Practice parameters for the treatment of narcolepsy and other hypersomnias of central origin

Pathophysiology and Individualized Treatment of Hypothalamic Obesity Following Craniopharyngioma and Other Suprasellar Tumors: A Systematic Review

The development of hypothalamic obesity (HO) following craniopharyngioma (CP) and other suprasellar tumors leads to reduced patient quality of life. No treatment algorithms are currently available for management of HO. Depending on which hypothalamic nuclei are destroyed, the pathophysiologic mechanisms and clinical symptoms that contribute to HO differ among patients. Herein, we review the contribution of the hypothalamus to the pathophysiologic mechanisms and symptoms underlying CP-associated HO. Additionally, we performed a systematic search of MEDLINE and Embase to identify all intervention studies for weight management in patients with CP or other suprasellar tumors published until September 2017. The search yielded 1866 publications, of which 40 were included. Of these 40 studies, we identified four modalities for intervention (i.e., lifestyle, dietary, pharmacotherapeutic, or surgical) within six clinical domains (i.e., psychosocial disorders, hyperphagia, sleep disturbances, decreased energy expenditure, hyperinsulinemia, and hypopituitarism). We used the findings from our systematic review, in addition to current knowledge on the pathophysiology of HO, to develop an evidence-based treatment algorithm for patients with HO caused by CP or other suprasellar tumors. Although the individual effects of the HO interventions were modest, beneficial individual effects may be achieved when the pathophysiologic background and correct clinical domain are considered. These two aspects can be combined in an individualized treatment algorithm with a stepwise approach for each clinical domain. Recently elucidated targets for HO intervention were also explored to improve future management of HO for patients with CP and other suprasellar tumors.

Management Of Excessive Sleepiness In Patients With Narcolepsy And OSA: Current Challenges And Future Prospects

Excessive daytime sleepiness (EDS) can be caused by insufficient sleep but is also a manifestation of medical or sleep disorders and a side effect of medications. It impacts quality of life and creates safety concerns in the home, at work, and on the roads. Screening questionnaires can be used to estimate EDS, but further evaluation is necessary. EDS is a common symptom of both narcolepsy and obstructive sleep apnea (OSA). Polysomnography and multiple sleep latency testing are used to diagnose these disorders. However, isolating the primary etiology of EDS can be challenging and may be multifactorial. Untreated OSA can show polysomnographic findings that are similar to narcolepsy. The effects of sleep deprivation and certain medications can also affect the polysomnographic results. These challenges can lead to misdiagnosis. In addition, narcolepsy and OSA can occur as comorbid disorders. If EDS persists despite adequate treatment for either disorder, a comorbid diagnosis should be sought. Thus, despite advances in clinical practice, appropriate management of these patients can be challenging. This review is focused on EDS due to OSA and narcolepsy and addresses some of the challenges with managing this patient population.

Orexin supplementation in narcolepsy treatment: A review

Narcolepsy is a rare, chronic neurological disease characterized by excessive daytime sleepiness, cataplexy, vivid hallucinations, and sleep paralysis. Narcolepsy occurs in approximately 1 of 3000 people, affecting mainly adolescents aged 15 to 30 years. Recently, people with narcolepsy were shown to exhibit extensive orexin/hypocretin neuronal loss. The orexin system regulates sleep/wake control via complex interactions with monoaminergic, cholinergic and GABA-ergic neuronal systems. Currently, no cure for narcolepsy exists, but some symptoms can be controlled with medication (eg, stimulants, antidepressants, etc). Orexin supplementation represents a more sophisticated way to treat narcolepsy because it addresses the underlying cause of the disease and not just the symptoms. Research on orexin supplementation in the treatment of sleep disorders has strongly increased over the past two decades. This review focuses on a brief description of narcolepsy, the mechanisms by which the orexin system regulates sleep/wake cycles, and finally, possible therapeutic options based on orexin supplementation in animal models and patients with narcolepsy.

Neuroendocrine aspects of improving sleep in epilepsy

Sleep plays an intricate role in epilepsy and can affect the frequency and occurrence of seizures. With nearly 35% of U.S. adults failing to obtain the recommended 7 h of sleep every night, understanding the complex relationship between sleep and epilepsy is of utmost relevance. Sleep deprivation is a common trigger of seizures in many persons with epilepsy and sleep patterns play a role in the occurrence of seizures. Some patients have their first seizure or repeated seizures after an "all-nighter" at college or after a long period of chronic sleep deprivation. The strength of the relationship between sleep and seizures varies between patients, but improving sleep and optimizing seizure control can have significant positive effects on the quality of life for all these patients. Research has shown that the changes in the brain's electrical and hormonal activity occurring during normal sleep-wake cycles can be linked to both sleep and seizure patterns. Many questions remain to be answered about sleep and epilepsy. How can sleep deprivation trigger an epileptic seizure? How do circadian and hormonal changes influence sleep pattern and seizure occurrence? Can hormones or sleeping pills help with sleep in epilepsy? In this article we discuss these and many other questions on sleep in epilepsy, with an emphasis on sleep architecture, hormone changes, mechanistic factors, and possible prevention strategies.

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.

