Sleep-Wake Disorders in Childhood

PURPOSE OF REVIEW

The presentation of sleep issues in childhood differs from the presentation in adulthood and may be more subtle. Sleep issues may affect children differently than adults, and distinct treatment approaches are often used in children.

RECENT FINDINGS

Sodium oxybate was approved by the US Food and Drug Administration (FDA) in October 2018 for an expanded indication of treatment of sleepiness or cataplexy in patients with narcolepsy type 1 or narcolepsy type 2 aged 7 years or older, with side effect and safety profiles similar to those seen in adults. Restless sleep disorder is a recently proposed entity in which restless sleep, daytime sleepiness, and often iron deficiency are observed, but children do not meet the criteria for restless legs syndrome or periodic limb movement disorder.

SUMMARY

Children's sleep is discussed in this article, including normal sleep patterns and effects of insufficient sleep. Sleep disorders of childhood are reviewed, including insomnia, obstructive sleep apnea, restless legs syndrome, parasomnias, narcolepsy, and Kleine-Levin syndrome. Children with neurologic issues or neurodevelopmental disorders frequently have sleep disorders arising from an interaction of heterogeneous factors. Further attention to sleep may often be warranted through a polysomnogram or referral to a pediatric sleep specialist. Sleep disorders may cause indelible effects on children's cognitive functioning, general health, and well-being, and awareness of sleep disorders is imperative for neurologists who treat children.

Neuroimaging in the Kleine-Levin Syndrome

PURPOSE OF REVIEW

The purpose was to review the most recent literature on neuroimaging in the Kleine-Levin syndrome (KLS). We aimed to investigate if frontotemporal and thalamic dysfunction are key KLS signatures, and if recent research indicates other brain networks of interest that elucidate KLS symptomatology and aetiology.

RECENT FINDINGS

In a comprehensive literature search, we found 12 original articles published 2013-2018. Most studies report deviations related to cerebral perfusion, glucose metabolism, or blood-oxygen-level-dependent responses in frontotemporal areas and/or the thalamus. Studies also report dysfunction in the temporoparietal junction and the oculomotor network that also were related to clinical parameters. We discuss these findings based on recent research on thalamocortical networks and brain stem white matter tracts. The hypothesis of frontotemporal and thalamic involvement in KLS was confirmed, and additional findings in the temporoparietal junction and the oculomotor system suggest a broader network involvement, which can be investigated by future high-resolution and multimodal imaging.

The sleep architecture of Saudi Arabian patients with Kleine-Levin syndrome

OBJECTIVES

To establish baseline sleep architecture during an acute attack of Kleine-Levin syndrome (KLS) in a cohort of Saudi Arabian KLS patients and compare these characteristics with other published cohorts. Methods: This was a retrospective cohort study of the polysomnographic characteristics of 10 typical symptomatic Saudi Arabian KLS patients attending the University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia between 2002 and 2015. Data were captured by nocturnal polysomnography during an acute attack of hypersomnia and compared with other published cohorts identified via a systematic literature search.  Results: Self-reported time asleep during episodes (11.1±6.7 hours) and recorded total sleep time (TST) (322.5±108.7 minutes) were generally shorter than other published cohorts. Sleep efficiency was poor at 75.0%±25.1%, with low relative amounts of rapid eye movement (REM) sleep (16.5±5.9% of TST) and deep non-REM sleep (stage N3; 10.5±6.0% of TST) and high relative amounts of non-REM sleep (stage N1; 7.0±4.3% of TST). The sleep architecture of Saudi Arabian KLS patients was similar to other published cohorts.  Conclusions: Sleep architecture of our cohort was relatively normal and broadly similar to other published studies, the main features being low sleep efficiency and low relative amounts of REM and stage N3 sleep. Time-course polysomnography studies with functional imaging may be useful to further establish the exact pathophysiology of this disease.

Kleine-Levin syndrome. Familial cases and comparison with sporadic cases

Objectives:

To highlight the occurrence of familial cases and addresses, whether familial Kleine-Levine syndrome (KLS) presents the same spectrum of disease, as that seen in sporadic KLS.

