Restless sleep disorder in children with epileptic and non-epileptic nocturnal attacks.

Restless sleep disorder (RSD) is an important sleep disorder characterised by the presence of frequent large muscle movements (LMM) during sleep, which may be comorbid to other conditions/diseases. In this study, we investigated the frequency and the characteristics of RSD among children who were evaluated by polysomnography (PSG) due to epileptic and non-epileptic nocturnal attacks. We analysed consecutively children younger than 18 years who were referred for PSG recording due to abnormal motor activities during sleep. The diagnosis of nocturnal events as sleep-related epilepsy was made based on the current consensus. Patients who were referred with suspicion of sleep-related epilepsy, but who were diagnosed to have non-epileptic nocturnal events and children with a definitive diagnosis of NREM sleep parasomnias were also enrolled. Sixty-two children were analysed in this study (17 children with sleep-related epilepsy, 20 children with NREM parasomnia, and 25 children with nocturnal events not otherwise classified [neNOS]). The mean number of LMM, LMM index, LMM-associated with arousal and its index were all significantly higher in children with sleep-related epilepsy. Restless sleep disorder was present in 47.1% of patients with epilepsy, 25% of patients with parasomnia, and in 20% of patients with neNOS. The mean A3 duration and the A3 index were higher in children with sleep-related epilepsy and RSD compared with those with parasomnia and restless sleep disorder. Patients with RSD had lower ferritin levels than those without RSD in all subgroups. Our study demonstrates a high prevalence of restless sleep disorder in children with sleep-related epilepsy, associated with an increased cyclic alternating pattern.

Analysis of QRS complex morphology in children and adolescents with obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) leads to many cardiovascular, neurologic, metabolic, and neurocognitive consequences. Conduction deficits, deviations in electrical axis, and changes in QRS morphology reflect the impairments in cardiac muscle activity and underlie the cardiovascular complications of OSAS. Here we aimed to determine the relationship between OSAS and changes in the cardiac conduction system in children and adolescents. During the 6-month duration of the study, all children having the diagnosis of OSAS in Sleep and Disorders Unit following a full-night polysomnography (PSG) were consecutively evaluated. ECGs were performed and analyzed in the Division of Pediatric Cardiology, Department of Pediatrics. The maximum spatial vector size (QRSmax), QRS electrical axis (EA), left and right ventricular hypertrophy, and the presence of fragmented QRS (fQRS) or prolonged R or S wave were examined in detail. A total of 17 boys with OSAS and 13 healthy boys participated in the study. The mean QRSmax and the QRSmax on V5 derivative were significantly lower in the patient group compared to those in the control group (p = 0.011 and p = 0.017, respectively). EA was similar between the two groups. While none of the patients with OSAS nor the control group had left ventricular hypertrophy, only one boy with OSAS had right ventricular hypertrophy according to ECG-derived analysis. The percentage of fQRS or notched R or S waves was significantly higher in patients with OSAS compared to healthy controls (p = 0.035), especially in children below the age of 5 years (p = 0.036).  Conclusion: This study demonstrated that male children and adolescents with OSAS have a combination of QRS complex changes characterized by low QRS voltages, and increased frequency of fragmented QRS. These findings reflect that the electrical remodeling and structural remodeling of the myocardium are considerably affected by OSAS in children and adolescents, leading to ventricular changes and intraventricular conduction problems. What is Known: • Pediatric obstructive sleep apnea syndrome (OSAS) characterized by recurrent intermittent hypoxemia, hypercapnia, and sleep fragmentation results in sympathetic nervous system activation, increased inflammation, and hypoxic endothelial dysfunction. When left untreated, OSAS leads to many cardiovascular, neurologic, metabolic and neurocognitive consequences, and also to sudden infant death syndrome in young children, probably due to the involvement of the cardiac conduction system. What is New: • This study demonstrated that mean QRSmax was significantly lower in male children and adolescents with OSAS, reflecting the structural and electrical remodeling of the myocardium, and one boy with OSAS had RVH according to ECG-derived analysis. The percentage of fQRS or notched R or S waves was much higher in boys with OSAS, especially in children below the age of five years. These finding showed that myocardium was considerably affected to impair the intraventricular conduction in younger children with OSAS.

Distinctive sleep complaints and polysomnographic findings in antibody subgroups of autoimmune limbic encephalitis.

