Yaron Dagan | Tel Hai College (original) (raw)
Papers by Yaron Dagan
Journal of Psychosomatic Research, Oct 1, 1996
The purpose of this study was to examine systematically our previous clinical impression regardin... more The purpose of this study was to examine systematically our previous clinical impression regarding the prevalence of personality disorders in patients suffering from circadian rhythm sleep disorders (CRSD). We hypothesized that, in a group of patients suffering from CRSD, there would be a higher frequency of personality disorders than in a group of healthy controls. The experimental group consisted of CRSD patients diagnosed according to a clinical interview and actigraphic recordings. The control group consisted of healthy volunteers in whom CRSD had been ruled out by means of a self-administered questionnaire. Both groups were assessed for personality disorders using the MCMI, a diagnostic tool based on Millon's biopsychosocial theory of personality and the PRQ-R, a diagnostic tool based on the DMS-III-R. Both tests provided clear and significant support for the hypothesis that individuals suffering from CRSD are characterized to a greater extent by personality disorders than a control group. No specific characteristic pattern or profile of personality disorders was clearly detected. Correct early diagnosis and treatment of CRSD may improve afflicted individuals' adaptive capabilities and perhaps even prevent the development of a personality disorder. This suggests how important a greater awareness of CRSD on the part of the professional community may be.
Journal of Blood Disorders and Transfusion, 2021
Study Objectives: Insomnia is a common sleep disorder with a prevalence of 10-15% in the populati... more Study Objectives: Insomnia is a common sleep disorder with a prevalence of 10-15% in the population. The primary aim of our study is to assess the development of tolerance to chronic hypnotic administration in patients with insomnia. An additional aim is to describe the prevalence of hypnotic treatment among patients with insomnia. Methods: This is a retrospective study including all members of Maccabi Health Services above the age of 18 years, of data collected between 2011 and 2014. A chronic user was defined as a person who purchased 180 and more sleeping pills per year. Results: Only 20% of the insomnia patients treated with hypnotics were chronic users. Between 2011 and 2014, we observed a constant increase of 2.5% per year in the number of chronic users. The number of hypnotics taken by chronic users was not different between the genders or between types of hypnotics. A positive correlation was found between age and number of hypnotics among chronic users. The majority of the long-term chronic patients either did not change or decreased the number of sleeping pills they consumed. Conclusion: Our results suggest that chronic insomnia patients do not develop tolerance to treatment with hypnotics.
Environmental health perspectives, Aug 17, 2016
PubMed, May 1, 2009
The prevalence of chronic insomnia in the adult population in Israel is 29.8%, which is comparabl... more The prevalence of chronic insomnia in the adult population in Israel is 29.8%, which is comparable to other Western countries. The consequences of insomnia include fatigue, accidents, low level of well-being, and a high need for medical services. One of the well-known treatments for insomnia is sleeping pills. Physicians are educated that hypnotics are an appropriate treatment for transient insomnia but not for chronic use. It is believed that transient users are at high risk of becoming addicted to sleep medications although research has not proven this theory. NonetheLess, physicians often try to convince insomnia patients not to use these medications. In the U.S.A., only 3% of chronic insomniacs use sleep medications. There are no data on the use of sleep medications in Israel. The present study was performed using a large database comprised of 1.1 million adult patients of Maccabi Health Services. It is the first study examining sleep medication usage habits of the adult population in IsraeL. The main findings are: 2.8% of Maccabi patients use sleep medications, however only 4.5% of this group are chronic users; most chronic users started sleep medications at the age of 65 or older and they suffer more than the transient users from medical conditions such as ischemic heart disease, hypertension, and diabetes mellitus, have higher usage of antidepressant and anxiolytic medication, receive greater national financial support and are more likely to be new immigrants. The results of this study should evoke physicians to reassess their position against prescribing sleep medications to patients for whom it may help in relieving their insomnia.
John Wiley & Sons, Inc. eBooks, Nov 4, 2005
... YARON DAGAN, KATY BORODKIN Sheba Medical Center, Tel Hashomer, Israel LIAT AYALON * ... 15. C... more ... YARON DAGAN, KATY BORODKIN Sheba Medical Center, Tel Hashomer, Israel LIAT AYALON * ... 15. Chesson AL Jr, Anderson WM, Littner M, Davila D, Hartse K, Johnson S, Wise M, Rafecas J. Practice parameters for the non-pharmacologic treatment of chronic insomnia. ...
