A strategic neurological research agenda for Europe: Towards clinically relevant and patient-centred neurological research priorities

BACKGROUND AND PURPOSE

Neurological disorders constitute a significant portion of the global disease burden, affecting >30% of the world's population. This prevalence poses a substantial threat to global health in the foreseeable future. A lack of awareness regarding this high burden of neurological diseases has led to their underrecognition, underappreciation, and insufficient funding. Establishing a strategic and comprehensive research agenda for brain-related studies is a crucial step towards aligning research objectives among all pertinent stakeholders and fostering greater societal awareness.

METHODS

A scoping literature review was undertaken by a working group from the European Academy of Neurology (EAN) to identify any existing research agendas relevant to neurology. Additionally, a specialized survey was conducted among all EAN scientific panels, including neurologists and patients, inquiring about their perspectives on the current research priorities and gaps in neurology.

RESULTS

The review revealed the absence of a unified, overarching brain research agenda. Existing research agendas predominantly focus on specialized topics within neurology, resulting in an imbalance in the number of agendas across subspecialties. The survey indicated a prioritization of neurological disorders and research gaps.

CONCLUSIONS

Building upon the findings from the review and survey, key components for a strategic and comprehensive neurological research agenda in Europe were delineated. This research agenda serves as a valuable prioritization tool for neuroscientific researchers, as well as for clinicians, donors, and funding agencies in the field of neurology. It offers essential guidance for creating a roadmap for research and clinical advancement, ultimately leading to heightened awareness and reduced burden of neurological disorders.

Role of sleep in neurodegeneration: the consensus report of the 5th Think Tank World Sleep Forum

Sleep abnormalities may represent an independent risk factor for neurodegeneration. An international expert group convened in 2021 to discuss the state-of-the-science in this domain. The present article summarizes the presentations and discussions concerning the importance of a strategy for studying sleep- and circadian-related interventions for early detection and prevention of neurodegenerative diseases. An international expert group considered the current state of knowledge based on the most relevant publications in the previous 5 years; discussed the current challenges in the field of relationships among sleep, sleep disorders, and neurodegeneration; and identified future priorities. Sleep efficiency and slow wave activity during non-rapid eye movement (NREM) sleep are decreased in cognitively normal middle-aged and older adults with Alzheimer's disease (AD) pathology. Sleep deprivation increases amyloid-β (Aβ) concentrations in the interstitial fluid of experimental animal models and in cerebrospinal fluid in humans, while increased sleep decreases Aβ. Obstructive sleep apnea (OSA) is a risk factor for dementia. Studies indicate that positive airway pressure (PAP) treatment should be started in patients with mild cognitive impairment or AD and comorbid OSA. Identification of other measures of nocturnal hypoxia and sleep fragmentation could better clarify the role of OSA as a risk factor for neurodegeneration. Concerning REM sleep behavior disorder (RBD), it will be crucial to identify the subset of RBD patients who will convert to a specific neurodegenerative disorder. Circadian sleep-wake rhythm disorders (CSWRD) are strong predictors of caregiver stress and institutionalization, but the absence of recommendations or consensus statements must be considered. Future priorities include to develop and validate existing and novel comprehensive assessments of CSWRD in patients with/at risk for dementia. Strategies for studying sleep-circadian-related interventions for early detection/prevention of neurodegenerative diseases are required. CSWRD evaluation may help to identify additional biomarkers for phenotyping and personalizing treatment of neurodegeneration.

Narcolepsy type 1 and Sydenham chorea - Report of 3 cases and review of the literature

OBJECTIVES/BACKGROUND

Narcolepsy type 1 (NT1) is an immune-mediated disorder characterized by excessive daytime sleepiness, cataplexy, low levels of hypocretin-1 in the cerebrospinal fluid, and a strong association with the HLA DQB1*06:02 allele. There is evidence for streptococcal infections as one pathogenic factor that may lead to NT1 as part of a multifactorial pathogenesis. Elevated titers of Antistreptolysin-O antibodies and increased inflammatory activity in response to streptococci antigens have been described in patients with NT1. Sydenham chorea (SC) results from a post-streptococcal autoimmune process targeting basal ganglia neurons. Despite this common trigger, SC has been interpreted as a misdiagnosis in a few described cases of patients who were first diagnosed with SC and later with NT1. Our goal was to analyze the association between SC and NT1.

PATIENTS/METHODS

We reviewed the literature and report three patients from three European sleep centers who were diagnosed with both SC and NT1 within a few months.

RESULTS

We describe the cases of one male (age 10) and two female (age 22 and 10) patients.

CONCLUSIONS

We argue that in those cases both diagnoses are justified, unlike reports of previous cases in which SC was considered a misdiagnosis in patients with NT1. It remains, however, unclear if the conditions occur independently or if there is an overlap disorder- an SC-like subtype of narcolepsy with a particular sequence of symptoms. Further studies need to clarify the causality of the relationship and the pathophysiology of the reported rare association.

Pitolisant-supported bridging during drug holidays to deal with tolerance to modafinil in patients with narcolepsy

STUDY OBJECTIVES

Modafinil is a common treatment for excessive daytime sleepiness (EDS) in narcolepsy. The long-term use of modafinil can lead to tolerance with the loss of efficacy and the continuous increase of its dose. Pharmacological strategies to deal with the tolerance to modafinil are lacking. We investigated the efficacy and safety of pitolisant-supported bridging during drug holidays in patients with tolerance to modafinil.

