Clinical and neurophysiological characteristics of 89 patients with narcolepsy and cataplexy from the Russian Narcolepsy Network.

STUDY OBJECTIVES: The first reports of narcolepsy with cataplexy in Russia were made by Mankovsky (The pathogenesis of narcolepsy (the case of epidemic encephalitis with cataplexy) published in the Sovremennaya psihonevrologia) in 1925. The largest series of patients (n = 110) was reported by A. Vein (doctoral thesis: Hypersomnia Syndrome) in 1964. However, until today, narcolepsy remained relatively unknown in Russia. The aim of this study is to report clinical and polysomnography (PSG)/multiple sleep latency test (MSLT) results in the Russian population and compare them with the European Narcolepsy Network (EU-NN) data (n = 1099) reported. METHODS: Eleven sleep centers from Russia agreed to participate and completed a questionnaire including 58 questions concerning demographic, clinical, PSG, and MSLT data. RESULTS: There were 89 patients with a mean age of 35.6 ± 16.9 years (± here and further indicates standard deviation), 58% males, and 42% females. Narcolepsy started at a mean age of 25.6 ± 14.6 years (range 5-74 years). The mean Epworth Sleepiness Scale score was 18.4 ± 3.5 points (range: 11-24). Sleep paralysis was reported by 59.1%, and hallucinations by 82% of patients. In MSLT, ≥ 2 sleep-onset REM (rapid eye movement) periods (SOREMPs) were found in 81.6%. No center provided human leukocyte antigen (HLA) or cerebral spinal fluid hypocretin data. CONCLUSIONS: Clinical and neurophysiological data from this first study of the Russian Narcolepsy Network suggest a similar profile to the recently reported EU-NN data. The more severe and higher percentage of patients with cataplexy and presenting with both excessive daytime sleepiness and cataplexy may reflect low awareness of narcolepsy in Russia. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; URL: https://clinicaltrials.gov/ct2/show/NCT05375890; Name: Clinical and Neurophysiological Characteristics of Narcolepsy; Identifier: NCT05375890. CITATION: Kuts A, Poluektov M, Zakharov A, et al. Clinical and neurophysiological characteristics of 89 patients with narcolepsy and cataplexy from the Russian Narcolepsy Network. J Clin Sleep Med. 2023;19(2):355-359.

European guideline for the diagnosis and treatment of insomnia.

This European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia. The guideline is based on a systematic review of relevant meta-analyses published till June 2016. The target audience for this guideline includes all clinicians involved in the management of insomnia, and the target patient population includes adults with chronic insomnia disorder. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to grade the evidence and guide recommendations. The diagnostic procedure for insomnia, and its co-morbidities, should include a clinical interview consisting of a sleep history (sleep habits, sleep environment, work schedules, circadian factors), the use of sleep questionnaires and sleep diaries, questions about somatic and mental health, a physical examination and additional measures if indicated (i.e. blood tests, electrocardiogram, electroencephalogram; strong recommendation, moderate- to high-quality evidence). Polysomnography can be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders), in treatment-resistant insomnia, for professional at-risk populations and when substantial sleep state misperception is suspected (strong recommendation, high-quality evidence). Cognitive behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (strong recommendation, high-quality evidence). A pharmacological intervention can be offered if cognitive behavioural therapy for insomnia is not sufficiently effective or not available. Benzodiazepines, benzodiazepine receptor agonists and some antidepressants are effective in the short-term treatment of insomnia (≤4 weeks; weak recommendation, moderate-quality evidence). Antihistamines, antipsychotics, melatonin and phytotherapeutics are not recommended for insomnia treatment (strong to weak recommendations, low- to very-low-quality evidence). Light therapy and exercise need to be further evaluated to judge their usefulness in the treatment of insomnia (weak recommendation, low-quality evidence). Complementary and alternative treatments (e.g. homeopathy, acupuncture) are not recommended for insomnia treatment (weak recommendation, very-low-quality evidence).

An evidence-based recommendation for a new definition of respiratory-related leg movements.

STUDY OBJECTIVES: Current sleep scoring rules exclude leg movements that occur near respiratory events from being scored as periodic leg movements during sleep (PLMS) but differ in whether they exclude leg movements occurring at the end (WASM/ IRLSSG) or during a respiratory event (AASM). The aim of the present study was to describe the distribution of leg movements in relation to respiratory events and to contribute to an evidence-based rule for the identification and scoring of respiratory-related leg movements (RRLMs). DESIGN: Retrospective chart review and analysis of polysomnographic recordings. SETTING: Clinical sleep laboratory. PARTICIPANTS: 64 patients with polysomnographic recordings between January 2010 and July 2011, aged 18 to 75 years, with AHI >20, ODI >10, more than 50% of apneas being obstructive, >15 leg movements of any type per hour of sleep, no more than 20% of total sleep time with artifacts and no medical condition or medication that could influence leg movements or respiratory disturbances. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Back-averaging of leg movement activity (LMA) with respect to respiratory events revealed that LMA was present shortly before the end of the respiratory events, but occurred mostly following respiratory events with peak onset of LMA 2.5 s after respiratory event termination. Increased LMA before the beginning of the respiratory event consisted mainly of the tail of LMA after the end of the previous respiratory event. Change-point analysis indicated that LMA was increased over an interval of -2.0 s to +10.25 s around the end of respiratory events. Changing the definition of RRLMs had a significant influence on PLMS counts. The number of patients with obstructive sleep apnea (OSA) with PLMS index >15 was 80% when considering the WASM/ IRLSSG definition, 67% for the AASM criteria, and 41% when based on the interval identified by change-point analysis (-2.0 to 10.25 s). CONCLUSIONS: Leg movements are not augmented at the beginning or middle of respiratory events but are increased around the end of respiratory events over a period significantly longer than specified in the AASM and the WASM/ IRLSSG rules. Both rules underestimate the number of RRLMs and thus overestimate the number of PLMS in patients with OSA.