PubMed, 2002
Circadian Rhythm Sleep Disorders (CRSD) are a group of sleep disorders characterized by a de-sync... more Circadian Rhythm Sleep Disorders (CRSD) are a group of sleep disorders characterized by a de-synchronization between a person's biological clock and the environmental 24-hour schedule. There are four main types of CRSD, namely, Delayed Sleep Phase Syndrome (DSPS) (the most common), Advanced Sleep Phase Syndrome (ASWD), Non-24-hour Sleep-Wake Syndrome (Free-Running Pattern) and Irregular (or Disorganized) Sleep Wake Pattern. These disorders lead to harmful psychological and functional difficulties and certain personality disorders may also be related to them. It has been found that psychotropic drugs, SSRI and haloperidol can cause CRSD, and this is also true for some cases of minor head trauma. They are often misdiagnosed and incorrectly treated due to the fact that many doctors are unfamiliar with them. This review describes the disorders, their consequences and available treatment.
Chronobiology International, Mar 3, 2020
The last several decades have been characterized by the widespread usage of digital devices, espe... more The last several decades have been characterized by the widespread usage of digital devices, especially smartphones. At the same time, there have been reports of both decline in sleep duration and quality and male fertility decline. The aim of this study was to assess the relationship between evening exposure to the light-emitting screens of digital media devices and measures of both sleep and sperm quality. Semen samples were obtained from 116 men undergoing fertility evaluation for the following sperm variables: volume (mL), pH, sperm concentration (million/mL), motility percentage (progressive% + non-progressive motility%), and total sperm count. Exposure to the screens of electronic devices and sleep habits was obtained by means of a questionnaire. Smartphone and tablet usage in the evening and after bedtime was negatively correlated with sperm motility (−0.392; −0.369; p < .05), sperm progressive motility (−0.322; −0.299; p < .05), and sperm concentration (−0.169; p < .05), and positively correlated with the percentage of immotile sperm (0.382; 0.344; p < .05). In addition, sleep duration was positively correlated with sperm total and progressive motility (0.249; 0.233; p < .05) and negatively correlated with semen pH (−0.349; p < .05). A significant negative correlation was observed between subjective sleepiness and total and progressive motility (−0.264; p < .05) as well as total motile sperm number (−0.173; p < .05). The results of this study support a link between evening and post-bedtime exposure to light-emitting digital media screens and sperm quality. Further research is required to establish the proposed causative link and may lead to the future development of relevant therapeutic and lifestyle interventions.
Chronobiology International, 2005
A patient who developed an irregular sleep-wake pattern following prolactin-secreting pituitary m... more A patient who developed an irregular sleep-wake pattern following prolactin-secreting pituitary microadenoma is described. The patient reported difficulties in sleep onset and awakening at the desired time, which caused major dysfunction in his daily life activities. Despite these difficulties, the sleep-related complaints of the patient remained unrecognized for as long as three yrs. Statistical analyses of the patient's rest-activity patterns revealed that the disruption of the sleep-wake circadian rhythm originated from a disharmony between ultradian (semicircadian) and circadian components. The circadian component displayed shorter than 24 h periodicity most of the time, but the semicircadian component fluctuated between longer and shorter than 12 h periods. Additionally, desynchrony in terms of period length was found in the tentative analyses of the rest-activity pattern, salivary melatonin, and oral temperature. While the salivary melatonin time series data could be characterized by a best-fit cosine curve of 24 h, the time series data of oral temperature was more compatible with 28 h best-fit curve. The rest-activity cycle during the simultaneous measurements, however, was best approximated by a best-fit curve of 21h. The dysregulation of circadian rhythms occurred concomitantly, but not beforehand, with the onset of pituitary disease, thus suggesting an association between the two phenomena. This association may have interesting implications to the modeling of the circadian time-keeping system. This case also highlights the need to raise the awareness to circadian rhythm sleep disorders and to consider disruptions of sleepwake cycle in patients with pituitary adenoma.
Psychiatry and Clinical Neurosciences, Dec 1, 1997
The aim of the present study was to compare the sleep of 12 children with attention deficit hyper... more The aim of the present study was to compare the sleep of 12 children with attention deficit hyperactivity disorder (ADHD) with that of 12 normal controls. The children were examined in their natural environment, using continuous actigraphic monitoring over several consecutive nights, as well as undergoing subjective parental reports. It was hypothesized that children diagnosed with ADHD would suffer from reduced sleep quality than children without ADHD. This hypothesis was supported by the actigraphic measures, but not supported by the subjective parental reports. It was also found that the sleep quality of the two groups differed over the course of the night, which suggests a difference in sleep architecture. Various possible explanations for these findings, their implications regarding the relationship between sleep and ADHD, and the resulting treatment ramifications are discussed, and suggestions for further research are provided.