METHODS

Narcolepsy patients on monotherapy with modafinil who developed symptoms of tolerance were eligible. The following alternating therapy regimen was established: Monday to Friday patients continued on modafinil whereas Saturday and Sunday they switched to pitolisant to "bridge" the EDS symptoms. Patients were assessed at baseline and after three months with the Epworth Sleepiness Scale (ESS) and the Ullanlinna Narcolepsy Scale (UNS). Health-related quality of life (HrQol) was evaluated by EuroQol5D. Adverse events were documented in the patients' diaries.

RESULTS

41 patients aged 30.9 ± 5.6 years were included. After three months of the alternating therapy regimen, the symptoms of tolerance decreased and the modafinil dose could be reduced by 41% (p < 0.01) resulting in better safety. The EDS improved on ESS (baseline: 18.2 ± 4.2, follow-up: 12.6 ± 4.0, p < 0.0001) and UNS (baseline: 25.8 ± 7.9, follow-up: 18.9 ± 5.9, p < 0.0001). The HrQol increased significantly.

CONCLUSION

Patients with tolerance to modafinil could benefit from pitolisant-supported bridging during drug holidays. This alternating pharmacological strategy proved to be safe and helped to reduce EDS and to decrease the modafinil dose. Further randomized controlled studies are required to evaluate the different strategies to deal with the tolerance to modafinil.

CLINICAL TRIAL REGISTRATION NUMBER

Clinical Trials.gov Identifier NCT05321355.

Real-world treatment of pediatric narcolepsy with pitolisant: A retrospective, multicenter study

BACKGROUND

First symptoms of narcolepsy mostly present during childhood. Pharmacological management options in children are limited, also due to approval status. Pitolisant is an inverse histamine 3 receptor agonist and has been approved for the treatment of adult narcolepsy with or without cataplexy by EMA and FDA. Clinical experience indicates for a beneficial use also in children and adolescents. Our goal was to evaluate the effects and tolerability of pitolisant in narcolepsy children/adolescents in a real-world setting.

METHODS

This multicentre retrospective observational study included 55 patients with narcolepsy from three international narcolepsy centers (Germany, France and Italy) who were treated with pitolisant. Patients were eligible if they were at least 6 years old and diagnosed with narcolepsy type 1 or 2. Demographic and clinical characteristics, questionnaires, sleep medicine and laboratory data were collected.

RESULTS

55 children/adolescents (25 girls, 45.45%, 30 boys, 54.55%) aged 6-18 years, with narcolepsy (type 1 = 92.7%, type 2 = 7.3%), were treated with pitolisant. The mean pitolisant dose was 34.1 mg/d. Treatment was effective for excessive daytime sleepiness (EDS) and cataplexy: the pediatric Epworth Sleepiness Scale (ESS) score decreased from 19 to 13.5 (p < 0.001) and the weekly cataplexy frequency improved from 7.9 at baseline to 5.2 (p < 0.001). Treatment with pitolisant was well tolerated. Side effects were mild and mostly short-term. Insomnia was reported most frequently (5.5%).

CONCLUSION

First real-world results suggest that pitolisant treatment is effective in improving EDS and cataplexy in children with narcolepsy, and also is well tolerated.

Complementary and alternative medicine use in narcolepsy

BACKGROUND

Management of narcolepsy includes behavior strategies and symptomatic pharmacological treatment. In the general population, complementary and alternative medicine (CAM) use is common in Europe (30%), also in chronic neurological disorders (10-20%). The aim of our study was to evaluate frequency and characteristics of CAM use in German narcolepsy patients.

METHODS

Demographic, disease-related data frequency and impact of CAM use were assessed in an online survey. Commonly used CAM treatments were predetermined in a questionnaire based on the National Center for Complementary and Alternative Medicine and included the domains: (1) alternative medical systems; (2) biologically based therapies; (3) energy therapies; (4) mind-body interventions, and (5) manipulative and body-based therapies.

RESULTS

We analyzed data from 254 questionnaires. Fifteen percent of participants were at the time of survey administration using CAM for narcolepsy, and an additional 18% of participants reported past use. Among the 33% of CAM users, vitamins/trace elements (54%), homoeopathy (48%) and meditation (39%) were used most frequently. 54% of the users described CAM as helpful. CAM users more frequently described having side effects from their previous medication (p = 0.001), and stated more frequently not to comply with pharmacological treatment than non-CAM users (21% vs. 8%; p = 0.024).

DISCUSSION

The use of CAM in narcolepsy patients is common. Our results indicate that many patients still feel the need to improve their symptoms, sleepiness and psychological well-being in particular. Frequent medication change, the experience of adverse events and low adherence to physician-recommended medication appears more frequent in CAM users. The impact of CAM however seems to be limited.

Solriamfetol real world experience study (SURWEY): Initiation, titration, safety, effectiveness, and experience during follow-up for patients with narcolepsy from Germany

BACKGROUND

Excessive daytime sleepiness (EDS) is a core narcolepsy symptom, for which solriamfetol (Sunosi®) was recently approved in the European Union. SURWEY characterises real-world strategies used by physicians when initiating solriamfetol, and patient outcomes after follow-up.

METHODS

SURWEY is an ongoing retrospective chart review conducted by physicians in Germany/France/Italy. Here, data are reported from 70 German patients with EDS and narcolepsy. Eligibility included age ≥18 years, reached a stable solriamfetol dose, and completed ≥6 weeks of treatment. Patients were classified (based on existing EDS treatment) into changeover, add-on, or new-to-therapy subgroups.