Using predicate and provenance information from a knowledge graph for drug efficacy screening

Background

Biomedical knowledge graphs have become important tools to computationally analyse the comprehensive body of biomedical knowledge. They represent knowledge as subject-predicate-object triples, in which the predicate indicates the relationship between subject and object. A triple can also contain provenance information, which consists of references to the sources of the triple (e.g. scientific publications or database entries). Knowledge graphs have been used to classify drug-disease pairs for drug efficacy screening, but existing computational methods have often ignored predicate and provenance information. Using this information, we aimed to develop a supervised machine learning classifier and determine the added value of predicate and provenance information for drug efficacy screening. To ensure the biological plausibility of our method we performed our research on the protein level, where drugs are represented by their drug target proteins, and diseases by their disease proteins.

Results

Using random forests with repeated 10-fold cross-validation, our method achieved an area under the ROC curve (AUC) of 78.1% and 74.3% for two reference sets. We benchmarked against a state-of-the-art knowledge-graph technique that does not use predicate and provenance information, obtaining AUCs of 65.6% and 64.6%, respectively. Classifiers that only used predicate information performed superior to classifiers that only used provenance information, but using both performed best.

Conclusion

We conclude that both predicate and provenance information provide added value for drug efficacy screening.

Electronic supplementary material

The online version of this article (10.1186/s13326-018-0189-6) contains supplementary material, which is available to authorized users.

Profile of pitolisant in the management of narcolepsy: design, development, and place in therapy

Narcolepsy is a rare sleep disorder characterized by excessive daytime sleepiness and rapid eye movement sleep dysregulation, manifesting as cataplexy and sleep paralysis, as well as hypnagogic and hypnopompic hallucinations. Disease onset may occur at any age, although adolescents and young adults are mainly affected. Currently, the diagnosis delay ranges from 8 to 10 years and drug therapy may only attenuate symptoms. Pitolisant is a first-in-class new drug currently authorized by the European Medicines Agency to treat narcolepsy with or without cataplexy in adults and with an expanded evaluation for the treatment of neurologic diseases such as Parkinson’s disease and epilepsy. This article reviews the pharmacokinetic and pharmacodynamic profile of pitolisant, highlighting its effectiveness and safety in patients with narcolepsy. We performed a systematic review of the literature using PubMed, Embase, and Google Scholar. We report on the efficacy and safety data of pitolisant in narcoleptic patients regarding cataplexy episodes and subjective and objective daytime sleepiness. The development program of pitolisant was characterized by eight Phase II/III studies. One proof-of-concept study followed by two pivotal studies, three randomized controlled trials, and two open studies were evaluated. Our review confirmed the effectiveness of pitolisant in treating major clinically relevant narcolepsy symptoms, including cataplexy, as compared to placebo. In addition, pitolisant revealed a safe profile when compared with placebo and active comparators. Headache, insomnia, and nausea were the prominent side effects. Further long-term randomized controlled trials comparing the efficacy of pitolisant with active comparators (ie, modafinil and sodium oxybate) may clarify its real place in therapy and its possible use as a first-line agent on the basis of its safety and tolerability.

Characterization of the Neurochemical and Behavioral Effects of Solriamfetol (JZP-110), a Selective Dopamine and Norepinephrine Reuptake Inhibitor

Excessive sleepiness (ES) is associated with several sleep disorders, including narcolepsy and obstructive sleep apnea (OSA). A role for monoaminergic systems in treating these conditions is highlighted by the clinical use of US Food and Drug Administration-approved drugs that act on these systems, such as dextroamphetamine, methylphenidate, modafinil, and armodafinil. Solriamfetol (JZP-110) is a wake-promoting agent that is currently being evaluated to treat ES in patients with narcolepsy or OSA. Clinical and preclinical data suggest that the wake-promoting effects of solriamfetol differ from medications such as modafinil and amphetamine. The goal of the current studies was to characterize the mechanism of action of solriamfetol at monoamine transporters using in vitro and in vivo assays. Results indicate that solriamfetol has dual reuptake inhibition activity at dopamine (DA; IC50 = 2.9 μM) and norepinephrine (NE; IC50 = 4.4 μM) transporters, and this activity is associated in vivo with increased extracellular concentration of DA and NE as measured by microdialysis. Solriamfetol has negligible functional activity at the serotonin transporter (IC50 > 100 μM). Moreover, the wake-promoting effects of solriamfetol are probably owing to activity at DA and NE transporters rather than other neurotransmitter systems, such as histamine or orexin. The dual activity of solriamfetol at DA and NE transporters and the lack of significant monoamine-releasing properties of solriamfetol might explain the differences in the in vivo effects of solriamfetol compared with modafinil or amphetamine. Taken together, these data suggest that solriamfetol may offer an important advancement in the treatment of ES in patients with narcolepsy or OSA.

A case report of hypersomnia in tetrasomy X improved with medical therapy

Tetrasomy X is a rare chromosomal anomaly in which sleep disorders have not been previously reported. We report on one patient with tetrasomy X and hypersomnia successfully treated with psychostimulant therapy. Sleep disorders are rarely reported in chromosomal anomalies. Clinicians should screen patients for sleep disorders and manage them appropriately.

Changes in Medical Services and Drug Utilization and Associated Costs After Narcolepsy Diagnosis in the United States

BACKGROUND

Healthcare utilization and the cost implications associated with undiagnosed and/or misdiagnosed narcolepsy have not been evaluated, and there is scant literature characterizing the newly diagnosed population with narcolepsy with respect to treatment patterns and resource utilization.

OBJECTIVE

To analyze the changes in medication use, healthcare utilization, and the associated costs after a new diagnosis of narcolepsy.