Chronobiology International, May 26, 2017
The use of electronic devices with light-emitting screens has increased exponentially in the last... more The use of electronic devices with light-emitting screens has increased exponentially in the last decade. As a result, humans are almost continuously exposed to unintentional artificial light. We explored the independent and combined effects of two aspects of screen illumination, light wavelength, and intensity, on sleep, its biological regulation, and related functional outcomes. The 2 × 2 repeated-measure design included two independent variables: screen light intensity (low ([LI] versus high [HI]) and wavelength (short [SWL] versus long [LWL]). Nineteen participants (11F, 8M; mean age 24.3 [±2.8] years) underwent four light conditions, LI/SWL, HI/SWL, LI/LWL, and HI/LWL, in counterbalanced order. Each light exposure lasted for two hours (21:00-23:00), following which participants underwent an overnight polysomnography. On each experimental night, oral temperature and urine samples (for melatonin analysis) were collected at multiple time points. Each morning, participants filled out questionnaires and conducted a computerized attention task. Irrespective of light intensity, SWL illumination significantly disrupted sleep continuity and architecture and led to greater self-reported daytime sleepiness. SWL light also altered biological rhythms, subduing the normal nocturnal decline in body temperature and dampening nocturnal melatonin secretion. Light intensity seemed to independently affect sleep as well, but to a lesser degree. Both light intensity and wavelength negatively affected morning attention. In sum, light wavelength seems to have a greater influence than light intensity on sleep and a widerange of biological and behavioral functions. Given the widespread use of electronic devices today, our findings suggest that screen light exposure at evening may have detrimental effects on human health and performance.
Neurology, Apr 2, 2007
To describe the physiologic and behavioral characteristics of circadian rhythm sleep disorders (C... more To describe the physiologic and behavioral characteristics of circadian rhythm sleep disorders (CRSDs) following minor traumatic brain injury (mTBI) in patients complaining of insomnia. Forty two patients with insomnia complaints following mTBI were screened. Those suspected of having CRSD underwent actigraphy, saliva melatonin and oral temperature measurement, and polysomnography. All patients also filled out a self-reported questionnaire to determine their circadian preference. Fifteen of the 42 patients (36%) with complaints of insomnia following mTBI were diagnosed with CRSD. Eight patients displayed a delayed sleep phase syndrome (DSPS), whereas seven displayed an irregular sleep-wake pattern (ISWP). Whereas all patients with DSPS exhibited a 24-hour periodicity of oral temperature rhythm, three of seven patients with ISWP lacked such a daily rhythm. In addition, ISWP patients exhibited smaller amplitude of oral temperature rhythm vs the DSPS group. Subjective Morningness-Eveningness Questionnaire scores were in accordance with the clinical diagnosis of DSPS or ISWP based on actigraphy. Minor traumatic brain injury might contribute to the emergence of circadian rhythm sleep disorders. Two types of these disorders were observed: delayed sleep phase syndrome and irregular sleep-wake pattern. The types differed in the subjective questionnaire scores and had distinct profiles of melatonin and temperature circadian rhythms.
Growth hormone & IGF research, Aug 1, 2001
A 68 year old patient with Laron syndrome (primary growth hormone (GH) resistance-insensitivity d... more A 68 year old patient with Laron syndrome (primary growth hormone (GH) resistance-insensitivity due to a molecular defect of the GH receptor) and severe obstructive sleep apnoea syndrome is described. Treatment with continuous positive air pressure therapy resulted in improved nocturnal sleep, daytime alertness and cognitive functions.
