Pediatric narcolepsy

Is there a role for repeating the multiple sleep latency test across childhood when initially non-diagnostic?

BACKGROUND

The gold standard investigation for central disorders of hypersomnolence is the Multiple Sleep Latency Test (MSLT). As the clinical features of these disorders of hypersomnolence evolve with time in children, clinicians may consider repeating a previously non-diagnostic MSLT. Currently there are no guidelines available regards the utility and timing of repeating paediatric MSLTs.

METHODS

Retrospective review of children aged 3-18years with ≥2MSLTs between 2005 and 2022. Narcolepsy was defined as mean sleep latency (MSL) <8min with ≥2 sleep onset REM (SOREM); idiopathic hypersomnia (IH) was defined as MSL <8min with <2 SOREM. MSLTs not meeting these criteria were labelled non-diagnostic.

RESULTS

19 children (9 female) with initial non-diagnostic MSLT underwent repeat MSLT, with 6 proceeding to a 3rd MSLT following 2 non-diagnostic MSLTs. The 2nd MSLT resulted in diagnosis in 6/19 (32 %) (3 narcolepsy, 3 IH); and 2/6 (33 %) 3rd MSLT were diagnostic (2 IH). Median age at initial MSLT was 7.5y (range 3.4-17.8y), with repeat performed after median of 2.9y (range 0.9-8.2y), and 3rd after a further 1.9 years (range 1.2-4.2y). Mean change in MSL on repeat testing was -2min (range -15.5min to +4.9min, p = 0.18). Of the 8 diagnostic repeat MSLTs, in addition to the MSL falling below 8 min, 2 children also developed ≥2 SOREM that had not been previously present.

CONCLUSIONS

A third of repeat MSLTs became diagnostic, suggesting repeat MSLT should be considered in childhood if clinical suspicion persists. Further work needs to address the ideal interval between MSLTs and diagnostic cut-points specific to the paediatric population.

Sleep-Related Drug Therapy in Special Conditions: Children

Pharmacologic treatment of the most common pediatric sleep disorders lacks evidence, and alternative methods, which have been proved to alleviate the symptoms, are preferred in most cases. The implementation of specific guidelines is of great importance because sleep disorders in children are not rare and they can negatively affect children's development and their cognitive and social skills. This article summarizes the current therapeutic management of sleep disorders in children, bearing in mind the absence of evidence-based guidelines on this topic.

Paediatric narcolepsy: a review of diagnosis and management

Narcolepsy is a chronic disabling neurological sleep disorder that requires lifelong treatment. We have outlined the clinical features of narcolepsy, the assessment and diagnosis process and have summarised the existing treatment options for children and adolescents with narcolepsy. In the future, the approach to management of paediatric narcolepsy should ideally be in a multidisciplinary setting, involving specialists in sleep medicine, sleep physiology, neurologists and psychologists/psychiatrists. A multidisciplinary approach will help to manage the potential impact of narcolepsy on children and adolescents who are in a stage of their life that is critical to their physical, emotional and social development and their academic attainment.

The Nexus Narcolepsy Registry: methodology, study population characteristics, and patterns and predictors of narcolepsy diagnosis

OBJECTIVE/BACKGROUND

The real-world experience of people with narcolepsy is not well understood.

PATIENTS/METHODS

The Nexus Narcolepsy Registry (NCT02769780) is a longitudinal, web-based patient registry of self-reported data from adults with physician-diagnosed narcolepsy. Surveys were electronically distributed every 6 months; the current analysis reports registry population demographics, narcolepsy diagnosis journey, and predictors of diagnostic delays.

RESULTS

The registry population included in this analysis (N = 1024) was predominantly female (85%) and White (92%), with a mean age of 37.7 years. Most participants had education/training beyond high school (93%). Mean (median) reported ages at narcolepsy symptom onset, first consultation for symptoms, and narcolepsy diagnosis were 18.1 (16), 26.4 (24), and 30.1 (28) years, respectively. A majority (59%) of participants reported ≥1 misdiagnosis, and 29% reported consulting ≥5 physicians before narcolepsy diagnosis. More than half (56%) of participants' first consultations for narcolepsy symptoms were with a general practitioner, whereas the diagnosing clinician was usually a sleep specialist (64%) or neurologist (27%). Pediatric symptom onset was associated with a longer mean interval to first consultation than adult symptom onset (10.7 and 4.6 years, respectively; P < 0.001) and a longer mean interval between first consultation and diagnosis (4.5 and 2.2 years, respectively; P < 0.001). Overall, mean (95% CI) time from symptom onset to diagnosis was 11.8 (11.1-12.5) years.