RESULTS

Patients' mean ± SD age was 36.9 ± 13.9 years. Changeover from prior EDS medication was the most common initiation strategy. Initial solriamfetol dose was typically 75 mg/day (69%). In 30 patients (43%), solriamfetol was titrated; 27/30 (90%) completed titration as prescribed, most within 7 days. Mean ± SD Epworth Sleepiness Scale (ESS) score was 17.6 ± 3.1 at initiation (n = 61) and 13.6 ± 3.8 at follow-up (n = 51). Slight/strong improvements in EDS were perceived for >90% of patients (patient and physician report). Sixty-two percent reported an effect duration of 6 to <10 h; 72% reported no change in perceived nighttime sleep quality. Common adverse events included headache (9%), decreased appetite (6%), and insomnia (6%); no cardiovascular events were reported.

CONCLUSIONS

Most patients in this study were switched from a prior EDS medication to solriamfetol. Solriamfetol was typically initiated at 75 mg/day; titration was common. ESS scores improved after initiation, and most patients perceived improvement in EDS. Common adverse events were consistent with those reported in clinical trials.

CLINICALTRIALS

GOV REGISTRATION

N/A.

039 Solriamfetol real world experience study (SURWEY): safety and effectiveness for patients with narcolepsy from Germany

Introduction

Solriamfetol is a dopamine/norepinephrine reuptake inhibitor approved in the EU for excessive daytime sleepiness (EDS) associated with narcolepsy. This real-world study characterises outcomes following solriamfetol initiation.

Methods

SURWEY is an ongoing retrospective chart review (Germany, France, Italy). Patients (≥18 years old, EDS due to narcolepsy, stable solriamfetol dose, ≥6 weeks of treatment) were classified by solriamfe- tol initiation: changeover (from existing EDS medications), add-on (to current EDS medication), or new- to-therapy (no current/prior EDS medication). Epworth Sleepiness Scale (ESS) scores, patient/physician impressions of improvement, and adverse events (AEs) were assessed.

Results

Among 78 German patients (36.9±13.9 years old; 56% female, 57% with cataplexy), changeo- ver was most common (n=43), followed by add-on (n=19) and new-to-therapy (n=8). Final follow-up was 15.9±7.0 weeks after initiation. Overall, ESS scores were 17.6±3.1 (n=61) at initiation and 13.6±3.8 at follow-up (n=51), indicating improvement of EDS (improvements similar across subgroups). Most patients perceived slight/strong improvements in their condition (physician report, 94%; patient report, 91%; results similar across subgroups). Common AEs: headache (9%), decreased appetite (6%), insomnia (6%).

Conclusion

In this real-world cohort of German patients with narcolepsy, EDS improved across all subgroups with solriamfetol treatment. AEs were consistent with those reported in clinical trials.

Support

Jazz Pharmaceuticals.

Narcolepsy: a model interaction between immune system, nervous system, and sleep-wake regulation

Narcolepsy is a rare chronic neurological disorder characterized by an irresistible excessive daytime sleepiness and cataplexy. The disease is considered to be the result of the selective disruption of neuronal cells in the lateral hypothalamus expressing the neuropeptide hypocretin, which controls the sleep-wake cycle. Diagnosis and management of narcolepsy represent still a substantial medical challenge due to the large heterogeneity in the clinical manifestation of the disease as well as to the lack of understanding of the underlying pathophysiological mechanisms. However, significant advances have been made in the last years, thus opening new perspective in the field. This review describes the current knowledge of clinical presentation and pathology of narcolepsy as well as the existing diagnostic criteria and therapeutic intervention for the disease management. Recent evidence on the potential immune-mediated mechanisms that may underpin the disease establishment and progression are also highlighted.

Prevalence, incidence, and health care utilization of patients with narcolepsy: a population-representative study

STUDY OBJECTIVES

Previous estimated prevalence of narcolepsy in Europe was 47 patients per 100,000 persons, with a yearly incidence of 0.64-1.37 per 100,000. However, analyses of representative datasets from large cohorts are limited. This study aimed to estimate the population-based diagnostic prevalence and incidence of narcolepsy in Germany, and to describe these patients and their health care resource utilization.

METHODS

This study used the InGef research database, an anonymized representative dataset of 4 million persons covered by statutory health insurance in Germany. Patients with confirmed narcolepsy diagnoses in 2018 were included. Mid-p exact tests were used to calculate 95%-confidence intervals. Patients with narcolepsy diagnoses and narcolepsy-targeting therapy in 2014-2018 were included to describe health care resource utilization in the year prior to diagnosis.

RESULTS

In 2018 diagnostic prevalence was estimated as 17.88 (95%-CI 16.45-19.40), and 12-month incidence as 0.79 (0.52-1.15) per 100,000 persons. 46% patients were in psycho-behavioral therapeutic treatment and 61% of employees had sick-leave days. One in three patients was hospitalized for any cause. 28% received antibiotics.

CONCLUSIONS

Diagnostic prevalence was lower, but incidence was consistent with previous reports, though previous estimates may diverge in terms of age/gender-distributions. Patients showed a substantial utilization of health care resources, including sick leave and hospitalization. Almost half the patients underwent psycho-behavioral treatment in the year prior to diagnosis, which might indicate high burden of psychiatric symptoms. The increased use of antibiotics could indicate more frequent infections than in the general population.

