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Søren Berg

    Søren Berg

    Lund University, Medicine, Faculty Member
    Sleep restrictions and sleep deprivation have become common in modern society, as many people report daily sleep below the recommended 8 hours per night. This study aimed to examine the effects of sleep deprivation on oculomotor... more
    Sleep restrictions and sleep deprivation have become common in modern society, as many people report daily sleep below the recommended 8 hours per night. This study aimed to examine the effects of sleep deprivation on oculomotor performance by recording smooth pursuit and saccadic eye movements after 24 and 36 hours of sleep deprivation. Another objective was to determine whether detected changes in oculomotor performance followed fluctuations according to a circadian rhythm and/or subjective Visuo-Analogue sleepiness Scale scores. Oculomotor responses were recorded from 18 subjects using electronystagmography, and comprised measurements of accuracy (i.e., the percentage of time the eye movement velocity was within the target velocity boundaries), velocity and latency. Continuous EEG recordings were used to validate that subjects had remained awake throughout the 36-hour period. Our findings showed that sleep deprivation deteriorated smooth pursuit gain, smooth pursuit accuracy and ...
    SummaryMicrovascular extravasation, lamina propria flooding and luminal entry of plasma are key features of airway inflammation. We have suggested that the extravasated plasma moves across the epithelial lining along hydrostatic pressure... more
    SummaryMicrovascular extravasation, lamina propria flooding and luminal entry of plasma are key features of airway inflammation. We have suggested that the extravasated plasma moves across the epithelial lining along hydrostatic pressure gradients. The present study, involving healthy subjects, tests this hypothesis by examining effects of experimentally applied negative and positive luminal pressures on nasal output of plasma at baseline and at histamine‐induced plasma exudation. The negative (−10 cmH2O) and positive (10 cmH2O) pressures were applied for 10 min after nasal spray administrations of diluent (saline) and histamine (0·5 mg). The mucosa was then lavaged and the lavage fluid levels of α2‐macroglobulin were measured as index of plasma exudation. Nasal administrations of diluent and histamine (0·5 mg) were also carried out without any pressure applications. Histamine produced significant mucosal exudation of plasma. The negative luminal pressure augmented this response sig...
    The aim of the study was to analyse differences in pharyngeal airway dimensions and head posture between obstructive sleep apnea patients with and without morphological deviations in the upper cervical spine and to analyse associations... more
    The aim of the study was to analyse differences in pharyngeal airway dimensions and head posture between obstructive sleep apnea patients with and without morphological deviations in the upper cervical spine and to analyse associations between pharyngeal airway dimensions and head posture in the total sample. The sample comprised 53 obstructive sleep apnea (OSA) patients of which 32.1% had upper spine morphological deviations. Accordingly two groups were defined: 17 OSA patients with morphological deviations in the upper spine and 36 without upper spine deviations. Pharyngeal airway dimensions in terms of distances, cross-sectional areas and volume and upper spine morphological deviations were evaluated on cone-beam computed tomography. Head posture was evaluated on two-dimensional generated lateral cephalograms. Differences were analysed and adjusted for age and gender by multiple linear regression analysis. OSA patients with upper spine morphological deviations had a significantly...
