Life effects of narcolepsy in 180 patients from North America, Asia and Europe compared to matched controls

Narcolepsy and psychiatric disorders: A bidirectional Mendelian randomization study

Since the introduction of the concept of narcolepsy, there has been a proliferation of discussions about its association with psychiatry. To elucidate the causal role of narcolepsy in the three psychiatric disorders [i.e., schizophrenia (SCZ), major depressive disorder (MDD), and attention-deficit hyperactivity disorder (ADHD)], we applied a bidirectional Mendelian randomization study using two stages (discovery stage and validation stage) and data from three different genome-wide association studies of narcolepsy. The estimates from different stages were combined using fixed-effects meta-analysis. Our findings suggest that narcolepsy is associated with an increased risk of SCZ. Conversely, MDD may be causally related to narcolepsy. A causal relationship between narcolepsy and ADHD was excluded.

Impact of Taiwan's 2021 COVID-19 lockdown on the symptom severity and quality of life of patients with narcolepsy

COVID-19 lockdowns can influence the sleep quality and daytime condition of patients with narcolepsy. Using data from our cohort study, we investigated changes in the quality of life and the symptom severity of patients with narcolepsy during Taiwan's 2021 lockdown and investigated differences by narcolepsy subtype, sex, and age. Patients with type 1 and type 2 narcolepsy (NT1 and NT2, respectively) aged 6-40 years were retrospectively recruited from our narcolepsy cohort study. These patients were regularly evaluated using the Short Form 36 Health Survey questionnaire (SF-36), the Epworth Sleepiness Scale (ESS), the visual analog scale (VAS) for hypersomnolence, the VAS for cataplexy and sleep diary. We compared the differences between the lockdown and the prelockdown periods by narcolepsy subtype, sex, and age. We used a paired t test analysis to compare differences in the SF-36, ESS, VAS scores and data of sleep diary between the prelockdown and lockdown periods (p1), and an independent t test analysis was used to compare the changes in different subgroups between the prelockdown and lockdown periods (p2). A total of 120 patients with narcolepsy were recruited (mean age 24.22 ± 6.87 years; 58% male); 80 of the patients had NT1 (mean age 25.25 ± 6.79 years; 60% male) and 40 had NT2 (mean age 22.16 ± 6.64, 53% male). During the lockdown period, the ESS score of total patients was decreased (p = 0.039) and body mass index was increased (p = 0.02). The NT1 group decreased significantly (p1 = 0.017), especially in men (p1 = 0.016) and adults (p1 = 0.04); scores for the VT domain of the SF-36 increased significantly in male and adult patients with NT2 (p1 = 0.048 and 0.012). Additionally, male patients with NT2 exhibited significantly decreased scores in the physical and emotional role functioning domains (p1 = 0.028, 0.024). The children and adolescents with NT1 had significantly decreased scores in the general health domain of the SF-36, but no significant change was noted in that of adults (p1 = 0.027, p2 = 0.012). We observed both negative and positive impacts of Taiwan's 2021 lockdown on patients with narcolepsy. A more flexible but structured daily routine with adequate sleep time should be considered for this population during lockdown and nonlockdown periods.

Quality of life changes and their predictors in young adult narcolepsy patients after treatment: A real-world cohort study

Background

We conducted a five-year prospective follow-up study to track the real-world quality of life of patients with narcolepsy after medication and analyzed predictors.

Methods

The study ultimately included 157 participants who completed 5-year follow-up, 111 had type 1 narcolepsy (NT1) and 46 had type 2 narcolepsy (NT2). Polysomnography, multiple sleep latency test, actigraphy and HLA-typing were conducted. The Short Form 36 Health Survey Questionnaire (SF-36), the Stanford Center for Narcolepsy Sleep Inventory, the Epworth Sleepiness Scale (ESS), the visual analog for hypersomnolence (VAS), and Conners' Continuous Performance Test were used. Descriptive statistics, repeated measures, and hierarchical linear models were applied for analysis.

Results

Most demographic and clinical data did not significantly differ between groups, but the NT1 group had significantly more overweight, more severe narcoleptic symptoms, more positive HLA typing, shorter mean sleep latency, and more sleep onset rapid eye movement periods. No significant change to the physical domains of SF-36 was found in the total group, but we observed significant changes in emotional role functioning and social function. The NT1 group showed significant improvements in physical role functioning, emotional role functioning, and social function. The NT2 group demonstrated significant improvements in emotional role functioning. At the baseline, the NT2 group had significantly better scores, but there was no significant group difference after treatment, except for physical and social function. ESS and VAS were significantly improved during follow-up. At the baseline, the NT1 group had significantly higher ESS and VAS scores, and continuously significantly higher ESS scores during follow-up. Narcolepsy types, HLA typing, age of onset, symptom severity, attention and vigilance were significantly correlated with SF-36.

Conclusion

Symptom control greatly associates with the quality of life in narcoleptic patients, and medication can play the most important role. Management targeting narcoleptic symptoms, attention impairment, and drug adherence should be provided.

Is memory impaired in narcolepsy type 1?