Methods:

Between September and December 2014, reports of familial cases of KLS were identified by searching the Library of Congress, PubMed, and Web of Science databases restricted to the English language, with no restriction on date of publication. All cases were reviewed to identify familial cases consistent with current diagnostic criteria for sporadic KLS.

Results:

Six reviews and 11 case reports describing cases of familial KLS were identified. In 17 of the 29 familial cases identified, sufficient clinical details were described to be confident that these cases were familial and consistent with the description of KLS in the International Classification of Sleep Disorders 3rd edition (ICSD-3), and recent detailed reviews of sporadic KLS.

Conclusion:

A significant number of familial cases of KLS have been described that are consistent with the ICSD-3 description of KLS, and indistinguishable from sporadic KLS. This suggests that study of familial KLS using modern genetic techniques may be useful in elucidating the pathogenesis of this rare condition.

Kleine-Levin syndrome: the first typical case in Thailand

Kleine-Levin syndrome (KLS) is a rare disorder characterized by periodic hypersomnia, cognitive and behavioral disturbances. Other unique symptoms in KLS are megaphagia, hypersexuality and some psychiatric disturbances such as compulsion and depression. Definite diagnosis requires the elimination of other potential etiologies. We reported a typical case of KLS in a young Thai man who suffered from seven episodes of periodic hypersomnia within 1.5 years and eventually he was diagnosed with Kleine-Levin syndrome after excluding known possible neurological conditions and sleep disorders.

[Kleine-Levin syndrome]

KLeine-Levin Syndrome (KLS) is a rare disease characterized by recurrent episodes of hypersomnia associated with cognitive and behavioral disturbances, compulsive eating behavior and hypersexuality. Episodes are separated by weeks or months of normal sleep and behavior. The disease predominantly affects adolescent males. The median duration of the disease is eight years. Fifteen percent of the KLS population is of Jewish origin and the incidence reported in Israel is unproportionately high. The etiology and pathophysiology are unknown. The current concept is that the disease is caused by genetic predisposition combined with environmental factors. Autoimmune etiology has also been suggested. KLS poses diagnostic and therapeutic challenges. Diagnosis is usually based on clinical manifestations. Physical examination including neurological evaluation is usually normal. EEG, brain imaging and CSF examination are normal. Stimulants are partially effective on sleepiness. Lithium was reported to induce positive effects in preventing or delaying recurrences. Increased awareness to KLS among physicians in Israel is important due to the relatively higher incidence of KLS among Jewish and IsraeLi patients.

Gabapentin for Kleine-Levin syndrome

We describe a 17-year-old girl with Kleine-Levin syndrome (KLS), in which gabapentin was effective for the prevention of attacks. (99)mTc-ECD SPECT revealed hyperperfusion of the thalamus and nucleus accumbens presenting in the symptomatic period, suggesting epilepsy-like neuronal discharge from these structures. Treatment for KLS has not been established, although lithium has been used in limited cases with insignificant efficacy. Here, we report a case of recurrent hypersomnia in which gabapentin was effective for the prevention of attacks. We speculate that the recurrent hypersomnia and behaviour disturbance are related to epilepsy-like neuronal discharge from the thalamus due to dysfunction in GABAnergic receptors.

Atypical Kleine–Levin syndrome: Can insomnia and anorexia be features too?

BACKGROUND

Kleine-Levin syndrome is an uncommon disorder with recurrent episodes of hypersomnia, clearly associated with behavioral abnormalities like binge eating, hypersexuality and abnormal behavior. Many patients may not necessarily fulfill minimum criteria described for diagnosis. We aim to report such patients with atypical presentation resembling the Kleine-Levin syndrome.

METHOD

We evaluated all patients at our clinic who had episodic disturbance in sleep and/or appetite lasting a few days to weeks, not necessarily fulfilling the International Classification of Sleep Disorders (ICSD) criteria for a diagnosis of Kleine-Levin syndrome, over 4 years. All clinical details, especially regarding sleep, appetite and behaviour during episodes, about prior and co-existing illnesses were noted. All patients were investigated with brain magnetic resonance imaging (MRI), electroencephalogram (EEG) and some with polysomnography.