METHODS

In this retrospective cohort study, we used data from the Truven Health Analytics MarketScan Research Databases, between January 2006 and March 2013, to identify patients who had a probable new diagnosis of narcolepsy-defined as a de novo medical claim for a multiple sleep latency test-which was preceded by ≥6 months of continuous insurance and was followed by a de novo diagnosis of narcolepsy. The utilization and cost of medical services and the percentage of patients filling prescriptions for narcolepsy-related medications were evaluated in 3 consecutive 1-year periods from the date of a positive multiple sleep latency test result (ie, index date), and each year's findings were compared with the annualized results from the 6-month preindex period.

RESULTS

A total of 3757 patients who met the definition of a new diagnosis of narcolepsy were identified. The total medical service utilization decreased each year from a preindex average of 28.2 visits per patient per year (PPPY) to 26.9 visits (P <.05), 23.1 visits (P <.0001), and 22.5 visits (P <.0001) PPPY in years 1, 2, and 3 postdiagnosis, respectively. In each outpatient service category, the medical services utilization decreased from preindex to year 3 postdiagnosis, including hospital outpatient and physician visits (P <.0001), and other outpatient and emergency department visits (P <.05). The percentage of patients receiving narcolepsy-related medications increased from 54.0% preindex to 77.4%, 70.0%, and 66.9% for years 1, 2, and 3 postindex (all P <.0001 vs preindex). The total medical service cost PPPY was $12,159 preindex and decreased to $10,708, $8543, and $9136 in years 1, 2, and 3 postindex (all P <.0001 vs preindex).

CONCLUSIONS

In this study, the confirmation of a diagnosis of narcolepsy was associated with decreasing utilization and associated costs of medical services in the first 3 years after diagnosis. The total costs encompassing medical services and pharmacy costs were relatively stable during this period.

Pediatric Sleep Disorders

PURPOSE OF REVIEW

This article provides an overview of the clinical features, diagnosis, and treatment of insomnia, restless legs syndrome, periodic limb movements of sleep, parasomnias, narcolepsy, and sleep-related breathing disorders among children and adolescents.

RECENT FINDINGS

Pediatric presentations of sleep disorders differ from adult presentations, making diagnosis challenging. Specific clinical syndromes, such as cataplexy in children with narcolepsy type 1, can have an altogether different presentation compared to adult-onset symptoms, contributing to diagnostic delays and potential misdiagnoses. More broadly, research shows strong associations between sleep and daytime cognition, mood, and behavior among children with and without neurologic conditions and thus suggests a need to identify and treat sleep problems to optimize daytime functioning.

SUMMARY

Addressing sleep problems in children with neurologic conditions and neurodevelopmental disorders improves quality of life for patients and their families and, in many cases, reduces neurologic disease burden.

The MSLT is Repeatable in Narcolepsy Type 1 But Not Narcolepsy Type 2: A Retrospective Patient Study

STUDY OBJECTIVES

To examine repeatability of Multiple Sleep Latency Test (MSLT) results in narcolepsy type 1 (NT1) and narcolepsy type 2 (NT2) according to the criteria of the International Classification of Sleep Disorders, Third Edition (ICSD-3).

METHODS

Repeatability of the MSLT was retrospectively evaluated in NT1 (n = 60) and NT2 (n = 54) cases, and controls (n = 15). All subjects had documented HLA-DQB1*06:02 status and/or hypocretin-1 levels from cerebrospinal fluid. All subjects had undergone 2 MSLTs (≥ 1 meeting ICSD-3 criteria for narcolepsy). Repeatability was explored in children versus adults and in those on versus not on medication(s). Subsample and multivariate analysis were performed.

RESULTS

Both MSLTs in unmedicated patients were positive for narcolepsy in 78%, 18%, and 7% of NT1, NT2, and controls, respectively. NT2 cases changed to idiopathic hypersomnia or to a negative MSLT 26% and 57% of the time, respectively. Although NT1 cases were 10 to 14 times more likely to demonstrate a second positive MSLT compared to NT2 cases (P < 10^-5) and controls (P < 10^-4), respectively, NT2 cases were not significantly different from controls (P = .64). Medication use (P = .009) but not adult versus children status (P = .85) significantly decreased the likelihood of a repeat positive MSLT.

CONCLUSIONS

In a clinical setting, a positive MSLT for narcolepsy is a more reproducible and stable feature in NT1 than NT2. The retrospective design of this study hinders interpretation of these data, as there are many different, and possibly opposing, reasons to repeat a MSLT in NT1 versus NT2 (ie, ascertainment bias). Additional systematic MSLT repeatability studies independent of confounds are ideally needed to confirm these findings.

Treatment of narcolepsy and other organic hypersomnias in children

The comprehensive management of chronic disorders such as hypersomnias of childhood requires combining life-style changes with rational pharmacotherapy that is based on treating the symptoms that are most bothersome, the age, comorbidities, and metabolic and endocrine status of the patient. The excessive sleepiness of narcolepsy and idiopathic hypersomnia is best treated with dextroamphetamine or methylphenidate preparations or modafinil/armodafinil. Cataplexy treatment requires sodium oxybate, tricyclic agents, selective norepinephrine reuptake inhibitors or selective serotonin reuptake inhibitors. Sodium oxybate is approved only for adults, thus its use in children is only on an off-label basis. Dual therapy, with both anti-cataplectic and stimulant medications may be required, as is close monitoring for treatment-emergent side effects.