Awakening to sleep disorders in Europe: Survey on education, knowledge and treatment competence of European residents and neurologists

OBJECTIVES

Sleep-wake disorders are common in the general population and in most neurological disorders but are often poorly recognized. With the hypothesis that neurologists do not get sufficient training during their residency, the Young European Sleep Neurologist Association (YESNA) of the European Academy of Neurology (EAN) performed a survey on postgraduate sleep education.

METHODS

A 16-item questionnaire was developed and distributed among neurologists and residents across European countries. Questions assessed demographic, training and learning preferences in sleep disorders, as well as a self-evaluation of knowledge based on five basic multiple-choice questions (MCQs) on sleep-wake disorders.

RESULTS

The questionnaire was completed by 568 participants from 20 European countries. The mean age of participants was 31.9 years (SD 7.4 years) and was composed mostly of residents (73%). Three-quarters of the participants reported undergraduate training in sleep medicine, while fewer than 60% did not receive any training on sleep disorders during their residencies. Almost half of the participants (45%) did not feel prepared to treat neurological patients with sleep problems. Only one-third of the participants correctly answered at least three MCQs. Notably, 80% of participants favoured more education on sleep-wake disorders during the neurology residency.

CONCLUSIONS

Education and knowledge on disorders in European neurological residents is generally insufficient, despite a strong interest in the topic. The results of our study may be useful for improving the European neurology curriculum and other postgraduate educational programmes.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND PURPOSE

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS), and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness (EDS) in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong); methylphenidate, amphetamine derivatives (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) EDS in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivatives (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

European guideline and expert statements on the management of narcolepsy in adults and children

BACKGROUND AND AIM

Narcolepsy is an uncommon hypothalamic disorder of presumed autoimmune origin that usually requires lifelong treatment. This paper aims to provide evidence-based guidelines for the management of narcolepsy in both adults and children.

METHODS

The European Academy of Neurology (EAN), European Sleep Research Society (ESRS) and European Narcolepsy Network (EU-NN) nominated a task force of 18 narcolepsy specialists. According to the EAN recommendations, 10 relevant clinical questions were formulated in PICO format. Following a systematic review of the literature (performed in Fall 2018 and updated in July 2020) recommendations were developed according to the GRADE approach.

RESULTS

A total of 10,247 references were evaluated, 308 studies were assessed and 155 finally included. The main recommendations can be summarized as follows: (i) excessive daytime sleepiness in adults-scheduled naps, modafinil, pitolisant, sodium oxybate (SXB), solriamfetol (all strong), methylphenidate, amphetamine derivates (both weak); (ii) cataplexy in adults-SXB, venlafaxine, clomipramine (all strong) and pitolisant (weak); (iii) excessive daytime sleepiness in children-scheduled naps, SXB (both strong), modafinil, methylphenidate, pitolisant, amphetamine derivates (all weak); (iv) cataplexy in children-SXB (strong), antidepressants (weak). Treatment choices should be tailored to each patient's symptoms, comorbidities, tolerance and risk of potential drug interactions.

CONCLUSION

The management of narcolepsy involves non-pharmacological and pharmacological approaches with an increasing number of symptomatic treatment options for adults and children that have been studied in some detail.

Insomnia in neurological diseases

Insomnia is defined as difficulties of initiating and maintaining sleep, early awakening and poor subjective sleep quality despite adequate opportunity and circumstances for sleep with impairment of daytime performance. These components of insomnia - namely persistent sleep difficulties despite of adequate sleep opportunity resulting in daytime dysfunction - appear secondary or co-morbid to neurological diseases. Comorbid insomnia originates from neurodegenerative, inflammatory, traumatic or ischemic changes in sleep regulating brainstem and hypothalamic nuclei with consecutive changes of neurotransmitters. Symptoms of neurological disorders (i.e motor deficits), co-morbidities (i.e. pain, depression, anxiety) and some disease-specific pharmaceuticals may cause insomnia and/or other sleep problems.This guideline focuses on insomnias in headaches, neurodegenerative movement disorders, multiple sclerosis, traumatic brain injury, epilepsies, stroke, neuromuscular disease and dementia.The most important new recommendations are: Cognitive behavioral therapy (CBTi) is recommended to treat acute and chronic insomnia in headache patients. Insomnia is one of the most frequent sleep complaints in neurodegenerative movement disorders. Patients may benefit from CBTi, antidepressants (trazodone, doxepin), melatonin and gaba-agonists. Insomnia is a frequent precursor of MS symptoms by up to 10 years. CBTi is recommended in patients with MS, traumatic brain injury and. Melatonin may improve insomnia symptoms in children with epilepsies. Patients with insomnia after stroke can be treated with benzodiazepine receptor agonists and sedating antidepressants. For patients with dementia suffering from insomnia trazodone, light therapy and physical exercise are recommended.

Efficacy of pitolisant in patients with high burden of narcolepsy symptoms: pooled analysis of short-term, placebo-controlled studies

STUDY OBJECTIVE

To evaluate the efficacy of pitolisant, a histamine 3 (H₃)-receptor antagonist/inverse agonist, in adult patients with high burden of narcolepsy symptoms.

