as myriad of clinical problems, including inattention, depression, headache, and seizures. Although most neurologic disorders are well characterized during the waking state, descriptions of signs and disabilities are frequently poorly described during rapid eye movement (REM) and non–rapid eye movement (NREM) sleep. Physiologic changes associated with sleep can cause an alteration of signs and function during both REM and NREM sleep. These changes may include alterations in muscle tone, central control of autonomic functions, and changes in cortical neurotransmitter system interaction and balance. This review is limited to the topics outlined in Table 1. These topics were chosen because they represent a group of problems seen by the practicing pediatric neurologist. We have intentionally avoided a discussion of sleep pathophysiology and primary sleep disorders (narcolepsy, circadian rhythm disturbances, and sleep apnea syn-
From the *Department of Pediatrics; Section of Neurology; University of Chicago Pritzker School of Medicine; Chicago, Illinois and † Department of Pediatrics; Division of Neurology; University of Florida College of Medicine; Gainesville, Florida.
© 2000 by Elsevier Science Inc. All rights reserved. PII S0887-8994(00)00174-0 ● 0887-8994/00/$20.00
dromes), except as they relate to primary neurologic disease.
Insufficient Sleep Syndrome The most common cause of excessive daytime sleepiness in children and adults is most likely insufficient sleep syndrome. The child does not obtain sufficient nocturnal sleep to maintain daytime alertness [1]. It is most often overlooked when assessing the child with school problems. Pre-adolescents sleep approximately 9-10 hours per night [2]. Their daytime alertness, as measured by the multiple sleep latency test, yields average sleep latencies that are greater than 19 minutes [2]. During adolescence, the total sleep time remains constant, with total REM time increasing by approximately 5% [3]. Sleep latency, as measured by the multiple sleep latency test, decreases by 30%. Multiple sleep latency tests recorded from college students demonstrated mean sleep latency times of less than 6 minutes [3]. Daily sleep habits change between the pre-adolescent and adolescent period. The pre-adolescent sleeps on average 1 hour more on school nights than on non-school nights, and the adolescent tends to sleep more on non-school nights than on school nights. This behavior change produces a “sleep debt” created during the school week. The child attempts to compensate for the lack of sleep by increasing sleep on non-school nights. By late adolescence, this 2-3 hours of extra sleep each non-school/ work night is the equivalent of an extra night of sleep for the adolescent or adult each weekend. Increasing the daily nocturnal sleep improves daytime alertness and is therapeutic. Sleep logs usually confirm less than 7 hours of sleep at night. In conjunction with increased sleep on weekends, decreased sleep latency and an absence of significant arousals are highly suggestive of insufficient sleep syndrome [3]. Intrinsic disorders of sleep, affective disorders, and psychophysiologic insomnia should be excluded if behavioral modification is not successful.
Communications should be addressed to: Dr. Kohrman; 5841 S. Maryland Ave; MC 3055; Chicago, IL 60637. Received July 12, 1999; accepted March 13, 2000.