CONCLUSIONS

The Nexus Narcolepsy Registry data indicate that onset of narcolepsy symptoms frequently occurs in childhood or adolescence. In many individuals, the diagnostic process is long and involves multiple physicians and frequent misdiagnosis.

Two cases of childhood narcolepsy mimicking epileptic seizures in video-EEG/EMG

Narcolepsy is characterized by excessive sleepiness, hypnagogic hallucinations, and sleep paralysis, and can occur with or without cataplexy. Here, we report two children with narcolepsy presenting with cataplexy mimicking epileptic seizures as determined by long-term video-electroencephalography (EEG) and electromyography (EMG) monitoring. Case 1 was a 15-year-old girl presenting with recurrent episodes of "convulsions" and loss of consciousness, who was referred to our hospital with a diagnosis of epilepsy showing "convulsions" and "complex partial seizures". The long-term video-polygraph showed a clonic attack lasting for 15 s, which corresponded to 1-2 Hz with interruption of mentalis EMG discharges lasting for 70-300 ms without any EEG changes. Narcolepsy was suspected due to the attack induced by hearty laughs and the presence of sleep attacks, and confirmed by low orexin levels in cerebrospinal fluid (CSF). Case 2 was an 11-year-old girl presenting with recurrent episodes of myoclonic attacks simultaneously with dropping objects immediately after hearty laughs, in addition to sleep attacks, hypnagogic hallucinations, and sleep paralysis. The long-term video-polygraph showed a subtle attack, characterized by dropping chopsticks from her hand, which corresponded to an interruption of ongoing deltoid EMG discharges lasting 140 ms without any EEG changes. A diagnosis of narcolepsy was confirmed by the low orexin levels in CSF. These cases demonstrate that children with narcolepsy may have attacks of cataplexy that resemble clonic or myoclonic seizures.

Sleep-Related Drug Therapy in Special Conditions: Children

Sleep disorders in children may lead to neurodevelopmental and neurocognitive deficits; it is important to diagnose and treat them properly. Apart from the existing challenges in diagnosis, another drawback is that few therapies are currently approved. In this article, a comprehensive summary of the most common pediatric sleep disorders, along with the various pharmacologic and nonpharmacologic approaches for their management, is presented. Special attention has been paid to the currently available treatment options for pediatric insomnia, obstructive sleep apnea, parasomnias, narcolepsy, and restless legs syndrome, and comparisons are made with the corresponding treatment options for sleep disorders in adults.

Correlates to Problem Behaviors in Pediatric Narcolepsy: A Pilot Study

STUDY OBJECTIVE

Excessive daytime sleepiness, the hallmark of narcolepsy, predisposes patients to serious performance decrements in multiple areas of function. Psychosocial dysfunction has been demonstrated in adults and children with narcolepsy. Several factors could influence psychosocial functioning in children. The objective of this study was to examine neurobehavioral problems in children with narcolepsy and to define associations with these problem behaviors.

METHODS

A cross-sectional study was performed where the Child Behavior Checklist (CBCL) was completed by guardians of children (age 18 years or younger) in whom narcolepsy with or without cataplexy was diagnosed (based on the International Classification of Sleep Disorders, Second Edition) between July 2008 and October 2014. Spearman correlations (continuous variables) and Wilcoxon rank-sum tests (categorical variables) were performed for the CBCL findings and narcolepsy factors previously shown to influence psychosocial functioning.

RESULTS

The participants' current age correlated significantly with multiple CBCL scales. Caregivers of younger participants reported higher total psychosocial problems and externalizing problems. In addition, caregivers of younger participants reported higher scores on indices measuring inattention, withdrawal, thought problems, aggression, and rule-breaking behaviors. Values of P < .001 were found for total psychosocial problems, externalizing behaviors, and thought problems (negative correlations of 0.66, 0.65, and 0.64, respectively).

CONCLUSIONS

Patients with pediatric narcolepsy have high rates of attention and emotional/behavior problems. These problems strongly correlated with age. Younger children expressed higher emotional, behavioral, and attention problems. Sleep physicians need to be aware of and assess the mental and behavioral health of their pediatric patients with narcolepsy.