Memory deficits in narcolepsy with cataplexy type 1 (NT1) have been poorly studied, and the results are controversial. Patients with NT1 usually report memory deficits, which are not seen in objective memory assessments. This study aimed to assess attention and memory processes in NT1 patients using standardised neuropsychological tests and to compare the results with a control group. Performance in memory and attention tests was studied in 12 NT1 patients (diagnosed according to ICSD-3 criteria) and the results compared with those of 14 control subjects. All participants completed questionnaires on sleepiness and depression symptoms. Significant differences were found in the depression symptoms questionnaire. Regarding neuropsychological assessment, NT1 patients performed worse in attention than the control group in that they processed fewer stimuli and achieved fewer correct stimuli. However, no significant differences were found in the memory test results, and the performance was similar between both groups. After application of the Holm-Bonferroni correction, the only differences that remained significant were those in the ESS and in BDI-II scores. Our results showed that memory processes are preserved in NT1 patients and that memory complaints may not be associated with an objective memory deficit. In addition, the significant difference observed for patients in the depression questionnaire could explain the subjective memory complaints.

Perceived challenges in pediatric narcolepsy: a survey of parents, youth, and sleep physicians

STUDY OBJECTIVES

To clarify the most common and problematic symptoms, psychosocial challenges, and comorbidities among youth with narcolepsy based on input from key stakeholders.

METHODS

A nationwide cross-sectional survey of youth with narcolepsy, parents, and sleep physicians.

RESULTS

Overall, 116 parents, 35 youth, and 30 providers completed the entire survey. Symptoms that were rated as most common and problematic by both parents and youth were (in descending order) as follows: daytime sleepiness, disturbed nighttime sleep, mood challenges, cataplexy, sleep-related hallucinations, and sleep paralysis. Most of the 18 queried psychosocial concerns were identified as substantial challenges by both adults and youth, including difficulty focusing and memory, school, worry and anxiety, diet and nutrition, lack of motivation, mood problems, and relationship problems. In contrast, while physicians did recognize some of these challenges, they rated medication side effects and driver's license issues as relatively greater challenges.

CONCLUSIONS

These data highlight the high prevalence of psychosocial challenges, discordance between physician and family ratings of challenges, and a high rate of medical comorbidities in youth with narcolepsy and support the application of a biopsychosocial framework in the assessment and treatment of pediatric narcolepsy.

Intellectual Abilities of Children with Narcolepsy

High cognitive functioning could be a protective factor for school difficulties, behavioral and mood impairments in children with narcolepsy. To investigate this factor, we studied the intellectual abilities of 74 children with narcolepsy (43 boys, 11.7 years old at diagnosis, 91% of cataplexies, 64% obese, 100% HLA positive for DR-DQB1*06:02). All children underwent a one-night polysomnography followed by Multiple Sleep Latency Tests, an evaluation of intelligence quotient (IQ), and filled standardized questionnaires. Thirty-eight percent had high potentialities (HP defined by IQ > 130) and 48% had school difficulties. Using non-parametric tests, we found that HP children reported less difficulties at school and tended to have less impulsivity, conduct, and learning disorders than those without HP. They also tended to be less obese and had less desaturation. Using a multivariate regression analysis, we found an association between the REM sleep percentage and the IQ. REM sleep could be involved in the dynamic changes contributing to the equilibrium of intellectual functioning. This study highlights that despite their frequent school difficulties, narcolepsy per se is unlikely to be a cause of intellectual disability in children. Prompt diagnosis and management of comorbidities such as obesity and obstructive sleep apnea (OSA) could improve cognitive and school performances in these children.

Bedřich Roth: pioneer in sleep medicine

Bedřich Roth was a Czech neurologist who dedicated his professional life to the study of sleep medicine. Shortly after WW2 he initiated a research program with an exclusive focus on narcolepsy and the hypersomnias. At the young age of 38 years, he published his first book. It was in Czech but had extensive English and Russian summaries. In 1967 he spent a study period in Marseille with Professor Henri Gastaut, who was very impressed by this bright and hardworking young neurologist. Dr. Roth, with his colleague Sona Nevšímalová, was the first to publish on the high frequency of depression in patients with narcolepsy and hypersomnia. He was the first person to define Idiopathic Hypersomnia and, along with Allan Rechtschaffen, to document the high frequency of sleep drunkenness in such patients. His many contributions, and his 65th birthday, were celebrated in 1984. Dr. Roth developed Hodgkin's lymphoma and passed away in November 1989. A conference celebrating his life and career took place in Prague in 2009. In 2015 the annual worldwide Idiopathic Hypersomnia Awareness Week organized by Michelle Chadwick celebrated the 35th anniversary of his 1980 book "Narcolepsy and Hypersomnia". Dr. Roth was the first physician to dedicate his entire career to sleep medicine and his publications predated by more than two decades those of all other authors. Bedřich Roth should therefore be considered to be the true father of sleep medicine. He was known widely for his integrity, humility, honesty, and his perseverance to achieve his goals.

Therapeutic Strategies for Mitigating Driving Risk in Patients with Narcolepsy

Narcolepsy is a central nervous system hypersomnia disorder characterized by uncontrollable episodes of daytime sleep, sleep state instability, and cataplexy (sudden loss of muscle tone precipitated by emotion). Individuals with narcolepsy report more frequent sleep-related crashes, near crashes, and drowsy driving than drivers with other sleep disorders. As such, evaluating risk of sleep-related crashes is of great importance for this patient population. There are no established guidelines for ensuring driving safety in patients with narcolepsy; however, many providers currently use a combination of subjective report, report of prior crashes or near-misses, report of previously falling asleep while driving, sleepiness screening tools, and maintenance of wakefulness testing (MWT) to determine risk. Driving simulator tests, though often unavailable to the clinician, provide data to support the use of MWT for evaluation of alertness in drivers with narcolepsy. Treatments such as modafinil may improve driving performance; however, the impact of other treatments such as stimulants and sodium oxybate on driving has not been extensively studied. Behavioral and lifestyle modifications may also reduce risk, including scheduled naps, driving only short distances, and avoiding driving after meals, sedating medications, and alcohol intake. Even with effective treatment, alertness in patients with narcolepsy may never reach that of normal drivers; however, studies have suggested that narcolepsy patients may be able to drive safely with appropriate limitations.