INTRODUCTION: Sleep disturbances are being increasingly recognized in association with autoimmune encephalitis (AIE). We investigated the prevalence of sleep-related symptoms and polysomnographic features of patients with AIE and the long-term outcomes in these patients in a multi-center, prospective study from Turkey. METHODS: We prospectively evaluated patients with definite AIE in a common database including demographics, AIE-related and sleep-related symptomatology. Maximum and latest modified Rankin scores (mRS) and Liverpool Outcome Score (LOS) were noted. RESULTS: Of 142 patients, 87 patients (61.3%) fulfilled the criteria for definite AIE (mean age, 46.8+18.8 years; 51.7% women; mean disease duration, 21.0+38.4 months). 78.9% of patients had at least one or more new onset or worsened sleep-related symptomatology: insomnia (55.3%), excessive daytime sleepiness (EDS, 28.0%), sleep apnea (18.7%), REM sleep behavior disorder (RBD, 17.3%), restless legs syndrome (10.7%) and oneiric stupor (9.3%). Sleep efficiency, N3 and REM sleep were decreased and N1 sleep was increased in patients with Ab[+] AIE. LOS points were highest in those with insomnia and sleep apnea, and lowest in those with EDS, RBD and oneiric stupor. RBD and sleep apnea were more common in anti-LG1 Ab[+] group than anti-NMDAR Ab[+] group. Index of periodic leg movements was highest in anti-LG1 Ab[+] group. Patients with EDS and oneiric stupor had more common memory problems. Maximum and latest mRS scores were positively correlated with EDS and oneiric stupor. EDS, RBD and oneiric stupor were negatively correlated with LOS points. CONCLUSION: Our study emphasizes the presence and importance of early diagnosis of sleep disturbances in AIE in regard to their deteriorative influences on disease prognosis.

Classical complement pathway factor alterations in narcolepsy.

OBJECTIVE: Narcolepsy is a chronic sleep disorder long hypothesised to be an autoimmune disease. Complement-mediated immune mechanisms have not been investigated in detail in narcolepsy. Our aim was to establish the significance of classical pathway activation in narcolepsy. METHODS: Sera of 42 narcolepsy patients and 26 healthy controls were screened with ELISA to determine the levels of C1q, C3a, C4d and complement component 4 binding protein (C4BP). A home-made ELISA method was developed to detect antibodies to C4BP-alpha (anti-C4BPA). The correlation between complement levels and clinical findings was examined. RESULTS: C1q levels were significantly higher in narcolepsy patients while C4d and C4BP levels were significantly lower compared to healthy controls. C3a levels were comparable among patients and controls. Eleven narcolepsy patients showed serum anti-C4BPA levels. Total rapid eye movements (REM) time, sleep onset latency, REM sleep latency, sleep activity, percentage of wakefulness after sleep onset and Epworth sleepiness scale scores were correlated with levels of different complement factors. CONCLUSION: Complement-mediated immune mechanisms might partake in narcolepsy pathogenesis. The precise role of autoantibodies on complement level alterations needs to be investigated. Levels of complement factors and degradation products may potentially be utilised as biomarkers to predict the clinical severity of narcolepsy.

[Treatment approach to apnestic breathing in a patient with vocal cord paralysis due to Arnold Chiari malformation and tracheostomy]. / Arnold Chiari malformasyonu nedeniyle vokal kord paralizisi gelisen ve trakeostomi takilan hastada apnöstik solunuma tedavi yaklasimi.

Arnold Chiari malformation (ACM) is herniation of brain stem structures, especially cerebellar tonsils, from the foramen magnum into the cervical spinal canal. Sleep-related respiratory disorders are reported at a higher rate in this patient group than the general population, at about 60-75%. A 43-year-old male patient was diagnosed with ACM type 1.5 at the center where he applied with complaints of weakness in the extremities, speech disorder and syncope triggered by coughing, and a decompression of posterior fossa (PFD) was applied to the patient. Since 2018, the apnea attacks, which were able to be 6-7 times a night every night, last in 30 seconds, with eyes open, inactivity and bruising, have started in the patient, so in all night-time polysomnography (PSG) examination for diagnostic purpose, apnestic breathing including continuous, central and mixed type apneas in sleep and wakefulness was detected. Different modes (CPAP, BPAP-S/T, ASV) were tried with the cannula placed on the tracheostomy in the PSG performed for non-invasive mechanical ventilation therapy, but none alone was effective. In the patient, whom IVAPS/AVAPS mode was tried, all abnormal breathing events, irregular apnetic breathing pattern and oxygen desaturations were effectively controlled in all positions, wakefulness and all sleep stages with pressure support, respiratory rate and tidal volume support. PFD is recommended as the first-line treatment for the treatment of obstructive or central type apneas in ACM; Information on non-invasive mechanical ventilation therapy is insufficient. In this case, we aimed to present the difficulties in the diagnosis and treatment of sleep-related respiratory disorders in a patient whom ACM diagnosed, PFD was applied but underwent permanent trachoestomy due to bilateral vocal cord paralysis.