Growing Up with Type 1 Narcolepsy: Its Anthropometric and Endocrine Features

STUDY OBJECTIVES

To evaluate the effect of type 1 narcolepsy (NT1) on anthropometric and endocrine features in childhood/adolescence, focusing on patterns and correlates of weight, pubertal development, and growth in treated and untreated patients.

METHODS

We collected anthropometric (height, weight, body mass index (BMI) z-scores), pubertal, metabolic, and endocrine data from 72 NT1 patients at diagnosis and all available premorbid anthropometric parameters of patients from their pediatric files (n = 30). New measurements at 1-y reassessment in patients undergoing different treatments were compared with baseline data.

RESULTS

We detected a high prevalence of overweight (29.2%), obesity (25%), metabolic syndrome (18.8%), and precocious puberty (16.1%), but no signs of linear growth alterations at diagnosis. According to anthropometric records, weight gain started soon after NT1 onset. At 1-y follow-up reassessment, sodium oxybate treatment was associated with a significant BMI z-score reduction (-1.29 ± 0.30, p < 0.0005) after adjusting for baseline age, sex, sleepiness, and BMI.

CONCLUSIONS

NT1 onset in children/adolescents is associated with rapid weight gain up to overweight/obesity and precocious puberty without affecting growth. In our study, sodium oxybate treatment resulted in a significant weight reduction in NT1 overweight/obese patients at 1-y follow-up.

Narcolepsy and cataplexy: a pediatric case report

Narcolepsy is characterized by excessive sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis during the rapid eye movement period of sleep. Herein, we present a boy aged eight years who was diagnosed as having narcolepsy and cataplexy about thirteen months after his first presentation. He was admitted with symptoms of daytime sleepiness. In the follow-up, cataplexy in the form of head dropping attacks developed seven months after the first admission. The patient was investigated for different prediagnoses and was eventually diagnosed as having narcolepsy and cataplexy through polysomnography and multiple sleep latency tests thirteen months after the first presentation. He is being followed up and is under drug therapy; his symptoms have improved substantially.

Narcolepsy in a three-year-old girl: A case report

OBJECTIVE

Narcolepsy is characterized by excessive daytime somnolence associated with sleep paralysis, hallucinations when falling asleep or awakening, and cataplexy. Early recognition of pediatric narcolepsy is essential for growth and development. We experienced a case of narcolepsy in a three-year-old girl.

METHODS

The patient underwent brain MRI and 24h video-electroencephalogram (EEG) monitoring. Polysomnography (PSG) with multiple sleep latency test (MSLT) and human leukocyte antigen (HLA) DQ typing was performed.

RESULTS

The brain MRI was normal. 24h video-EEG monitoring revealed no abnormal slow or epileptiform discharge on interictal EEG, and no EEG change during tongue thrusting, dropping head with laughter, or flopping down, which was consistent with cataplexy associated with narcolepsy. A mean sleep latency of 2.5 min and four episodes of sleep-onset REM periods in five naps were observed in PSG with MSLT. She was positive in HLA-DQB1*0602. Based on these findings, she was diagnosed as narcoleptic with cataplexy.

CONCLUSION

The history, combined with PSG and MSLT, was helpful in the diagnosis of narcolepsy. We report a case of early-onset narcolepsy presenting with excessive sleepiness and cataplexy.

Psychosocial Characteristics of Children with Central Disorders of Hypersomnolence Versus Matched Healthy Children

BACKGROUND

Hypersomnia of central origin from narcolepsy or idiopathic hypersomnia (IHS) is characterized by pathological levels of excessive daytime sleepiness (EDS). Central hypersomnia has historically been underdiagnosed and poorly understood, especially with respect to its impact on daytime functioning and quality of life in children.

OBJECTIVE

Describe the psychosocial adjustment of children treated for narcolepsy or IHS on school performance, quality of life, and physical/extracurricular activities.

METHODS

Using a matched case control design, we compared child self- and parent-reported data from thirty-three 8- to 16-year-olds with an established diagnosis of narcolepsy or IHS, according to ICSD-2 criteria, to that of 33 healthy children matched by age, race/ethnicity, gender, and household income. Assessments evaluated academic performance, quality of life and wellness, sleepiness, and participation in extracurricular activities.