Effectiveness and side-effect profile of stimulant therapy as monotherapy and in combination in the central hypersomnias in clinical practice

Effectiveness and side-effect profile data on pharmacotherapy for daytime sleepiness in central hypersomnias are based largely upon randomized controlled trials. Evidence regarding the use of combination therapy is scant. The aim of this study was to examine the effectiveness and occurrence of drug-related side effects of these drugs in routine clinical practice. Adult patients diagnosed with a central hypersomnia during a 54-month period at a tertiary sleep disorders centre were identified retrospectively. Side effects were recorded at every follow-up visit. A total of 126 patients, with 3275 patient-months of drug exposure, were categorized into narcolepsy type 1 (n = 70), narcolepsy type 2 (n = 47) and idiopathic hypersomnia (n = 9). Modafinil was the most common drug used as a first-line treatment (93%) and in combination therapy (70%). Thirty-nine per cent of the patients demonstrated a complete, 25% partial and 36% a poor response to treatment. Combination treatment improved daytime sleepiness in 55% of the patients with residual symptoms despite monotherapy. Sixty per cent of patients reported side effects, and 30% reported treatment-limiting side effects. Drugs had similar side-effect incidence (P = 0.363) and their side-effect profile met those reported in the literature. Twenty-seven per cent of the patients received combination treatment and had fewer side effects compared to monotherapy (29.4% versus 60%, respectively, P = 0.001). Monotherapy appears to achieve satisfactory symptom control in most patients with central hypersomnia, but significant side effects are common. Combination therapy appears to be a useful and safe option in patients with refractory symptoms.

Effect of sodium oxybate, modafinil, and their combination on disrupted nighttime sleep in narcolepsy

OBJECTIVE

To assess the effects of three narcolepsy treatment modalities on sleep stage shifts associated with disrupted nighttime sleep (DNS) using data from a clinical trial.

METHODS

Polysomnograms were reviewed from 155 patients (who had these data available at baseline and 8 weeks) of the 278 patients who were randomized to placebo, 9-g sodium oxybate (SXB)/nightly, 200-600 mg/d modafinil, or SXB + modafinil. Major outcomes of these post hoc analyses, analyzed using analysis of covariance, were change from baseline in number of shifts from Stages N2/3/rapid eye movement (REM) to Stage N1/Wake, and from Stage N1/Wake to REM. Sleep quality was evaluated using the sleep-quality question from the Pittsburgh Sleep Quality Index.

RESULTS

SXB alone or in combination with modafinil significantly decreased the number of shifts from Stage N2/3/REM to Stage N1/Wake (p < 0.01); least-squares mean change in number of shifts from baseline was -0.6, -16.5, 1.8, and -13.7 in the placebo, SXB, modafinil and SXB + modafinil groups, respectively. A similar pattern was observed for changes in shifts from REM to Stage N1/Wake and from Stage N1/Wake to REM. Relative to placebo, sleep quality significantly improved with SXB and SXB + modafinil (p ≤ 0.05) but not with modafinil alone.

CONCLUSION

These results show that SXB with and without modafinil significantly consolidated sleep and improved patient-reported sleep quality relative to placebo. In contrast, no such effects were observed with modafinil alone, suggesting a specific effect of SXB on DNS in addition to its effect on daytime sleepiness. CLINICALTRIALS.

GOV IDENTIFIER

NCT00066170.

Idiopathic Hypersomnia

Idiopathic hypersomnia (IH) is a chronic neurologic disorder of daytime sleepiness, accompanied by long sleep times, unrefreshing sleep, difficulty in awakening, cognitive dysfunction, and autonomic symptoms. The cause is unknown; a genetic predisposition is suggested. Autonomic, inflammatory, or immune dysfunction has been proposed. Diagnosis involves a clinical history and objective testing. There are no approved treatments for IH, but modafinil is typically considered first-line. A substantial fraction of patients with IH are refractory or intolerant to standard treatments, and different treatment strategies using novel therapeutics are necessary. Even with current treatment options, quality of life and safety may remain impaired.

Assessment of tolerance to the effects of methamphetamine on daytime and nighttime activity evaluated with actigraphy in rhesus monkeys

RATIONALE

Methamphetamine is one of the most largely consumed illicit drugs, and its use is associated with abuse liability and several adverse health effects, such as sleep impairment. Importantly, sleep quality can influence addiction treatment outcomes. Evidence suggests that tolerance can develop to the sleep-disrupting effects of stimulant drugs.

OBJECTIVE

The aim of the present study was to investigate the development of tolerance to the actigraphy-based sleep-disrupting and stimulant effects of methamphetamine self-administration in rhesus monkeys.

METHODS

Methamphetamine (0.03 mg/kg/inf, i.v.) self-administration was carried out following three different protocols: 14 consecutive days of self-administration, 5 days/week for 3 weeks, with a 2-day interval between 5-day blocks of self-administration, and 3 days/week for 3 weeks, with a 4-day interval between 3-day blocks of self-administration. Daytime activity and activity-based sleep measures were evaluated with Actiwatch monitors a week before (baseline parameters) and throughout each protocol.

RESULTS

Methamphetamine self-administration markedly disrupted sleep-like measures and increased daytime activity. Tolerance developed to those effects with repeated methamphetamine intake exceeding five consecutive days. Inclusion of washout periods (2 or 4 days) between blocks of methamphetamine self-administration attenuated the development of tolerance, with longer breaks from methamphetamine intake being more effective in maintaining the sleep-disrupting and stimulant effects of methamphetamine.

CONCLUSIONS

Tolerance can develop to the stimulant and sleep-disrupting effects of methamphetamine self-administration. Interruption of drug intake extends the effects of methamphetamine on sleep-like measures and daytime activity.