METHODS

Data were pooled from two randomized, placebo-controlled, 7- or 8-week studies of pitolisant (titrated to a potential maximum dose of 35.6 mg/day) in adults with narcolepsy. Analyses included three independent patient subgroups: Epworth Sleepiness Scale (ESS) baseline score ≥16, Maintenance of Wakefulness Test (MWT) sleep latency ≤8 min, and ≥15 cataplexy attacks per week.

RESULTS

The analysis populations included 118 patients for ESS (pitolisant, n = 60; placebo, n = 58), 105 for MWT (pitolisant, n = 59; placebo, n = 46), and 31 for cataplexy (pitolisant, n = 20; placebo, n = 11). On the ESS, least-squares mean change from baseline was significantly greater for pitolisant (-6.1) compared with placebo (-2.3; P < 0.001). Significantly more pitolisant-treated patients were classified as treatment responders: ESS score reduction ≥3, 69.0% in the pitolisant group versus 35.1% in the placebo group (P = 0.001); final ESS score ≤10, 36.2% versus 10.5%, respectively (P = 0.005). On the MWT, mean sleep latency increased from 3.5 min to 10.4 min with pitolisant and from 3.4 min to 6.8 min with placebo (P = 0.017). Least-squares mean change in the weekly rate of cataplexy was significantly greater for pitolisant (-14.5; baseline, 23.9; final, 9.4) compared with placebo (-0.1; baseline, 23.1; final, 23.0; P = 0.004). Headache was the most common adverse event with pitolisant.

CONCLUSIONS

Pitolisant, at once-daily doses up to 35.6 mg, was efficacious for reducing excessive daytime sleepiness and cataplexy in patients with severe narcolepsy symptom burden.

[Narcolepsy in adults: Definition, etiology and treatment]

Narcolepsy is a hypersomnolence disorder of central origin that presents with a disturbance of the wake-sleep regulation. Lead symptoms consist of excessive daytime sleepiness and cataplexy. Nowadays, two types of narcolepsy are distinguished. Type 1 narcolepsy, formerly known as narcolepsy with cataplexy, is based on hypocretin deficiency. The cause of type 2 narcolepsy, formerly known as narcolepsy without cataplexy, remains mainly unknown. A multimodal approach is necessary for diagnosis. The mean latency between the onset of disease and diagnosis in Europe ranges 14 years. Narcolepsy has a major impact on workability and quality of life. The management of narcolepsy is usually life-long and includes non-pharmacological approaches and a symptomatic pharmacological treatment.

0762 Efficacy Of Pitolisant In Patients With High Burden Of Narcolepsy Symptoms

Introduction

Recent literature suggests that histamine may play an important role in narcolepsy. This post hoc analysis evaluates the efficacy of pitolisant, a histamine 3 (H3)-receptor antagonist/inverse agonist, in patients with high burden of the main narcolepsy symptoms.

Methods

Data were pooled from 2 randomized, placebo-controlled, 7- and 8-week studies of pitolisant (individually titrated; maximum dose, 35.6 mg/day) in adults with narcolepsy. Analyses included 3 independent patient subgroups: baseline score of &gt;16 on the Epworth Sleepiness Scale (ESS), sleep latency of ≤8 minutes on the Maintenance of Wakefulness Test (MWT), and ≥15 cataplexy attacks per week.

Results

The analysis populations included 108 patients for the ESS (pitolisant, n=54; placebo, n=54), 105 for the MWT (pitolisant, n=59; placebo, n=46), and 31 for cataplexy (pitolisant, n=20; placebo, n=11). Mean change in ESS from baseline was significantly greater for pitolisant (-6.1) compared with placebo (-2.6; P=0.0002). A significantly greater percentage of pitolisant-treated patients were classified as treatment responders: for ESS score reduction ≥3, 68.5% in the pitolisant group versus 35.2% in the placebo group (P=0.0006); for final ESS score ≤10, 35.2% versus 9.3%, respectively (P=0.0026). Mean increase in sleep latency on the MWT was significantly greater for pitolisant (7.0 minutes) compared with placebo (3.4 minutes; P=0.0089). Decrease in mean weekly rate of cataplexy was significantly greater for pitolisant (baseline, 21.8; final, 3.9) compared with placebo (baseline, 20.9; final, 18.2); the rate ratio was 0.35 (95% CI, 0.26‒0.47; P&lt;0.001). The adverse event profile in the analysis populations was consistent with the known safety profile for pitolisant; headache was the most common adverse event in pitolisant-treated patients (10.0%-20.4%).

Conclusion

In patients with severe symptom burden, pitolisant produced significantly greater improvements in excessive daytime sleepiness and cataplexy compared with placebo, highlighting the important role of histamine in narcolepsy.

Support

Bioprojet Pharma and Harmony Biosciences, LLC.

0764 Pitolisant In The Treatment Of Patients With Narcolepsy: A 2-year, Prospective, Observational, Single-center Study

Introduction

Pitolisant, a selective histamine H3 receptor antagonist/inverse agonist, increases histamine release in the brain. The efficacy of pitolisant in adults with narcolepsy was demonstrated in randomized, placebo-controlled trials. This study evaluated long-term use of pitolisant in clinical practice.

Methods

This prospective, open-label, 2-year, observational study was conducted at a major narcolepsy center in Germany and enrolled adults with a diagnosis of narcolepsy who had no prior treatment with pitolisant. Assessments included excessive daytime sleepiness (Epworth Sleepiness Scale [ESS]), weekly rate of cataplexy (WRC), and health-related quality of life (Short-Form Veterans RAND [VR-36]).