Neuropsychological Alterations in Narcolepsy with Cataplexy and the Expression of Cognitive Deficits

OBJECTIVES

The objective of our study was to assess attention processes and executive function in patients with narcolepsy with cataplexy (NT1). To do so, we compared the results with those of a control group from the general population using an extensive neuropsychological test battery.

METHODS

We studied 28 patients with NT1 and 28 healthy control participants matched for age, gender, and educational level. They all completed questionnaires on sleepiness, anxiety, and depression symptoms. In addition, they underwent neuropsychological tests. The ability to maintain attention was assessed using three computer tasks with different levels of complexity.

RESULTS

Patients had significantly more daytime sleepiness than controls. A significant negative correlation between depression and disease duration was found in NT1 patients. The results of the anxiety questionnaire correlated with the presence of sleep paralysis. There were significant differences in information processing speed subtasks. Patients made significantly more omissions and generally reacted slower and more variably than controls in computerized tasks. As for executive function, patients performed worse in phonologic fluency tasks than controls. However, when the influence of processing speed on fluency tasks was statistically controlled, part of this significant difference disappeared.

CONCLUSIONS

Our results indicate that the negative correlation between depression and disease duration probably reflects progressive adaptation to the functional burden of the disease. Information processing speed plays a fundamental role in the expression of cognitive deficits. We emphasized the need to control the influence of processing speed and sustained attention in the neuropsychological assessment of NT1 patients.

Health-related quality of life in patients with narcolepsy types 1 and 2 from a Sleep Center in Brazil

INTRODUCTION

Narcolepsy patients have higher prevalence of comorbidities, such as obesity, depression, and pain. Narcolepsy symptoms and concomitant medical conditions can impact the daily activities of patients. The objective of this study is to describe the quality of life in a sample of patients with narcolepsy, and the influence of the nutritional status in health domains.

METHODS

At Unifesp, two groups of 33 patients (narcolepsy types 1 and 2 meeting 2014 criteria, concerning hypocretin-1) and 33 controls without sleepiness, matched by age and sex, filled out the SF-36.

RESULTS

Narcolepsy groups, regardless of their nutritional status, had significantly lower scores in all domains, compared to controls, mainly in Role-physical, Role-emotional, and Energy/Fatigue. Role-physical score was lower in type 1 than in type 2 and controls (37.8±1.0 vs. 50.0±1.2 vs. 85.6±1.6; p<0.0001). Obese with type 2 narcolepsy scored lower than type 1 in physical scales.

CONCLUSION

In a Sleep Center in São Paulo, Brazil, physical and mental health were impaired in narcolepsy types 1 and 2. The first report of the poor health status in Brazilians with narcolepsy type 2 suggests that obesity negatively affects physical domains.

Risk of Burn Injury in Patients With Narcolepsy: A Nationwide Population-Based Cohort Study

Narcolepsy is a rare brain disorder characterized by excessive daytime sleepiness (EDS), cataplexy, hypnagogic hallucinations, and sleep paralysis. Stimulants have been used to relieve the symptoms of EDS. Narcolepsy symptoms may pose a risk to burn injury. The study aimed to investigate the risk of burn injury in narcolepsy patients and to examine the relationship between the use of stimulants and the risk of burn injury. In all, 507 narcolepsy patients and 504 controls matched by gender, age, index year, and Charlson Comorbidity Index (CCI) score were enrolled between 1998 and 2012, then followed until the end of 2013 using Taiwan's National Health Insurance Research Database. During the follow-up period, participants who developed burn injury were identified. Cox regression analysis was used to calculate the hazard ratio (HR) with 95% confidence interval (CI) of the burn incidence rate between narcolepsy patients and unaffected controls. Narcolepsy patients had a significantly increased risk of burn injury compared to unaffected controls (5.37 versus 2.69 per 1,000 person-years, HR: 2.04, 95% CI: 1.13-3.67) after adjusting for gender, age, CCI score, urbanization degree, and duration of stimulants use. Also, the use of stimulants in narcolepsy patients was associated with a lower incidence rate of developing burn injury, but the risk estimate was not statistically significant after adjusting for the above-mentioned variables. This study shows narcolepsy patients have an increased risk of burn injury and the use of stimulants may reduce the burn incidence rate, providing a reference for developing prevention interventions.

Risk of bone fractures in patients with narcolepsy: a nationwide population-based cohort study

OBJECTIVES

Narcolepsy symptoms, such as excessive daytime sleepiness or cataplexy, can pose a risk to safety. Stimulants or antidepressants have been used to treat these symptoms. The study investigated the risk of bone fractures in narcolepsy patients. Also, the exposure pattern of stimulants and antidepressants to the risk of bone fractures was examined.

METHODS

In all, 493 narcolepsy patients and 490 controls matched by gender, age, index year, and comorbidity severity were enrolled between 1998 and 2012, then followed until the end of 2013 using Taiwan's National Health Insurance Research Database. During the follow-up period, participants who developed bone fractures were identified. Cox regression analysis was used to calculate the hazard ratio (HR) with 95% confidence interval (CI) for the incidence rates of bone fractures between narcolepsy patients and unaffected controls.