bioRxiv (Cold Spring Harbor Laboratory), Mar 1, 2023
Study Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing conditi... more Study Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing condition characterized by repetitive cessations in breathing during sleep. Current standard of care for OSA management is continuous positive air pressure (CPAP) devices, which often suffer from low tolerance due to limited adherence. Capitalizing on the unique neurocircuitry of the olfactory system and its retained function during sleep, we set out to test the feasibility of transient, respiration-based olfactory stimulation as a treatment for OSA symptoms. Methods: Thirty-two OSA patients (AHI ≥ 15 events/hour) were recruited and underwent two polysomnography sessions, 'Odor' and 'Control', counterbalanced for order. In 'Odor' night, patients were presented with transient olfactory stimulation delivered via a computer-controlled olfactometer. The olfactometer, equipped with a wireless monitoring unit, analyzed respiratory patterns and presented stimulation upon detection of respiratory events. No odor was presented 'Control' nights. Results: Olfactory stimulation reduced AHI (Apnea-Hypopnea Index) (n = 17, 49.2±10.2 years, range: 30-66; p = 0.02, BF 10 = 115.85), reflecting an average decrease of 31.3% in the number of events. Post hoc planned comparisons revealed a reduction in HI (Hypopnea Index) (p = 0.02, BF 10 = 2.39), but not AI (Apnea Index) (p = 0.26, BF 10 = 1.56). This effect was not linked to baseline symptoms severity (ρ =-0.042, p = 0.87) and did not vary across odorants (F(4,64) = 0.56, p = 0.67). Finally, olfactory stimulation did not affect sleep structure (all p > 0.44, all BF01 > 2.9). Conclusions: Olfactory stimulation during sleep was effective in reducing OSA symptoms severity and may provide a novel treatment modality, therefore prompting continued research on this front. .
Dialogues in Clinical Neuroscience, Dec 31, 2005
umans, like many other mammals, are awake through the daytime hours and sleep during the night. I... more umans, like many other mammals, are awake through the daytime hours and sleep during the night. In some people, this normal sleep-wake rhythm, so taken for granted by most of us, can become chronically impaired, leading to a group of disorders called circadian rhythm sleep disorders (CRSDs). CRSDs are characterized by a misalignment between the timing of the individual's sleep-wake rhythm and the 24-h social and physical environment. In patients with CRSDs, sleep episodes occur at inappropriate times, often causing waking periods to occur at undesired times. Consequently, the patient complains of insomnia or excessive daytime sleepiness and impairment in various areas of functioning. The second edition of the International Classification of Sleep Disorders (ICSD-2) 1 divides disorders of sleep-wake schedule into three major categories: CRSDs of primary origin, behaviorally induced CRSDs, and CRSDs due to a substance. Behaviorally induced CRSDs can emerge as a consequence of the individual's voluntary choice to create a temporal mismatch between his or her sleep-wake cycle and environmental conditions, as happens in shift work and jet lag. This review will focus on primary CRSDs and behavioral and psychiatric consequences of these disorders. Alterations of the sleep-wake schedule following treatment with psychoactive medications will also be described in some detail. Four types of primary CRSD are listed in the ICSD-2: • Delayed sleep phase type, also known as delayed sleep phase syndrome (DSPS), which is characterized by habitual sleep-wake times that are delayed usually more than 2 h relative to conventional or socially acceptable times (Figure 1A). When forced to follow an environmentally imposed schedule, these patients 357
Biological Psychiatry, Sep 1, 1991
Awakening thresholds from sleep stage 3/4 were investigated in 19 DSM-Ill-deflned, warrelated pos... more Awakening thresholds from sleep stage 3/4 were investigated in 19 DSM-Ill-deflned, warrelated post-traumatic stress disorder (PTSD) patients compared with 6 normal controls. Patients had significantly higher awakening thresholds and significantty longer iatencies to an arousal response than controls. Thes~ results are interpreted to suggest modifications in the depth of sleep as one of the long-term sequelae of traumatic events.
Chronobiology International, 1999
The present article presents a survey of the characteristics of our case series of 322 patients s... more The present article presents a survey of the characteristics of our case series of 322 patients suffering from circadian rhythm sleep disorders (CRSDs), a case-control study comparing a group of 50 CRSD patients and 56 age- and gender-matched normal subjects, and a proposal for new guidelines for improving the diagnosis of CRSD. The major findings were that 83.5% of our CRSD patients who seek medical help are of the delayed sleep phase syndrome (DSPS) type; 89.6% report that the onset of CRSD occurred in early childhood or adolescence; CRSD exhibits no gender differences: a familial trait exists in 44% of patients; and learning disorders (19.3%) and personality disorders (22.4%) in the DSPS-type patients are of high prevalence. The findings of this study point to the importance of clinician awareness of the clinical picture of patients presenting with CRSD so that early diagnosis and effective treatment can be achieved to prevent harmful consequences.
