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Khatami R, Landolt HP, Achermann P, Adam M, Rétey JV, Werth E, Schmid D, Bassetti CL. Challenging sleep homeostasis in narcolepsy-cataplexy: implications for non-REM and REM sleep regulation. Sleep 2008; 31:859-67. [PMID: 18548831 DOI: 10.1093/sleep/31.6.859] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES We recently proposed insufficient non-rapid eye movement sleep (NREMS) intensity to contribute to disturbed nocturnal sleep in patients with narcolepsy-cataplexy (NC). To test this hypothesis, we investigated the effect of physiologically intensified NREMS in recovery sleep following sleep deprivation. DESIGN Nocturnal baseline and recovery sleep architecture, and the sleep electroencephalogram (EEG) before and after 40 hours of sustained wakefulness were compared between 6 drug-free patients with NC (age range: 19-37 years) and 6 individually matched, healthy control subjects (18-43 years). MEASUREMENTS Sleep and sleep EEG power spectra (C3A2 derivation). The dynamics of the homeostatic Process S were estimated from the time course of slow-wave activity (SWA, spectral power within 0.75-4.5 Hz) across consecutive NREMS episodes. SETTINGS Sleep research laboratory. RESULTS In baseline, SWA decreased across consecutive NREMS episodes in patients with NC and control subjects. The build-up of SWA, however, was attenuated in NC in the second episode (P = 0.01) due to a higher number of short wake periods (P = 0.02). Prolonged wakefulness increased initial SWA in both groups (P = 0.003) and normalized the baseline differences between patients and control subjects in the time course of SWA in NREMS. The changed dynamics of SWA in the patients in recovery sleep when compared with baseline were associated with reduced numbers of intermittent wake periods in the first (P = 0.01) and second (P = 0.04) NREMS episodes. All patients, but no control subjects, showed a sleep-onset rapid eye movement period (SOREMP) in both baseline and recovery sleep. Sleep deprivation increased SOREMP duration (P = 0.03). CONCLUSIONS Increased SWA after sleep deprivation indicates that sleep homeostasis is functional in NC. Increased NREMS intensity in recovery sleep postpones sleep fragmentation, supporting our concept that sleep fragmentation is directly related to insufficient NREMS intensity in NC. The persistence of SOREMP despite enhanced NREMS pressure suggests an abnormal interaction between NREMS and REMS regulatory processes.
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Affiliation(s)
- Ramin Khatami
- Department of Neurology, University Hospital Zürich, Switzerland
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102
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Fronczek R, Overeem S, Reijntjes R, Lammers GJ, van Dijk JG, Pijl H. Increased heart rate variability but normal resting metabolic rate in hypocretin/orexin-deficient human narcolepsy. J Clin Sleep Med 2008; 4:248-254. [PMID: 18595438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
STUDY OBJECTIVES We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were determined in the fasted resting state. Subjects included 15 untreated, hypocretin-deficient male narcoleptics and 15 male controls matched for age and body mass index. RESULTS Spectral power analysis revealed greater heart rate and blood pressure variability in hypocretin-deficient male narcoleptic patients (heart rate: p = 0.01; systolic blood pressure: p = 0.02; diastolic: p < 0.01). The low to high frequency ratio of heart rate power did not differ between groups (p = 0.48), nor did resting metabolic rate (controls: 1767 +/- 226 kcal/24 h; patients: 1766 +/- 227 kcal/24h; p = 0.99). CONCLUSIONS Resting metabolic rate was not reduced in hypocretin-deficient narcoleptic men and therefore does not explain obesity in this group. Whether the increased heart rate and blood pressure variability--suggesting reduced sympathetic tone--is involved in this regard remains to be elucidated.
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Affiliation(s)
- Rolf Fronczek
- Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, Leiden, The Netherlands.
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103
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Abstract
Neuroimaging methods can be used to investigate whether sleep disorders are associated with specific changes in brain structure or regional activity. However, it is still unclear how these new data might improve our understanding of the pathophysiology underlying adult sleep disorders. Here we review functional brain imaging findings in major intrinsic sleep disorders (i.e., idiopathic insomnia, narcolepsy, and obstructive sleep apnea) and in abnormal motor behavior during sleep (i.e., periodic limb movement disorder and REM sleep behavior disorder). The studies reviewed include neuroanatomical assessments (voxel-based morphometry, magnetic resonance spectroscopy), metabolic/functional investigations (positron emission tomography, single photon emission computed tomography, functional magnetic resonance imaging), and ligand marker measurements. Based on the current state of the research, we suggest that brain imaging is a useful approach to assess the structural and functional correlates of sleep impairments as well as better understand the cerebral consequences of various therapeutic approaches. Modem neuroimaging techniques therefore provide a valuable tool to gain insight into possible pathophysiological mechanisms of sleep disorders in adult humans.
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104
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de Vicente Alvarez-Manzaneda EE. [Advances in the diagnosis and treatment of narcolepsy-cataplexy syndrome]. Rev Neurol 2008; 46:550-556. [PMID: 18446698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Narcolepsy is a disabling sleep disorder that is characterised by excessive daytime sleepiness and abnormal manifestations in REM (rapid eye movement) sleep that include, among other symptoms, cataplexy (the sudden loss of muscle tone triggered by strong emotions). Studies on the prevalence of narcolepsy-cataplexy in Europe and the United States have yielded a figure of 0.013-0.067% in the general population. Although its prevalence is low, it is probably under-diagnosed for a number of different reasons, the most important perhaps being the difficulties involved in its diagnosis. DEVELOPMENT Because its diagnosis is essentially clinical, complementary tests can often be very helpful. Today, it is one of the most extensively studied sleep disorders at the molecular level. Human narcolepsy is associated with diminished hypocretin/orexin concentrations, unlike the case of canine narcolepsy, where mutations in the Hcrt receptor have been found. The treatment of narcolepsy must be tailored to meet the needs of each patient after an individual analysis of his or her symptoms. Daytime sleepiness can be controlled by drugs that stimulate the central nervous system, the most common being methylphenidate and modafinil. Cataplexy is usually treated with tricyclic antidepressants and selective serotonin reuptake inhibitors. The appearance of new drugs like sodium oxybate sheds a ray of light on the dark horizon of patients with narcolepsy-cataplexy syndrome. CONCLUSION Early identification of excessive daytime sleepiness by primary care physicians and specialists is essential for a better management and follow-up of these patients.
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105
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Lin JS, Dauvilliers Y, Arnulf I, Bastuji H, Anaclet C, Parmentier R, Kocher L, Yanagisawa M, Lehert P, Ligneau X, Perrin D, Robert P, Roux M, Lecomte JM, Schwartz JC. An inverse agonist of the histamine H3 receptor improves wakefulness in narcolepsy: Studies in orexin−/− mice and patients. Neurobiol Dis 2008; 30:74-83. [PMID: 18295497 DOI: 10.1016/j.nbd.2007.12.003] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2007] [Revised: 12/11/2007] [Accepted: 12/14/2007] [Indexed: 11/30/2022] Open
Affiliation(s)
- Jian-Sheng Lin
- INSERM-U628, 69373-Lyon, France; Faculté de Médecine, Université Claude Bernard, 69373-Lyon, France.