The Medical and Economic Burden of Narcolepsy: Implications for Managed Care

BACKGROUND

The neurologic disorder narcolepsy results from dysregulation of the sleep-wake cycle and is primarily characterized by chronic, severely excessive daytime sleepiness and cataplexy, an emotionally induced muscle weakness. The prevalence of narcolepsy is approximately 0.05%, and onset generally occurs during the first 2 decades of life. Narcolepsy is believed to be an autoimmune disorder with destruction of hypocretin-producing neurons in the lateral hypothalamus.

OBJECTIVES

To provide an enhanced understanding of narcolepsy and establish the need for early diagnosis and rapid initiation of effective treatment for patients with narcolepsy.

DISCUSSION

Narcolepsy reduces daily functioning and is associated with a substantial medical and economic burden, with many patients being on full disability. The annual direct medical costs are approximately 2-fold higher in patients with narcolepsy than in matched controls without this condition ($11,702 vs $5261, respectively; P <.0001). Further contributing to the overall burden is a lack of recognition of the signs and symptoms of narcolepsy and an absence of easily measurable biomarkers, resulting in a diagnostic delay that often exceeds 10 years and may be associated with misdiagnosis and inappropriate resource utilization. Because narcolepsy generally has an onset in childhood or in adolescence, is often misdiagnosed, has no known cure, and requires lifelong treatment, it is an important disease from a managed care perspective. Clinical features, as well as objective testing, should be used to ensure the timely diagnosis and treatment of patients with narcolepsy.

CONCLUSION

Policies for the diagnosis and treatment of narcolepsy should be based on the current treatment guidelines, but they should also encourage shared decisions between clinicians and patients to allow for individualized diagnostic and treatment choices, as suggested in best practice recommendations.

Pharmacologic Management of Excessive Daytime Sleepiness

Excessive daytime sleepiness (EDS) is related to medical and social problems, including mental disorders, physical diseases, poor quality of life, and so forth. According to the International Classification of Sleep Disorders, Third Edition, diseases that result from EDS are narcolepsy type 1, narcolepsy type 2, idiopathic hypersomnia, hypersomnia due to a medical disorder, and others. EDS is usually treated using amphetamine-like central nervous system stimulants or modafinil and its R-enantiomer, armodafinil, wake-promoting compounds unrelated to amphetamines; a variety of new drugs are under development. The side effects of some stimulants are potent and careful selection and management are required.

Sleep-Disordered Breathing and Excessive Daytime Sleepiness

Sleep-related breathing disorders include obstructive sleep apnea (OSA), central sleep apnea, sleep-related hypoventilation, and sleep-related hypoxemia. Excessive daytime sleepiness (EDS) is frequently reported by patients with OSA but is not invariably present. The efficacy of positive airway pressure therapy in improving EDS is well established for OSA, but effectiveness is limited by suboptimal adherence. Non-OSA causes of sleepiness should be identified and treated before initiating pharmacotherapy for persistent sleepiness despite adequately treated OSA. Further research on the identification of factors that promote EDS in the setting of OSA is needed to aid in the development of better treatment options.

Patient-Reported Measures of Narcolepsy: The Need for Better Assessment

STUDY OBJECTIVES

Narcolepsy, a chronic disorder of the central nervous system, is clinically characterized by a symptom pentad that includes excessive daytime sleepiness, cataplexy, sleep paralysis, hypnopompic/hypnagogic hallucinations, and disrupted nighttime sleep. Ideally, screening and diagnosis instruments that assist physicians in evaluating a patient for type 1 or type 2 narcolepsy would be brief, easy for patients to understand and physicians to score, and would identify or rule out the need for electrophysiological testing.

METHODS

A search of the literature was conducted to review patient-reported measures used for the assessment of narcolepsy, mainly in clinical trials, with the goal of summarizing existing scales and identifying areas that may require additional screening questions and clinical practice scales.

RESULTS

Of the seven scales reviewed, the Epworth Sleepiness Scale continues to be an important outcome measure to screen adults for excessive daytime sleepiness, which may be associated with narcolepsy. Several narcolepsy-specific scales have demonstrated utility, such as the Ullanlinna Narcolepsy Scale, Swiss Narcolepsy Scale, and Narcolepsy Symptom Assessment Questionnaire, but further validation is required.

CONCLUSIONS

Although the narcolepsy-specific scales currently in use may identify type 1 narcolepsy, there are no validated questionnaires to identify type 2 narcolepsy. Thus, there remains a need for short, easily understood, and well-validated instruments that can be readily used in clinical practice to distinguish narcolepsy subtypes, as well as other hypersomnias, and for assessing symptoms of these conditions during treatment.

Safety and efficacy of long-term use of sodium oxybate for narcolepsy with cataplexy in routine clinical practice

Background

Sodium oxybate is licensed in Europe for the treatment of narcolepsy with cataplexy in adults. The aim of this study was to assess the efficacy and safety of sodium oxybate in clinical practice in patients with narcolepsy and cataplexy refractory to other treatments.

Materials and methods

This was a retrospective single centre study including patients with severe narcolepsy with cataplexy refractory to other treatments, who were initiated on sodium oxybate between 2009 and 2015. Patients were allowed to be on other stimulants or/and anti-cataplectic agents. Epworth sleepiness scale (ESS) and weekly cataplexy events were recorded. Side effects (SEs) were recorded at every follow-up visit.