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Table 1. Sleep-related disorders in neurologic disease during childhood Insufficent sleep syndrome Sleep and epilepsy Electrical status epilepticus of sleep Frontal lobe epilepsy/nocturnal paroxysmal dystonia Benign rolandic epilepsy Rett syndrome Benign sleep myclonus Muscle disease and sleep Congenital myopathies Duchene’s dystropy Myotonic dystrophy Myasthenia gravis Depression Attention-deficit–hyperactivity disorder Tourette’s syndrome Insomnia Psychophysiologic insomnia Sleep state misperception Sleep-related breathing disorders Achondroplasia Chiari malformation Down syndrome Prader-Willi syndrome Blindness Irregular sleep-wake cycle Non–24-hour sleep-wake cycle Headache Cluster Tension Migraine
Sleep-Related Epilepsy Sleep-related epilepsy accounts for 30% of seizure disorders in children. In generalized seizure disorders, Janz [4] determined that 34% of seizures occurred from arousal, 45% only in sleep, and 21% both diurnally and nocturnally. Interictal activation is observed primarily in NREM sleep. Focal discharges during REM sleep were evident in approximately 25% of children with epilepsy who underwent nocturnal recordings. These discharges did not correlate with seizure semiology, seizure frequency, therapeutic agents, or patient age [5]. Frequent nocturnal seizures can fragment sleep, leading to impairment of daytime function. Antiepileptic agents are also believed to improve sleep abnormalities [6]. Children with epilepsy underperform in achievement testing compared with age and intelligence quotient–matched control groups. It is hypothesized that underachievement in some children may in part be secondary to poor daytime alertness resulting from sleep fragmentation [7]. The interactions between seizures, antiepileptic agents, and sleep require further study. Electrical Status Epilepticus of Sleep Subclinical electrical status epilepticus of sleep is associated with continuous bilateral spike-and-wave discharges occurring during 85% or more of NREM sleep. A
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prolonged duration of months to years is not uncommon and produces profound loss of intellectual function [1]. Most patients have previously demonstrated other seizure semiology. The syndrome is often refractory to therapy. Intellectual function may not improve after normalization of the electroencephalographic (EEG) recordings. Valproic acid is the drug of choice. The response to therapy is often poor. Multiple antiepileptic regimens, including steroids, have been used. Lamotrigine and topiramate should also be considered in monotherapy or polytherapy. Nocturnal Frontal Lobe Epilepsy Nocturnal frontal lobe epilepsy remains a diagnostic challenge. The episodes have been labeled as parasomnias, nocturnal episodic dystonia, and normal sleep movements. Seizures are often bizarre in character. Detection with surface EEG recordings is often difficult. Patients demonstrate several minimal (e.g., scratching or rubbing the nose and the head) and minor (e.g., pelvic thrusting or swinging with dystonic component) attacks. One half present with major episodes (e.g., sudden elevation of the head and trunk from the bed with complex behaviors) that occur mainly during NREM sleep. Motor attacks were characterized by stereotypy, sudden onset, short duration, and repetitiveness [8]. In 80%, epileptiform abnormalities were evident. An autosomal-dominant form has been described, with an average age at seizure onset of 8 years [9,10]. This mutation is associated with an alteration of a central nicotinic acetylcholine receptor. Nocturnal Events That May Mimic Epilepsy The parasomnias are often confused with seizure manifestations. Rarely, sleep walking can mimic partial complex seizures. Polysomnography often demonstrates events occurring during delta sleep. Extended EEG montages should be used to confirm nocturnal seizures. Sleep walking tends to occur during the first half of the night. If events occur during the early morning hours, a diagnosis of REM behavior disorder should be excluded. Confusional arousals and night terrors may also mimic nocturnal seizures. Rhythmic movement disorders consist of a group of rhythmic movements involving the head and neck. Head turning, head banging, and body rocking are observed, usually at sleep onset and may persist into light sleep [1]. They are often quite stereotyped and can be confused with partial seizures. Gastroesophageal reflux may result in pulmonary aspiration and exacerbate asthma. The syndrome may mimic central and obstructive apnea or seizure disorders. Events are temporally associated with feeding, and the diagnosis is confirmed by upper gastrointestinal studies or recording esophageal pH during sleep. Normal pH studies in children with frank clinical aspiration secondary to gastroesophageal reflux have been observed in children made NPO for the study.
Rett Syndrome
Sleep-Disordered Breathing
Although 67% of patients with Rett syndrome have hyperventilation and apnea while awake, sleep apnea is rare. During sleep, Marcus et al. [11] observed no difference in the duration of periodic breathing, number of episodes of central apnea with desaturation, or number of episodes of obstructive apnea or end-tidal carbon dioxide tension between patients with Rett syndrome and control patients. However, low sleep efficiency, long sleep-onset latency, and short and fragmented total sleep time are observed. A therapeutic trial of melatonin was effective in decreasing sleep-onset latency during 3 weeks of treatment [12]. Percy et al. [13] observed that naltrexone modified some of the respiratory disturbance in Rett syndrome. However, motor function loss and more rapid progression of the disorder suggested a deleterious effect of naltrexone [13]. Bromocriptine therapy demonstrated improvements in communication and relaxation in some of the patients; a more regular sleep pattern was observed in four, hyperpnea disappeared in five, and teeth grinding in three of 12 patients and a reduction in stereotypic hand activities occurred in five and signs of improved motor abilities in three patients [14].