    Objective Nocturnal gastroesophageal reflux (nGER) has been associated with respiratory diseases. Our aim was to study a questionnaire method to identify nGER subjects with respiratory involvement in a general population. Material and... more
    Objective Nocturnal gastroesophageal reflux (nGER) has been associated with respiratory diseases. Our aim was to study a questionnaire method to identify nGER subjects with respiratory involvement in a general population. Material and methods A subgroup of Icelandic participants in the European Community Respiratory Health Survey III (ECRHS III) reporting symptoms of nGER (n  =  48) as well as age and gender paired controls (n  =  42) were studied further by a structured interview, questionnaires, laryngeal fibrescopy, and exhaled breath condensate. A subgroup underwent 24-h oesophageal pH impedance (24-h MII-pH) measurements. Symptoms of nGER were assessed with a modified version of the reflux disease questionnaire (RDQ), where symptoms were divided into daytime and nocturnal. A report of nGER both at baseline and at follow-up was defined as persistent nGER. Results Participants reporting persistent nGER had significantly more signs of laryngopharyngeal reflux according to the reflux finding score than those without nGER (Mean ± SD: 5.1 ± 2.3 vs. 3.9 ± 2.2, p  =  0.02). Of the 16 persistent nGER subjects that underwent 24-h MII-pH, 11 had abnormal gastroesophageal reflux, but none of three control subjects (69% vs. 0%). Pepsin was more commonly found in exhaled breath condensate in the nGER group (67% vs. 45%, p  =  0.04). Conclusions Participants with nGER symptoms at least once a month, reported on two occasions, had a high level of positive 24-h MII-pH measurements, laryngeal inflammation and pepsin in exhaled breath condensate. This nGER definition identified a representable group for studies on nGER and respiratory diseases in a general population.
    The effect of reducing reverberation time was studied in 12 subjects during sleep. EEG-arousals following specific sound stimuli were significantly reduced (p<0.007) when reverberation time was reduced with sound-absorbing... more
    The effect of reducing reverberation time was studied in 12 subjects during sleep. EEG-arousals following specific sound stimuli were significantly reduced (p<0.007) when reverberation time was reduced with sound-absorbing ceiling-tiles. On average reverberation was reduced 0.124 seconds at similar sound levels. It is proposed that increased sound absorption, i.e. reduced reverberation time, by contributing to a better acoustic environment may reduce sound-induced sleep fragmentation.
    To compare upper airway pressures in snorers and nonsnorers during sleep and wakefulness. Case series of snorers and nonsnoring controls. Sleep clinic of a university hospital. We used open catheters to measure differential nasopharyngeal... more
    To compare upper airway pressures in snorers and nonsnorers during sleep and wakefulness. Case series of snorers and nonsnoring controls. Sleep clinic of a university hospital. We used open catheters to measure differential nasopharyngeal and hypopharyngeal pressures in 8 nonapneic snorers with excessive daytime tiredness and 10 healthy nonsnoring controls. Measurements were performed during sleep (with the mouth taped to ensure exclusively nasal breathing) and wakefulness. When awake, the subjects were either seated (with the head neutral, flexed, extended, or rotated) or recumbent (dorsal and lateral positions). Comparison of pressures within the group as a function of body position and between the groups as a function of snoring. Differential nasal and pharyngeal pressures were similar in seated snorers and nonsnorers independently of head position. Assumption of recumbency resulted in significantly increased pharyngeal pressures in nonsnorers (26 +/- 18 Pa seated vs. 52 +/- 46 Pa recumbent, p < .05) and snorers (50 +/- 35 Pa seated vs. 93 +/- 38 recumbent, p < .01). The increase was higher in snorers than nonsnorers. During snoring, sleep differential pharyngeal pressures in snorers were markedly increased compared to quiet sleep (567 +/- 450 Pa during snoring epochs vs. 117 +/- 82 Pa during nonsnoring epochs, p < .01). Compared to nonsnorers, recumbent nonapneic snorers have elevated differential pharyngeal pressures indicative of increased upper airway resistance and reduced airway patency; this is present during wakefulness and sleep.