RESULTS

Compared to healthy controls, children with central hypersomnia had poorer daytime functioning in multiple domains. Children with hypersomnia missed more days of school and had lower grades than healthy controls. Children with hypersomnia had poorer quality of life by both parent and child report. Children with hypersomnia were significantly sleepier, had higher BMI, and were more likely to report a history of recent injury. Finally, children with hypersomnia engaged in fewer after-school activities than healthy controls.

CONCLUSIONS

A range of significant psychosocial consequences are reported in children with hypersomnia even after a diagnosis has been made and treatments initiated. Health care professionals should be mindful of the psychosocial problems that may present in children with hypersomnia over the course of treatment.

Narcolepsy in children: a diagnostic and management approach

OBJECTIVE

To provide a diagnostic and management approach for narcolepsy in children.

METHODS

Narcolepsy is a chronic disabling disorder characterized by excessive daytime sleepiness, cataplexy, hypnogogic and/or hypnopompic hallucinations, and sleep paralysis. All four features are present in only half of the cases. Excessive daytime sleepiness is the essential feature of narcolepsy at any age and is usually the first symptom to manifest. A combination of excessive daytime sleepiness and definite cataplexy is considered pathognomonic of narcolepsy syndrome.

RESULTS

New treatment options have become available over the past few years. Early diagnosis and management can significantly improve the quality of life of patients with narcolepsy with cataplexy.

CONCLUSION

This review summarizes the pathophysiology, clinical features, and management options for children with narcolepsy.

Neuropsychological findings in childhood narcolepsy

Narcolepsy with cataplexy is a severely disabling disorder very often arising in childhood. Data on neuropsychological impairment in children are scant. We administered standardized neuropsychological tests to 13 children with narcolepsy with cataplexy. Overall, our patients displayed multiple patterns of cognitive and behavioral dysfunction, and often academic failure (7 cases out of 13). All children had a normal full intelligence quotient (IQ), but 3 patients presented a significantly higher and 2 a significantly lower Verbal IQ compared to Performance IQ, respectively. Mean sleep latency was significantly correlated (P < .05) to alertness functions. Eight patients displayed behavioral problems: emotional symptoms and conduct problems prevailed. Childhood narcolepsy with cataplexy represents a risk factor for subtle and heterogeneous cognitive impairments potentially resulting in academic failure, despite the normal IQ. These children also have a certain psychopathological risk. All this seems to be at least partially detached from the direct effects of daytime sleepiness.

Sleep disorders in children

Sleep disorders are very common in childhood and are often amenable to simple advice and parental education. Questions about sleep should be an integral part of every paediatric consultation. Children with underlying syndromes or complex medical conditions often have multiple sleep issues. Excessive sleepiness in children requires careful history-taking and consideration of specialised investigation. Obstructive sleep apnoea (OSA) is a common condition in childhood with important health implications. The high prevalence of OSA warrants rigorous attempts to identify children at higher risk and manage them appropriately. Adenotonsillectomy is a highly efficacious therapy for paediatric OSA. A current major issue is to improve ways of distinguishing mild from severe OSA before a child undergoes adenotonsillectomy, as those with more severe disease are at increased risk of postoperative complications and should undergo adenotonsillectomy in a tertiary centre. Children with obesity and other comorbid conditions are at increased risk of persisting OSA despite adenotonsillectomy. Topical (nasal) steroids and/or anti-inflammatory agents have a role in the non-surgical treatment of mild OSA. Continuous positive airway pressure and orthodontic interventions are treatment options for treatment of persisting OSA in children.

The maintenance of wakefulness test in pediatric narcolepsy

Objective tools are needed to assess the response to treatment in pediatric narcolepsy. This article presents a single-center experience documenting the use of the maintenance of wakefulness test (MWT) in a pediatric series. This study reviewed the charts of children with narcolepsy who had an MWT performed between January 2008 and June 2012. A cutoff was used for mean sleep latency: <8 minutes for inadequate control of hypersomnia, and >20 minutes to indicate adequate control on medications. Thirteen tests were performed on 10 children (median age 15.8 years, range 8.7-20.3 years) with narcolepsy, of which six had cataplexy and three were boys. Comorbid conditions included Prader-Willi syndrome, bipolar affective disorder, and epilepsy (n = 1 each). The median mean sleep latency for all studies was 16 minutes (range 5.8-40 minutes). Sleep-onset rapid eye movement sleep events were seen in three of 13 studies. In seven patients, findings from the MWT resulted in changes in management. These data suggest that the MWT may be a useful and feasible test for assessing response to treatment in children with narcolepsy. Future research is needed to obtain normative MWT data on children with and without narcolepsy.