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106
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Shin YK, Yoon IY, Han EK, No YM, Hong MC, Yun YD, Jung BK, Chung SH, Choi JB, Cyn JG, Lee YJ, Hong SC. Prevalence of narcolepsy-cataplexy in Korean adolescents. Acta Neurol Scand 2008; 117:273-8. [PMID: 17922892 DOI: 10.1111/j.1600-0404.2007.00930.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Narcolepsy typically begins between adolescence and early adulthood causing severe neuropsychiatric impairments, but few prevalence studies are available on adolescent narcoleptics. In the present study, we investigated the prevalence of narcolepsy-cataplexy in adolescents. METHODS In total 20,407 students, aged 14-19 years, participated in this study. Ullanlinna Narcolepsy Scale (UNS) was applied to all subjects and those with a UNS score of > or =14 were contacted by phone for semi-structured interview. Subjects then suspected of having narcolepsy participated in a laboratory investigation, which included polysomnography and HLA typing, or were interviewed in detail by telephone. RESULTS Three subjects were finally diagnosed as narcolepsy with cataplexy and seven subjects might be diagnosed as narcolepsy without cataplexy. Among three narcoleptics with cataplexy, two subjects were HLA-DQB1*0602 and DRB1*1501 positive, but one subject had no test of HLA typing. The prevalence of narcolepsy with cataplexy in Korean adolescence was thus determined to be 0.015% (95% confidence interval = 0.0-0.0313%). CONCLUSION This epidemiologic study is the first of its type on adolescent narcolepsy to use the International Classification of Sleep Disorders, 2nd edition (ICSD-2) diagnostic criteria. Considering those cases with an onset after adolescence were not included, the prevalence of narcolepsy with cataplexy determined in the present study is comparable with that of other studies in adults.
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Affiliation(s)
- Y K Shin
- Department of Psychiatry, St Vincent's Hospital, The Catholic University of Korea, Suwon, Korea
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107
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Abstract
Repeated injections of delta sleep-inducing peptide (DSIP) were given to a 35-year-old male narcoleptic. Effects on wakefulness and sleep were evaluated by self-reports, performance tests, multiple sleep latency test and all-night polysomnography. DSIP reduced the frequency of sleep attacks and increased activity, alertness and performance during day-time. The sleep period was compressed by DSIP with enhancement of REM sleep. The results suggest that the effects are due to an accentuation of circadian and ultradian rhythms by DSIP.
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108
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Abstract
Activation of different areas in the forebrain evokes different types of goal directed adaptive behaviors. An important component of these different patterns of behavior is the locomotion that brings the animal to or away from a particular location. Here I review the role of projections from forebrain structures to the mesopontine tegmentum of the brainstem where neural mechanisms for initiation of locomotion and regulation of postural muscle tone are located that are activated during locomotor behavior. It is interesting is to understand how signals that converge from the forebrain structures to the mesopontine tegmentum control locomotor behavior, because the mesopontine tegmentum receives inhibitory efferents from the basal ganglia and excitatory efferents from the limbic-hypothalamic system and the neocortex. Here I hypothesize that the mesopontine tegmentum has functional gating mechanisms that determine whether the subject will initiate and select volitionally guided or emotionally triggered locomotor behaviors, depending on the behavioral context.
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Affiliation(s)
- Kaoru Takakusaki
- Department of Physiology, Division of Neural Function, Asahikawa Medical College, Midorigaoka-Higashi, 2-1, Asahikawa 078-8510, Japan.
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109
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Goriguchi J. [Concept of sleep-wakefulness disorders and understanding of their status]. Seishin Shinkeigaku Zasshi 2008; 110:125-133. [PMID: 18456978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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110
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Abstract
Narcolepsy is a chronic sleep disorder that affects human beings and animals. Up to 17 breeds of dogs are affected sporadically, and familial forms occur in dobermanns, labrador retrievers and dachshunds. These dogs display characteristics strikingly similar to those of human narcolepsy, including cataplexy (a sudden loss of muscle tone in response to emotional stimulation) and a shorter sleep latency. It has recently been shown that the aetiology of both the familial form (receptor null mutation) and the sporadic form (loss of ligand production) of canine narcolepsy is associated with a deficit in hypocretin/orexin neurotransmission. Hypocretin deficiency can be detected by the measurement of hypocretin-1 in cerebrospinal fluid, and this could be used to diagnose hypocretin ligand deficient cases in clinical practice. Narcolepsy is neither progressive nor life-threatening, but the clinical signs persist throughout life, and lifelong treatment and care are required. This article reviews the recent progress in narcolepsy research in dogs, and describes the diagnosis and treatment of the disease.
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Affiliation(s)
- M Tonokura
- Fujita Animal Hospital, Ageo, Saitama 362, Japan
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111
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Dodel R, Peter H, Spottke A, Noelker C, Althaus A, Siebert U, Walbert T, Kesper K, Becker HF, Mayer G. Health-related quality of life in patients with narcolepsy. Sleep Med 2007; 8:733-41. [PMID: 17512797 DOI: 10.1016/j.sleep.2006.10.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 10/20/2006] [Accepted: 10/23/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND To evaluate the health-related quality of life (HRQoL) in patients suffering from narcolepsy. METHODS Subjects included 75 narcoleptic patients diagnosed at the Hephata Klinik, Germany, who met the International Classification of Sleep Disorders (ICSD) criteria for narcolepsy. A standardized telephone interview was used to inquire about the disease and its burdens to the patients. HRQoL was recorded using the 36-item short-form Medical Outcomes Study (SF-36) as well as the Euroqol (EQ-5D). Frequency and factors of influence on decreased HRQoL were evaluated by using bivariate and multivariate analyses. RESULTS Patients with narcolepsy had considerably lower scores on all eight domains of the SF-36 compared to the general German population. In particular, scores were poor for the dimensions "physical role", "vitality", and "general health perception". Forty-eight percent of the patients reported problems in at least one of the EQ-5D items; most frequent were problems in the dimension "usual activity" (63.8%), "pain/discomfort" (61.7%) and "anxiety/depression" (41.1%). Difficulty maintaining "self-care" was documented only by 6.8%. The mean VAS score was 60.7%. Interestingly, signs and symptoms of narcolepsy, except for irresistible sleep episodes (p<0.03), had only a minor impact on HRQoL. Multivariate analyses confirmed a strong influence of employment status, living with a partner, excessive daytime sleepiness (EDS) and professional advancement. CONCLUSIONS HRQoL is considerably reduced in patients, with narcolepsy affecting the different dimensions to various degrees. Factors other than clinical signs and symptoms are associated also with poor HRQoL. Measures should be taken to integrate those factors into healthcare guidelines in order to improve the quality of life in patients with narcolepsy.
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Affiliation(s)
- Richard Dodel
- Department of Neurology, Philipps-University, Marburg, Germany.
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112
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Abstract
OBJECTIVES - This study was aimed to investigate the comprehensive range of cognitive performance using the objective computerized assessment system in narcolepsy and age, gender, and IQ-matched healthy comparison. MATERIALS AND METHODS - The cognitive functions of 24 patients with narcolepsy and 24 healthy comparison subjects were assessed. RESULTS - Narcoleptics performed more frequent omission and commission errors in the vigilance test, and more frequent omission errors in the continuous performance test. Narcoleptics' response time was slower than healthy volunteers, and the differences were more exaggerated in more complex tasks. The simple repetitious working performance was more impaired in the narcoleptic subjects than in healthy comparison subjects. Narcolepsy group showed worse performances in the determination unit than the comparison group, and this impairment became more salient in faster stimuli relative to slower ones. CONCLUSIONS - Narcoleptics have deficits of efficiency in attention allocation and execution as well as simple vigilance problem.
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Affiliation(s)
- K S Ha
- Department of Psychiatry, Seoul National University College of Medicine, Seoul National University Bungdang Hospital, Kyeonggi, Korea
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113
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del Cid-Pellitero E, Garzón M. [Modulation by the hypocretinergic/orexinergic neurotransmission system in sleep-wakefulness cycle states]. Rev Neurol 2007; 45:482-490. [PMID: 17948215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
INTRODUCTION The hypocretins/orexins are neuropeptides synthesized by a small neuronal cell group located in the posterior and lateral hypothalamus. These peptides have been considered modulators of the sleep-wakefulness cycle since their discovery in 1998; the hypocretinergic/orexinergic system is very active during wakefulness. In addition, the absence of either these peptides or their receptors is associated to narcolepsy-cataplexy, a disease in which the sleep-wakefulness cycle is completely disorganized. DEVELOPMENT Hypocretinergic/orexinergic neurons directly activate the cerebral cortex and neuronal cell groups of the reticular activating system containing noradrenaline, serotonin, dopamine, acetylcholine and histamine, through which they may also indirectly activate the cerebral cortex and enhance wakefulness; as well, these neurons inhibit REM sleep generation in the ventral pontine tegmentum. The decrease in the activity of hypocretinergic/orexinergic neurons during sleep inhibits the aminergic and cholinergic neurons of the reticular activating core, decreasing cortical activation and renewing REM sleep generation in the ventral pontine tegmentum. CONCLUSIONS Hypocretins/orexins modulate wakefulness and EEG activation in part through their actions on reticular core neurons projecting to the cortex and suppress REM sleep generation through inhibition of ventral pontine tegmentum neurons within the ventral oral pontine tegmentum. The hypoactivity of this system supports the sleep cycle fragmentation and general disorganization appearing in narcolepsy, as well as momentary interruption of wakefulness by REM sleep episodes.