Central and obstructive apneas are common complications for patients with muscle disease. Normal breathing requires the action of the diaphragm, intercostal muscles, and bulbar musculature. Obstruction can occur at the pharyngeal level because of primary bulbar weakness or because of the inability of the diaphragm and intercostal muscles to overcome the normal change in airway resistance produced by progression from waking to NREM sleep to REM sleep. This problem is intensified by the natural loss of intercostal muscle tone accompanying REM sleep [21]. Muscle fatigue producing hypoventilation occurs primarily in the early morning hours during REM sleep [22]. Diaphragmatic paralysis may result from birth trauma, surgical injury, myelopathies, poliomyelitis, syringomyelia, myopathies, and neuropathies. Hypoventilation and central apnea during REM sleep can be observed in patients with diaphragmatic paralysis, despite normal waking respiratory function. Therapy with diaphragmatic pacing or nocturnal ventilation may be necessary. Nocturnal oxygen supplementation may be of benefit if the carbondioxide drive is normal. Weakness of the diaphragm or intercostal muscles (or both) is often observed in patients with muscular dystrophy. The use of polysomnography to assess cardiorespiratory status and respiratory muscle fatigue in patients with Duchenne’s dystrophy demonstrates that the first sign of respiratory weakness is obstructive apnea during REM sleep in these patients [22]. The central control of respiration in patients with Duchenne’s dystrophy is normal. In contrast, patients with myotonic dystrophy have greater variability in waking tidal volumes and respiratory cycle times than normal and almost exclusively periodic breathing in light sleep (stage 1 and 2) [23]. Broughton et al. [24] demonstrated neuropsychologic abnormalities beyond those expected from daytime sleepiness in patients with myotonic dystrophy.
Benign Neonatal Sleep Myoclonus Synchronous myoclonic jerks of the arms and legs during quiet sleep are the hallmark of benign sleep myoclonus [1]. Asymmetry may be present, and myoclonus is not associated with EEG changes. Administration of diazepam exacerbates myoclonus [15]. The pathophysiologic mechanism of benign neonatal sleep myoclonus may be similar to the rat pup seizure model described by Moshe [16], in which exacerbation of seizures occurs in the rat pup with administration of diazepam, but the seizures were responsive to baclofen. In this example, benzodiazepine receptors in the brainstem change specificity as the rat matures, with expected seizure control in the adult rat with benzodiazepine administration [16]. Early in the course of infantile spasms, the EEG is often normal and may be confused with neonatal sleep myoclonus. Muscle Disease and Sleep Congenital Myopathies Hypoventilation is common in children with congenital myopathies, with desaturation at less than 90% for 49% of the total sleep time present in eight children in one study [17]. Respiratory abnormalities in nemaline myopathy were first observed in REM sleep [18]. Obstructive apnea has been reported in association with mitochondrial encephalomyopathy [19]. Chronic hypoventilation has been associated with increased brainstem gliosis. It is hypothesized that gliosis may play a role in the loss of central respiratory control in these patients [20].