Pediatric narcolepsy: clinical and therapeutical approaches

Narcolepsy occurs during childhood in combination with cataplexy in one-third of the subjects. Symptoms may develop rapidly over a few weeks or months, with excessive daytime sleepiness and cataplexy being the most dramatic and observable symptoms. It can be secondary to brain tumors or several rare diseases, but in most cases narcolepsy with or without cataplexy is a primary condition, better explained by the selective loss of hypocretin neurons in posterolateral hypothalamus. A specific HLA allele, HLA-DQB1*0602, is involved and the disease is thought to be autoimmune. Tribbles 2-specific antibodies have been identified. Recent medications have greatly improved the symptoms and wellbeing of young patients. However, these treatments are delivered off-label in the pediatric population. There is an absolute necessity for well-conducted clinical trials in order to improve treatment in children and adolescents with narcolepsy and to evaluate clinical efficacy and good tolerance of medications. Nonpharmacological approaches are certainly helpful and should be promoted systematically, especially in very young children. Narcolepsy of recent onset in children or adolescents should be considered a therapeutic emergency, even though immunotherapy is still controversial.

Psychological distress mediates the association between daytime sleepiness and consumption of sweetened products: cross-sectional findings in a Catholic Middle-Eastern Canadian community

OBJECTIVE

To examine the associations between consumption of sweetened products, daytime sleepiness (DS) and psychological distress (PD) in a Catholic Middle-Eastern Canadian community, and to test the hypothesis that the association between DS and consumption of sweetened products is mediated by PD.

DESIGN

A cross-sectional study.

SETTING

A Catholic Middle-Eastern Canadian community.

PARTICIPANTS

186 men and women aged between 18 and 60 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Sweetened product consumption was measured using a food frequency questionnaire (total sugars/day). DS and PD were measured using standardised questionnaires. The generalised linear model was used to estimate associations between sweetened product consumption, age, sex, self-reported body mass index, DS and PD. Baron and Kenny's four-step approach in addition to the Sobel test were used to establish mediation.

RESULTS

Average DS score was 8.2 (SD=4.5) with 19.5% having excessive scores (>12). Mean PD score was 20.8 (SD=6.2) with 11.8% having high distress scores. Average consumption of sweetened products was 15.5 g/day (SD=13.9). Baron and Kenny's three steps to establish partial mediation were confirmed. First, DS was associated with consumption of sweetened products (p<0.03). Second, DS and PD were correlated (r=0.197; p<0.04). Third, PD was associated with consumption of sweetened products (p<0.01) when both PD and DS were entered as predictors in a multivariate regression. However, Baron and Kenny's fourth step to establish complete mediation was not met. The effect of DS on consumption of sweetened products controlling for PD was reduced, but it was not zero. Finally, the Sobel test was significant (2.14; p<0.03).

CONCLUSIONS

The association between DS and consumption of sweetened products in the Catholic Middle-Eastern Canadian community is partially mediated by psychological distress. Further work should test this mediation relationship in larger samples and verify the potential effects of other sleep variables in this relationship.

Cases of pediatric narcolepsy after misdiagnoses

Narcolepsy is characterized by recurrent brief attacks of irresistible sleepiness. Signs can begin during childhood. However, diagnoses are frequently delayed by 10-15 years because of unfamiliarity with pediatric narcolepsy and variable presentations of its associated features (cataplexy, hypnagogic/hypnopompic hallucinations, and sleep paralysis). Therefore, patients may remain untreated during their formative years. Three children with narcolepsy who were initially misdiagnosed are described. Each child's signs were initially related to depression, hypothyroidism, jaw dysfunction, or conversion disorder. However, after a multiple sleep latency test, the diagnosis of narcolepsy was established. All three patients were treated appropriately with stimulant medications, selective serotonin reuptake inhibitors, or sodium oxybate, and demonstrated positive responses. Although no definitive cure exists for narcolepsy, early recognition and appropriate symptomatic treatment with medications can allow affected children to improve quality of life and achieve normality, both academically and socially.