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Affiliation(s)
- E del Cid-Pellitero
- Departamento de Anatomía, Histología ya Neurociencia, Universidad Autónoma de Madrid, Madrid, Spain
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114
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Dauvilliers Y, Abril B, Charif M, Quittet P, Bauchet L, Carlander B, Touchon J. Reversal of symptomatic tumoral narcolepsy, with normalization of CSF hypocretin level. Neurology 2007; 69:1300-1. [PMID: 17875919 DOI: 10.1212/01.wnl.0000276948.46213.64] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Y Dauvilliers
- Neurology Department, Gui de Chauliac Hospital, National Reference Network for Orphan Diseases, Narcolepsy and Idiopathic Hypersomnia, Montpellier, France.
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115
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Abstract
STUDY OBJECTIVES To assess the presence of polysomnographic characteristics of REM sleep behavior disorder (RBD) in narcolepsy; and to quantify REM sleep parameters in patients with narcolepsy, in patients with "idiopathic" RBD, and in normal controls. DESIGN Sleep laboratory study PARTICIPANTS Sixteen patients with narcolepsy and cataplexy matched for age and sex with 16 patients with "idiopathic" RBD and with 16 normal controls were studied. MEASUREMENTS AND RESULTS Higher percentages of REM sleep without atonia, phasic electromyographic (EMG) activity, and REM density were found in patients with narcolepsy than normal controls. In contrast, RBD patients had a higher percentage of REM sleep without atonia but a lower REM density than patients with narcolepsy and normal controls. Based on a threshold of 80% for percentage of REM sleep with atonia, 50% of narcoleptics and 87.5% of RBD patients had abnormal REM sleep muscle activity. No significant behavioral manifestation in REM sleep was noted in either narcoleptics or controls. We also found a higher frequency of periodic leg movements during wake (PLMW) and during sleep (PLMS) in narcoleptic patients compared to controls. CONCLUSIONS The present study demonstrates abnormalities in REM sleep motor regulation with an increased frequency of REM sleep without atonia, phasic EMG events and PLMS in narcoleptic patients when compared to controls. These abnormalities were seen more prominently in patients with RBD than in narcoleptics, with the exception of the PLMS index. We proposed that dysfunctions in hypocretin/dopaminergic system may lead to motor dyscontrol in REM sleep that results in dissociated sleep/wake states.
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Affiliation(s)
- Yves Dauvilliers
- Department of Neurology, Hôpital Gui de Chauliac, Inserm, U888, Université de Montpellier 1, Montpellier, France
| | - Sylvie Rompré
- Sleep Disorders Center, Hôpital du Sacré-Cœur, Université de Montréal, Canada
| | - Jean-Françis Gagnon
- Sleep Disorders Center, Hôpital du Sacré-Cœur, Université de Montréal, Canada
| | - Mélanie Vendette
- Sleep Disorders Center, Hôpital du Sacré-Cœur, Université de Montréal, Canada
| | - Dominique Petit
- Sleep Disorders Center, Hôpital du Sacré-Cœur, Université de Montréal, Canada
| | - Jacques Montplaisir
- Sleep Disorders Center, Hôpital du Sacré-Cœur, Université de Montréal, Canada
- Address correspondence to: Jacques Montplaisir, MD, PhD,
Centre d'étude du sommeil et des rythmes biologiques, Hôpital du Sacré-Coeur de Montréal, 5400 boul. Gouin Ouest, Montreal, Quebec, Canada, H4J 1C5(514) 338-2693(514) 338-2531
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116
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Abstract
The blink reflex of acoustic startle reflex (ASR) is modulated by emotions and a loss of physiological aversive ASR potentiation is reported in humans following amygdala lesions. Patients with narcolepsy-cataplexy (NC) were found to have normal ASR, but they failed to exhibit startle potentiation during unpleasant stimuli. This absence of aversive ASR potentiation gives support to the hypothesis of an amygdala dysfunction in human NC.
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Affiliation(s)
- Ramin Khatami
- Department of Neurology, University Hospital, Zürich, Switzerland
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117
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Affiliation(s)
- Mark S. Blumberg
- Program in Behavioral and Cognitive Neuroscience, Department of Psychology,University of Iowa, Iowa City, IA
| | - Karl Æ. Karlsson
- Department of Biomedical Engineering, School of Science and Engineering, Reykjavik University, Reykjavik, Iceland
| | - Adele M. H. Seelke
- Program in Behavioral and Cognitive Neuroscience, Department of Psychology,University of Iowa, Iowa City, IA
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118
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Abstract
STUDY OBJECTIVES To compare electroencephalogram (EEG) dynamics during nocturnal sleep in patients with narcolepsy-cataplexy and healthy controls. Fragmented nocturnal sleep is a prominent feature and contributes to excessive daytime sleepiness in narcolepsy-cataplexy. Only 3 studies have addressed changes in homeostatic sleep regulation as a possible mechanism underlying nocturnal sleep fragmentation in narcolepsy-cataplexy. DESIGN, SETTING AND PARTICIPANTS Baseline sleep of 11 drug-naive patients with narcolepsy-cataplexy (19-37 years) and 11 matched controls (18-41 years) was polysomnographically recorded. The EEG was subjected to spectral analysis. INTERVENTIONS None, baseline condition. MEASUREMENTS AND RESULTS All patients with narcolepsy-cataplexy but no control subjects showed a sleep-onset rapid eye movement (REM) episode. Non-REM (NREM)-REM sleep cycles were longer in patients with narcolepsy-cataplexy than in controls (P = 0.04). Mean slow-wave activity declined in both groups across the first 3 NREM sleep episodes (P<0.001). The rate of decline, however, appeared to be steeper in patients with narcolepsy-cataplexy (time constant: narcolepsy-cataplexy 51.1 +/- 23.8 minutes [mean +/- SEM], 95% confidence interval [CI]: 33.4-108.8 minutes) than in controls (169.4 +/- 81.5 minutes, 95% CI: 110.9-357.6 minutes) as concluded from nonoverlapping 95% confidence interval of the time constants. The steeper decline of SWA in narcolepsy-cataplexy compared to controls was related to an impaired build-up of slow-wave activity in the second cycle. Sleep in the second cycle was interrupted in patients with narcolepsy-cataplexy, when compared with controls, by an increased number (P = 0.01) and longer duration (P = 0.01) of short wake episodes. CONCLUSIONS Insufficient NREM sleep intensity is associated with nonconsolidated nocturnal sleep in narcolepsy-cataplexy. The inability to consolidate sleep manifests itself when NREM sleep intensity has decayed below a certain level and is reflected in an altered time course of slow-wave activity across NREM sleep episodes.