Myasthenia Gravis Central and obstructive sleep apnea are the result of muscle weakness in myasthenia. Little has been published on sleep and children with myasthenia. In adults, 60% of patients have apnea and hypopnea during REM sleep. Cognitive testing demonstrates normal vigilance but decreased memory in myasthenic patients with sleep apnea [25]. The duration of illness also correlated with the severity of the apnea [26]. We prefer bi-level positive airway pressure (BiPAP) therapy with a constant rate to tracheostomy in severely affected children. Attention-Deficit–Hyperactivity Disorder Although the etiology of attention-deficit– hyperactivity disorder is multifactorial, sleep problems in this group of
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children are common. The behavioral effects of sleep fragmentation are different in children and adults. Most adults and older, usually obese, adolescents complain of excessive daytime sleepiness. This finding is thought to be secondary to the frequent arousals. The behavioral response of children is often one of paradoxical hyperactivity as they increase motor activity to stay awake. Emotional liability may also be observed [27]. Children tend to have obstructive hypopnea with relatively few complete apneic events. They tend to have less arousals and shorter arousals than adults with obstructive apnea. Severe obstructive sleep apnea can impair cognition in children [28]. Periodic leg movements can also produce sleep fragmentation. Frank symptoms of restless leg syndrome can also prolong sleep latency [29]. Picchetti et al. [29] recorded more than five periodic limb movements per hour in 18 of 27 patients with attention-deficit– hyperactivity disorder. Restless leg syndrome was clinically evident in eight of 18 patients. Tourette’s Syndrome The movements of Tourette’s syndrome can persist during sleep. Sleep complaints are commonly reported. Drake et al. [30] in a study of Tourette’s syndrome observed that patients had increased nocturnal awakenings and movements when tics persisted to sleep. The prevalence of sleep fragmentation and loss of slow-wave sleep was greatest in patients with Tourette’s syndrome and attention-deficit– hyperactivity disorder. Those patients with Tourette’s syndrome and obsessive-compulsive signs demonstrated increased sleep latency, decreased REM sleep, and decreased REM sleep latency [30]. Allen et al. [31] also demonstrated a similar correlation in male children with Tourette’s syndrome and attention-deficit– hyperactivity disorder using a sleep questionnaire. Most sleep problems identified by the questionnaire were arousal related. Insomnia
Sleep State Misperception Patients, who actually sleep normally, will misperceive the time spent asleep, resulting in the misperception of inadequate sleep [1]. Children often have little recollection of sleep events and an increased frequency of parasomnias; however, this sleep state misperception is a rare cause of insomnia in childhood. Both the sleep latency and total sleep times are normal [1]. Treatment is aimed at reassurance; hypnotics should be avoided.
Sleep-Related Breathing Disorders Chiari Malformation Breathing problems in Chiari malformations are variable. Rebreathing hyperoxic hypercapnic ventilatory and arousal responses are frequently blunted in older children with myelomeningocele and Chiari malformation type 2; isocapnic hypoxic rebreathing ventilatory responses are only rarely affected. The hypoxic ventilatory response is usually preserved in children with myelomeningocele and Chiari malformation type 2 [32]. In a recent polysomnographic study of 83 patients, 37% had no abnormalities, 42% had mild abnormalities, and 20% had moderate or severe abnormalities. Central apnea predominated in 12 of 17 patients in the moderate/severe group. Obstruction was observed in five of 17. Adenotonsillectomy did not improve obstruction in three of five patients, suggesting other abnormalities in pharyngeal muscle control were present. Thoracic or thoracolumbar myelomeningocele, previous posterior fossa decompression, and pulmonary function abnormalities were associated with an increased risk of sleep-disordered breathing [33]. The intracranial pressure may rise up to 50 cm H2O after the onset of obstruction in patients with myelomeningocele, hydrocephalus, Chiari malformation, or syringomyelia. Adenotonsillectomy resolves the pressure changes and airway obstruction. It is hypothesized that these pressure swings may contribute to syrinx formation in these patients [34].
Psychophysiologic Insomnia Psychologic stressors that hinder sleep onset may produce psychophysiologic insomnia [1]. Other than prolonged sleep latency, sleep is normal. Patients with psychophysiologic insomnia often sleep better away from home or when on vacation. Falling asleep while reading or watching television is common for these patients because they have difficulty falling asleep in bed. Patients develop an association of bed with their daily life stressors. Disassociating stress from the sleep environment, through relaxation techniques, self-hypnosis, and creating a “worry time” several hours before bedtime in which patients sit down and contemplate their problems, should be the first approach to therapy. Prolonged use of sedative/hypnotics is not recommended.