Rapid eye movement sleep without atonia constitutes increased risk for neurodegenerative disorders.

OBJECTIVES: REM (rapid eye movement) sleep without atonia (RSWA) is a polysomnographic finding used in diagnosis of REM sleep behavior disorder (RBD). Clinical significance of idiopathic RSWA (iRSWA) unaccompanied by RBD is not known. We designed a prospective study to investigate whether iRSWA constitutes an increased risk for developing neurodegenerative disorders. MATERIALS AND METHODS: Between January 2010 and December 2014, a total of 4362 patients underwent a full-night video-polysomnography. Upon detailed clinical and polysomnographical examination, patients with iRSWA and idiopathic RBD (iRBD) were enrolled into this study and followed up at every six months for at least 4 years up to 9 years. RESULTS: We had a total of 31 patients with iRBD and 67 patients with iRSWA. Mean age was higher in iRBD group than those in iRSWA group (P = .016). Restless legs syndrome/Willis-Ekbom disease was significantly more common in patients with iRBD than those in patient with iRSWA (P < .001). Eighteen patients with iRSWA (26.8%) developed iRBD after 2.6 + 2.2 years. Six patients with iRSWA (8.9%) developed neurodegenerative disorders following 2.4 + 1.5 years; four were diagnosed as Parkinson's disease (PD) and two developed probable Alzheimer-type dementia. In patients with iRBD, eight patients (25.8%) developed neurodegenerative disorders-all was Parkinson's disease-following 2.6 + 2.2 years. Development of neurodegenerative diseases was positively correlated with age (P < .001) and periodic leg movements in sleep in both groups (P < .010). CONCLUSIONS: These results show that iRSWA may also be accepted as a risk factor in the development of PD or neurodegenerative diseases. Advanced age and periodic leg movements in sleep seem to be correlated with higher risk.

Effects of Sleep-Related Disorders on the Prognosis of Amyotrophic Lateral Sclerosis.

BACKGROUND/OBJECTIVE: In this study, we demonstrated the effects of obstructive sleep apnea syndrome (OSAS) on the prognosis of amyotrophic lateral sclerosis (ALS). However, the effects of sleep-related disorders other than breathing problems are still waiting to be delineated. METHODS: In this longitudinal retrospective and prospective study, we investigated 73 patients with ALS compared to 20 healthy subjects, to determine sleep-related disorders and their impact on disease prognosis. RESULTS: In patients with ALS, the mean respiratory disturbance index (RDI) was 28.0/h, which was significantly higher than that in the controls (p < 0.001). OSAS was present in 67% of the patients, sleep-related hypoxemia was observed in 13.7% of the patients, and 5.4% had central sleep apnea syndrome. In patients with bulbar-onset disease, higher RDI was almost significantly associated with lower survival (p = 0.056). The mean index of periodic leg movements in sleep was significantly higher in patients with ALS (34.0 ± 19.9/h) than that in the controls (12.5 ± 15.5/h; p < 0.001). Periodic leg movements disorder (PLMD) was diagnosed in 23 patients with ALS (31.5%); fragmentary myoclonus was present in 13.7% of patients, and REM-sleep behavior disorder was diagnosed in 4 patients (5.4%). The presence of PLMD in addition to OSAS was significantly associated with worse prognosis and poorer survival (p = 0.040). CONCLUSIONS: These findings emphasize that sleep-related disorders other than OSAS deserve attention in ALS. ALS is a catastrophic and frustrating disease for both patients and physicians; thus, the diagnosis and treatment of comorbid sleep disorders could improve the survival of patients with ALS.

Assessment of Impact of Dietary Patterns on Obstructive Sleep Apnea Patients.