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Affiliation(s)
- Ramin Khatami
- Department of Neurology, University Hospital Zürich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Hans-Peter Landolt
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Julia V. Rétey
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - Esther Werth
- Department of Neurology, University Hospital Zürich, Switzerland
| | - Johannes Mathis
- Department of Neurology, Inselspital, University Hospital Berne, Berne, Switzerland
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119
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Zhang S, Lin L, Kaur S, Thankachan S, Blanco-Centurion C, Yanagisawa M, Mignot E, Shiromani PJ. The development of hypocretin (orexin) deficiency in hypocretin/ataxin-3 transgenic rats. Neuroscience 2007; 148:34-43. [PMID: 17618058 PMCID: PMC2042962 DOI: 10.1016/j.neuroscience.2007.05.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 05/22/2007] [Accepted: 05/24/2007] [Indexed: 11/17/2022]
Abstract
Narcolepsy is linked to a widespread loss of neurons containing the neuropeptide hypocretin (HCRT), also named orexin. A transgenic (TG) rat model has been developed to mimic the neuronal loss found in narcoleptic humans. In these rats, HCRT neurons gradually die as a result of the expression of a poly-glutamine repeat under the control of the HCRT promoter. To better characterize the changes in HCRT-1 levels in response to the gradual HCRT neuronal loss cerebrospinal fluid (CSF) HCRT-1 levels were measured in various age groups (2-82 weeks) of wild-type (WT) and TG Sprague-Dawley rats. TG rats showed a sharp decline in CSF HCRT-1 level at week 4 with levels remaining consistently low (26%+/-9%, mean+/-S.D.) thereafter compared with WT rats. In TG rats, HCRT-1 levels were dramatically lower in target regions such as the cortex and brainstem (100-fold), indicating decreased HCRT-1 levels at terminals. In TG rats, CSF HCRT-1 levels significantly increased in response to 6 h of prolonged waking, indicating that the remaining HCRT neurons can be stimulated to release more neuropeptide. Rapid eye movement (REM) sleep in TG rats (n=5) was consistent with a HCRT deficiency. In TG rats HCRT immunoreactive (HCRT-ir) neurons were present in the lateral hypothalamus (LH), even in old rats (24 months) but some HCRT-ir somata were in various stages of disintegration. The low output of these neurons is consistent with a widespread dysfunction of these neurons, and establishes this model as a tool to investigate the consequences of partial hypocretin deficiency.
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Affiliation(s)
- S Zhang
- Stanford University, 701 Welch Road, Room 145, Palo Alto, CA 94304-5742, USA
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120
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Overeem S, Afink J, Bakker M, Lammers GJ, Zwarts M, Bloem BR, van Dijk JG. High frequency repetitive transcranial magnetic stimulation over the motor cortex: No diagnostic value for narcolepsy/cataplexy. J Neurol 2007; 254:1459-61. [PMID: 17579803 PMCID: PMC2778683 DOI: 10.1007/s00415-007-0562-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 12/19/2006] [Accepted: 01/03/2007] [Indexed: 12/03/2022]
Affiliation(s)
- S. Overeem
- Dept. of Neurology, Radboud University Nijmegen Medical Centre, 9101, 6500 HB Nijmegen, The Netherlands
- Dept. of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - J. Afink
- Dept. of Neurology, Radboud University Nijmegen Medical Centre, 9101, 6500 HB Nijmegen, The Netherlands
| | - M. Bakker
- Dept. of Neurology, Radboud University Nijmegen Medical Centre, 9101, 6500 HB Nijmegen, The Netherlands
| | - G. J. Lammers
- Dept. of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - M. Zwarts
- Dept. of Neurology, Radboud University Nijmegen Medical Centre, 9101, 6500 HB Nijmegen, The Netherlands
| | - B. R. Bloem
- Dept. of Neurology, Radboud University Nijmegen Medical Centre, 9101, 6500 HB Nijmegen, The Netherlands
| | - J. G. van Dijk
- Dept. of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
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121
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Martínez-Rodríguez JE, Iranzo A, Casamitjana R, Graus F, Santamaria J. [Comparative analysis of patients with narcolepsy-cataplexy, narcolepsy without cataplexy and idiopathic hypersomnia]. Med Clin (Barc) 2007; 128:361-4. [PMID: 17386240 DOI: 10.1157/13099970] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND OBJECTIVE To evaluate the distribution of clinical, electrophysiological and biological variables, and their relationship with the CSF hypocretin-1 levels, in patients with central hypersomnias diagnosed as narcolepsy-cataplexy (NC), narcolepsy without cataplexy (NnC) and idiopathic hypersomnia (IH) based on the ICSD-2 criteria. PATIENTS AND METHOD We performed in all patients a clinical interview, a nocturnal polysomnogram and a multiple sleep latency test (MSLT), HLA analysis and measurement of CSF Hcrt-1 levels (low < or = 110 pg/mL). RESULTS Out of 51 patients, 31 were classified as NC, 11 as NnC and 8 as IH. 34 patients (66.7%) had low CSF Hcrt-1 levels (29 NC, 3 NnC and 1 IH). In the NC group, 96.1% were HLA DQB1*0602 positive and 91% had low CSF Hcrt-1 levels. The most frequent variables found in NC patients and in those with a low CSF Hcrt-1 levels were cataplexy, fragmented nocturnal sleep, short refreshing naps, automatic behavior, HLA DQB1*0602, and, in the MSLT, a short mean sleep latency, a higher number of REM sleep episodes and a short mean latency of REM sleep episodes. A long nocturnal sleep time and morning sleep drunkenness, 2 variables used in the ICSD-2 for the diagnosis of IH, were not different among the three groups of hypersomnias. CONCLUSIONS Central hypersomnias have a superposition of several clinical, electrophysiological and biological variables that makes sometimes difficult the differential diagnosis. The measurement of CSF Hcrt-1 levels may help in the diagnosis of those patients with unclear clinical or electrophysiological forms.
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Affiliation(s)
- José E Martínez-Rodríguez
- Servicio de Neurología, Hospital Clínic, Universitat de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, España
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Kim YK, Yoon IY, Shin YK, Cho SS, Kim SE. Modafinil-induced hippocampal activation in narcolepsy. Neurosci Lett 2007; 422:91-6. [PMID: 17600622 DOI: 10.1016/j.neulet.2007.04.085] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 03/27/2007] [Accepted: 04/09/2007] [Indexed: 11/22/2022]
Abstract
This study was undertaken to investigate regional metabolic abnormalities and to determine the effects of modafinil in narcoleptics on cerebral glucose metabolism using [(18)F] fluorodeoxyglucose positron emission tomography (FDG PET). Eight narcoleptic patients participated in the study. Two [(18)F] FDG PET scans were obtained before and after 2 weeks of modafinil treatment. To identify the effect of modafinil on regional cerebral abnormalities in narcoleptics, pre- and post-treatment PET scans were compared using paired t-statistics with voxel-wised manner. In narcolepsy patients, significant decreases in cerebral glucose metabolism were observed in the midbrain and upper pons, bilateral hypothalamus, posterior thalamus, hippocampus and right parahippocampus as compared with healthy subjects. After treatment, a significant increase in glucose metabolism in the left hippocampus was found in comparison with pre-treatment scan. This study demonstrated that modafinil activates the hippocampus which receives the afferents from hypothalamus, the center of sleep-wake rhythm.
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Affiliation(s)
- Yu Kyeong Kim
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, Korea
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123
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Honda K. [Animal models of sleep research]. Nihon Yakurigaku Zasshi 2007; 129:413-7. [PMID: 17575416 DOI: 10.1254/fpj.129.413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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Abstract
Narcolepsy is characterized by excessive daytime sleepiness (EDS), cataplexy and/or other dissociated manifestations of rapid eye movement (REM) sleep (hypnagogic hallucinations and sleep paralysis). Narcolepsy is currently treated with amphetamine-like central nervous system (CNS) stimulants (for EDS) and antidepressants (for cataplexy). Some other classes of compounds such as modafinil (a non-amphetamine wake-promoting compound for EDS) and gamma-hydroxybutyrate (GHB, a short-acting sedative for EDS/fragmented nighttime sleep and cataplexy) given at night are also employed. The major pathophysiology of human narcolepsy has been recently elucidated based on the discovery of narcolepsy genes in animals. Using forward (i.e., positional cloning in canine narcolepsy) and reverse (i.e., mouse gene knockout) genetics, the genes involved in the pathogenesis of narcolepsy (hypocretin/orexin ligand and its receptor) in animals have been identified. Hypocretins/orexins are novel hypothalamic neuropeptides also involved in various hypothalamic functions such as energy homeostasis and neuroendocrine functions. Mutations in hypocretin-related genes are rare in humans, but hypocretin-ligand deficiency is found in many narcolepsy-cataplexy cases. In this review, the clinical, pathophysiological and pharmacological aspects of narcolepsy are discussed.