Respiratory-related leg movements and their relationship with periodic leg movements during sleep.

STUDY OBJECTIVES: To describe the time structure of leg movements (LM) in obstructive sleep apnea (OSA) syndrome, in order to advance understanding of their clinical significance. LOCATION: Sleep Research Centre, Oasi Institute (IRCCS), Troina, Italy. SETTING: Sleep laboratory. PATIENTS: Eighty-four patients (16 females, 68 males, mean age 55.1 y, range 29-74 y). METHODS: Respiratory-related leg movements (RRLM) and those unrelated to respiratory events (NRLM) were examined within diagnostic polysomnograms alone and together for their distributions within the sleep period and for their periodicity. MEASUREMENTS AND RESULTS: Patients with OSA and RRLM exhibited more periodic leg movements in sleep (PLMS), particularly in NREM sleep. A gradual decrease in number of NRLM across the sleep period was observed in patients with RRLM. This pattern was less clear for RRLM. Frequency histograms of intermovement intervals of all LMs in patients with RRLM showed a prominent first peak at 4 sec, and a second peak at approximately 24 sec coincident with that of PLMS occurring in the absence of OSA. A third peak of lowest amplitude was the broadest with a maximum at approximately 42 sec. In patients lacking RRLM, NRLM were evident with a single peak at 2-4 sec. A stepwise linear regression analysis showed that, after controlling for a diagnosis of restless legs syndrome and apnea-hypopnea index, PLMS remained significantly associated with RRLM. CONCLUSION: The time structure of leg movements occurring in conjunction with respiratory events exhibit features of periodic leg movements in sleep occurring alone, only with a different and longer period. This brings into question the validity, both biologic and clinical, of scoring conventions with their a priori exclusion from consideration as periodic leg movements in sleep.

High intention to fall asleep causes sleep fragmentation.

The aim of this study was to investigate the effects of intention to fall asleep on sleep quality in good sleepers using polysomnographic and subjective nap parameters. We hypothesized that high intention to sleep would lead to arousal, worsening sleep quality. A counterbalanced 2 × 2 experimental design with one intra-individual (neutral versus motivating instruction) and one inter-individual (instruction sequence) variable was used. Thirty-three good sleepers (22 females; mean age: 24.1 ± 8.4 years) each attended two 1-h daytime polysomnographic recording sessions in the laboratory. When providing motivating instruction, the experimenter insisted on the importance of falling asleep as quickly as possible and promised a financial reward. Compared with neutral instruction, motivating instruction was associated with increased waking after sleep onset, number of awakenings and arousal index during napping. No relationship between instruction and subjective nap appraisal was found. The effect of high intention on sleep fragmentation remained significant after controlling for habitual napping, depression, anxiety and sleepiness. Thus, our findings suggest that high intention to fall asleep worsened sleep quality, especially in terms of sleep fragmentation, in good sleepers.

Longitudinal polysomnographic assessment from acute to subacute phase in infratentorial versus supratentorial stroke.

BACKGROUND: Regulation of sleep and sleep-related breathing resides in different brain structures. Vascular lesions can be expected to differ in their consequences on sleep depending on stroke topography. However, studies addressing the differences in sleep and sleep-related breathing depending on stroke topography are scarce. The aim of the present investigation was to compare the sleep and sleep-related breathing of patients with supratentorial versus infratentorial stroke. METHODS: This study was part of the prospective multicenter study SAS-CARE-1 (Sleep-Disordered Breathing in Transient Ischemic Attack (TIA)/Ischemic Stroke and Continuous Positive Airway Pressure (CPAP) Treatment Efficacy (SAS-CARE); NCT01097967). We prospectively included 14 patients (13 male, age 66 ± 6 years) with infratentorial lesions and 14 patients (14 male, age 64 ± 7 years) with supratentorial lesions, matched for age and stroke severity. Polysomnography was recorded in all during the acute phase within 9 days after stroke onset and 3 months later. RESULTS: During the acute phase after stroke, patients with infratentorial lesions had significantly more sleep-related breathing disorders than patients with supratentorial lesions with an apnea-hypopnea index >20 observed in 8 (57%) patients with infratentorial stroke and in only 2 (14%) patients with supratentorial stroke. Sleep-related breathing improved from the acute to the subacute phase (3 months), albeit remaining elevated in a significant proportion of subjects. Sleep parameters did not differ between the two patient groups but there was a general improvement of sleep from the acute to the subacute phase which was comparable for both patient groups. Although stroke severity was mild, recovery after 3 months was worse in patients with infratentorial stroke with 12 of 14 patients with supratentorial stroke being symptom free (NIHSS = 0), while this was the case for only 6 of 14 patients with infratentorial stroke. CONCLUSIONS: Patients with infratentorial lesions are at an increased risk for sleep-related breathing disorders, which are frequent in this group. Monitoring of sleep-related breathing is therefore especially recommended in patients with infratentorial stroke. Because of the absence of reliable differences in sleep parameters between the two patient groups, polygraphy, with reduced diagnostic costs, rather than polysomnography could be considered. The higher prevalence of sleep-related breathing disorders and the poorer recovery of patients with infratentorial lesions suggest that early treatment interventions should be considered.