Journal of Psychosomatic Research, Oct 1, 1996
The purpose of this study was to examine systematically our previous clinical impression regardin... more The purpose of this study was to examine systematically our previous clinical impression regarding the prevalence of personality disorders in patients suffering from circadian rhythm sleep disorders (CRSD). We hypothesized that, in a group of patients suffering from CRSD, there would be a higher frequency of personality disorders than in a group of healthy controls. The experimental group consisted of CRSD patients diagnosed according to a clinical interview and actigraphic recordings. The control group consisted of healthy volunteers in whom CRSD had been ruled out by means of a self-administered questionnaire. Both groups were assessed for personality disorders using the MCMI, a diagnostic tool based on Millon&amp;amp;amp;amp;amp;#39;s biopsychosocial theory of personality and the PRQ-R, a diagnostic tool based on the DMS-III-R. Both tests provided clear and significant support for the hypothesis that individuals suffering from CRSD are characterized to a greater extent by personality disorders than a control group. No specific characteristic pattern or profile of personality disorders was clearly detected. Correct early diagnosis and treatment of CRSD may improve afflicted individuals&amp;amp;amp;amp;amp;#39; adaptive capabilities and perhaps even prevent the development of a personality disorder. This suggests how important a greater awareness of CRSD on the part of the professional community may be.
Journal of Blood Disorders and Transfusion, 2021
Study Objectives: Insomnia is a common sleep disorder with a prevalence of 10-15% in the populati... more Study Objectives: Insomnia is a common sleep disorder with a prevalence of 10-15% in the population. The primary aim of our study is to assess the development of tolerance to chronic hypnotic administration in patients with insomnia. An additional aim is to describe the prevalence of hypnotic treatment among patients with insomnia. Methods: This is a retrospective study including all members of Maccabi Health Services above the age of 18 years, of data collected between 2011 and 2014. A chronic user was defined as a person who purchased 180 and more sleeping pills per year. Results: Only 20% of the insomnia patients treated with hypnotics were chronic users. Between 2011 and 2014, we observed a constant increase of 2.5% per year in the number of chronic users. The number of hypnotics taken by chronic users was not different between the genders or between types of hypnotics. A positive correlation was found between age and number of hypnotics among chronic users. The majority of the long-term chronic patients either did not change or decreased the number of sleeping pills they consumed. Conclusion: Our results suggest that chronic insomnia patients do not develop tolerance to treatment with hypnotics.
Environmental health perspectives, Aug 17, 2016
PubMed, May 1, 2009
The prevalence of chronic insomnia in the adult population in Israel is 29.8%, which is comparabl... more The prevalence of chronic insomnia in the adult population in Israel is 29.8%, which is comparable to other Western countries. The consequences of insomnia include fatigue, accidents, low level of well-being, and a high need for medical services. One of the well-known treatments for insomnia is sleeping pills. Physicians are educated that hypnotics are an appropriate treatment for transient insomnia but not for chronic use. It is believed that transient users are at high risk of becoming addicted to sleep medications although research has not proven this theory. NonetheLess, physicians often try to convince insomnia patients not to use these medications. In the U.S.A., only 3% of chronic insomniacs use sleep medications. There are no data on the use of sleep medications in Israel. The present study was performed using a large database comprised of 1.1 million adult patients of Maccabi Health Services. It is the first study examining sleep medication usage habits of the adult population in IsraeL. The main findings are: 2.8% of Maccabi patients use sleep medications, however only 4.5% of this group are chronic users; most chronic users started sleep medications at the age of 65 or older and they suffer more than the transient users from medical conditions such as ischemic heart disease, hypertension, and diabetes mellitus, have higher usage of antidepressant and anxiolytic medication, receive greater national financial support and are more likely to be new immigrants. The results of this study should evoke physicians to reassess their position against prescribing sleep medications to patients for whom it may help in relieving their insomnia.
John Wiley & Sons, Inc. eBooks, Nov 4, 2005
... YARON DAGAN, KATY BORODKIN Sheba Medical Center, Tel Hashomer, Israel LIAT AYALON * ... 15. C... more ... YARON DAGAN, KATY BORODKIN Sheba Medical Center, Tel Hashomer, Israel LIAT AYALON * ... 15. Chesson AL Jr, Anderson WM, Littner M, Davila D, Hartse K, Johnson S, Wise M, Rafecas J. Practice parameters for the non-pharmacologic treatment of chronic insomnia. ...