Results

The study enrolled 147 patients: mean age, 29.9 years; 57.1% female, 65.3% with cataplexy, and 66.7% with disrupted nighttime sleep. In patients who were tested, CSF hypocretin-1 was &lt;110 pg/mL in 70.8% (51/72), and 79.4 % (77/97) were HLA-DQB1*0602 positive. The pitolisant dose was 35.6 mg/d in 38.1% of patients at Month 3, and 73.5% at Month 24. Most patients received concomitant narcolepsy medications (63.3% at baseline; 79.6% at month 24). Mean ESS score decreased from 16.2 at baseline to 12.4 at Month 12 and 12.6 at Month 24. Mean WRC was reduced by 31% at Month 24. Significant improvement in quality of life was noted at Months 12 and 24 on VR-36 subscales that assess general health perception, vitality, and social function. In all, 38 patients (25.8%) discontinued from the study before Month 24: 15.0% for lack of efficacy and 10.8% due to adverse events. The most common adverse events were disrupted nighttime sleep (29.3% of patients), headache (15.5%), and nausea (12.2%).

Conclusion

These real-world data show that long-term treatment with pitolisant (usually with 35.6 mg/d) was efficacious for reducing EDS and cataplexy and improving quality of life in patients with narcolepsy. Treatment was generally well tolerated.

Support

Writing support funded by Harmony Biosciences, LLC.

Portable PSG for sleep stage monitoring in sports: Assessment of SOMNOwatch plus EEG

Current sport-scientific studies mostly neglect the assessment of sleep architecture, although the distribution of different sleep stages is considered an essential component influencing an athlete's recovery and performance capabilities. A mobile, self-applied tool like the SOMNOwatch plus EEG might serve as an economical and time-friendly alternative to activity-based devices. However, self-application of SOMNOwatch plus EEG has not been validated against conventional polysomnography (PSG) yet. For evaluation purposes, 25 participants (15 female, 10 male; M _age = 22.92 ± 2.03 years) slept in a sleep laboratory on two consecutive nights wearing both, conventional PSG and SOMNOwatch plus EEG electrodes. Sleep parameters and sleep stages were compared using paired t-tests and Bland-Altman plots. No significant differences were found between the recordings for Sleep Onset Latency, stages N1 to N3 as well as Rapid Eye Movement stage. Significant differences (Bias [95%-confidence interval]) were present between Total Sleep Time (9.95 min [-29.18, 49.08], d = 0.14), Total Wake Time (-13.12 min [-47.25, 23.85], d = -0.28), Wake after Sleep Onset (-11.70 min [-47.25, 23.85], d = -0.34) and Sleep Efficiency (2.18% [-7.98, 12.34], d = 0.02) with small effect sizes. Overall, SOMNOwatch plus EEG can be considered a valid and practical self-applied method for the examination of sleep. In sport-scientific research, it is a promising tool to assess sleep architecture in athletes; nonetheless, it cannot replace in-lab PSG for all clinical or scientific purposes.

Narcolepsy and adjuvanted pandemic influenza A (H1N1) 2009 vaccines - Multi-country assessment

BACKGROUND

In 2010, a safety signal was detected for narcolepsy following vaccination with Pandemrix, an AS03-adjuvanted monovalent pandemic H1N1 influenza (pH1N1) vaccine. To further assess a possible association and inform policy on future use of adjuvants, we conducted a multi-country study of narcolepsy and adjuvanted pH1N1 vaccines.

METHODS

We used electronic health databases to conduct a dynamic retrospective cohort study to assess narcolepsy incidence rates (IR) before and during pH1N1 virus circulation, and after pH1N1 vaccination campaigns in Canada, Denmark, Spain, Sweden, Taiwan, the Netherlands, and the United Kingdom. Using a case-control study design, we evaluated the risk of narcolepsy following AS03- and MF59-adjuvanted pH1N1 vaccines in Argentina, Canada, Spain, Switzerland, Taiwan, and the Netherlands. In the Netherlands, we also conducted a case-coverage study in children born between 2004 and 2009.

RESULTS

No changes in narcolepsy IRs were observed in any periods in single study sites except Sweden and Taiwan; in Taiwan incidence increased after wild-type pH1N1 virus circulation and in Sweden (a previously identified signaling country), incidence increased after the start of pH1N1 vaccination. No association was observed for Arepanrix-AS03 or Focetria-MF59 adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the case-control study nor for children born between 2004 and 2009 in the Netherlands case-coverage study for Pandemrix-AS03.

CONCLUSIONS

Other than elevated narcolepsy IRs in the period after vaccination campaigns in Sweden, we did not find an association between AS03- or MF59-adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the sites studied, although power to evaluate the AS03-adjuvanted Pandemrix brand vaccine was limited in our study.

Coexisting narcolepsy (with and without cataplexy) and multiple sclerosis : Six new cases and a literature review

BACKGROUND

There are increasing data suggesting the involvement of the immune system in narcolepsy. The co-occurrence of narcolepsy with other autoimmune disorders (including multiple sclerosis, MS) is rare.

PATIENTS AND METHODS

International multicenter sleep center survey and literature review on narcolepsy with (NC) and without (NwC) cataplexy.