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Affiliation(s)
- Seiji Nishino
- Stanford University School of Medicine, Department of Psychiatry and Behavioral Sciences, Sleep and Circadian, Neurobiology Laboratory, Center for Narcolepsy, 1201 Welch Road, P213, Palo Alto, CA 94304, USA.
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Abstract
INTRODUCTION We assessed the effect of periodic leg movements (PLMs) on sleep architecture in narcolepsy patients by comparing sleep patterns in narcoleptics of comparable age with and without PLMs. METHODS Patients diagnosed with narcolepsy between January 1999 and December 2005 were divided into those with PLM index >or= 5/hr and <5/hr. Each patient underwent polysomnographic recording followed by a multiple sleep latency test (MSLT). RESULTS There were 47 patients, of mean age 28.9 +/- 1.8 years, 31 (66%) with PLM index >or= 5/hr and 16 (34%) with PLM index <5/hr. Arousal index, PLM arousals and total number of arousals were all significantly higher in narcoleptics with PLM index >or= 5/hr than in those with PLM index <5/hr. Significant correlations were found between PLM index and arousal index, stage shifts, Stage 1 and average sleep latency on MSLT. CONCLUSIONS Our findings demonstrated that narcolepsy patients with PLMs have a higher arousal index and increased PLM arousals compared with narcolepsy patients without PLMs. The contribution of the above to the perceived sleep quality and daytime sleepiness is not clear.
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Affiliation(s)
- A Bahammam
- Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia.
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126
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Abstract
Robust association between narcolepsy and RBD
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Abstract
Recent population studies have identified important interrelationships between sleep duration and body weight regulation. The hypothalamic hypocretin/orexin neuropeptide system is able to influence each of these. Disruption of the hypocretin system, such as occurs in narcolepsy, leads to a disruption of sleep and is often associated with increased body mass index. We examined the potential interrelationship between the hypocretin system, metabolism and sleep by measuring locomotion, feeding, drinking, body temperature, sleep/wake and energy metabolism in a mouse model of narcolepsy (ataxin-ablation of hypocretin-expressing neurons). We found that locomotion, feeding, drinking and energy expenditure were significantly reduced in the narcoleptic mice. These mice also exhibited severe sleep/wake fragmentation. Upon awakening, transgenic and control mice displayed a similar rate of increase in locomotion and food/water intake with time. A lack of long wake episodes partially or entirely explains observed differences in overall locomotion, feeding and drinking in these transgenic mice. Like other parameters, energy expenditure also rose and fell depending on the sleep/wake status. Unlike other parameters, however, energy expenditure in control mice increased upon awakening at a greater rate than in the narcoleptic mice. We conclude that the profound sleep/wake fragmentation is a leading cause of the reduced locomotion, feeding, drinking and energy expenditure in the narcoleptic mice under unperturbed conditions. We also identify an intrinsic role of the hypocretin system in energy expenditure that may not be dependent on sleep/wake regulation, locomotion, or food intake. This investigation illustrates the need for coordinated study of multiple phenotypes in mouse models with altered sleep/wake patterns.
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Affiliation(s)
- Shengwen Zhang
- Psychiatry and Behavioural Sciences, Stanford University, Palo Alto, CA 94304-5742, USA
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128
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Li J, Xu Y, Dong XS, Han X, He ZM, Lü YH, Wang L, He QY, Han F. [Changes of sleep architecture in patients with narcolepsy]. Zhonghua Yi Xue Za Zhi 2007; 87:619-21. [PMID: 17550733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To investigate the sleep architectures of patients with narcolepsy. METHODS 38 drug-naive narcoleptic patients, 25 males and 13 females, aged 21 +/- 6.5, and 44 age-, sex ratio-, and BMI-matched normal persons underwent polysomnography (PSG) and multiple sleep latency test (MSLT) during one night sleep. Conventional visual scoring of the polysomnograms was performed according to the international. RESULTS The sleep latency of the patients was 5.6 min, however, 30 patients (79%) complained of fragmented nocturnal sleep and difficulty to fall asleep again. The sleep efficiency of the narcoleptics was 81.7% +/- 12.5%, significantly lower than that of the normal persons (87.1% +/- 7.9%, P = 0.029). The non-rapid eye movement (NREM) I sleep accounted for (21.5 +/- 12.2)% in the patients, a proportion significantly higher than that of the normal persons [(10.3 +/- 6.3)%, P = 0.000]). The AHI of the patients was 0.6 +/- 1.3 times/h, not significantly different from that of the normal persons (0.5 +/- 1.1 times/h). Although the rapid eye movement (REM) period and eye movement density of the narcoleptics were significantly increased, their REM period duration was not significantly different from that of the normal subjects (17.7% +/- 6.9% vs 18.9% +/- 5.5%, P = 0.23), probably due to the interruption of REM sleep by more frequent arousals in narcoleptics. PSG did not show significant periodic leg movements in these 2 groups. CONCLUSION One of the important symptoms of narcolepsy, night sleep disturbance may contribute to the pathological sleepiness of narcolepsy during daytime.
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Affiliation(s)
- Jing Li
- Department of Pulmonary Medicine, People's Hospital, Beijing University, Beijing 100044, China
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129
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Janeiro M, Camblor E, Fernández R, Núñez D. [Narcolepsy and anesthesia]. Rev Esp Anestesiol Reanim 2007; 54:198-9. [PMID: 17436663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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Abstract
STUDY OBJECTIVES In healthy subjects, sleep propensity increases when the distal skin temperature increases relative to the proximal skin temperature. This increase results from increased blood flow in the skin of the extremities and is, among other factors, controlled by the hypothalamic circadian clock, as is sleep. Because narcolepsy is characterized by hypothalamic alterations, we studied skin temperature in narcoleptic patients in relation to their characteristically increased sleep propensity during the day. DESIGN Distal and proximal skin temperature and their gradient (DPG) were measured during a Multiple Sleep Latency Test. This allowed temperature to be studied during wakefulness, at sleep onset and during sleep. SETTING Tertiary narcolepsy referral center in a university hospital. PATIENTS Fifteen unmedicated narcolepsy patients with cataplexy and 15 controls. INTERVENTIONS None. MEASUREMENTS AND RESULTS In subjects in the waking state, DPG was higher in narcoleptics than in controls throughout the day (time by group interaction, p < .0001), due to increased distal skin temperature and decreased proximal skin temperature. The increase in DPG was related to a shorter subsequent sleep-onset latency (p = .02). Once asleep, narcoleptics maintained their elevated distal skin temperature and DPG (p < .0001), whereas proximal skin temperature increased to reach normal levels. CONCLUSIONS This is the first demonstration of a dramatic alteration of daytime skin temperature control in narcolepsy. Even awake narcoleptic patients showed a DPG higher than that which healthy controls achieve when asleep. This observation suggests that hypocretin deficiency in narcolepsy affects skin-temperature regulation and invites further examination. Skin-temperature control might ultimately even have therapeutic implications for the alleviation of narcoleptic symptoms.
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Affiliation(s)
- Rolf Fronczek
- Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands.
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131
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Chavaillaz O, Frey JG. [Narcolepsy: current view]. Rev Med Suisse 2007; 3:448-50, 452-5. [PMID: 17424795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Narcolepsy is a primary sleep disorder which may or may not arise associated with catalepsy. It is a relatively frequent disease with 2 peaks of appearance in childhood and in young adulthood. It has genetic components which do not seem sufficient for its demonstration. It often depends on the environment and its clinical picture can be very variable, particularly in children. It is thus under-diagnosed and often confused with other diseases. In this short review of the literature we discuss: narcolepsy's history, clinical evaluation, diagnoses criteria, patient's history, clinical status and complementary examinations, clinical picture in the child and in the teenager, epidemiology, neurobiology, differential diagnoses, symptomatic narcolepsy, current treatments and internet sites of reference.