Results

90 patients were prescribed sodium oxybate, with a total of 3116 patient-months of drug exposure. ESS and weekly cataplexy events were significantly reduced by sodium oxybate for all patients (ΔESS = 4.3 ± 4.4 and Δcataplexy = 21.8 ± 18.5 events/week; p < 0.0001, respectively). The required maintenance dose could not be predicted based upon gender, body mass index, or clinical factors. 60% of patients were able to reduce or come off other medications. Half of the patients experienced at least one SE, and 26.6% had to stop treatment due to limiting SEs. Nausea, mood swings and enuresis were the most commonly reported SEs. SEs that led to drug discontinuation, particularly psychosis, were associated with increasing age and were observed early after the initiation of the drug.

Conclusions

Sodium oxybate provides a good clinical efficacy and acceptable safety profile in routine clinical practice for the treatment of patients suffering from narcolepsy with cataplexy. A quarter of patients experience SEs requiring withdrawal of the drug with older patients being more vulnerable to the more serious SEs.

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Sodium oxybate improves alertness in refractory to treatment patients with narcolepsy with cataplexy.

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Sodium oxybate improves cataplexy in refractory to treatment patients with narcolepsy with cataplexy.

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1/4 of the patients had to withdraw from the drug due to side effects.

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In half of the patients sodium oxybate led to reduction of other drug dosages and in 10% to discontinuation.

Evaluation of the effect of JZP-110 in patients with narcolepsy assessed using the Maintenance of Wakefulness Test censored to 20 minutes

OBJECTIVE

To evaluate the effects of JZP-110 on the Maintenance of Wakefulness Test (MWT) with data censored to include only the first 20 min of a 40-min MWT.

METHODS

In a 4-week, placebo-controlled crossover design (Study 201; N = 33) and a 12-week parallel-group design (Study 202; N = 93), JZP-110 was evaluated in narcolepsy patients using changes from baseline in the 40-min MWT as the primary endpoint. Effect sizes based on the change from baseline in mean MWT sleep latency were calculated using 20-min censored MWT data and compared to 40-min MWT data.

RESULTS

In Study 201, mean (standard deviation) changes in MWT sleep latency were 12.7 (10.6) min with JZP-110 versus 0.9 (6.0) min with placebo (P = 0.0002) for 40-min data, and 8.9 (6.3) versus 0.4 (4.6) min for 20-min censored data (P < 0.0001). In Study 202, mean changes in MWT sleep latency were 12.8 (10.3) min with JZP-110 versus 2.1 (7.9) min with placebo (P < 0.0001) for 40-min data, and 8.9 (5.5) versus 1.1 (5.6) min for 20-min censored data (P < 0.0001). In Studies 201 and 202, respectively, Cohen's d effect sizes were large and numerically greater for 20-min censored data (1.54 and 1.41) versus 40-min data (1.37 and 1.17).

CONCLUSIONS

In patients with narcolepsy, JZP-110 significantly improved the ability to stay awake compared with placebo, with large effect sizes using both the 40-min and 20-min censored MWT data.

Behavioral Sleep Medicine Services for Hypersomnia Disorders: A Survey Study

Patients with hypersomnia disorders (HD) suffer from debilitating symptoms that result in reduced functioning, depression, anxiety, and overall worse quality of life. Little is known about the need and desire of this population to utilize behavioral sleep medicine (BSM) interventions that focus on psychosocial functioning and quality of life, and there have been limited attempts to develop such interventions. The purpose of this survey study was to gather patient-centered data on engagement in pharmacological and nonpharmacological interventions, the psychosocial impact of HD symptoms on quality of life and mental health, and potential interest in BSM services, such as cognitive behavioral therapy, mindfulness or yoga, and support groups. We obtained responses from 371 individuals with HD (65.2% narcolepsy and 34.8% idiopathic hypersomnia) to an Internet-based survey. Overall, HD patients reported engagement in pharmacological and nonpharmacological interventions, with narcolepsy patients reporting more perceived effectiveness than those with idiopathic hypersomnia. In addition, HD patients reported a strong negative impact on psychosocial functioning, with elevations in depression and anxiety symptoms along with significant impact on functioning and quality of life. The majority (71.7-85.5%) voiced at least some interest in BSM services. These data suggest that there is substantial interest and need for BSM services that focus on assessment and treatment of psychosocial functioning related to HD.

Safety and efficacy of pitolisant on cataplexy in patients with narcolepsy: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Histaminergic neurons are crucial to maintain wakefulness, but their role in cataplexy is unknown. We assessed the safety and efficacy of pitolisant, a histamine H3 receptor inverse agonist, for treatment of cataplexy in patients with narcolepsy.

METHODS

For this randomised, double-blind, placebo-controlled trial we recruited patients with narcolepsy from 16 sleep centres in nine countries (Bulgaria, Czech Republic, Hungary, Macedonia, Poland, Russia, Serbia, Turkey, and Ukraine). Patients were eligible if they were aged 18 years or older, diagnosed with narcolepsy with cataplexy according to version two of the International Classification of Sleep Disorders criteria, experienced at least three cataplexies per week, and had excessive daytime sleepiness (defined as an Epworth Sleepiness Scale score ≥12). We used a computer-generated sequence via an interactive web response system to randomly assign patients to receive either pitolisant or placebo once per day (1:1 ratio). Randomisation was done in blocks of four. Participants and investigators were masked to treatment allocation. Treatment lasted for 7 weeks: 3 weeks of flexible dosing decided by investigators according to efficacy and tolerance (5 mg, 10 mg, or 20 mg oral pitolisant), followed by 4 weeks of stable dosing (5 mg, 10 mg, 20 mg, or 40 mg). The primary endpoint was the change in the average number of cataplexy attacks per week as recorded in patient diaries (weekly cataplexy rate [WCR]) between the 2 weeks of baseline and the 4 weeks of stable dosing period. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01800045.