RESULTS

Narcolepsy patients had a significantly increased risk of bone fractures compared with unaffected controls (19.6 versus 12.3 per 1000 person-years, HR: 1.74, 95% CI: 1.29-2.35). In addition, the use of stimulants in narcolepsy patients showed lower incidence rates of bone fractures compared to non-users (incidence rates were 14.2, 11.9, and 20.0 per 1000 person-years, respectively, among frequent users, infrequent users, and non-users), but the risk estimate was not statistically significant. The evidence for associations between antidepressant use in narcolepsy patients and bone fractures was contradictory.

CONCLUSION

This study highlights the need to pay attention to the risk of bone fractures in narcolepsy patients, and the importance of adequate stimulants use might reduce the risk of bone fractures.

Academic and professional paths of narcoleptic patients: the Narcowork study

OBJECTIVE/BACKGROUND

To study educational and professional pathways of narcoleptic patients and examine demographic, disease-related and environmental factors associated with a better academic and professional prognosis.

PATIENTS/METHODS

In sum, 69 narcoleptic patients (51 narcolepsy type 1 and 18 narcolepsy type 2, age 42.5 ± 18.2 years) were enrolled in this pilot monocentric cross-sectional study with a comparison group (80 age- and sex-matched controls) between October 2017 and July 2018 in Lyon Center for Sleep Medicine. They completed questionnaires about their academic and professional trajectories and specific scales of quality of life (EuroQol quality of life scale EQ-5D-3L), depression (beck depression inventory, BDI), sleepiness (Epworth Sleepiness Scale, ESS) and narcoleptic symptoms severity (narcolepsy severity scale, NSS).

RESULTS

No difference in grade repetition or final obtained diploma was observed between patients and controls, but patients evaluated their academic curricula as more difficult (45.5% vs 16.9%, p = 0.0007), complained for more attentional deficits (75% vs 22.1%, p < 0.0001), and had needed more educational reorientation (28.6% vs 9.9%, p = 0.01). Even if no difference was observed in occupational category and professional status, patients expressed significantly less satisfaction about their work. Patients had more signs of depression [OR severe depression = 4.4 (1.6-12.6), p = 0.02] and their quality of life was significantly decreased (67.3 ± 18.4 vs 80.6 ± 13.2, p = 0.0007) as compared to controls. Multivariate analysis showed that a more favorable professional career was associated with a better quality of life.

CONCLUSIONS

Educational and professional pathways do not seem to be significantly impaired in narcoleptic patients, but their experience and quality of life are affected. These findings may allow to reassure patients and should lead to a more comprehensive management of the disease.

CLINICAL TRIAL REGISTRATION

Narcowork, https://clinicaltrials.gov/ct2/show/NCT03173378, N° NCT03173378.

Evidence for cognitive resource imbalance in adolescents with narcolepsy

The study investigated brain activity changes during performance of a verbal working memory task in a population of adolescents with narcolepsy. Seventeen narcolepsy patients and twenty healthy controls performed a verbal working memory task during simultaneous fMRI and EEG acquisition. All subjects also underwent MRS to measure GABA and Glutamate concentrations in the medial prefrontal cortex. Activation levels in the default mode network and left middle frontal gyrus were examined to investigate whether narcolepsy is characterized by an imbalance in cognitive resources. Significantly increased deactivation within the default mode network during task performance was observed for the narcolepsy patients for both the encoding and recognition phases of the task. No evidence for task performance deficits or reduced activation within the left middle frontal gyrus was noted for the narcolepsy patients. Correlation analyses between the spectroscopy and fMRI data indicated that deactivation of the anterior aspect of the default mode in narcolepsy patients correlated more with increased concentrations of Glutamate and decreased concentrations of GABA. In contrast, deactivation in the default mode was correlated with increased concentrations of GABA and decreased concentrations of Glutamate in controls. The results suggested that narcolepsy is not characterized by a deficit in working memory but rather an imbalance of cognitive resources in favor of monitoring and maintaining attention over actual task performance. This points towards dysregulation within the sustained attention system being the origin behind self-reported cognitive difficulties in narcolepsy.

Assessing readiness to drive in adolescents with narcolepsy: what are providers doing?

PURPOSE

There are no universally accepted guidelines for assessing driving readiness in adolescents with narcolepsy. The purpose of the present study was to survey pediatric sleep medicine providers regarding their current practice patterns for assessing driving readiness in adolescents with narcolepsy, knowledge of their state laws regarding physician reporting of unsafe drivers, and opinions regarding what physician duty ought to be.

METHODS

This was an anonymous web-based survey distributed via the PedSleep listserv, which serves as a hub of communication for pediatric sleep medicine providers.

RESULTS

A total of 52 pediatric sleep providers from 25 different states completed the survey. Eighty-eight percent of providers routinely assess driving readiness in adolescents with narcolepsy. Factors rated as "absolutely essential" by at least 50% of respondents included the following: history of previous fall-asleep crash or near miss, sleepiness (reported by patient), sleepiness (reported by caregiver), and cataplexy (reported by patient). Providers included maintenance of wakefulness testing: never (34%), if patient reports no/mild sleepiness (10%), if patient reports moderate/severe sleepiness (25%), or always regardless of patient symptoms (30%), and the median minimally acceptable result was 30 min (25-75th: 20-40 min). There was substantial lack of knowledge regarding legal obligations for reporting.

CONCLUSIONS

These results demonstrate great variability in practice patterns among pediatric sleep medicine providers for assessing driving readiness in adolescents with narcolepsy. In addition, it shows limited knowledge of the providers about their respective states' laws. Further studies are required to identify the best approach to assess residual sleepiness in this population.