RESULTS

A total of 26 patients (pts), 6 in the survey and 20 in the literature were found. Two different types of association were identified: (1) Symptomatic type (5 pts): MS preceding the onset of narcolepsy, which was always without cataplexy (NwC); sleep onset REM episodes (SOREM) and hypocretin deficiency were observed in some, and lesions in the hypothalamus in all patients. (2) Coexisting type (18 pts): MS preceding or following the appearance of NC with SOREM, hypocretin deficiency but no lesions in the hypothalamus. A positive effect of steroids, immunoglobulins or natalizumab on narcolepsy symptoms was observed in four patients.

DISCUSSION

Narcolepsy and MS are rarely associated. In addition to NwC secondary to hypothalamic demyelination, some patients present a coexistence of MS with NC without detectable hypothalamic lesions. The rarity of reports on this association probably reflects underrecognition. The elucidation of underlying genetic and immune mechanisms needs further studies.

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.

Psychiatric Comorbidities in Restless Legs Syndrome

Restless legs syndrome (RLS) is a neurological sleep disorder with frequent (39%) coexisting psychiatric comorbidities. Patients with any psychiatric comorbidity had fewer periodic leg movements in sleep. Psychiatric disorders should be taken into account in patients with RLS.

Cystatin F is a biomarker of prion pathogenesis in mice

Misfolding of the cellular prion protein (PrP^C) into the scrapie prion protein (PrP^Sc) results in progressive, fatal, transmissible neurodegenerative conditions termed prion diseases. Experimental and epidemiological evidence point toward a protracted, clinically silent phase in prion diseases, yet there is no diagnostic test capable of identifying asymptomatic individuals incubating prions. In an effort to identify early biomarkers of prion diseases, we have compared global transcriptional profiles in brains from pre-symptomatic prion-infected mice and controls. We identified Cst7, which encodes cystatin F, as the most strongly upregulated transcript in this model. Early and robust upregulation of Cst7 mRNA levels and of its cognate protein was validated in additional mouse models of prion disease. Surprisingly, we found no significant increase in cystatin F levels in both cerebrospinal fluid or brain parenchyma of patients with Creutzfeldt-Jakob disease compared to Alzheimer’s disease or non-demented controls. Our results validate cystatin F as a useful biomarker of early pathogenesis in experimental models of prion disease, and point to unexpected species-specific differences in the transcriptional responses to prion infections.

Post Tick-Borne Encephalitis Virus Vaccination Narcolepsy with Cataplexy

STUDY OBJECTIVES

Narcolepsy with cataplexy (NC) is a chronic neurological disorder thought to result from an altered immune response based on a genetic predisposition coupled with environmental factors. Pandemrix vaccination has been reported to increase the risk of narcolepsy. We aimed at identifying other vaccines associated with the onset of narcolepsy.

METHODS

Case series and retrospective database study.

RESULTS

We identified four cases of NC following a tick-borne encephalitis (TBE) vaccination with FSME Immun. Additional four cases could be detected in the database of the Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines in Germany.

CONCLUSIONS

Our findings implicate TBE vaccination as a potential additional environmental factor for the development of NC and add additional evidence for an immunological mechanism in the pathogenesis of the disease.

Genetic variants of methionine metabolism and DNA methylation

Aim: Altered DNA methylation is associated with important and common pathologies such as cancer. The origin of altered DNA methylation is unknown. The methyl groups for DNA methylation are provided by methionine metabolism. This metabolism is characterized by a high interindividual variability, which is in part explained by genetic variants. Methods: In a cohort of 313 individuals derived from a family-based study with index cases of cerebrovascular disease, we analyzed whether global methylation of leukocyte DNA was associated with age, gender, homocysteine plasma levels or functionally relevant genetic variants. Results: We observed an association of the G-allele of the methionine synthase variant c.2756A>G (D919G) with global methylation (% methylation ± 1 SD, AA: 41.3 ± 14.9; AG: 36.4 ± 18.2; GG: 30.8 ± 16.9; F = 4.799; p = 0.009). The methionine synthase variant c.2756A>G is associated with various types of cancer. Conclusion: Our data suggest that an impact on DNA methylation may contribute to the clinical relevance of the methionine synthase variant.

The presence of oligoclonal IgG bands in human CSF during the course of neurological diseases

The analysis of cerebrospinal fluid (CSF) is an important tool for the diagnosis of neurological diseases. However, there is limited knowledge about the representativity of a single oligoclonal band (OCB) analysis for a neurological disease during its clinical course. In this study, we analyzed the presence of OCB in the CSF of patients who underwent lumbar puncture more than once. We retrospectively analyzed anonymized data from serial 17,002 CSF analyses done in the CSF laboratory of the Department of Neurology, University Hospital Zurich. We included cases with documented diagnosis in whom OCB were determined more than once. We included 144 patients. The median time span between the first and second OCB analysis was 274 days (range, 1-3,533 days). The result of the second OCB analysis was identical in 109 cases, and different in 35 (24 %). Twenty-five patients acquired and ten patients lost OCB over time. Three of 24 MS patients did not show OCB at the first CSF analysis, but in the second. In the entire group, newly occurring OCB were often associated with new symptoms or occurred after the acute phase of CNS infectious diseases, supposedly as a consequence of the immune reaction. A loss of OCB was often associated with remissions from diseases, e.g., during effective treatment. In patients with neurological diseases, both initially positive and negative OCB results may change over time, which often parallels the clinical condition. Such variability must be taken into account for the interpretation of OCB results.

