Sleep research in 2020 : COVID-19-related sleep disorders

Peer reviewe

Rahutute jalgade sündroom

Rahutute jalgade sündroomi (RLS) iseloomustab tahtmatu jalgade liigutamine une ajal. Sageli põhjustab see une katkemise. Häire esineb kuni 15%-l inimestest. RLS on arstidele seni vähe tuntud, kuid otstarbeka raviga on võimalik selle häirega inimeste vaevusi leevendada. Eesti Arst 2007; 86 (3): 207–21

Attention-Deficit/Hyperactivity Disorder Patients May Have Undiagnosed Narcolepsy

Background Attention-deficit/hyperactivity disorder (ADHD) patients have many comorbidities. Narcoleptic patients have a big prevalence of ADHD (15%-30%). Both groups suffer from similar symptoms and benefit from the same class of medications. As such, narcolepsy could be masked in ADHD patients. Low serum ferritin has been found both in ADHD patients as well as in patients with narcolepsy. Materials & methods We enrolled 26 participants (14 ADHD patients and 12 controls). They answered several questionnaires, and blood samples were obtained from 20 participants. We had clear exclusion criteria. Results Using the Ullanlinna Narcolepsy Scale (UNS), we identified three possible narcolepsy patients within the ADHD group and no suspects in the control group. There was a statistically significant negative correlation between serum iron levels and ADHD symptom severity. No correlation was found measuring serum ferritin levels. Conclusions Narcolepsy may be more common within ADHD patients than in the general population. Some of these patients could benefit from a change in medication. Low serum iron and ferritin levels could he relevant in ADHD pathophysiology. This requires further exploratory research.Peer reviewe

Patients with a Higher Number of Periodic Limb Movements Have Higher Nocturnal Blood Pressure

There is growing evidence that periodic limb movements in sleep (PLMS) may lead to increased blood pressure (BP) values during the night. The aim of this study was to assess if patients with disordered sleep and an increased number of PLMS have higher BP values at night. We analyzed 100 polysomnographic (PSG) recordings of patients with disordered sleep, with the exclusion of sleep-related breathing disorders. Patients also registered beat-to-beat blood pressure during PSG. We compared the BP of patients with an increased number of PLMS (more than 5 PLMS per hour of sleep) during the night (examined group, n = 50) to the BP of patients with a PLMS number within the normal range (up to 5 PLMS per hour of sleep) (control group, n = 50). Patients from the examined group had significantly higher values of systolic BP during the night (119.7 mmHg vs. 113.3 mmHg, p = 0.04), sleep (119.0 mmHg vs. 113.3 mmHg, p = 0.04), and wake (122.5 mmHg vs. 117.2 mmHg, p = 0.04) periods and of diastolic BP during the night (75.5 mmHg vs. 70.6 mmHg, p = 0.04) and wake (77.6 mmHg vs. 71.5 mmHg, p = 0.01) periods. Our results suggest a relationship between the number of PLMS during the night and the values of nocturnal blood pressure. It is possible that their treatment could lower nocturnal BP in patients with sleep disorders, therefore improving their vascular risk profile.Peer reviewe

Patients with a Higher Number of Periodic Limb Movements Have Higher Nocturnal Blood Pressure

There is growing evidence that periodic limb movements in sleep (PLMS) may lead to increased blood pressure (BP) values during the night. The aim of this study was to assess if patients with disordered sleep and an increased number of PLMS have higher BP values at night. We analyzed 100 polysomnographic (PSG) recordings of patients with disordered sleep, with the exclusion of sleep-related breathing disorders. Patients also registered beat-to-beat blood pressure during PSG. We compared the BP of patients with an increased number of PLMS (more than 5 PLMS per hour of sleep) during the night (examined group, n = 50) to the BP of patients with a PLMS number within the normal range (up to 5 PLMS per hour of sleep) (control group, n = 50). Patients from the examined group had significantly higher values of systolic BP during the night (119.7 mmHg vs. 113.3 mmHg, p = 0.04), sleep (119.0 mmHg vs. 113.3 mmHg, p = 0.04), and wake (122.5 mmHg vs. 117.2 mmHg, p = 0.04) periods and of diastolic BP during the night (75.5 mmHg vs. 70.6 mmHg, p = 0.04) and wake (77.6 mmHg vs. 71.5 mmHg, p = 0.01) periods. Our results suggest a relationship between the number of PLMS during the night and the values of nocturnal blood pressure. It is possible that their treatment could lower nocturnal BP in patients with sleep disorders, therefore improving their vascular risk profile

Patients with a Higher Number of Periodic Limb Movements Have Higher Nocturnal Blood Pressure

There is growing evidence that periodic limb movements in sleep (PLMS) may lead to increased blood pressure (BP) values during the night. The aim of this study was to assess if patients with disordered sleep and an increased number of PLMS have higher BP values at night. We analyzed 100 polysomnographic (PSG) recordings of patients with disordered sleep, with the exclusion of sleep-related breathing disorders. Patients also registered beat-to-beat blood pressure during PSG. We compared the BP of patients with an increased number of PLMS (more than 5 PLMS per hour of sleep) during the night (examined group, n = 50) to the BP of patients with a PLMS number within the normal range (up to 5 PLMS per hour of sleep) (control group, n = 50). Patients from the examined group had significantly higher values of systolic BP during the night (119.7 mmHg vs. 113.3 mmHg, p = 0.04), sleep (119.0 mmHg vs. 113.3 mmHg, p = 0.04), and wake (122.5 mmHg vs. 117.2 mmHg, p = 0.04) periods and of diastolic BP during the night (75.5 mmHg vs. 70.6 mmHg, p = 0.04) and wake (77.6 mmHg vs. 71.5 mmHg, p = 0.01) periods. Our results suggest a relationship between the number of PLMS during the night and the values of nocturnal blood pressure. It is possible that their treatment could lower nocturnal BP in patients with sleep disorders, therefore improving their vascular risk profile