Health-Related Quality of Life in Patients With Narcolepsy: A Review of the Literature

Narcolepsy is a chronic disorder characterized by symptoms of excessive daytime sleepiness, irresistible sleep attacks that may be accompanied by cataplexy brought on by emotions, sleep paralysis, and hypnagogic hallucinations. This is a review of 32 empirical articles on health-related quality of life (HRQoL) published in peer-reviewed journals over the past 37 years. Deleterious implications on education, recreation, driving, sexual life, and personality are associated with the disease with a consequent negative psychosocial impact. Sleepiness has an important influence on HRQoL, more than the other symptoms of this disorder that have disrupting roles, too. Therefore, patients with narcolepsy need assistance not only for medication prescription but also in terms of psychological and social support. It is also of importance to assess patients with narcolepsy carefully in terms of depressive symptoms because they may have a major impact on HRQoL with important clinical implications.

Narcolepsy type 1 and hypersomnia associated with a psychiatric disorder show different slow wave activity dynamics

The aim of the study was to compare electrophysiological parameters of night sleep in narcolepsy type 1 and hypersomnia associated with a psychiatric disorder. Fortyfour patients: 15 with narcolepsy type 1, 14 with hypersomnia associated with a psychiatric disorder and 15 age- and sex-matched controls participated in the study. The study subjects filled in the Athens Insomnia Scale (AIS) and the Beck Depression Inventory (BDI). The severity of daytime sleepiness was quantified subjectively using the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), and objectively using the Multiple Sleep Latency Test (MSLT). All subjects underwent polysomnography (PSG) on the two consecutive nights. The data from the second night was analysed. The slow wave activity (SWA, 1-4 Hz) was calculated for the three consecutive sleep cycles, and topographic delta power maps were plotted. In contrast to narcoleptics, psychiatric hypersomniacs had undisturbed nocturnal sleep, high sleep efficiency, normal non-rapid eye movement (NREM) and rapid eye movement (REM) sleep proportions, normal REM latency and sleep latencies on MSLT and PSG. The subjective and objective sleepiness was significantly higher in narcolepsy group than in psychiatric hypersomnia group. In all the study groups SWA was the most prominent in frontal areas, while the greatest between-group differences were found in the central areas. There were significant differences between the groups in SWA in the second NREM episode. The highest SWA was observed in the hypersomnia group, while the lowest in the narcolepsy group. Psychiatric hypersomniacs and controls did not differ in the SWA exponential decline over consecutive NREM episodes, whereas narcoleptics exhibited a steeper dissipation of sleep pressure from the first to the second NREM episode. In conclusion, narcolepsy type1 and hypersomnia associated with psychiatric disorder differ in the SWA dynamics. Narcoleptics presented with the altered dynamics of sleep homeostasis, whereas psychiatric hypersomniacs showed normal nocturnal sleep and normal sleep homeostasis.

Evaluation of the Sleepy Patient: Differential Diagnosis

Excessive daytime sleepiness is defined as the inability to maintain wakefulness during waking hours, resulting in unintended lapses into sleep. It is important to distinguish sleepiness from fatigue. The evaluation of a sleep patient begins with a careful clinical assessment that includes a detailed sleep history, medical and psychiatric history, a review of medications, as well as a social and family history. Physical examination should include a general medical examination with careful attention to the upper airway and the neurologic examination. Appropriate objective testing with a polysomnogram and a multiple sleep latency test if needed will help confirm the diagnosis and direct the appropriate treatment plan.

Pharmacological interventions for daytime sleepiness and sleep disorders in Parkinson's disease: Systematic review and meta-analysis

BACKGROUND

Daytime sleepiness and sleep disorders are frequently reported in Parkinson's disease (PD). However, their impact on quality of life has been underestimated and few clinical trials have been performed.

OBJECTIVES

We aimed to assess the efficacy and safety of pharmacological interventions for daytime sleepiness and sleep disorders in PD.

METHODS

Systematic review of randomized controlled trials comparing any pharmacological intervention with no intervention or placebo for the treatment of daytime sleepiness and sleep problems in PD patients.

RESULTS

Ten studies (n = 338 patients) were included. Four trials addressed interventions for excessive daytime sleepiness. Meta-analysis of the three trials evaluating modafinil showed a significant reduction in sleepiness, as assessed by the Epworth Sleepiness Scale (ESS) (- 2.24 points, 95% CI - 3.90 to - 0.57, p < 0.05). In one study, treatment with caffeine was associated with a non-significant improvement of 1.71 points in ESS (95% CI, - 3.57 to 0.13). The six remaining trials assessed interventions for insomnia and REM sleep Behaviour Disorder (RBD). Single study results suggest that doxepin and YXQN granules might be efficacious, while pergolide may be deleterious for insomnia and that rivastigmine may be used to treat RBD in PD patients. However, there is insufficient evidence to support or refute the efficacy of any of these interventions. No relevant side effects were reported.

CONCLUSIONS

Whilst providing recommendations, this systematic review depicts the lack of a body of evidence regarding the treatment of sleep disorders in PD patients; hence, further studies are warranted.