Current treatment of selected pediatric sleep disorders

While pediatric sleep disorders are relatively common, treatments are often not straightforward. There is often a paucity of gold standard studies and data available to guide clinicians, treatments may yield arguably incomplete results, interventions may require chronic use, and/ or involve multiple modalities including behavioral interventions that require high parental and family commitment. This review points out diagnostic differences compared to adults and focuses on current therapy for selected common pediatric sleep disorders including sleep disordered breathing/ obstructive sleep apnea, narcolepsy, and restless legs syndrome. Other common pediatric sleep disorders, such as insomnia and parasomnias, are not covered.

Clinical features of childhood narcolepsy. Can cataplexy be foretold?

BACKGROUND

Narcolepsy is a life-long disease characterized by abnormal regulation of the sleep-wake cycle and increased penetration of rapid eye movement (REM) sleep. In children, narcolepsy without cataplexy is more frequently seen than in adults. The aim of our study was to evaluate clinical and polysomnographic parameters to verify if cataplexy appearing later in life can be foretold.

METHODS

30 patients (12 boys), who contracted narcolepsy before the age of 18, were enrolled. All underwent clinical examination, nocturnal polysomnography (PSG), multiple sleep latency test (MSLT), HLA-DQB1∗0602 testing and, most of them Epworth Sleepiness Scale (ESS) rating. The Mann-Whitney rank and Fisher's tests were used for statistical analysis.

RESULTS

Narcolepsy without cataplexy (NwC) was diagnosed in 40% of the patients. The mean age at the first symptoms was 14.0 ± 3.0, at diagnosis 15.6 ± 3.1 years. Narcolepsy was accompanied by hypnagogic hallucinations in 15 and sleep paralysis in 12 patients. Frequent symptoms were sleep inertia during awakening, REM behavior symptoms, behavioral and serious school problems. BMI was higher in patients with narcolepsy-cataplexy (N-C). A high ESS score was indicative of excessive daytime sleepiness (17.1 ± 2.5). Mean MSLT sleep latency was 4.0 ± 3.1 min with 3.2 ± 1.4 sleep onset REM periods (SOREMs) with no difference between the two study groups. HLA typing revealed no differences either. The N-C group showed a higher degree of wakefulness and superficial non-REM (NREM) stage 1 with a lower NREM stage 3 during PSG.

CONCLUSION

Narcolepsy in childhood leaves very little scope for the prediction of cataplexy later in life.

Clinical and therapeutic aspects of childhood narcolepsy-cataplexy: a retrospective study of 51 children

STUDY OBJECTIVE

to report on symptoms and therapies used in childhood narcolepsy-cataplexy.

DESIGN, PATIENTS, AND SETTING

retrospective series of 51 children who completed the Stanford Sleep Inventory. HLA-DQB1*0602 typing (all tested, and 100% positive), polysomnography or Multiple Sleep Latency Test (76%), and cerebrospinal fluid hypocretin-1 measurements (26%, all with low levels) were also conducted. Prospective data on medication response was collected in 78% using a specially designed questionnaire.

MEASUREMENTS AND RESULTS

patients were separated into children with onset of narcolepsy prior to (53%), around (29%), and after (18%) puberty. None of the children had secondary narcolepsy. Clinical features were similar across puberty groups, except for sleep paralysis, which increased in frequency with age. Common features included excessive weight gain (84% ≥ 4 kg within 6 months of onset of narcolepsy) and earlier puberty (when compared with family members), notably in subjects who gained the most weight. Streptococcus-positive throat infections were reported in 20% of cases within 6 months of onset of narcolepsy. Polysomnographic features were similar across groups, but 3 prepubertal children did not meet Multiple Sleep Latency Test diagnostic criteria. Regarding treatment, the most used and continued medications were modafinil (84% continued), sodium oxybate (79%), and venlafaxine (68%). Drugs such as methylphenidate, tricyclic antidepressants, or selective serotonin reuptake inhibitors were often tried but rarely continued. Modafinil was reported to be effective for treating sleepiness, venlafaxine for cataplexy, and sodium oxybate for all symptoms, across all puberty groups. At the conclusion of the study, half of children with prepubertal onset of narcolepsy were treated "off label" with sodium oxybate alone or with the addition of one other compound. In older children, however, most patients needed more than 2 drugs.