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Abstract
Narcolepsy with cataplexy is a disabling sleep disorder affecting 0.02% of adults worldwide. It is characterised by severe, irresistible daytime sleepiness and sudden loss of muscle tone (cataplexy), and can be associated with sleep-onset or sleep-offset paralysis and hallucinations, frequent movement and awakening during sleep, and weight gain. Sleep monitoring during night and day shows rapid sleep onset and abnormal, shortened rapid-eye-movement sleep latencies. The onset of narcolepsy with cataplexy is usually during teenage and young adulthood and persists throughout the lifetime. Pathophysiological studies have shown that the disease is caused by the early loss of neurons in the hypothalamus that produce hypocretin, a wakefulness-associated neurotransmitter present in cerebrospinal fluid. The cause of neural loss could be autoimmune since most patients have the HLA DQB1*0602 allele that predisposes individuals to the disorder. Treatment is with stimulant drugs to suppress daytime sleepiness, antidepressants for cataplexy, and gamma hydroxybutyrate for both symptoms. Because narcolepsy is an under-recognised disease, it is important that general practitioners and other primary health-care workers identify abnormal daytime sleepiness early.
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Affiliation(s)
- Yves Dauvilliers
- Neurologie, CHU Montpellier Hôpital Gui-de-Chauliac and INSERM U888, Montpellier-France.
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Ferrillo F, Donadio S, De Carli F, Garbarino S, Nobili L. A Model-Based Approach to Homeostatic and Ultradian Aspects of Nocturnal Sleep Structure in Narcolepsy. Sleep 2007; 30:157-65. [PMID: 17326541 DOI: 10.1093/sleep/30.2.157] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVE We present a mathematical model of sleep-EEG structure applied to the analysis of sleep patterns in narcoleptics by combining the 2-process model of sleep regulation and the reciprocal interaction model of REM regulation suggested by McCarley and Hobson. The aim was the individuation of parameters characterizing narcoleptic sleep in comparison to controls. DESIGN Polysomnographic data were drawn from a previous study about sleep in narcolepsy. The mathematical model was fitted to quantitative EEG data by an optimization procedure. SETTING Polysomnographic data were recorded in single and sound attenuated hospital rooms, for one night following an adaptation night. PARTICIPANTS 9 narcoleptic subjects (7 males, 2 females, mean age 39.6 +/- 4.3 years) and 9 age- and sex- matched controls. MEASUREMENTS Slow Wave Activity (SWA) time series were evaluated by spectral analysis. The sleep model was fitted to SWA profile for each recording and to the averaged SWA profile for each group. Bartlett and Kolmogorov-Smirnov test were used to evaluate the goodness of fit and the accuracy of model predictions. RESULTS In both controls and narcoleptics the optimization procedure produced a good fit of SWA raw data. The only significant difference between the groups were the RemOn/RemOff coupling parameters, reflecting an enhanced strength of the REM oscillator in narcoleptics. CONCLUSIONS The mathematical model of sleep provides a substantial description of empirical patterns for both controls and narcoleptics. The variation of values in the parameters describing the strength of RemOn /RemOff interaction is the major feature characterizing narcoleptics; it can explain sleep onset REM periods (SOREMPs) and variations of REM-NREM sleep cycle duration.
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Affiliation(s)
- Franco Ferrillo
- Center of Sleep Medicine, S. Martino Hospital, DISM, University of Genoa, Genoa, Italy.
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Waihrich ES, Rodrigues RND, Silveira HA, Fróes FDFM, Rocha GHDS. Comparative analysis of multiple sleep latency tests (MSLT) parameters and occurrence of dreaming in patients with daytime sleepiness of narcoleptic and non-narcoleptic origin. Arq Neuropsiquiatr 2007; 64:958-62. [PMID: 17221004 DOI: 10.1590/s0004-282x2006000600014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Accepted: 09/19/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To compare MSLT parameters in two groups of patients with daytime sleepiness, correlated to the occurrence and onset of dreams. METHOD Patients were submitted to the MSLT between January/1999 and June/2002. Sleep onset latency, REM sleep latency and total sleep time were determined. The occurrence of dreams was inquired following each MSLT series. Patients were classified as narcoleptic (N) or non-narcoleptic (NN). RESULTS Thirty patients were studied, 12 were classified as narcoleptics (N group; 40%), while the remaining 18 as non-narcoleptic (NN group; 60%). Thirty MSLT were performed, resulting in 146 series. Sleep was detected in 126 series (86%) and dreams in 56 series (44.44%). Mean sleep time in the N group was 16.0+/-6.3 min, while 10.5+/-7.5 min in the NN group (p<0.0001). Mean sleep latency was 2.0+/-2.2 min and 7.2+/-6.0 min in the N and NN group, respectively (p<0.001). Mean REM sleep latency in the N group was 3.2+/-3.1min and 6.9+/-3.7 min in the NN group (p=0.021). Dreams occurred in 56.9% of the N group series and 28.4% in that of the NN group (p=0.0009). Dream frequency was detected in 29.8% and 75% of the NREM series of the N and NN groups, respectively (p=0.0001). CONCLUSION Patients from the N group, compared to the NN group, slept longer and earlier, demonstrated a shorter REM sleep onset and greater dream frequency. NN patients had a greater dream frequency in NREM series. Thus, the occurrence of dreams during NREM in the MSLT may contribute to differentially diagnose narcolepsy and daytime sleepiness.
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135
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Szelenberger W. [Hypersomnias of central origin]. Pneumonol Alergol Pol 2007; 75 Suppl 1:80-6. [PMID: 17440899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
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Terzano MG, Smerieri A, Del Felice A, Giglia F, Palomba V, Parrino L. Cyclic alternating pattern (CAP) alterations in narcolepsy. Sleep Med 2006; 7:619-26. [PMID: 16740406 DOI: 10.1016/j.sleep.2005.12.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 10/24/2005] [Accepted: 12/02/2005] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Narcolepsy is a sleep disorder with clinical symptoms attributed to a reduced activation of the arousal system. Cyclic alternating pattern (CAP) is the expression of rhythmic arousability during non-rapid eye movement (NREM) sleep. CAP parameters, arousals and conventional sleep measures were studied in narcoleptic patients with cataplexy. PATIENTS AND METHODS Data were collected from all-night polysomnographic (PSG) recordings and the multiple sleep latency test (MSLT) on the intervening day of 25 drug-naive patients (10 males and 15 females; mean age: 34+/-16 years) after adaptation and exclusion of other sleep disorders. A group of 25 age- and gender-matched normal sleepers were selected as controls. Each PSG recording was subdivided into sleep cycles. Analysis of CAP included classification of A phases into subtypes A1, A2, and A3. RESULTS There was an increase in sleep period time mainly due to an increased wake time after sleep onset. REM latency was sharply reduced. The percentage of NREM sleep was slightly reduced and the balance between light sleep (S1+S2) and deep sleep (S3+S4) showed a curtailment of the former, while deep sleep was slightly increased. Excluding sleep cycles with sleep onset REM periods (SOREMPs), the duration of ordered sleep cycles was not different between narcoleptics and controls. The two groups showed similar values of arousal index, while CAP time, CAP rate, number of CAP cycles and of phase A subtypes (in particular subtypes A1) were significantly reduced in narcoleptic patients. CONCLUSIONS The reduced periods of CAP in narcoleptic NREM sleep could be the electroencephalographic (EEG) expression of a generally reduced arousability or an increased strength of sleep-promoting forces in the balance between sleep and arousal systems. This can explain some of the clinical correlates of the disorder, i.e. excessive sleepiness, short sleep latency and impaired attentive performances, even without any sign of arousal-induced sleep fragmentation.
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Affiliation(s)
- Mario Giovanni Terzano
- Department of Neuroscience, Sleep Disorders Center, University of Parma, Via Gramsci, 14, 43100 Parma, Italy.