Health-related stigma as a determinant of functioning in young adults with narcolepsy

Symptoms of narcolepsy tend to arise during adolescence or young adulthood, a formative time in human development during which people are usually completing their education and launching a career. Little is known about the impact of narcolepsy on the social aspects of health-related quality of life in young adults. The purpose of this study was to examine relationships between health-related stigma, mood (anxiety and depression) and daytime functioning in young adults with narcolepsy compared to those without narcolepsy. Young adults (age 18–35) with narcolepsy (N = 122) and without narcolepsy (N = 93) were mailed a packet that included questionnaires and a self-addressed postage paid envelope. The questionnaire included demographic information and a composite of instruments including the SF 36, Functional Outcomes of Sleep Questionnaire (FOSQ), Fife Stigma Scale (FSS), Epworth Sleepiness Scale (ESS) and Hospital Anxiety and Depression Scale (HADS). Variable associations were assessed using descriptive statistics, ANOVA, Mann-Whitney U Test, correlations, stepwise multiple regression and path analysis. Young adults with narcolepsy perceived significantly more stigma and lower mood and health-related quality of life than young adults without narcolepsy (p<0.01). Health-related stigma was directly and indirectly associated with lower functioning through depressed mood. Fifty-two percent of the variance in functioning was explained by the final model in the young adults with narcolepsy. Health-related stigma in young adults with narcolepsy is at a level consistent with other chronic medical illnesses. Health-related stigma may be an important determinant of functioning in young adults with narcolepsy. Future work is indicated toward further characterizing stigma and developing interventions that address various domains of stigma in people with narcolepsy.

Quality measures for the care of patients with narcolepsy

ABSTRACT

The American Academy of Sleep Medicine (AASM) commissioned a Workgroup to develop quality measures for the care of patients with narcolepsy. Following a comprehensive literature search, 306 publications were found addressing quality care or measures. Strength of association was graded between proposed process measures and desired outcomes. Following the AASM process for quality measure development, we identified three outcomes (including one outcome measure) and seven process measures. The first desired outcome was to reduce excessive daytime sleepiness by employing two process measures: quantifying sleepiness and initiating treatment. The second outcome was to improve the accuracy of diagnosis by employing the two process measures: completing both a comprehensive sleep history and an objective sleep assessment. The third outcome was to reduce adverse events through three steps: ensuring treatment follow-up, documenting medical comorbidities, and documenting safety measures counseling. All narcolepsy measures described in this report were developed by the Narcolepsy Quality Measures Work-group and approved by the AASM Quality Measures Task Force and the AASM Board of Directors. The AASM recommends the use of these measures as part of quality improvement programs that will enhance the ability to improve care for patients with narcolepsy.

Hepatic encephalopathy and sleepiness: an interesting connection?

Sleep-wake abnormalities in patients with cirrhosis have been traditionally associated with hepatic encephalopathy (HE). In recent years, a certain amount of work has been devoted to the study of this relationship. This has lead to a modified picture, with weakening of the association between HE and poor night sleep, and the emergence of stronger links between HE and excessive daytime sleepiness. This brief review focuses on the evidence in favor of the interpretation of HE as a sleepiness syndrome, and on the diagnostic, therapeutic and social implications of such an interpretation.

Subjective deficits of attention, cognition and depression in patients with narcolepsy

OBJECTIVE

Patients with narcolepsy often complain about attention deficits in everyday situations. In comparison with these subjective complaints, deficits in objective testing are subtler. The present study assessed the relationships between subjective complaints, objectively measured cognitive performance, disease-related variables, and mood.

PATIENTS/METHODS

A total of 51 patients with narcolepsy and 35 healthy controls responded to questionnaires regarding subjectively perceived attention deficits, sleepiness, anxiety and depression. Moreover, they performed an extensive neuropsychological assessment tapping into attention, executive functions, and memory.

RESULTS

Patients rated their level of attention in everyday situations to be relatively poor. In an objective assessment of cognitive functioning, they showed only slight attention and executive function deficits. The subjective ratings of attention deficits significantly correlated with ratings of momentary sleepiness, anxiety, and depression, but not with objectively measured cognitive performance. Momentary sleepiness and depression predicted almost 39% of the variance in the ratings of subjectively perceived attention deficits.

CONCLUSION

The present study showed that sleepiness and depression, more than objective cognitive deficits, might play a role in the subjectively perceived attention deficits of patients with narcolepsy. The results suggested that when counselling and treating patients with narcolepsy, clinicians should pay attention to potential depression because subjective cognitive complaints may not relate to objective cognitive impairments.

Quality of life in children with narcolepsy

AIMS

To evaluate the health-related quality of life (HRQL) and its correlates in children and adolescents with narcolepsy.

METHODS

We compared the clinical characteristics of control subjects and patients with primary narcolepsy from data collected at the National Reference Centers for Narcolepsy.

RESULTS

The cohort included 69 control subjects (29 boys) and 117 patients (65 boys; 59 de novo patients). Cataplexy was present in 81% and DQB1*0602 was positive in 91%. The control children were older (13.5±3.2 vs. 11.6±3.1 years, P<0.001) and less obese (1.4% vs. 60%, P<0.001). Twenty-five percent of the patients and 15.6% of the control subjects had clinically significant depressive feelings on Children's Depression Inventory (CDI≥16) (NS). Fifty-three narcoleptic and 43 control adolescents, 31 narcoleptic children and 23 control children filled out the HRQL questionnaires as well as 83 parents of patients and 60 parents of control subjects. Narcolepsy seriously impacts HRQL in terms of vitality, physical well-being, relations with friends and leisure activities, especially in adolescents. Depression was the factor that most affected HRQL in both narcoleptic and control subjects. For the control subjects and the narcoleptic patients, when the CDI score was entered into the multivariable regression model adjusted for gender and age, no other continuous independent variable could significantly increase the likelihood of the model. When the CDI score increased by 1, the mean HRQL score decreased by 1.7 for narcoleptic patients and 1.5 for control subjects. Apnea-hypopnoea index, diagnosis delay, disease duration, obesity, the presence of cataplexy or treatment had no effects on HRQL.