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Achondroplasia Three groups of children with achondroplasia have been identified: group 1, obstructive apnea produced by a relative adenotonsillar hypertrophy as a result of midfacial hypoplasia; group 2, obstructive apnea associated with muscle weakness, a small foramen magnum, and hydrocephalus; and group 3, severe respiratory problems, including cor pulmonale, resulting in death resulting from cardiorespiratory failure. Tasker et al. [35] proposed that the etiology of these abnormalities is consistent with localized alteration of chondrocranial development and is rostral, intermediary, and caudal in groups 1, 2, and 3, respectively.
Down Syndrome
Blindness
Although obstructive apnea is commonly observed secondary to airway hypotonia in patients with Down syndrome, central apnea is also observed in those with Down syndrome who have normal airway anatomy. These apneas are associated with significant desaturation [36]. Obstructive apnea in Down syndrome is not associated with obesity, age, or congenital heart disease [37]. Aggressive correction of airway abnormalities and follow-up polysomnography in any patient with changes in mental status is recommended [38]. Lefaivre et al. [39] have advocated uvulopalatopharyngoplasty in children with Down syndrome. However, this procedure may serve only as a temporary correction of the airway obstruction. In our experience, regrowth of the pharyngeal tissues in such children is not uncommon [39].
The mammalian circadian pacemaker, the suprachiasmatic nuclei [44], functions to entrain the 24-hour day/ night cycle and coordinates the activity of other pacemakers with external light stimuli. Light sensed by the retina is encoded by the suprachiasmatic nuclei by way of the retinal hypothalamic tract. Without external cues (zeitgeber), humans have a free running sleep-wake cycle of approximately 25 hours. The alteration of external cues or the inability to synchronize one’s internal clock with the external environmental clock results in circadian sleep disorders. Clinically, blindness causes a loss of entrainment, leading to an irregular sleep-wake pattern or the non–24-hour sleep-wake disorder. With an irregular sleepwake pattern a total disorganization of sleep and waking is present, although the total sleep time during the 24-hour period remains normal. The major sleep period and episodes of sleep and waking occur intermittently throughout the day [1]. This pattern is similar to normal infant sleep, but the sleep periods are shorter. The syndrome also occurs in patients with diffuse brain injury from trauma or perinatal insults [45]. Melatonin administration to mimic physiologic melatonin secretion may be of benefit in patients with severe brain injury [46]. Blindness is the most common cause of the non–24-hour sleep-wake disorder. Blind patients continually have a 1-2– hour daily delay in their sleep phase [1]. Evening melatonin administration in this group of patients is an effective method to synchronize the circadian rhythm of these individuals with external cues [47].
Prader-Willi Syndrome Obesity, hyperphagia, and developmental delay are the most common manifestations of Prader-Willi syndrome. The genetics of this disorder remain of great interest, with clinical manifestations of Prader-Willi syndrome present when a paternally derived deletion of chromosome 15q11q13 or maternal uniparental heterodisomy in this chromosomal region occurs. If the maternal deletion is inherited, these children manifest Angelman’s syndrome. Obesity can lead to obstructive sleep apnea in these patients; however, respiratory abnormalities may be present before obesity. These abnormalities include an increased frequency of apneas, a decreased nadir of oxygen saturation, an increased maximum heart rate, and a blunted respiratory response to hypercapnia during NREM sleep [40]. The sleep architecture is altered in patients with PraderWilli syndrome. Increased sleep time and slow-wave sleep during both daytime and nighttime testing are observed. Those patients with excessive daytime sleepiness or shortened nocturnal REM latencies demonstrate an increased number of REM periods and a decreased average REM interval between REM periods compared with patients with Prader-Willi syndrome and nonshortened nocturnal REM latencies and control groups, which consisted of narcoleptic patients and obese patients [41]. In other studies, adults and children with Prader-Willi syndrome demonstrated little or no sleep apnea, but REM-related oxygen desaturation was quite common, with its severity significantly correlating with increased obesity. The results of these studies suggest that these patients have upper airway resistance syndrome, resulting in REM fragmentation and excessive daytime sleepiness, rather than frank apnea [42]. Sleep disturbances are not consistently associated with specific chromosomal abnormalities. Excessive daytime sleepiness and sleep-onset REM periods may be more common in patients with paternal deletions than in those with maternal uniparental heterodisomy [43].