PubMed, 2002
Circadian Rhythm Sleep Disorders (CRSD) are a group of sleep disorders characterized by a de-sync... more Circadian Rhythm Sleep Disorders (CRSD) are a group of sleep disorders characterized by a de-synchronization between a person's biological clock and the environmental 24-hour schedule. There are four main types of CRSD, namely, Delayed Sleep Phase Syndrome (DSPS) (the most common), Advanced Sleep Phase Syndrome (ASWD), Non-24-hour Sleep-Wake Syndrome (Free-Running Pattern) and Irregular (or Disorganized) Sleep Wake Pattern. These disorders lead to harmful psychological and functional difficulties and certain personality disorders may also be related to them. It has been found that psychotropic drugs, SSRI and haloperidol can cause CRSD, and this is also true for some cases of minor head trauma. They are often misdiagnosed and incorrectly treated due to the fact that many doctors are unfamiliar with them. This review describes the disorders, their consequences and available treatment.
Chronobiology International, Mar 3, 2020
The last several decades have been characterized by the widespread usage of digital devices, espe... more The last several decades have been characterized by the widespread usage of digital devices, especially smartphones. At the same time, there have been reports of both decline in sleep duration and quality and male fertility decline. The aim of this study was to assess the relationship between evening exposure to the light-emitting screens of digital media devices and measures of both sleep and sperm quality. Semen samples were obtained from 116 men undergoing fertility evaluation for the following sperm variables: volume (mL), pH, sperm concentration (million/mL), motility percentage (progressive% + non-progressive motility%), and total sperm count. Exposure to the screens of electronic devices and sleep habits was obtained by means of a questionnaire. Smartphone and tablet usage in the evening and after bedtime was negatively correlated with sperm motility (−0.392; −0.369; p < .05), sperm progressive motility (−0.322; −0.299; p < .05), and sperm concentration (−0.169; p < .05), and positively correlated with the percentage of immotile sperm (0.382; 0.344; p < .05). In addition, sleep duration was positively correlated with sperm total and progressive motility (0.249; 0.233; p < .05) and negatively correlated with semen pH (−0.349; p < .05). A significant negative correlation was observed between subjective sleepiness and total and progressive motility (−0.264; p < .05) as well as total motile sperm number (−0.173; p < .05). The results of this study support a link between evening and post-bedtime exposure to light-emitting digital media screens and sperm quality. Further research is required to establish the proposed causative link and may lead to the future development of relevant therapeutic and lifestyle interventions.
Chronobiology International, 2005
A patient who developed an irregular sleep-wake pattern following prolactin-secreting pituitary m... more A patient who developed an irregular sleep-wake pattern following prolactin-secreting pituitary microadenoma is described. The patient reported difficulties in sleep onset and awakening at the desired time, which caused major dysfunction in his daily life activities. Despite these difficulties, the sleep-related complaints of the patient remained unrecognized for as long as three yrs. Statistical analyses of the patient's rest-activity patterns revealed that the disruption of the sleep-wake circadian rhythm originated from a disharmony between ultradian (semicircadian) and circadian components. The circadian component displayed shorter than 24 h periodicity most of the time, but the semicircadian component fluctuated between longer and shorter than 12 h periods. Additionally, desynchrony in terms of period length was found in the tentative analyses of the rest-activity pattern, salivary melatonin, and oral temperature. While the salivary melatonin time series data could be characterized by a best-fit cosine curve of 24 h, the time series data of oral temperature was more compatible with 28 h best-fit curve. The rest-activity cycle during the simultaneous measurements, however, was best approximated by a best-fit curve of 21h. The dysregulation of circadian rhythms occurred concomitantly, but not beforehand, with the onset of pituitary disease, thus suggesting an association between the two phenomena. This association may have interesting implications to the modeling of the circadian time-keeping system. This case also highlights the need to raise the awareness to circadian rhythm sleep disorders and to consider disruptions of sleepwake cycle in patients with pituitary adenoma.
Psychiatry and Clinical Neurosciences, Dec 1, 1997
The aim of the present study was to compare the sleep of 12 children with attention deficit hyper... more The aim of the present study was to compare the sleep of 12 children with attention deficit hyperactivity disorder (ADHD) with that of 12 normal controls. The children were examined in their natural environment, using continuous actigraphic monitoring over several consecutive nights, as well as undergoing subjective parental reports. It was hypothesized that children diagnosed with ADHD would suffer from reduced sleep quality than children without ADHD. This hypothesis was supported by the actigraphic measures, but not supported by the subjective parental reports. It was also found that the sleep quality of the two groups differed over the course of the night, which suggests a difference in sleep architecture. Various possible explanations for these findings, their implications regarding the relationship between sleep and ADHD, and the resulting treatment ramifications are discussed, and suggestions for further research are provided.