CONCLUSIONS

Narcoleptic children and adolescents were at high risk for poor HRQL. Depressive symptoms had a major impact on HRQL. We recommend a more thorough assessment and management of psychological health in this population.

Factors associated with duration before receiving definitive diagnosis of narcolepsy among Japanese patients affected with the disorder

BACKGROUND

Narcolepsy (NA) is a sleep disorder characterized by excessive daytime sleepiness and an increased propensity of rapid eye movement sleep. If left untreated, NA can lead to academic underachievement or job loss because of dozing off or mistakes caused by inattentiveness due to sleepiness.

PURPOSE

Although untreated narcolepsy patients may suffer from many social disadvantages due to excessive daytime sleepiness, mostly it takes a long time to receive a definitive diagnosis of the disorder. This retrospective study investigated factors related to the period until definitive diagnosis among patients with narcolepsy in Japan.

METHODS

We enrolled 181 consecutive patients (108 men, 73 women; mean age 37.6 ± 16.6 years old; narcolepsy with cataplexy/narcolepsy without cataplexy = 131:50). Multivariate logistic regression analysis was performed with period until definitive diagnosis as the dependent variable and descriptive clinical variables as the independent variables.

RESULTS

The mean period until receiving the diagnosis among the participants was 9.9 ± 10.1 years. More than half of the patients first learned about the disorder from information provided by the media. Multivariate logistic analysis indicated that adult onset (p < 0.01), onset in 1995 or later (p < 0.001), and first learning about the disorder from a sleep disorder specialist physician or a general practitioner (p < 0.001) were associated with a time taken for receiving a definitive diagnosis less than or equal to the median value (7 years).

CONCLUSION

Improving access to information about the concept of the disorder and the medical institutions specialized in sleep disorders, especially via the Internet, would be necessary to promote early diagnosis of the disorder.

Orexin gene therapy restores the timing and maintenance of wakefulness in narcoleptic mice

STUDY OBJECTIVES

Narcolepsy is caused by selective loss of the orexin/hypocretin-producing neurons of the hypothalamus. For patients with narcolepsy, chronic sleepiness is often the most disabling symptom, but current therapies rarely normalize alertness and do not address the underlying orexin deficiency. We hypothesized that the sleepiness of narcolepsy would substantially improve if orexin signaling were restored in specific brain regions at appropriate times of day.

DESIGN

We used gene therapy to restore orexin signaling in a mouse model of narcolepsy. In these Atx mice, expression of a toxic protein (ataxin-3) selectively kills the orexin neurons.

INTERVENTIONS

To induce ectopic expression of the orexin neuropeptides, we microinjected an adeno-associated viral vector coding for prepro-orexin plus a red fluorescence protein (AAV-orexin) into the mediobasal hypothalamus of Atx and wild-type mice. Control mice received an AAV coding only for red fluorescence protein. Two weeks later, we recorded sleep/wake behavior, locomotor activity, and body temperature and examined the patterns of orexin expression.

MEASUREMENTS AND RESULTS

Atx mice rescued with AAV-orexin produced long bouts of wakefulness and had a normal diurnal pattern of arousal, with the longest bouts of wake and the highest amounts of locomotor activity in the first hours of the night. In addition, AAV-orexin improved the timing of rapid eye movement sleep and the consolidation of nonrapid eye movement sleep in Atx mice.

CONCLUSIONS

These substantial improvements in sleepiness and other symptoms of narcolepsy demonstrate the effectiveness of orexin gene therapy in a mouse model of narcolepsy. Additional work is needed to optimize this approach, but in time, AAV-orexin could become a useful therapeutic option for patients with narcolepsy.

Excessive daytime sleepiness assessed by the Epworth Sleepiness Scale and its association with health related quality of life: a population-based study in China

Background

Excessive daytime sleepiness (EDS) is a common condition worldwide that has many negative effects on people who were afflicted with it, especially on their health-related quality of life (HRQOL). The Epworth Sleepiness Scale (ESS) is a commonly used method for evaluating EDS in English-speaking countries. This paper reported the prevalence of subjective EDS in China as assessed by the Mandarin version of the ESS; tested the scale’s response rate, reliability and validity; and investigated the relationship between ESS scores and HRQOL.

Methods

A population-based sample of 3600 residents was selected randomly in five cities in China. The demographic information was collected, subjective EDS was assessed by the Mandarin version of the ESS (ESS scores >10), and HRQOL was evaluated by the Mandarin version of the 36-item Short Form Health Survey (SF-36).

Results

The Mandarin version of ESS had very few missing responses, and the average response rate of its eight items was 97.92%. The split-half reliability coefficient and Cronbach’s α coefficient were 0.81 and 0.80, respectively. One factor was identified by factor analysis with an eigenvalue of 2.78. The ESS scores showed positive skewness in the selected sample, with a median (Q1, Q3) of 6 (3, 0). 644 (22.16%) respondents reported subjective EDS, and all of the scores of the eight dimensions of the SF-36 were negatively correlated with ESS scores.

Conclusions

The Mandarin version of ESS is an acceptable, reliable, and valid tool for measuring EDS. In addition, subjective EDS is common in China, based on the ESS results, and impairs HRQOL.

The burden of narcolepsy with cataplexy: how disease history and clinical features influence socio-economic outcomes

OBJECTIVE

To investigate in narcolepsy with cataplexy (NC) patients of working age (18-65 years) the influence of age at onset, age at diagnosis and clinical features on socio-occupational conditions, disease-related economic burden, and quality of life.

METHODS

One hundred consecutive patients underwent a semistructured interview on socio-occupational aspects, NC-related direct and indirect costs, and NC history. Questionnaires were used to evaluate excessive daytime sleepiness, cataplexy, depressive symptoms, and quality of life.