FINDINGS

The trial was done between April 19, 2013, and Jan 28, 2015. We screened 117 patients, 106 of whom were randomly assigned to treatment (54 to pitolisant and 52 to placebo) and, after dropout, 54 patients from the pitolisant group and 51 from the placebo group were included in the intention-to-treat analysis. The WCR during the stable dosing period compared with baseline was decreased by 75% (WCR_final=2·27; WCR_baseline=9·15; WCR_{final/baseline}=0·25) in patients who received pitolisant and 38% (WCR_final=4·52; WCR_baseline=7·31; WCR_{final/baseline}=0·62) in patients who received placebo (rate ratio 0·512; 95% CI 0·43-0·60, p<0·0001). Treatment-related adverse events were significantly more common in the pitolisant group than in the placebo group (15 [28%] of 54 vs 6 [12%] of 51; p=0·048). There were no serious adverse events, but one case of severe nausea in the pitolisant group. The most frequent adverse events in the pitolisant group (headache, irritability, anxiety, and nausea) were mild or moderate except one case of severe nausea. No withdrawal syndrome was detected following pitolisant treatment; one case was detected in the placebo group.

INTERPRETATION

Pitolisant was well tolerated and efficacious in reducing cataplexy. If confirmed in long-term studies, pitolisant might constitute a useful first-line therapy for cataplexy in patients with narcolepsy, for whom there are currently few therapeutic options.

FUNDING

Bioprojet, France.

Risks associated with use of stimulant medications in patients with obstructive sleep apnea and cardiomyopathy: a case-control study

OBJECTIVES

Stimulant medications are indicated in patients with obstructive sleep apnea (OSA) who experience sleepiness despite optimal control of sleep-disordered breathing. The safety of stimulant medications in patients with OSA and co-morbid cardiomyopathy is unknown. We performed a case-control study to assess cardiovascular outcomes and mortality risk associated with stimulant use in this group of patients.

METHODS

A total of 162 subjects with OSA and cardiomyopathy were identified. Subjects who used stimulant medications for ≥1 month were designated as cases. Age-and-sex-matched controls not taking these medications were randomly chosen from the same cohort. Outcomes assessed were mortality, implantable cardioverter-defibrillator (ICD) and pacemaker insertion.

RESULTS

Twenty-two cases and 44 controls were included in the analyses. Mean age was 62.6 ± 15 years, 72% were male. Median duration of medication use was 27 months (range 1-98). There were four deaths among cases versus eight among controls. Four cases had a pacemaker and six had an ICD inserted, compared to six and eight respectively in the control group. Age (p = 0.01) and positive airway pressure (PAP) compliance (p = 0.01), but not stimulant medication use (p = 1.00) were associated with mortality on univariate analysis. In multiple logistic regression analyses accounting for body mass index, apnea-hypopnea index/respiratory disturbance index, PAP compliance, ejection fraction and duration of follow up, use of stimulant medication was not associated with mortality (p = 0.50), pacemaker (p = 0.20) or ICD (p = 0.90) implantation.

CONCLUSIONS

Stimulant medications were not associated with elevated risk of mortality, pacemaker or ICD implantation in this case-control study, even after accounting for multiple confounders.

New developments in the management of narcolepsy

Narcolepsy is a life-long, underrecognized sleep disorder that affects 0.02%-0.18% of the US and Western European populations. Genetic predisposition is suspected because of narcolepsy's strong association with HLA DQB1*06-02, and genome-wide association studies have identified polymorphisms in T-cell receptor loci. Narcolepsy pathophysiology is linked to loss of signaling by hypocretin-producing neurons; an autoimmune etiology possibly triggered by some environmental agent may precipitate hypocretin neuronal loss. Current treatment modalities alleviate the main symptoms of excessive daytime somnolence (EDS) and cataplexy and, to a lesser extent, reduce nocturnal sleep disruption, hypnagogic hallucinations, and sleep paralysis. Sodium oxybate (SXB), a sodium salt of γ hydroxybutyric acid, is a first-line agent for cataplexy and EDS and may help sleep disruption, hypnagogic hallucinations, and sleep paralysis. Various antidepressant medications including norepinephrine serotonin reuptake inhibitors, selective serotonin reuptake inhibitors, and tricyclic antidepressants are second-line agents for treating cataplexy. In addition to SXB, modafinil and armodafinil are first-line agents to treat EDS. Second-line agents for EDS are stimulants such as methylphenidate and extended-release amphetamines. Emerging therapies include non-hypocretin-based therapy, hypocretin-based treatments, and immunotherapy to prevent hypocretin neuronal death. Non-hypocretin-based novel treatments for narcolepsy include pitolisant (BF2.649, tiprolisant); JZP-110 (ADX-N05) for EDS in adults; JZP 13-005 for children; JZP-386, a deuterated sodium oxybate oral suspension; FT 218 an extended-release formulation of SXB; and JNJ-17216498, a new formulation of modafinil. Clinical trials are investigating efficacy and safety of SXB, modafinil, and armodafinil in children. γ-amino butyric acid (GABA) modulation with GABA_A receptor agonists clarithromycin and flumazenil may help daytime somnolence. Other drugs investigated include GABA_B agonists (baclofen), melanin-concentrating hormone antagonist, and thyrotropin-releasing hormone agonists. Hypocretin-based therapies include hypocretin peptide replacement administered either through an intracerebroventricular route or intranasal route. Hypocretin neuronal transplant and transforming stem cells into hypothalamic neurons are also discussed in this article. Immunotherapy to prevent hypocretin neuronal death is reviewed.