Headache Headache has been reported to coexist with primary sleep disorders and after sleep deprivation. A cluster headache typically occurs during the first REM period. Patients frequently report waking 1-2 hours after sleep onset with a headache. Episodic clusters usually last 2 weeks to 3 months. They are circannual and circadian in nature. Cluster periods are usually more frequent at the times of maximum and minimum daylight (i.e., 2 weeks after the summer and winter solstices). Several investigators have documented cluster headaches in patients with obstructive sleep apnea syndrome [48,49]. Anecdotal reports have suggested that treating the obstructive sleep apnea may prevent or lessen the incidence of cluster headaches. In adults, prospective studies have revealed a significant incidence of primary sleep disorders in patients with chronic headaches [50]. Identified sleep disorders have included obstructive sleep apnea syndrome, periodic leg movements, psychophysiologic insomnia, and fibromyalgia. All those with sleep disorders described disrupted sleep. Seventy percent of those with sleep disorders had been prescribed hypnotics because of complaints of poor sleep. Headache improved in all patients who were
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Table 2.
Components of sleep history
Bedtime Associated routines and rituals? When is lights-out time? How long does it take to fall asleep? Sleep-onset—sudden awakening? Are there hypnogogic hallucinations? Are there uncomfortable sensations? Are there uncontrolled movements? Nighttime behavior Are there arousals? When do arousals occur? How frequently do arousals occur? Are there behaviors associated with arousals? Does the child have difficulty falling asleep? Are there abnormal movements or sounds during the night? Does the child snore or have apnea? Is there enuresis or encorpresis? Does the child bite the tongue or is there blood on the bedclothes? In what position does the child sleep? Is the child restless? Morning awakening When does the child awaken? How long does it take for the child to be alert? Is the child refreshed? Is there sleep paralysis? Are there abnormal movements at arousal? Is there early morning headache, nausea, or vomiting? Daytime behavior Is the child sleepy during the day? When does this sleepiness manifest? Does the child nap during the daytime? How long is the nap? What is the length of time to fall alseep? Does the nap refresh? What is the child’s behavior on awakening? General concerns What is the duration of the problem? Is the source of concern related to the problem; the child, parent, or school, or a combination? Is there family or personal stress? Is there drug or alcohol use? Is there excessive caffeine use? Is the child depressed?
treated for their sleep disorder and not for their headache [50]. Headaches that occur mostly on waking have been observed in high association with sleep disorders [51]. In a cohort of 304 adult patients who completed a sleep questionnaire before undergoing polysomnography, 18% diagnosed with obstructive sleep apnea reported frequent morning headaches, 21% with other sleep disorders reported morning headaches, and 38% with no identifiable sleep disorder reported frequent morning headaches. Chronic headaches in one third of such patients may improve after treatment of obstructive sleep apnea [52]. Nocturnal sleep recordings with cassette EEG in patients with chronic headaches demonstrated reduced sleep time, sleep efficiency, decreased sleep latency, frequent awakenings, and reduced delta sleep [53]. Although patients with migraine exhibit increased REM sleep and REM latency, subjects with tension headaches have reduced
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REM sleep. Thus patients with an identifiable sleep disorder will present with a chief complaint of headache. The headaches will usually improve after the diagnosis and treatment of the sleep disorder. Future studies will help to identify patients with headache at risk of sleep disorders and the pathophysiology and treatment. In conclusion, sleep disorders are commonly observed in patients referred for neurologic problems. These problems are often not identified. Use of a careful sleep history will improve the diagnostic yield of the clinician. Table 2 provides a general outline for taking a sleep history in clinical practice [54]. The identification and treatment of a primary sleep disorder in many cases will improve the daytime functioning of these patients.
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