Objective Obstructive sleep apnea syndrome (OSAS) is characterized by episodic cessations of breathing due to upper airway obstruction during sleep, which may cause disturbances in dietary patterns resulting from appetite-related hormonal changes. The aim of the present study was to investigate the relationship between OSAS and nutritional and dietary patterns. Materials and Methods A total of 20 female and 53 male OSAS patients aged > 30 years were enrolled. Demographic data, as well as data on smoking and alcohol habits, were noted, anthropometric measures were made, and a questionnaire regarding chronic diseases including OSAS and four questionnaires on recent food intake frequency and content of nutrition were filled out. The content of nutrition was noted under seven categories: meat, legumes, milk and dairy products, fruits and vegetables, bread and cereals, fat and carbohydrates, and beverages. Results The severity of OSAS (assessed by the apnea-hypopnea index. AHI) was positively correlated with the body mass index (BMI), the circumferences of the waist, chest, and buttocks, and, in males, with the circumference of the neck as well. There was no correlation between the AHI and nutritional habits in terms of the frequency of meals or snacks, the scores on the Snoring, Tiredness, Observed Apnea, and High Blood Pressure-Body Mass Index, Age, Neck Circumference, and Gender (STOP-BANG) Questionnaire and the corresponding macro- and micronutrients. Worsening apnea scores led to increased intake of macronutrients of carbohydrate and protein and micronutrients of niacin and pyridoxine ( p < 0.05), and decreased intake of fat ( p < 0.05). Conclusion The present study demonstrated an association between OSAS severity and recent food intake, manifested in increased intake of carbohydrates, niacin, and pyridoxine, and decreased fat intake.

An Evaluation of DNA Methylation Levels and Sleep in Relation to Hot Flashes: A Cross-Sectional Study.

Objectives: We aimed to evaluate the DNA methylation levels in perimenopausal and postmenopausal women, measured through Long Interspersed Element-1 (LINE-1) and Alu, and the sleep parameters in relation to the presence of hot flashes (HFs). Methods: This cross-sectional study included 30 peri- or postmenopausal women aged between 45 and 55. The menopausal status was determined according to STRAW + 10 criteria and all participants had a low cardiovascular disease (CVD) risk profile determined by Framingham risk score. The sample was divided into two groups based on the presence or absence of HFs documented in their medical history during their initial visit: Group 1 (n = 15) with HFs present and Group 2 (n = 15) with HFs absent. The patients had polysomnography test and HFs were recorded both by sternal skin conductance and self-report overnight. Genomic DNA was extracted from the women's blood and methylation status was analyzed by fluorescence-based real-time quantitative PCR. The quantified value of DNA methylation of a target gene was normalized by ß-actin. The primary outcome was the variation in methylation levels of LINE-1 and Alu and sleep parameters according to the presence of HFs. Results: LINE-1 and Alu methylation levels were higher in Group 1 (HFs present), although statistically non-significant. LINE-1 methylation levels were negatively correlated with age. Sleep efficiency was statistically significantly lower for women in Group 1 (HFs present) (74.66% ± 11.16% vs. 82.63% ± 7.31%; p = 0.03). The ratio of duration of awakening to total sleep time was statistically significantly higher in Group 1 (HFs present) (22.38% ± 9.99% vs. 15.07% ± 6.93, p = 0.03). Objectively recorded hot flashes were significantly higher in Group 1 (4.00 ± 3.21 vs. 1.47 ± 1.46, p = 0.03). None of the cases in Group 2 self-reported HF despite objectively recorded HFs during the polysomnography. The rate of hot flash associated with awakening was 41.4% in the whole sample. Conclusions: Women with a history of hot flashes exhibited lower sleep efficiency and higher awakening rates. Although a history of experiencing hot flashes was associated with higher LINE-1 and Alu methylation levels, no statistical significance was found. Further studies are needed to clarify this association. This study was funded by the Scientific Research Projects Coordination Unit of Istanbul University-Cerrahpasa. Project number: TTU-2021-35629.

A cross-sectional study on restless legs syndrome (RLS) in polycythemia vera (PV): is iron deficiency the only culprit?