Quantifying respiratory variation with force sensor measurements

Measuring the variation of the respiratory rate makes it possible to analyze the structure of sleep. The variation is high when awake or in REM sleep, and decreases in deep sleep. With sleep apnea, the respiratory variation is disturbed. We present a novel method for extracting respiratory rate variation from indirect measurements of respiration. The method is particularly suitable for force sensor signals, because, in addition to the respiratory phenomenon, they typically contain also other disturbing features, which makes the accurate detection of the respiratory rate difficult. Respiratory variation is calculated by low-pass filtering a force sensor signal at different cut-off frequencies and, at every time instant, selecting one of them for the determination of respiration cycles. The method was validated with a single-night reference recording, which showed that the proposed method detects the respiratory variation accurately. Of the 3421 calculated respiration cycle lengths, 95.9% were closer than 0.5 seconds to the reference.Peer reviewe

Heart Rate Variability in Head-Up Tilt Tests in Adolescent Postural Tachycardia Syndrome Patients

Introduction:Postural tachycardia syndrome (POTS) is a suspected dysautonomia with symptoms of orthostatic intolerance and abnormally increased heart rate while standing. We aimed to study cardiac autonomic nervous system functioning in head-up tilt (HUT) in adolescents with POTS to find out if parasympathetic tone is attenuated in the upright position. Methods:We compared characteristics of a group of 25 (females 14/25; 56%) adolescents with POTS and 12 (females 4/12; 34%) without POTS aged 9-17 years. We compared heart rate variability with high- and low-frequency oscillations, and their temporal changes in HUT. Results:The high-frequency oscillations, i.e., HF, attenuated in both groups during HUT (p<0.05), but the attenuation was bigger in POTS (p= 0.04). In the beginning of HUT, low-frequency oscillations, i.e., LF, increased more in POTS (p= 0.01), but in the end of HUT, an attenuation in LF was seen in the POTS group (p<0.05), but not in the subjects without POTS. There were no associations of previous infections or vaccinations with POTS. Subjects with POTS were sleepier and their overall quality of life was very low. Conclusion:The results imply to an impaired autonomic regulation while standing in POTS, presenting as a lower HF and higher LF in the beginning of HUT and an attenuated LF in the prolonged standing position.Peer reviewe

Severity of symptoms persists for decades in fibromyalgia-a 26-year follow-up study

The aim of this study is to find out the outcome of 28 patients who got the diagnosis of primary fibromyalgia (pFM) 26 years ago. In 1986, 56 patients with widespread pain were examined and filled in a base questionnaire (BQ). Of them, 42 fulfilled the Yunus criteria for pFM. Twenty-six years later, addresses of 38 patients were found, and an extensive follow-up questionnaire (FupQ) was mailed to them. Of them, 28 (74%) answered the FupQ. This included nine identical questions with the BQ and questions concerning changes in their symptoms and quality of life (Qol). Three patients (11%) had healed from fibromyalgia (FM), and 23% reported having one or several symptomless periods lasting at least 1 year. In others (n = 25), all but pain and ache showed slight deterioration. Despite the aging and FM, the level of functional ability evaluated by Stanford Health Assessment Questionnaire (HAQ) remained at the same level (BQ 0.41 vs. Fup 0.44, p = 0.82). The sum score of reported symptoms (n = 21) did not change significantly (10.8 (SD 2.9) vs. 11.1 (SD 4.1), p = 0.75). Experienced sleeplessness increased most significantly (27 vs. 65%, p = 0.0034). Exercising did not have a significant influence on the changes of the measured parameters. However, the three healed patients exercised regularly. Symptoms of FM have persisted in most patients for decades without significant deterioration of self-reported functional ability. About one fourth of patients had experienced long symptomless periods during their illness. Three patients (11%) reported that they have healed from FM.Peer reviewe

Ullanlinna Narcolepsy Scale in diagnosis of narcolepsy

Study objectives To validate Ullanlinna Narcolepsy Scale (UNS) as a screening tool for narcolepsy in a clinical population and to compare it with Swiss Narcolepsy Scale (SNS) and Epworth Sleepiness Scale (ESS). Methods UNS questionnaires of 267 participants visiting Helsinki Sleep Clinic were analyzed. The diagnoses of the participants were narcolepsy type 1 (NT1, n = 89), narcolepsy type 2 (NT2, n = 10), other hypersomnias (n = 24), sleep apnea (n = 37), restless legs syndrome or periodic limb movement disorder (n = 56), and other sleep-related disorders (n = 51). In addition, ESS and SNS scores in a subset of sample (total N = 167) were analyzed and compared to UNS. Results Mean UNS score in NT1 was 22.0 (95% confidence interval [CI] = 20.4 to 23.6, range 9-43), which was significantly higher than in other disorders, including NT2 (mean 13.7, 95% CI = 10.3 to 17.1, range 7-21, p = .0013). Sensitivity and specificity of UNS in separating NT1 from other disorders were 83.5% and 84.1%, respectively. Positive and negative predictive values were 82.5% and 85.1%, respectively. Sensitivities of SNS and ESS in NT1 were 77.2% and 88.6%, and specificities 88.6% and 45.5%, respectively. There were no differences in receiver operating characteristic curves between UNS and SNS. UNS had moderate negative correlation with hypocretin-1 levels (r(s) = -.564, p <.001), and mean sleep latency in multiple sleep latency test (r(s)= -.608, p <.001). Conclusions UNS has high specificity and sensitivity for NT1 in a sleep clinic setting. UNS scores below 9 strongly suggest against the diagnosis of narcolepsy.Peer reviewe