RESULTS

NC patients (51 males, mean age 37±11.5 years) had educational and occupational levels similar to those of the Italian population of the same age range, but married less often, especially if NC onset occurred at a young age. Total annual NC-related costs were €9814 ± 10,372 per patient. Multivariate analyses showed that patients with NC onset before the age of 30 years had a higher educational level, married less frequently, and were less frequently unemployed or inactive (retired, housewife). Patients diagnosed before the age of 30 years were less frequently unemployed or inactive, had fewer work changes, and had a better general health perception. Irresistible sleepiness was associated with work absences and higher indirect costs. Depressive symptoms were strongly associated with lower quality-of-life scores.

CONCLUSIONS

NC age at onset and at diagnosis modulates the disease-related burden. A diagnosis at a young age could improve patients' occupational prognosis, and their general health perception.

Determinants of depressive symptoms in narcoleptic patients with and without cataplexy

The present prospective study assesses depressive symptoms in narcoleptic patients with (NC+) and without (NC-) cataplexy (46 women, 40 men) and age- and sex- matched healthy controls. Seventy patients were under treatment with stimulants and/or anticataplectics. All subjects completed the Beck Depression Inventory (BDI), the Zung Self-Rating Depression Scale (SDS), the Global Impression of Severity of Depression (GSD), the Profile of Mood States (POMS) and Epworth Sleepiness Scale. Patients with narcolepsy were more depressed than controls (higher scores in BDI, GSD, SDS, and POMS [in the total score and in all subscale scores]); however, between the NC+ and NC- patient groups, no differences were found. Our study shows that the women and the patients using antidepressants and stimulants (combination) have a higher probability for depressive symptoms independent of the presence of cataplexy. The lack of difference between NC+ and NC- in the level of depression supports the assumption that the major psychosocial burden in narcolepsy is not necessarily associated with the presence of cataplexy.

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.

A 5-year prospective cohort study on health-related quality of life in patients with narcolepsy

OBJECTIVE

To evaluate the 5-year variation of health-related quality of life (HRQoL) and mood symptoms in a cohort of patients with narcolepsy.

METHODS

Adults attending the Sleep Centre of the Department of Neurological Sciences, University of Bologna in 1997 and meeting the International Classification of Sleep Disorders-Revised criteria for the diagnosis of narcolepsy were eligible. Included patients self-administered the Medical Outcome Short Form-36 (SF-36) and the Zung depression scale (ZDS) prospectively in 1998 and 2003.

RESULTS

There was no significant difference between 1998 and 2003 measures of SF-36 and ZDS in the 54 patients included. About 25% of them showed moderate or severe mood symptoms in both observations. ZDS score (inversely) and duration of disease (directly) explained a percentage of variance of role physical, vitality (VT), social functioning (SF) and role emotional. At the second observation VT and SF had a further percentage of variance explained by excessive daytime sleepiness (EDS) and age at onset. Self-reported diabetes frequency doubled after 5 years (from 7% to 17%).

CONCLUSIONS

Patients with narcolepsy show a stable impairment of HRQoL in a 5-year period with respect to Italian normative data. Mood status and EDS negatively influence their HRQoL while disease duration has a positive influence.

Emerging treatments for narcolepsy and its related disorders

IMPORTANCE OF THE FIELD

Narcolepsy is a chronic sleep disorder, characterized by excessive daytime sleepiness (EDS), cataplexy, hypnagogic hallucinations, sleep paralysis and nocturnal sleep disruption. Non-pharmacological treatments (i.e., behavioral modification) are often helpful for the clinical management of narcoleptic patients. As these symptoms are often disabling, most patients need life-long treatments. Over 90% of diagnosed narcoleptic patients are currently prescribed medications to control their symptoms; however, available treatments are merely symptomatic.

AREAS COVERED IN THIS REVIEW

This review presents a description of the clinical symptoms of narcolepsy, followed by a discussion of the state-of-the-art knowledge regarding the disorder and related emerging treatments. In preparing this review, an extensive literature search was conducted using Pubmed. Only selected references from 1970 to 2008 are cited.

WHAT THE READER WILL GAIN

This review focuses on emerging treatments for human narcolepsy, and the reader will gain significant knowledge of current and future treatment for this and related disorders. Traditionally, amphetamine-like stimulants (i.e., dopaminergic release enhancers) have been used for clinical management to improve EDS, and tricyclic antidepressants have been used as anticataplectics. However, treatments have recently evolved which utilize better tolerated compounds, such as modafinil (for EDS) and adrenergic/serotonergic selective reuptake inhibitors (as anticataplectics). In addition, night time administration of a short-acting sedative, gamma-hydroxybutyrate, has been used for the treatment for EDS and cataplexy. As a large majority of human narcolepsy is hypocretin peptide deficient, hypocretin replacement therapy may also be a new therapeutic option; yet, this option is still unavailable. In addition to the hypocretin-based therapy, a series of new treatments are currently being tested in animal and/or humans models. These potential options include novel stimulant and anticataplectic drugs as well as immunotherapy, based on current knowledge of the pathophysiology of narcolepsy with cataplexy.

TAKE HOME MESSAGE

We expect that more pathophysiology-based treatments, capable of curing and/or preventing narcolepsy and related diseases, will be available in near future. As cases of EDS, associated with other neurological conditions (i.e., symptomatic narcolepsy or narcolepsy due to medical conditions), are often linked with hypocretin deficiency, these novel therapeutic options may also be applied to treatment of these disabling conditions.