INTRODUCTION: In polycythemia vera (PV) patients undergoing phlebotomy, iron deficiency (ID) may develop. ID has been linked to restless legs syndrome (RLS), and in one study, 29.6% of PV patients had RLS. We aimed to evaluate the frequency of RLS in PV and to evaluate factors that might play a role in RLS development among PV and essential thrombocythemia (ET) patients. METHODS: We consecutively included PV cases as the patient group, and ET and ID patients and healthy subjects (HSs) were included as controls. Those with conditions that could lead to RLS were excluded. All subjects were questioned according to the diagnostic criteria of the International Restless Legs Syndrome Study Group. RESULTS: Twenty-seven PV, 23 ET, and 22 ID patients and 23 HSs were included. RLS was detected in 25.9%, 34.8%, and 45.5% of PV, ET, and ID patients, respectively. None of the HSs had RLS. In univariate analysis, interferon-α and anagrelide use, magnesium levels, and the Leeds assessment of neuropathic symptoms and signs (LANSS) scores had a significant impact on RLS in PV and ET patients (p = 0.014, p = 0.032, p = 0.036, and p = 0.003, respectively). CONCLUSION: RLS was more common among PV and ET patients than HSs, which was irrespective to the iron status. RLS was more frequent in ET patients than that observed in PV cases, indicating that ID may not be the only causative factor for RLS development in PV. Further prospective studies are needed to determine the prevalence and risk factors of RLS developing in PV and ET.

Polysomnographic characteristics of sleep-related bruxism: What are the determinant factors for temporomandibular disorders?

OBJECTIVE: This study aimed to evaluate the clinical and polysomnographic characteristics of sleep bruxism (SB) and delineate the determinant factors for temporomandibular disorders (TMD). METHODS: Forty-six patients were allocated into the SB group (n = 26) and control group (n = 20). The signs and symptoms of TMD were recorded using the Research Diagnostic Criteria for TMD. Patients underwent a full-night polysomnographic recording and masseter and temporal muscle electromyographic recordings. Clinical and polysomnographic data in patients with SB were analyzed in relation to TMD. RESULTS: The presence of TMJ sounds was significantly correlated with the number of bruxism bursts. Intra-articular pain in the TMJ was neither correlated with clinical nor polysomnographic parameters in patients with SB. CONCLUSION: Lower sleep efficiency in patients with SB was caused by a higher number of bruxism episodes. Morning headaches were associated with the severity of SB during rapid eye movement sleep.

Cyclic Alternating Pattern Analysis in Periodic Leg Movements in Sleep in Patients With Obstructive Sleep Apnea Syndrome Before and After Positive Airway Pressure Treatment.

PURPOSE: Cyclic alternating pattern (CAP) is known to increase in many conditions of sleep disruption and sleep disorders, including obstructive sleep apnea syndrome and periodic limb movements in sleep (PLMS). Periodic limb movements in sleep associated with obstructive sleep apnea syndrome may vanish after positive airway pressure treatment, may persist, or emerge at treatment night. Here, the authors aimed to investigate the underlying pathophysiology of nonvanishing, vanishing, or newly emergent PLMS. METHODS: The authors designed a prospective study and included 10 patients with nonvanishing PLMS during positive airway pressure therapy, 10 patients with vanishing PLMS, 10 patients with newly emergent PLMS, and 10 patients without PLMS at both nights. The CAP analysis was performed in detail at diagnostic polysomnography recording and at positive airway pressure titration. The changes in CAP parameters were evaluated in regard to nonvanishing, vanishing, or newly emergent PLMS. RESULTS: Periodic limb movements in sleep related to A1 subtype of CAP were observed to decrease under positive airway pressure titration more than PLMS related to A3 subtype of CAP. The A3 subtype of CAP was higher in patients with vanishing PLMS than those with newly emergent PLMS. The newly emergent PLMS were mostly related to A1 subtype of CAP compared with A3 subtype of CAP. CONCLUSIONS: This study showed that vanishing, nonvanishing, or newly emerging PLMS may indeed represent different underlying pathophysiology. The authors suggest that organization of sleep and preservation of ultradian rhythms during titration may determine whether PLMS will be vanished or persist. Newly emergent PLMS may probably arise from a separate central generator by the activation of higher cortical areas.

Contribution of brainstem circuits in pathophysiology of NREM-sleep parasomnias.

OBJECTIVE: We aimed to investigate the brainstem circuits to reveal if there was any abnormality in these circuits in clinically diagnosed patients with NREM parasomnias during wakefulness. METHODS: Twelve patients with NREM-sleep parasomnia diagnosed according to ICSD-3 criteria and a control group of 16 healthy subjects were enrolled into our study. We analyzed the auditory startle reflex (ASR), blink reflex (BR), prepulse inhibition (PPI) of BR and recovery excitability of BR. RESULTS: There was a trend for longer responses from orbicularis oculi and sternocleidomastoid muscles after auditory stimulation in the patients compared to those in the healthy subjects. The recovery percentages at 200 ms and 300 ms showed a borderline significance in the patients. No significant difference was found in the R2-PPI between the patients and healthy subjects. CONCLUSIONS: Our results suggest a mildly enhanced ASR and relatively early facilitation of BR excitability in patients with NREM-sleep parasomnia during daytime. Although our findings suggest involvement of brainstem networks in NREM-sleep parasomnia during wakefulness, it would be better to study these networks at night and during daytime to see if there is any contribution.