CONCLUSION

this study reports on the clinical features of childhood narcolepsy and documents the safe use of treatments commonly used in adults in young children.

Narcolepsy: a review

Narcolepsy is a lifelong sleep disorder characterized by a classic tetrad of excessive daytime sleepiness with irresistible sleep attacks, cataplexy (sudden bilateral loss of muscle tone), hypnagogic hallucination, and sleep paralysis. There are two distinct groups of patients, ie, those having narcolepsy with cataplexy and those having narcolepsy without cataplexy. Narcolepsy affects 0.05% of the population. It has a negative effect on the quality of life of its sufferers and can restrict them from certain careers and activities. There have been advances in the understanding of the pathogenesis of narcolepsy. It is thought that narcolepsy with cataplexy is secondary to loss of hypothalamic hypocretin neurons in those genetically predisposed to the disorder by possession of human leukocyte antigen DQB1*0602. The diagnostic criteria for narcolepsy are based on symptoms, laboratory sleep tests, and serum levels of hypocretin. There is no cure for narcolepsy, and the present mainstay of treatment is pharmacological treatment along with lifestyle changes. Some novel treatments are also being developed and tried. This article critically appraises the evidence for diagnosis and treatment of narcolepsy.

Treatment of cataplexy in Niemann-Pick disease type C with the use of miglustat

Cataplexy is the sudden muscle weakness brought on by strong emotions, particularly joking, laughter, or anger. Cataplexy may involve only certain group of muscles or the entire voluntary musculature. In rare cases, symptoms of cataplexy can be seen during the course of some inherited diseases (Niemann-Pick type C (NPC), Prader-Willi syndrome, myotonic dystrophy, Norrie disease). We report the successful use of miglustat, a reversible inhibitor of the enzyme glucosylceramide synthase, approved for use in Gaucher's disease, and which catalyses the first step in the biosynthesis of most glycosphingolipid, in a boy with NPC with cataplexy. A 9-year-old boy was admitted for assessments of frequent "drop attacks" while laughing. The filipin fluorescence tests of cultured skin fibroblasts revealed massive accumulation of unesterified cholesterol, confirming the diagnosis of NPC disease. Molecular studies confirmed the diagnosis of NPC too. After approval from the bioethics committee, miglustat was initiated on the child at 100mg three times a day. Cataplectic attacks disappeared completely after 6 months on treatment, and patient continues to be in remission from the cataplectic attacks at 16 months follow-up. There was no further progression of neurological signs or symptoms or splenomegaly, with some improvement in cognitive function as well as social, affective and attention problems, up-gaze, and gait. Miglustat was well tolerated with no side effects observed. In summary, this is the first report of miglustat treatment of cataplexy in NPC. Long-term follow-up for continuing efficacy and tolerability in a larger cohort with NPC is needed to substantiate our observation.

[Narcolepsy with and without cataplexy: an uncommon disabling and unrecognized disease]

Although narcolepsy is a relatively uncommon condition, its impact on a child's life can be dramatic and disabling. Narcolepsy is characterized by excessive daytime sleepiness (EDS), with brief "sleep attacks" at very unusual times and usually associated with cataplexy (sudden loss of muscle control while awake, resulting in a fall, triggered by laughter). Other symptoms frequently reported are sleep paralysis (feeling of being unable to move or speak, even totally aware), hypnagogic hallucinations (vivid dreamlike experiences difficult to distinguish from reality) or disturbed night time sleep. Some children also experience depression or overweight-obesity. Although narcolepsy has been thoroughly studied, the exact cause is unknown. It appears to be a disorder of cerebral pathways that control sleep and wakefulness, involving dorsolateral hypothalamus and hypocretin. A genetic factor has been suggested, but narcolepsy in relatives is rare. Researchers have suggested that a set of genes combines with additional factors in a person's life to cause narcolepsy. The effective treatment of narcolepsy requires not only medication (usually stimulants, antidepressants and sodium oxybate), but also adjustments in life-style (scheduled naps). Management of this condition in children demands a comprehensive approach to the patient, that includes a correct diagnosis, pharmacological and non-pharmacological treatment and adjustments in the environment. These strategies can improve the child's self-esteem and ability to obtain a good education.