Chronobiology International, May 26, 2017
The use of electronic devices with light-emitting screens has increased exponentially in the last... more The use of electronic devices with light-emitting screens has increased exponentially in the last decade. As a result, humans are almost continuously exposed to unintentional artificial light. We explored the independent and combined effects of two aspects of screen illumination, light wavelength, and intensity, on sleep, its biological regulation, and related functional outcomes. The 2 × 2 repeated-measure design included two independent variables: screen light intensity (low ([LI] versus high [HI]) and wavelength (short [SWL] versus long [LWL]). Nineteen participants (11F, 8M; mean age 24.3 [±2.8] years) underwent four light conditions, LI/SWL, HI/SWL, LI/LWL, and HI/LWL, in counterbalanced order. Each light exposure lasted for two hours (21:00-23:00), following which participants underwent an overnight polysomnography. On each experimental night, oral temperature and urine samples (for melatonin analysis) were collected at multiple time points. Each morning, participants filled out questionnaires and conducted a computerized attention task. Irrespective of light intensity, SWL illumination significantly disrupted sleep continuity and architecture and led to greater self-reported daytime sleepiness. SWL light also altered biological rhythms, subduing the normal nocturnal decline in body temperature and dampening nocturnal melatonin secretion. Light intensity seemed to independently affect sleep as well, but to a lesser degree. Both light intensity and wavelength negatively affected morning attention. In sum, light wavelength seems to have a greater influence than light intensity on sleep and a widerange of biological and behavioral functions. Given the widespread use of electronic devices today, our findings suggest that screen light exposure at evening may have detrimental effects on human health and performance.
Neurology, Apr 2, 2007
To describe the physiologic and behavioral characteristics of circadian rhythm sleep disorders (C... more To describe the physiologic and behavioral characteristics of circadian rhythm sleep disorders (CRSDs) following minor traumatic brain injury (mTBI) in patients complaining of insomnia. Forty two patients with insomnia complaints following mTBI were screened. Those suspected of having CRSD underwent actigraphy, saliva melatonin and oral temperature measurement, and polysomnography. All patients also filled out a self-reported questionnaire to determine their circadian preference. Fifteen of the 42 patients (36%) with complaints of insomnia following mTBI were diagnosed with CRSD. Eight patients displayed a delayed sleep phase syndrome (DSPS), whereas seven displayed an irregular sleep-wake pattern (ISWP). Whereas all patients with DSPS exhibited a 24-hour periodicity of oral temperature rhythm, three of seven patients with ISWP lacked such a daily rhythm. In addition, ISWP patients exhibited smaller amplitude of oral temperature rhythm vs the DSPS group. Subjective Morningness-Eveningness Questionnaire scores were in accordance with the clinical diagnosis of DSPS or ISWP based on actigraphy. Minor traumatic brain injury might contribute to the emergence of circadian rhythm sleep disorders. Two types of these disorders were observed: delayed sleep phase syndrome and irregular sleep-wake pattern. The types differed in the subjective questionnaire scores and had distinct profiles of melatonin and temperature circadian rhythms.
Growth hormone & IGF research, Aug 1, 2001
A 68 year old patient with Laron syndrome (primary growth hormone (GH) resistance-insensitivity d... more A 68 year old patient with Laron syndrome (primary growth hormone (GH) resistance-insensitivity due to a molecular defect of the GH receptor) and severe obstructive sleep apnoea syndrome is described. Treatment with continuous positive air pressure therapy resulted in improved nocturnal sleep, daytime alertness and cognitive functions.