Changes in sleep structure and sleep spindles are associated with the neuropsychiatric profile in paradoxical insomnia.

AIM: Sleep spindles have an important role in the pathophysiology and perception of sleep. We aimed to investigate the link between sleep spindles and microstructural architecture of sleep in regard to psychiatric characteristics in paradoxical insomnia. METHOD: A total of 40 participants (20 with paradoxical insomnia, 20 healthy controls) were included in the study. All participants were evaluated by somnologists and undergone a full-night polysomnography at sleep laboratory. In addition, psychiatric interview was made by the same psychiatrist, and questionnaires were performed to assess the dimensions of the personality such as the neuroticism or extroversion (Eysenck Personality Questionnaire, EPQR-A); to evaluate the tendency to exaggerate somatic perceptions (Somatosensory Amplification Scale, SSAS), somatic parts of dissociation (Somatoform Dissociation Questionnaire, SDQ-20), and somatization (Somatization Scale, SS); to measure participants' feelings about their health and disease anxiety (Health Anxiety Inventory, HAI-18), and the level of uncontrollable and persistent anxiety (Penn State Worry Questionnaire, PSWQ); to investigate the tendency to ruminative thinking (Ruminative Thought Style Questionnaire, RTSQ), alexithymia (Toronto Alexithymia Scale, TAS-20); and to define the presence and the severity of depressive symptoms (Beck Depression Inventory, BDI). RESULTS: The duration and frequency of the sleep spindles were similar between two groups, while the density was significantly decreased in paradoxical insomnia. The duration of sleep spindles, on the other hand, showed positive correlations with the extroversion dimension scores of EPQR-A and PSWQ scores. DISCUSSION: Sleep protective mechanisms are disturbed in paradoxical insomnia as shown by the lower density of sleep spindles. In addition, fast spindle activity is associated with the personality traits, characterized by an increase in the expression of feelings and the level of anxiety.

The role of pedunculopontine nucleus in isolated REM sleep behavior disorder and REM sleep without atonia.

INTRODUCTION: The aim of this study was to analyze the functions of pedunculopontine nucleus (PPN) in isolated REM sleep behavior disorder (iRBD) and REM sleep without atonia (RSWA) to investigate the role of PPN in dream-enacting motor behaviors in RBD. We evaluated the activity of PPN through the prepulse modulation (PPM) together with other brainstem reflexes to investigate the differences in changes at brainstem. METHODS: We included nine patients with isolated RSWA and 10 patients with iRBD. For diagnosis, all patients underwent polysomnography. None of the patients had parkinsonism or dementia. We also included 17 healthy participants with similar age and sex. Blink reflex (BR), PPM of BR, recovery excitability of BR, and auditory startle reflex (ASR) were recorded in all participants. RESULTS: There was a prepulse inhibition deficit in iRBD and RSWA groups compared to healthy subjects. The BR-R2 recovery at 200 ms interval was also higher in patients with iRBD and RSWA. In ASR recordings, the response probabilities were higher in the RBD group compared to RSWA and control groups. CONCLUSION: The PPM was abnormal in both iRBD and RSWA whereas ASR was enhanced in iRBD. We suggest that there are certain similarities and differences in the pathophysiologies of iRBD and RSWA.

Increased photosensitivity following short sleep in sleep deprived patients.