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Mazzetti M, Campi C, Mattarozzi K, Plazzi G, Tuozzi G, Vandi S, Vignatelli L, Cipolli C. Semantic priming effect during REM-sleep inertia in patients with narcolepsy. Brain Res Bull 2006; 71:270-8. [PMID: 17113956 DOI: 10.1016/j.brainresbull.2006.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 09/13/2006] [Accepted: 09/13/2006] [Indexed: 11/25/2022]
Abstract
Patients with narcolepsy-cataplexy (NC) present excessive daytime sleepiness (EDS), cataplexy and an altered architecture of nocturnal sleep, with frequent episodes of REM-sleep at sleep onset (SOREM-sleep). This altered organization of nocturnal sleep may be accompanied by some differences in the functioning of the cognitive processes involved in the access, organization and consolidation of information during sleep. This study attempts to ascertain whether the activation of semantic memory during REM-sleep, as measured using a technique of semantic priming (namely, the facilitation of the activation of strongly-related rather than weakly-related and, overall, unrelated pairs of prime-target words) is different in NC patients compared to normal subjects. A lexical decision task (LDT) was carried out twice in wakefulness (at 10a.m. and after a 24h interval) and twice in the period of sleep inertia following awakening from SOREM and 4th-cycle REM-sleep on 12 NC patients and from 1st- and 4th-cycle REM-sleep on 12 matched controls. Reaction time (RT) to target words, taken as a measure of the semantic priming effect, proved to be longer (a) in NC patients than in control subjects; (b) in the period of REM-sleep inertia than in wakefulness; (c) in the first rather than the second session; and (d) for unrelated compared to weakly-related and, overall, strongly-related prime-target pairs. RT in post-REM-sleep sessions was less impaired, compared to waking sessions, and less dependent on the associative strength of prime-target pairs in NC patients than in normal subjects. Finally, RT of NC patients, although longer than that of normal subjects in waking sessions, significantly improved in the second session, as a consequence of either the amount of exercise or the consolidation advantage provided by REM-sleep for the procedural components of the task. The whole picture suggests a greater effectiveness of the activation of semantic memory during (SO)REM-sleep in NC patients rather than in normal subjects, and overall for the organization of new and unexpected relationships (such as those between unrelated pairs) between items of information.
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Ferri R, Zucconi M, Manconi M, Bruni O, Ferini-Strambi L, Vandi S, Montagna P, Mignot E, Plazzi G. Different Periodicity and Time Structure of Leg Movements During Sleep in Narcolepsy/Cataplexy and Restless Legs Syndrome. Sleep 2006; 29:1587-94. [PMID: 17252889 DOI: 10.1093/sleep/29.12.1587] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES To analyze periodic leg movements (PLM) during sleep in patients with narcolepsy and compare the results with those obtained in normal controls and subjects with restless legs syndrome (RLS). METHODS We recruited 40 HLA DQB1*0602-positive patients with narcolepsy/cataplexy, 22 with RLS, and 22 controls. The time structure of their polysomnographically recorded LMs was analyzed by means of an approach particularly able to consider their periodicity. MEASUREMENTS AND RESULTS Nineteen patients with narcolepsy had a PLM index greater than 15. The distribution of inter-LM intervals was clearly bimodal in RLS and narcoleptics, with 1 peak at 2 to 4 seconds and another at around 22 to 26 seconds; in the range 22 to 40 seconds, patients with RLS had values significantly higher than patients with narcolepsy. All periodicity parameters were significantly lower in the narcolepsy group. Finally, the distribution of the number of PLM per hour of sleep was bell shaped in normal controls and patients with narcolepsy, whereas patients with RLS showed a progressive decrease throughout the night. CONCLUSION Most narcoleptic patients show a high number of LMs that are significantly less periodic than those of patients with RLS. PLM are in functional interrelationship with the cyclic alternating pattern, which is reduced in patients with narcolepsy; decreased arousal fluctuations during sleep may be one of the factors influencing the reduction in periodicity of LMs during sleep in narcolepsy.
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Affiliation(s)
- Raffaele Ferri
- Sleep Research Centre, Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy.
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Tanaka S, Honda Y, Inoue Y, Honda M. Detection of autoantibodies against hypocretin, hcrtrl, and hcrtr2 in narcolepsy: anti-Hcrt system antibody in narcolepsy. Sleep 2006; 29:633-8. [PMID: 16774153 DOI: 10.1093/sleep/29.5.633] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES The impairment of hypocretin neurotransmission system is considered to play a major role in the pathophysiology of narcolepsy. It has been hypothesized that autoimmune abnormalities underlie the etiology of narcolepsy, based on the tight association with HLA-DRB1*1501/ DQB1*0602. It remains unclear if autoantibodies against hypocretin receptors (hcrtrl and hcrtr2) are involved in narcolepsy. DESIGN We have developed a novel radioligand binding assay to address this question. Sera from 181 patients with narcolepsy, 10 patients with other hypersomnias, and 91 control subjects were used. Human [35S]-Hcrt, hcrtrl, and hcrtr2 were synthesized by in vitro transcription/translation system. The immune complex of autoantibody and each [35S]-protein were immunoprecipitated and quantified using a radioligand-binding assay. RESULTS We detected autoantibodies against hypocretin in 3 patients, hcrtrl in 1 patient, and hcrtr2 in 5 patients with narcolepsy. Positive reactions were also found against hcrtrl in 2 and hcrtr2 in 1 control subjects. No relationships were found between these autoantibodies and HLA-DRB1*1501/DQB1*0602 haplotypes, presence of cataplexy, presence of subjective nocturnal sleep disruption, or the score on the Epworth Sleepiness Scale. CONCLUSIONS Although we have detected autoantibodies against the hypocretin neurotransmission system, our results do not support the hypothesis that autoantibody-mediated dysfunction in the hypocretin system underlies the pathophysiology of narcolepsy.
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Affiliation(s)
- Susumu Tanaka
- The Sleep Disorders Project, Department of Sleep Disorders Research, Tokyo Institute of Psychiatry, Setagaya-ku, Tokyo, Japan.
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140
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Reeves WC, Heim C, Maloney EM, Youngblood LS, Unger ER, Decker MJ, Jones JF, Rye DB. Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study. BMC Neurol 2006; 6:41. [PMID: 17109739 PMCID: PMC1660569 DOI: 10.1186/1471-2377-6-41] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Accepted: 11/16/2006] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS. METHODS This study recruited CFS cases and non-fatigued controls from a population based study of CFS in Wichita, Kansas. Participants spent two nights in the research unit of a local hospital and underwent overnight polysomnographic and daytime multiple sleep latency testing in order to characterize sleep architecture. RESULTS Approximately 18% of persons with CFS and 7% of asymptomatic controls were diagnosed with severe primary sleep disorders and were excluded from further analysis. These rates were not significantly different. Persons with CFS had a significantly higher mean frequency of obstructive apnea per hour (p = .003); however, the difference was not clinically meaningful. Other characteristics of sleep architecture did not differ between persons with CFS and controls. CONCLUSION Although disordered breathing during sleep may be associated with CFS, this study generally did not provide evidence that altered sleep architecture is a critical factor in CFS. Future studies should further scrutinize the relationship between subjective sleep quality relative to objective polysomnographic measures.
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Affiliation(s)
- William C Reeves
- Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA
| | - Christine Heim
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Elizabeth M Maloney
- Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA
| | - Laura Solomon Youngblood
- Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA
| | - Elizabeth R Unger
- Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA
| | - Michael J Decker
- Dept. of Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - James F Jones
- Viral Exanthems & Herpesvirus Branch, Division of Viral & Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control & Prevention, Atlanta, GA, USA
| | - David B Rye
- Dept. of Neurology, Emory University School of Medicine, Atlanta, GA, USA
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141
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Abstract
Narcolepsy is a neurological disorder that is characterized by excessive daytime sleepiness and cataplexy--a loss of muscle tone generally triggered by certain strong emotions with sudden onset. The underlying cause of most cases of human narcolepsy is a loss of neurons that produce hypocretin (Hcrt, also known as orexin). These cells normally serve to drive and synchronize the activity of monoaminergic and cholinergic cells. Sleepiness results from the reduced activity of monoaminergic, cholinergic and other cells that are normally activated by Hcrt neurons, as well as from the loss of Hcrt itself. Cataplexy is caused by an episodic loss of activity in noradrenergic cells that support muscle tone, and a linked activation of a medial medullary cell population that suppresses muscle tone. Current treatments for narcolepsy include stimulants to combat sleepiness and antidepressants to reduce cataplexy. Sodium oxybate produces both reductions in cataplexy and improved waking alertness. Future treatments are likely to include Hcrt or Hcrt agonists to reverse the underlying neurochemical deficit.