bioRxiv (Cold Spring Harbor Laboratory), Mar 1, 2023
Study Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing conditi... more Study Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing condition characterized by repetitive cessations in breathing during sleep. Current standard of care for OSA management is continuous positive air pressure (CPAP) devices, which often suffer from low tolerance due to limited adherence. Capitalizing on the unique neurocircuitry of the olfactory system and its retained function during sleep, we set out to test the feasibility of transient, respiration-based olfactory stimulation as a treatment for OSA symptoms. Methods: Thirty-two OSA patients (AHI ≥ 15 events/hour) were recruited and underwent two polysomnography sessions, 'Odor' and 'Control', counterbalanced for order. In 'Odor' night, patients were presented with transient olfactory stimulation delivered via a computer-controlled olfactometer. The olfactometer, equipped with a wireless monitoring unit, analyzed respiratory patterns and presented stimulation upon detection of respiratory events. No odor was presented 'Control' nights. Results: Olfactory stimulation reduced AHI (Apnea-Hypopnea Index) (n = 17, 49.2±10.2 years, range: 30-66; p = 0.02, BF 10 = 115.85), reflecting an average decrease of 31.3% in the number of events. Post hoc planned comparisons revealed a reduction in HI (Hypopnea Index) (p = 0.02, BF 10 = 2.39), but not AI (Apnea Index) (p = 0.26, BF 10 = 1.56). This effect was not linked to baseline symptoms severity (ρ =-0.042, p = 0.87) and did not vary across odorants (F(4,64) = 0.56, p = 0.67). Finally, olfactory stimulation did not affect sleep structure (all p > 0.44, all BF01 > 2.9). Conclusions: Olfactory stimulation during sleep was effective in reducing OSA symptoms severity and may provide a novel treatment modality, therefore prompting continued research on this front. .
Dialogues in Clinical Neuroscience, Dec 31, 2005
umans, like many other mammals, are awake through the daytime hours and sleep during the night. I... more umans, like many other mammals, are awake through the daytime hours and sleep during the night. In some people, this normal sleep-wake rhythm, so taken for granted by most of us, can become chronically impaired, leading to a group of disorders called circadian rhythm sleep disorders (CRSDs). CRSDs are characterized by a misalignment between the timing of the individual's sleep-wake rhythm and the 24-h social and physical environment. In patients with CRSDs, sleep episodes occur at inappropriate times, often causing waking periods to occur at undesired times. Consequently, the patient complains of insomnia or excessive daytime sleepiness and impairment in various areas of functioning. The second edition of the International Classification of Sleep Disorders (ICSD-2) 1 divides disorders of sleep-wake schedule into three major categories: CRSDs of primary origin, behaviorally induced CRSDs, and CRSDs due to a substance. Behaviorally induced CRSDs can emerge as a consequence of the individual's voluntary choice to create a temporal mismatch between his or her sleep-wake cycle and environmental conditions, as happens in shift work and jet lag. This review will focus on primary CRSDs and behavioral and psychiatric consequences of these disorders. Alterations of the sleep-wake schedule following treatment with psychoactive medications will also be described in some detail. Four types of primary CRSD are listed in the ICSD-2: • Delayed sleep phase type, also known as delayed sleep phase syndrome (DSPS), which is characterized by habitual sleep-wake times that are delayed usually more than 2 h relative to conventional or socially acceptable times (Figure 1A). When forced to follow an environmentally imposed schedule, these patients 357
Biological Psychiatry, Sep 1, 1991
Awakening thresholds from sleep stage 3/4 were investigated in 19 DSM-Ill-deflned, warrelated pos... more Awakening thresholds from sleep stage 3/4 were investigated in 19 DSM-Ill-deflned, warrelated post-traumatic stress disorder (PTSD) patients compared with 6 normal controls. Patients had significantly higher awakening thresholds and significantty longer iatencies to an arousal response than controls. Thes~ results are interpreted to suggest modifications in the depth of sleep as one of the long-term sequelae of traumatic events.
Chronobiology International, 1999
The present article presents a survey of the characteristics of our case series of 322 patients s... more The present article presents a survey of the characteristics of our case series of 322 patients suffering from circadian rhythm sleep disorders (CRSDs), a case-control study comparing a group of 50 CRSD patients and 56 age- and gender-matched normal subjects, and a proposal for new guidelines for improving the diagnosis of CRSD. The major findings were that 83.5% of our CRSD patients who seek medical help are of the delayed sleep phase syndrome (DSPS) type; 89.6% report that the onset of CRSD occurred in early childhood or adolescence; CRSD exhibits no gender differences: a familial trait exists in 44% of patients; and learning disorders (19.3%) and personality disorders (22.4%) in the DSPS-type patients are of high prevalence. The findings of this study point to the importance of clinician awareness of the clinical picture of patients presenting with CRSD so that early diagnosis and effective treatment can be achieved to prevent harmful consequences.