RESULTS

Eighteen patients (5 females, 13 males) ranging in age from 12 to 55 years (median 18 years) were included in the study. The median duration of symptoms was 1.5 years, and the median number of episodes in each patient was six. The range of episode length was 18-300 h with a mean of 91.2h. Fourteen patients had a history of hypersomnia, 3 had only insomnia and 3 had both during their episodes, while 5 patients reported hyperphagia, 11 reduced appetite and 2 no change in appetite. Ictal EEG revealed evidence of sleep, while polysomnography showed reduced rapid eye movement (REM) latency and normal sleep architecture during the episode. MRI was normal in all patients, except one who showed non-specific abnormalities. All patients showed improvement with carbamazepine.

CONCLUSION

There are many patients with episodic alteration in sleep, appetite and behaviour with a course and treatment response similar to the classical Kleine-Levin syndrome, who otherwise do not fit the classical description for diagnosis of this condition.

Episodic Diencephalic Hypoperfusion in Kleine-Levin Syndrome

A 22 year-old woman suffered from recurrent episodes of hypersomnia, apathy, and hyperphagia. The symptoms occurred 3 to 4 times per year, and each attack lasted 2 to 3 weeks. 99mTc-ethylcysteinate dimer brain single photon emission computed tomography (SPECT) was performed during symptomatic and asymptomatic periods. To localize brain regions with perfusion changes during symptomatic period, asymptomatic SPECT was subtracted from symptomatic SPECT. The subtracted SPECT showed significant hypoperfusion in the left hypothalamus, bilateral thalami, basal ganglia, bilateral medial and dorsolateral frontal regions, and left temporal lobe during the symptomatic period. These cerebral hypoperfusion areas support the diencephalic hypothesis and clinical symptoms of Kleine-Levin syndrome.

SPECT findings in the Kleine-Levin syndrome

STUDY OBJECTIVES

The Kleine-Levin Syndrome, is a rare disorder with onset during teenage years, but little is known on etiopathogenesis. Seven subjects with Kleine-Levin Syndrome accumulated over time had systematic SPECT studies during (n=5) and out (n=7) of the symptomatic period.

SUBJECTS

Seven boys with symptom onset between 11 and 17 years of age and at least 2 episodes per year were followed for a mean of 6 years.

METHODS

Electroencephalogram awake-asleep, computed tomography scan, and magnetic resonance imaging studies were performed before Tc-99m ECD single photon emission tomography (SPECT) obtained during day 4 or 5 (n=5) and at least 1 month away from the symptomatic period (n=7).

RESULTS

All imaging tests except SPECT were normal. Hypoperfusion of both thalami were seen during the symptomatic period that completely disappeared during the asymptomatic period. Hypoperfusion in other regions were also noted in some, but not all subjects. They persisted during the asymptomatic period in 2 cases over the temporal lobe (2/7 cases), frontal lobe (1/7 cases), and basal ganglia (1/7 cases). The largest amount of persistent hypoperfusion was seen in the subject with longest clinical evolution.

CONCLUSION

Hypoperfusion of the thalamus is a consistent finding during the symptomatic period, but perfusion abnormalities may persist even during the asymptomatic period. The longer the duration of the syndrome, the more extended the hypoperfusion regions during the asymptomatic period.

Short-term memory dysfunction in Kleine-Levin syndrome

BACKGROUND

A previous investigation at our department of a young man with typical Kleine-Levin syndrome revealed short-term memory dysfunction as well as hypoperfusion of the temporal lobes on single photon emission tomography (SPECT) (CERETEC) examination, 6 and 7 years after recovery, suggesting long lasting or even permanent cerebral dysfunction.

PATIENTS AND METHODS

We investigated four cases with classical adolescent Kleine-Levin syndrome characterized by hypersomnia and typical associated symptoms. We used neuropsychological testing and SPECT (CERETEC) of the brain. The results from the previous report related to above is included.