INTRODUCTION: We aimed to determine the effect of short day-time sleep on photoparoxysmal epileptic activity in sleep-deprived patients. METHODS: We retrospectively reviewed video-EEG recordings performed between 2003 and 2015. All recordings following at least four hours of sleep deprivation, including intermittent photic stimulation (IPS) both before and after sleep with any form of epileptiform activity were included. The study group was divided into four subgroups: (1) no photoparoxysmal response (PPR) group, with epileptiform activities other than PPRs; (2) increment group, with PPR duration increased by ≥200% after vs. before sleep; (3) no significant change group, with PPR duration increased between 50% and 200% after vs. before sleep; (4) decrement group, with PPR duration increased ≤50% after vs. before sleep. RESULTS: A total number of 5805 EEG recordings from 459 patients was analyzed. Photosensitivity was present in 98 patients (21.4%). The PPRs after sleep were increased in 70% of the photosensitive patients, did not change in 23%, and were decreased in 7%. The increase in duration of PPRs was statistically significant (P<0.001). In our cohort, photosensitivity would have been detected in 67 patients if IPS was applied only before sleep and in 91 patients if IPS was applied only after awakening (P<0.05). CONCLUSIONS: This study demonstrates that photosensitivity is enhanced after awakening from a short sleep following sleep deprivation. Thus, we recommend performing IPS after awakening to increase sensitivity to detect photoparoxysmal epileptiform discharges.

Demonstration of sympathetic dysfunction in patients with obstructive sleep apnea syndrome by measuring sympathetic skin responses from the neck.

OBJECTIVE: We aimed to study the sympathetic sudomotor responses via the sympathetic skin responses (SSR) from bilateral hands and right and left sides of the neck in patients with obstructive sleep apnea syndrome (OSAS). METHODS: A total of 31 patients with OSAS diagnosed by whole-night polysomnography and 18 healthy volunteers were consecutively enrolled into this prospective study. RESULTS: The SSRs from hands were not obtained in two patients with OSAS (6.4%) and in one volunteer (5.5%); the attainability of SSRs from hands was similar between patients and healthy controls (p = 0.698). The SSRs from neck were not obtained in 22 patients with OSAS (70.9%), but only in two healthy volunteers (11.1%, p <0.001). The mean amplitudes of SSRs from both right and left sides of neck were significantly lower in patients with OSAS than those in controls (p <0.001). After effective treatment of OSAS, the SSRs from hands were obtained in all patients (100% vs 93.6% before treatment, p = 0.560). The attainability of SSRs from bilateral sides of the neck was significantly improved after treatment (80%) in compared to before treatment (29.1%, p <0.001). The amplitudes of SSRs obtained from the neck were also significantly increased after treatment (p <0.004). CONCLUSIONS: Our results show that there is sympathetic dysfunction in OSAS, which could be demonstrated by sudomotor response abnormalities from neck area and reversed following effective treatment of OSAS. SSR studies from the neck area may therefore be accepted as an easy and effective method for demonstrating the sympathetic dysfunction in OSAS and for monitoring the efficacy of OSAS treatment.

What Does One Sleep-Onset REM Period­During Either Nocturnal Polysomnography or Multiple Sleep Latency Test­Mean in Differential Diagnosis of Central Hypersomnias?

PURPOSE: The differentiation of narcolepsy without cataplexy from idiopathic hypersomnia is based on the number of sleep-onset rapid eye movement periods (SOREMPs) observed by multiple sleep latency test (MSLT) and nocturnal polysomnography. The main aim of this study was to investigate the utility of SOREMP in differential diagnosis of central hypersomnias. METHODS: The authors retrospectively evaluated consecutive 101 patients with a normal polysomnography other than the presence of SOREMP and/or REM without atonia and a latency of ≤8 minutes in MSLT. RESULTS: The authors classified patients as follows: 52 patients had at least 2 SOREMPs (narcolepsy group), 23 had no SOREMPs (idiopathic hypersomnia group), and 26 patients had only 1 SOREMP (intermediate group). In polysomnographic recordings, both mean sleep latency and REM latency were significantly shorter in the narcolepsy (P = 0.012, P < 0.001, respectively) and intermediate groups (P = 0.005 and P = 0.035, respectively) compared with the idiopathic hypersomnia group. In MSLT recordings, sleep latency was 2.7 ± 2.2 minutes in the narcolepsy group, 3.6 ± 1.4 minutes in the intermediate group, and 5.2 ± 2.7 minutes in the idiopathic hypersomnia group (P < 0.001). The mean REM latency and sleep stages SOREMPs arised from were similar between the narcolepsy and intermediate groups. CONCLUSIONS: To date, SOREMPs in MSLT and polysomnography remain the sole electrodiagnostic feature that discriminates narcolepsy without cataplexy from idiopathic hypersomnia. Different parameters or combined criteria are being increasingly investigated to increase the sensitivity and specificity of MSLT. The findings showed an altered instability of REM sleep not only in patients with 2 or more SOREMPs in MSLT but also in patients with one SOREMP.