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.

Theory of singular-phase reconstruction for an optical speckle field in the turbulent atmosphere.

Analytical expressions are derived and computational algorithms are constructed for retrieving optical-field phase distribution under strong scintillation. The input data for the phase reconstruction are the wave-front slopes registered by a Hartmann sensor or shearing interferometer. The theory is based on representing the slope-vector field as the sum of its potential and solenoid components; it introduces the concept of phase-source and phase-vortex density and uses strict integral expressions relating these quantities to the wave-front slopes. To overcome the difficulties arising from the singular character of phase distribution, use is made of regularization of the wave-front slopes. The slopes can be measured with an ideal point wave-front sensor. It is shown that the slopes measured at the output of a nonideal sensor can be treated as regularized values of these slopes. Numerical simulation of phase unwrapping from the reference values of the wave-front slopes has shown that the algorithm designed for visualization of local phase singularities and those for phase reconstruction are very helpful in eliminating the measurement noise.