RESULTS

Examination with SPECT (CERETEC) during remission revealed hypoperfusion of the temporal lobes and fronto-temporal region in two of four cases. There were normal findings in two. Neuropsychological testing performed during remission showed reduction in the short-term memory capacity in all four cases.

CONCLUSION

It is striking that all the cases investigated showed short-term memory dysfunction. One patient who had recovered from paroxysmal symptoms (hypersomnia attacks and bulimia) 6 years earlier showed progress in the short-term memory dysfunction. A pathologic condition in the temporal lobes may be suspected in Kleine-Levin syndrome.

Photosensitivity during the hypersomnic phase in a patient with Kleine-Levin syndrome

The case of an adolescent with Kleine-Levin syndrome is presented who exhibited a consistent and predictable photoparoxysmal self-limited response to intermittent photic stimulation during all relapses of his hypersomnic phase. A possible cause of this association that has not been previously reported is speculated based on observations concerning the two disorders.

Familial Kleine-Levin syndrome: two siblings with unusually long hypersomnic spells

Kleine-Levin syndrome is a rare, sporadic disorder, with discrete spells of hypersomnolence occurring during adolescence, variously accompanied by megaphagia, behavioral changes, psychosis, and mild autonomic symptoms. Familial cases have not previously been reported. We describe 2 siblings who shared uncharacteristically prolonged episodes of hypersomnolence, and the HLA-DR2 haplotype. In one patient, levels of cerebrospinal fluid orexin (hypocretin) during an attack were normal. The presence of an increased sleep drive, despite the occurrence of large amounts of ostensibly restorative sleep, suggests the possible existence of a disorder of sleep satiety.

[SPECT-identified hypoperfusion of the left temporomesial structures in a Kleine-Levin syndrome]

A 13-year-old boy developed typical features of Kleine-Levin syndrome. Routine investigations and MRI were normal. SPECT, performed both during an attack and during a symptom-fee period, demonstrated clear hypoperfusion of the left mesiotemporal structures. The possible implications of this finding are discussed.

A case of Kleine-Levin syndrome examined with SPECT and neuropsychological testing

A case of Kleine-Levin syndrome with typical periodic hypersomnia and bulimia was diagnosed. On examination with single photo emission tomography (SPECT) (CERETEC) during a relapse period and 2 weeks later there was marked cortical hypoperfusion of the frontal and temporal lobes, especially on the left side as well as in the right parietal lobe. Neuropsychological testing performed 1 week after a relapse showed a reduction in encoding to memory function of verbal learning indicating neocortical damage of the left fronto-temporal region. A follow-up 2 months later after the patient had spontaneously recovered showed only a slight left fronto-temporal disturbance. CT and MRI of the brain were normal although the MRI showed a large and asymmetric mamillary body. Neuropsychological testing 6 years after recovery showed pronounced reduction in short-time verbal and visual memory. Seven years after recovery SPECT demonstrated a normalized frontal perfusion but still a slight hypoperfusion in the left temporal lobe. Our results correlate to autopsy findings in two cases described previously.

Clinical and polysomnographic characteristics of 34 patients with Kleine-Levin syndrome

There is only scant information on sleep characteristics and long-term follow-up in patients with Kleine-Levin syndrome (KLS). This study describes the clinical course, results of polysomnography and long-term follow-up in a relatively large group of patients with KLS. During the years 1982-97, we encountered 34 patients (26 males and eight females) with KLS. We were able to obtain the original polysomnographs from 28 males and four females. In 25 patients, data regarding their present state of health were obtained. Fourteen agreed to be present at a detailed interview and examination while 11 gave the information by phone. The mean age at onset was 15.8 +/- 2.8 years and the mean diagnostic delay, 3.8 +/- 4.2 years. The mean duration of a single hypersomnolent attack was 11.5 +/- 6.6 days. The main abnormal findings extracted out of 35 polysomnographs obtained from 32 patients during and/or in-between attacks included: decreased sleep efficiency, and frequent awakenings from sleep stage 2. All 25 patients reported present perfect health, with no evidence of behavioral or endocrine dysfunction. In adolescents with periodic hypersomnia, the diagnosis of KLS should be explored. Sleep recordings during a hypersomnolent period will often show frequent awakenings from sleep stage 2. The long-term prognosis is excellent.