Genetic variants of homocysteine metabolism and multiple sclerosis: a case-control study

Methylenetetrahydrofolate reductase (MTHFR) is necessary for the synthesis of methionine and S-adenosylmethionine, which is necessary for CNS (re-)myelination. The MTHFR variant c.1298A>C was associated with the development of relapsing remitting multiple sclerosis (RRMS) in a German population. This study aimed at analyzing whether further genetic variants of methionine metabolism are associated with the development or the clinical course of RRMS. Therefore, genomic DNA of 147 serial German RRMS patients and 147 matched healthy controls was genotyped for five polymorphic variants of methionine metabolism. Statistical analyses were performed using multivariate binary and linear regression analyses. We show that the insertion allele of cystathionine beta-synthase (CBS) c.844_855ins68bp and the G-allele of reduced folate carrier 1 (RFC1) c.80G>A were associated with an earlier age of onset of MS, suggesting gene-dose effects (median age of onset in years: 25-26-32; standardized regression coefficient beta: 0.216; p=0.030, and 29-31-35 years; beta: 0.282; p=0.005, respectively). Conclusively, mutant variants of CBS and RFC1 may be associated with the age of RRMS onset. Since methionine metabolism can be manipulated by supplementation of vitamins and amino acids, our data provide a rationale for novel ideas of preventive and therapeutic strategies in RRMS.

Is preeclampsia associated with restless legs syndrome?

OBJECTIVE

Restless legs syndrome (RLS) is a common neurologic disorder. Secondary RLS includes pregnancy and iron deficiency. Prevalence of RLS in pregnancy ranges from 11% to 27%. We aimed to assess the frequency and characteristics of RLS in pregnancy in a Peruvian population and to evaluate the possible pregnancy or delivery complications due to RLS.

METHODS

We assessed 218 consecutive expectant mothers at the inpatient clinic of the Hospital San Bartolome in Lima, Peru. Assessment was performed by using the standard diagnostic criteria for RLS and by using a clinical and diagnostic interview. Questionnaires for RLS severity, idiopathic RLS (IRLS), and excessive daytime sleepiness (EDS) according to the Epworth sleepiness scale (ESS) were used. Blood examination was performed for hemoglobin and hematocrit. For comparison, RLS patients were matched for age and body mass index (BMI) with pregnant women without RLS.

RESULTS

Out of 218 patients, 40 (18.4%) fulfilled diagnostic criteria for RLS. In RLS patients, prophylactic iron supplementation therapy during pregnancy was less frequently taken (P=.02). Pregnant women with RLS had a higher ESS score than pregnant controls (10.6 +/- 3.1 vs 7.6. +/- 3.6; P<.001). Preeclampsia was more frequent in RLS (7/40 vs 1/39; P=.03).

CONCLUSIONS

In our study, RLS was frequent in pregnant Peruvian women, especially in those without prophylactic iron supplementation. RLS patients described more EDS. Preeclampsia was more common in RLS. Our study is the first study to indicate a possible association between RLS and preeclampsia.

Elevated CSF histamine levels in multiple sclerosis patients

Background

Histamine is an ubiquitous inflammatory mediator of numerous physiological processes. Histamine and its receptors have been implicated in multiple sclerosis (MS) disease pathogenesis. We prospectively enrolled 36 MS patients and 19 age and gender-matched healthy volunteers for cerebrospinal fluid (CSF) histamine analysis.

Findings

CSF histamine levels in MS patient samples were significantly higher (median: 35.6 pg/ml) than in controls (median: 5.5 pg/ml; Beta = 0.525, p < 0.001). In addition, histamine increased with age (Pearson’s correlation, p < 0.003).

Conclusions

Histamine may be an important factor for both the initiation and maintenance of chronic inflammatory diseases of the central nervous system. Our observation encourages a deeper investigation of the role of histamine in MS.

Efficiency of sodium oxybate in episodic cluster headache

We report the case of a 60-year-old man suffering from episodic cluster headache treated successfully with sodium oxybate. Sodium oxybate may be a therapeutic option in attacks of episodic cluster headache.

A possible genetic link between MTHFR genotype and smoking behavior

Background

Hyperhomocysteinemia is an independent risk factor for stroke and other vascular events. The variant methylenetetrahydrofolate reductase (MTHFR) C677T is associated with elevated homocysteine levels, cardiovascular disease and stroke, which supports a causal relationship between hyperhomocysteinemia and vascular disease. However, MTHFR variants have also been reported to be associated with smoking behavior, which could be an important confounder.

Methodology/Principal Findings

We analyzed the MTHFR variants C677T and A1298C in two independent samples of 525 and 535 individuals, respectively. 21% of the non-smokers, but only 12% of the smokers were homozygous carriers of both MTHFR wildtype alleles, i.e. 677CC and 1298AA (Chi² = 15.8; p<0.001; binary regression). Plasma homocysteine levels were higher in smokers (13.9±4.1 µmol/L) than in non-smokers (12.6±4.0 µmol/L; F = 11.4; p = 0.001; ANOVA). Smoking MTHFR 677TT individuals had the highest plasma homocysteine levels (16.2±5.2 µmol/L), non-smoking 677CC individuals had the lowest (12.2±13.6 µmol/L).

Conclusions/Significance

In our study samples, MTHFR variants and smoking behaviour were associated with homocysteine plasma levels. In addition, the MTHFR variants were associated with smoking behaviour. Such an association may be a relevant confounder between MTHFR variants, homocysteine plasma levels and vascular diseases.