    Sleep medicine is evolving globally into a medical subspeciality in its own right, and in parallel, behavioural sleep medicine and sleep technology are expanding rapidly. Educational programmes are being implemented at different levels in... more
    Sleep medicine is evolving globally into a medical subspeciality in its own right, and in parallel, behavioural sleep medicine and sleep technology are expanding rapidly. Educational programmes are being implemented at different levels in many European countries. However, these programmes would benefit from a common, interdisciplinary curriculum. This 'catalogue of knowledge and skills' for sleep medicine is proposed, therefore, as a template for developing more standardized curricula across Europe. The Board and The Sleep Medicine Committee of the European Sleep Research Society (ESRS) have compiled the catalogue based on textbooks, standard of practice publications, systematic reviews and professional experience, validated subsequently by an online survey completed by 110 delegates specialized in sleep medicine from different European countries. The catalogue comprises 10 chapters covering physiology, pathology, diagnostic and treatment procedures to societal and organizational aspects of sleep medicine. Required levels of knowledge and skills are defined, as is a proposed workload of 60 points according to the European Credit Transfer System (ECTS). The catalogue is intended to be a basis for sleep medicine education, for sleep medicine courses and for sleep medicine examinations, serving not only physicians with a medical speciality degree, but also PhD and MSc health professionals such as clinical psychologists and scientists, technologists and nurses, all of whom may be involved professionally in sleep medicine. In the future, the catalogue will be revised in accordance with advances in the field of sleep medicine.
    To investigate whether distal esophageal acidification occurs during sleep in patients suspected of sleep-disordered breathing, and whether such acidification is related to respiratory abnormalities. Fourteen middle-aged, snoring men all... more
    To investigate whether distal esophageal acidification occurs during sleep in patients suspected of sleep-disordered breathing, and whether such acidification is related to respiratory abnormalities. Fourteen middle-aged, snoring men all complaining of daytime sleepiness and suspected of having obstructive sleep apnea. Sleep laboratory, Pulmonary Department, Landspitali University Hospital, Reykjavik, Iceland. Each patient underwent full nocturnal polysomnography testing, which included continuous monitoring of esophageal pressure (Pes) and pH. We identified all pH events, which were defined as a reduction in esophageal pH of >/= 1.0. During each pH event, the respiratory recordings where examined for the presence of apneas or hypopneas, and Pes was recorded. The data were analyzed to determine the possible relationships between pH events and respiratory events, and between changes in pH and changes in Pes. We found that there were more respiratory events than pH events. The mean (+/- SD) number of apneas and hypopneas per hour of sleep was 33 +/- 22, whereas the mean number of pH events per hour of sleep was 7 +/- 6. Overall, 81% of all pH events were associated with respiratory events. Correlation analysis did not reveal any significant relationship between pH events and the magnitude of Pes or apnea-hypopnea index. Episodes of esophageal acidification are common in patients with sleep apnea, and are usually associated with respiratory and pressure events. However, changes in pH were independent of the magnitude of the Pes.
    ... Søren Berg berg@scansleep.eu ... 1National Reporting and Learning Service, National Patient Safety Agency, London W1T 5HD 2Department of Gastroenterology, Royal Hallamshire Hospital and the University of Sheffield, Sheffield... more
    ... Søren Berg berg@scansleep.eu ... 1National Reporting and Learning Service, National Patient Safety Agency, London W1T 5HD 2Department of Gastroenterology, Royal Hallamshire Hospital and the University of Sheffield, Sheffield Correspondence to: F Healey frances.healey ...
    The effects of central sleep apnea in Cheyne-Stokes respiration on sleep-related symptoms and quality of life are not very well established. We aimed to investigate whether Cheyne-Stokes respiration is related to health-related quality of... more
    The effects of central sleep apnea in Cheyne-Stokes respiration on sleep-related symptoms and quality of life are not very well established. We aimed to investigate whether Cheyne-Stokes respiration is related to health-related quality of life. We also studied the impact on daytime sleepiness and nocturnal dyspnea. Included were 203 consecutive patients, stabilized following in-hospital treatment for decompensated congestive heart failure. They underwent overnight cardiorespiratory sleep apnea recordings in hospital and answered a set of questions on symptoms and health-related quality of life questionnaires in the form of the Nottingham Health Profile and the Minnesota Living with Heart Failure Questionnaire. After excluding seven patients with predominantly obstructive apneas and 14 with insufficient recordings, 182 patients were included in the final analysis. One third of the patients had an apnea-hypopnea index (AHI) of >30. Falling asleep in front of the television was the only symptom related to (AHI). Nocturnal dyspnea, daytime sleepiness, generic quality of life or disease-specific quality of life were not related to AHI. Cheyne-Stokes respiration was not associated with health-related quality of life, daytime sleepiness or nocturnal dyspnea among patients stabilized following treatment for congestive heart failure.