Neuropsychological sequelae in Kleine-Levin syndrome: case report

Kleine-Levin syndrome is characterized by periodic hypersomnia, hyperphagia, sexual disinhibitions and behavioral disturbances. The prognosis is generally benign, with normal cognitive and social functions after the episodes. We describe a typical case of Kleine-Levin syndrome associated with apparent academic decline, neuropsychological sequelae and personality alterations after the second episode of the illness. Further research in the natural history of Kleine-Levin syndrome is needed, for example, to determine whether early intervention would improve long-term prognosis.

The Kleine-Levin syndrome. Report of a case and review of the literature

Kleine-Levin syndrome is a rare self-limited disorder which usually affects adolescent males and is characterized by episodic hypersomnia, increased appetite, and behavioral/psychiatric disturbances. Individuals are normal between the attacks. The case of an adolescent boy is presented who suffered from recurrent sleepiness, hyperphagia, and behavioral disturbances such as rocking, punching and pacing, and was originally misdiagnosed as suffering from encephalitis. Before the diagnosis of Kleine-Levin was given, the patient underwent unnecessary investigations and treatment which, in turn, complicated his clinical condition both physically as well as psychologically. In the course of five years he had four such episodes which appeared to have progressively milder manifestations. Between episodes he was normal. It is important that the diagnosis is suspected early, especially in adolescent males who present with recurrent episodes of somnolence, increased appetite, and abnormal behavior, since it most often represents a benign and self-limited entity and does not warrant extensive investigations or treatment. It is also important to distinguish this syndrome from more serious organic and psychiatric diseases with more serious prognoses. The differential diagnosis of this syndrome is discussed and a review of the literature is presented including evidence and hypotheses regarding its pathophysiology.

Kleine-Levin syndrome and psychosis: observation from an unusual case

OBJECTIVE

This study evaluated the possible pathologic relation between Kleine-Levin syndrome (KLS) and mood disorders.

BACKGROUND

A 28-year-old man with a remote history of KLS had the sudden onset of a manic episode with psychotic features after the end of hypersomnolence.

METHOD

The patient received an extensive laboratory examination, including single photon emission computed tomography and magnetic resonance imaging.

RESULTS

Single photon emission computed tomography showed decreased tracer perfusion in the basal ganglion, hypothalamus, and right frontotemporal region. Magnetic resonance imaging revealed a cystic lesion in the pineal region.

CONCLUSIONS

Hypothalamic dysfunction has been described in KLS and mood disorders, but pineal gland dysfunction has been mentioned only rarely. The clinical and neuroimaging findings suggest the need for further study of KLS.

Kleine-Levin syndrome and Parkinsonian symptoms--a case report

We report the case of a 54-year-old male patient, who developed the symptoms of Kleine-Levin syndrome (KLS) at the age of fifty. Four years later Parkinsonian symptoms (PS) appeared. The possible relationship between both KLS and PS, e.g. regarding neuroendocrinological similarities, will be discussed to explain the subsequent onset of PS after the manifestation of KLS in this patient.

[Wake disorders. I. Primary wake disorders]