Efficacy, Safety, and Tolerability of Armodafinil Therapy for Hypersomnia Associated with Dementia with Lewy Bodies: A Pilot Study

BACKGROUND/AIMS

Hypersomnia is common in dementia with Lewy bodies (DLB). We assessed the efficacy, safety, and tolerability of armodafinil for hypersomnia associated with DLB.

METHODS

We performed a 12-week pilot trial of armodafinil therapy (125-250 mg orally daily) in DLB outpatients with hypersomnia. The patients underwent neurologic examinations, a neuropsychological battery, laboratory testing, electrocardiography, and polysomnography. Efficacy was assessed at 2, 4, 8, and 12 weeks. Safety assessment included laboratory examinations, QTc interval, and heart rate. Tolerability was assessed by analysis of adverse events. Data were analyzed using the last-observation-carried-forward method.

RESULTS

Of 20 participants, 17 completed the protocol. The median age was 72 years, most of the participants were men (80%), and most had spouses as caregivers. The Epworth Sleepiness Scale (p < 0.001), Maintenance of Wakefulness Test (p = 0.003), and Clinical Global Impression of Change (p < 0.001) scores improved at week 12. The Neuropsychiatric Inventory total score (p = 0.003), visual hallucinations (p = 0.003), and agitation (p = 0.02) improved at week 4. Caregiver overall quality of life improved at week 12 (p = 0.004). No adverse events occurred.

CONCLUSION

These pilot data suggest improvements in hypersomnia and wakefulness and reasonable safety and tolerability of armodafinil therapy in hypersomnolent patients with DLB. Our findings inform the use of pharmacologic strategies for managing hypersomnolence in these patients.

Assessing narcolepsy with cataplexy in children and adolescents: development of a cataplexy diary and the ESS-CHAD

OBJECTIVE

The aim of this study was to qualitatively evaluate concepts for incorporation into a daily diary to capture cataplexy frequency and to assess the content validity of the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD) in pediatric patients with narcolepsy.

PATIENTS AND METHODS

Face-to-face concept elicitation and cognitive interviews were conducted with children (7-9 years; n=13) and adolescents (10-17 years; n=16) who have narcolepsy with cataplexy, and their parents/caregivers.

RESULTS

Similarities and differences were noted between narcolepsy concepts described by children and their parents/caregivers, suggesting some different but complementary perspectives; parents may not recognize cataplexy symptoms/triggers as well as children, but parents have greater recognition of the circumstances of falling asleep. Cataplexy diary modifications included changes in definitions and examples of cataplexy, using child-friendly terminology, adding a quantitative question to determine daily frequency, and standardizing the questionnaire for evening administration with self-completion by the child. Modifications were made to ESS-CHAD for child-friendly wording and to ensure that items reflect activities (eating, watching TV/video) and environments (school, bus/car transport) in which children are likely to participate. Two ESS-CHAD versions were proposed: one with a 1-month recall period, for general use, and the other with a recall period of "since your last study visit," for research, which could be shorter or longer than 1 month (as short as 1 week).

CONCLUSION

The cataplexy diary and ESS-CHAD were modified for the assessment of children and adolescents. Further psychometric validation is recommended. These measures are being used in a Phase III, placebo-controlled clinical trial of sodium oxybate in children and adolescents with narcolepsy.

Current and Future Treatment Options for Narcolepsy: A Review

Narcolepsy is a chronic neurological sleep disorder with potentially disabling symptoms ranging from occupational concerns to mental health difficulties. Recent advances related to the neurobiological basis of narcolepsy have led to newer pharmacological treatment options and adjunctive behavioral techniques that support symptom management. This article outlines evidence-based pharmacologic therapies, behavioral techniques, and psychosocial costs related to narcolepsy. Psychosocial factors, although frequently acknowledged, deserve further attention and awareness from researchers and providers. The American Academy of Sleep Medicine's (AASM) Quality Measure Drivers and potential future treatment options are also discussed.

Diagnosis and management of narcolepsy in the Indian scenario

INTRODUCTION

The diagnosis and management of narcolepsy in the Indian context needs to be revisited especially in the wake of concerns raised by sleep medicine experts that the entity could be formidably underdiagnosed, as well as undertreated in our setting.

MATERIALS AND METHODS

The history, clinical records, polysomnographic/multiple sleep latency test data, and treatment records of five hundred consecutive patients attending a dedicated sleep clinic between the years 2013 and 2016 were retrospectively analyzed. The response to treatment measures and improvement in daytime functioning were periodically assessed by personal/telephonic interview and E-mail communication.

RESULTS

Thirteen patients were diagnosed with narcolepsy based on the standard criteria of which three had cataplexy. The mean age of presentation was 23.23 years and the male:female ratio was 2.25:1. The mean duration from the onset of symptoms to diagnosis was 4.2 years. Two patients responded to nonpharmacological interventions alone, and six to modafinil, while two patients remained symptomatic and required treatment with methylphenidate. One patient was lost to follow-up, while two others are due for their first follow-up.

CONCLUSION

A refurbished outlook of the diagnostic methodology and treatment paths tailored to our clinical scenario can potentially impact the future of narcolepsy management and research in our country.