    Results from a previous study showed that sexuality was negatively affected in females with untreated obstructive sleep apnea (OSA). Data are sparse on the long-term effects of nocturnal continuous positive airway pressure (CPAP)... more
    Results from a previous study showed that sexuality was negatively affected in females with untreated obstructive sleep apnea (OSA). Data are sparse on the long-term effects of nocturnal continuous positive airway pressure (CPAP) treatment on sexual difficulties and sexual distress in female patients with OSA. The aim of the present study was to investigate the effects after 1 year of CPAP treatment on sexual difficulties, sexual distress, and manifest sexual dysfunction in female patients with OSA. The effect of CPAP on life satisfaction was also investigated. Fifty-four therapy-compliant, female patients (age 22-71) received a survey before and after 1 year of nocturnal CPAP treatment. The questions on this survey were drawn from three self-administered questionnaires: two on sexuality and one on life satisfaction. The results were compared with a population sample. The Epworth Sleepiness Scale was used for assessment of daytime sleepiness. The Female Sexual Function Index, Female...
    Previous studies showing a strong relationship between Cheyne-Stokes respiration and the severity of left ventricular systolic dysfunction have usually been done in selected patient populations with lower age and a higher proportion of... more
    Previous studies showing a strong relationship between Cheyne-Stokes respiration and the severity of left ventricular systolic dysfunction have usually been done in selected patient populations with lower age and a higher proportion of males than the "typical" in-hospital patient with heart failure. The purpose of the present study was test the strength of this relationship in unselected patients admitted to hospital due to decompensated chronic heart failure. We evaluated 191 patients (32% women), mean age 73 years, ready for discharge from the heart failure unit in the University Hospital of Malmo, Sweden. The patients underwent echocardiography for determination of left ventricular ejection fraction and left ventricular inner diastolic diameter. A respiratory investigation during sleep was performed the last night before discharge. We found that 66% of the patients had Cheyne-Stokes respiration more than 10% of the total recording time. Only 7 (3.6%) of the patients had...
    To clarify the relationship between symptoms, clinical signs and physiological abnormalities that were motivating the initiation of home mechanical ventilation in patients suffering from neuromuscular diseases. From The Swedish Home... more
    To clarify the relationship between symptoms, clinical signs and physiological abnormalities that were motivating the initiation of home mechanical ventilation in patients suffering from neuromuscular diseases. From The Swedish Home Mechanical Ventilation Register we identified 352 patients with neuromuscular diseases and we looked at circumstances (acute vs elective) and clinical motives for starting ventilatory support. Home mechanical ventilation was commenced electively in 268 patients (76%) and among these daytime sleepiness was the most common motive, being reported in 56% of the patients. In the 24 children with spinal muscular atrophy, however, 96% started ventilation electively and cough insufficiency was the most common motive. The patients were moderately hypercapnic (PaCO(2): 7.0 kPa, SD 1.3). None of the clinical motives were related to the PaCO(2) level. Average PaO(2) was above 8 kPa in all groups, but lowest in the patients with post-polio and dystrophia myotonica. Mean vital capacity was close to 40% of predicted, but significantly lower in the Duchenne patients (26% of predicted). Daytime sleepiness was the most common clinical symptom motivating home mechanical ventilation in this group of patients with chronic hypercapnic respiratory insufficiency secondary to neuro/myopathies. Respiratory function testing is therefore suggested to be included in the diagnostic work up of daytime sleepiness in these patients.