Primary wake disorders encompass various conditions of excessive daytime sleepiness and/or increased nighttime sleep, of unknown origin beginning most often in adolescence and of chronic or recurrent natural history. The best known of these conditions is narcolepsy associating two major clinical features, irresistible episodes of sleep, sleep onset REM periods and an almost constant association with HLA DR2-DQ1. The prevalence of the condition is close to the one of multiple sclerosis but positive diagnosis requires most often over 10 years to be made. The treatment of excessive daytime sleepiness has recently benefited from a new non-amphetamine awakening compound, modafinil, active in 60 to 70 p. 100 of the cases. The treatment of cataplexy still relies on antidepressants, tricyclics or selective serotonin reuptake blockers. Major advances in pathophysiology and pathogeny have been obtained through a natural model of the disease, canine narcolepsy. Pharmacological studies point to the importance of alpha-1 b adrenergic mechanisms in cataplexy, while dopaminergic systems seem more involved in excessive daytime sleepiness. As concerns genetics, the HLA DQB1*0602 gene predisposes to narcolepsy. In the canine model it is mirrored by an autosomal recessive gene showing a strong homology with the human immunoglobulin gene mu-switch. Familial studies have shown that besides typical phenotypes, attenuated forms of the condition characterized by isolated recurrent daytime naps and/or lapses into sleep do exist. In addition one or several other genes may be involved. Narcolepsy is multifactorial, including one or several genes as well as environmental factors. Idiopathic hypersomnia is noted for very long night sleep, difficulty waking up and more or less constant excessive daytime sleepiness. In contrast with narcolepsy sleep in not refreshing. There is no polysomnographic or immunogenetic special feature. Idiopathic hypersomnia is 10 times less frequent than narcolepsy. It is often overdiagnosed due to insufficient knowledge of other causes of excessive daytime sleepiness such as the upper airway resistance syndrome. Modafinil is also of great value in the treatment of idiopathic hypersomnia. In the absence of an animal model, pathophysiology and pathogeny are still poorly understood. Even rarer is the Kleine-Levin syndrome which is easily distinguishable through its recurrent character and its tendency to progressively disappear. It mainly occurs in early adolescent males. Its main features are episodes of sleep of a week duration recurring at a several months' interval along with disturbances of alimentary and sexual behavior. There is no satisfactory treatment of hypersomniac episodes. On the other hand a prophylactic treatment with carbamazepine or lithium may be active. Pathophysiology remains unsettled in spite of some evidence of a hypothalamic functional disturbance.

Novel chromosomal abberation in a patient with a unique sleep disorder

A 45 year old woman presenting with periodic hypersomnia for 17 years is reported on. She would sleep for three weeks followed by the same period awake. Polysomnography in the somnolent period disclosed an excess of total sleeping time with remarkably increased stage 1, 3/4, and REM sleep, without cataplexy or sleep paralysis. HLA typing was incompatible with narcolepsy or REM sleep behavioural disorder. Her chromosomes showed premature centromere division with chromatid puffing in areas of constitutive heterochromatin, which is exclusively found in the syndrome of infants termed Roberts' syndrome/SC phocomelia. Other laboratory findings were not normal. It is suggested that the present case is a novel sleep disorder related to a unique chromosomal aberration.

[Kleine-Levin syndrome--diagnostic and therapeutic problems]

An overview of the literature is given and an attempt is made to describe the diagnostic problems associated with this etiologically unclear disorder. The only successful therapy to date is treatment with lithium. A case study is presented of a 14-year-old boy with typical symptoms. Within a period of 12 months the boy had 6 episodes characterized by hypersomnia and hyperphagia, each lasting between 8 and 14 days. The symptom-free intervals lasted from 10 days to 8 months. Extensive medical and neurological evaluation including single-photon emission-computed tomography (SPECT) showed no abnormalities, and no criteria for another psychiatric disorder were met. After the sixth episode we considered treating the patient with lithium, but this option was rejected by his family. The patient has remained asymptomatic (36-month follow-up). A possible relationship to endogenous psychotic disorders and the role of neurotransmitter metabolism are discussed. Computer-assisted analysis of electroencephalographic activity revealed high signal complexity, which we believe suggests a primary cortical regulatory defect.

The sleeping aviator--aeromedical disposition of Kleine-Levin syndrome

We present the case of an aviator with Kleine Levin syndrome (KLS). History, physical examination, and special studies presented confirm the diagnosis of this syndrome. Our patient presented as an atypical case of KLS with respect to the presenting symptoms and to frequency of the episodes (6 years apart). He exhibited only intense somnolence, easy arousability, photophobia, hyperacousis, and a voracious appetite. Following a complete medical work up we recommended that an applicant with such a classical case of KLS be disqualified as a crewmember; however, in cases such as that presented above a limited waiver may be considered. The aeromedical significance of this case is to reinforce the importance of screening candidates and seeking precise diagnosis of a past illness or hospitalization.