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Affiliation(s)
- Jerome M Siegel
- Brain Research Institute, University of California, Los Angeles (UCLA), and VA Greater Los Angeles Healthcare System, CA, USA.
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142
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Knudsen S, Jennum PJ. [Narcolepsy--new implications of molecular biology]. Ugeskr Laeger 2006; 168:3699-704. [PMID: 17069732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Narcolepsy is a common but underdiagnosed sleep disorder characterized by excessive daytime sleepiness and abnormal manifestations of REM sleep: cataplexy, sleep paralysis and hypnagogogic hallucinations. Sleep onset REM periods (SOREMPs) are diagnostic. Within the last five years the pathogenesis has become clearer: narcolepsy is associated with almost total absence of the neuropeptides hypocretin-1 and -2 in the hypothalamus and CSF. A low level of CSF hypocretin is now recognized as a new diagnostic tool. This review provides updated knowledge of narcolepsy.
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Affiliation(s)
- Stine Knudsen
- Amtssygehuset i Glostrup, Dansk Center for Søvnmedicin, Klinisk Neurofysiologisk Afdeling, Glostrup.
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Billiard M, Bassetti C, Dauvilliers Y, Dolenc-Groselj L, Lammers GJ, Mayer G, Pollmächer T, Reading P, Sonka K. EFNS guidelines on management of narcolepsy. Eur J Neurol 2006; 13:1035-48. [PMID: 16987156 DOI: 10.1111/j.1468-1331.2006.01473.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Management of narcolepsy with or without cataplexy relies on several classes of drugs, namely stimulants for excessive daytime sleepiness and irresistible episodes of sleep, antidepressants for cataplexy and hypnosedative drugs for disturbed nocturnal sleep. In addition, behavioral measures can be of notable value. Guidelines on the management of narcolepsy have already been published. However contemporary guidelines are necessary given the growing use of modafinil to treat excessive daytime sleepiness in Europe within the last 5-10 years, and the decreasing need for amphetamines and amphetamine-like stimulants; the extensive use of new antidepressants in the treatment of cataplexy, apart from consistent randomized placebo-controlled clinical trials; and the present re-emergence of gamma-hydroxybutyrate under the name sodium oxybate, as a treatment of all major symptoms of narcolepsy. A task force composed of the leading specialists of narcolepsy in Europe has been appointed. This task force conducted an extensive review of pharmacological and behavioral trials available in the literature. All trials were analyzed according to their class evidence. Recommendations concerning the treatment of each single symptom of narcolepsy as well as general recommendations were made. Modafinil is the first-line pharmacological treatment of excessive daytime sleepiness and irresistible episodes of sleep in association with behavioral measures. However, based on several large randomized controlled trials showing the activity of sodium oxybate, not only on cataplexy but also on excessive daytime sleepiness and irresistible episodes of sleep, there is a growing practice in the USA to use it for the later indications. Given the availability of modafinil and methylphenidate, and the forseen registration of sodium oxybate for narcolepsy (including excessive daytime sleepiness, cataplexy, disturbed nocturnal sleep) in Europe, the place of other compounds will become fairly limited. Since its recent registration cataplexy sodium oxybate has now become the first-line treatment of cataplexy. Second-line treatments are antidepressants, either tricyclics or newer antidepressants, the later being increasingly used these past years despite few or no randomized placebo-controlled clinical trials. As for disturbed nocturnal sleep the best option is still hypnotics until sodium oxybate is registered for narcolepsy. The treatments used for narcolepsy, either pharmacological or behavioral, are diverse. However the quality of the published clinical evidences supporting them varies widely and studies comparing the efficacy of different substances are lacking. Several treatments are used on an empirical basis, specially antidepressants for cataplexy, due to the fact that these medications are already used widely in depressed patients, leaving little motivation from the manufacturers to investigate efficacy in relatively rare indications. Others, in particular the more recently developed substances, such as modafinil or sodium oxybate, are evaluated in large randomized placebo-controlled trials. Our objective was to reinforce the use of those drugs evaluated in randomized placebo-controlled trials and to reach a consensus, as much as possible, on the use of other available medications.
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Affiliation(s)
- M Billiard
- School of Medicine, University of Montpellier, Montpellier, France.
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144
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Zeitzer JM, Nishino S, Mignot E. The neurobiology of hypocretins (orexins), narcolepsy and related therapeutic interventions. Trends Pharmacol Sci 2006; 27:368-74. [PMID: 16766052 DOI: 10.1016/j.tips.2006.05.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 03/09/2006] [Accepted: 05/22/2006] [Indexed: 10/24/2022]
Abstract
Narcolepsy is characterized by excessive daytime sleepiness, cataplexy and other manifestations of dissociated rapid eye movement sleep. Narcolepsy is typically treated with amphetamine-like stimulants (sleepiness) and antidepressants (cataplexy). Newer compounds, such as modafinil (non-amphetamine wake-promoting compound for excessive daytime sleepiness) and sodium oxybate (short-acting sedative for fragmented nighttime sleep, cataplexy, excessive daytime sleepiness), are increasingly used. Recent discoveries indicate that the major pathophysiology of human narcolepsy is the loss of lateral hypothalamic neurons that produce the neuropeptide hypocretin (orexin). Approximately 90% of people diagnosed as having narcolepsy with cataplexy are hypocretin ligand deficient. This has led to the development of new diagnostic tests (cerebrospinal fluid hypocretin-1 measurements). Hypocretin receptor agonists are likely to be ideal therapeutic options for hypocretin-deficient narcolepsy but such compounds are still not available in humans.
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Affiliation(s)
- Jamie M Zeitzer
- Department of Psychiatry, Stanford University, 701-B Welch Road, Palo Alto, CA 94304, USA.
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Arnulf I, Lin L, Zhang J, Russell IJ, Ripley B, Einen M, Nevsimalova S, Bassetti C, Bourgin P, Nishino S, Mignot E. CSF Versus Serum Leptin in Narcolepsy: Is There an Effect of Hypocretin Deficiency? Sleep 2006; 29:1017-24. [PMID: 16944669 DOI: 10.1093/sleep/29.8.1017] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVE To determine if hypocretin deficiency is associated with abnormally low serum leptin levels, a putative cause of increased body mass index in narcoleptics. DESIGN Cross-sectional controlled study. PARTICIPANTS Three hundred seventy subjects, including 111 healthy controls, 93 narcoleptic subjects with hypocretin deficiency (cerebrospinal fluid [CSF] hypocretin-1 levels < 110 pg/mL), 72 narcoleptic subjects with normal hypocretin levels, and 89 subjects with other sleep disorders INTERVENTION After completing the Stanford Sleepiness Inventory, participants underwent spinal taps and blood sampling for measurement of CSF leptin and hypocretin-1 levels, HLA DQB1*0602 phenotyping, and serum leptin and C-reactive protein levels. RESULTS Serum leptin levels were similar in narcoleptic subjects, whether hypocretin-deficient (13.2 +/- 1.7 ng/mL, mean +/- SEM) or not (13.0 +/- 1.8 ng/mL), controls (10.1 +/- 1.1 ng/mL) and subjects with other sleep disorders (11.5 +/- 1.6 ng/mL). Similarly, the CSF leptin levels and the CSF: serum leptin ratios (an indicator of brain leptin uptake) were not different between groups. Serum and CSF leptin levels were higher in women and in subjects with higher body mass indexes. Leptin brain uptake decreased in women, in the aged, and in more-obese subjects. In contrast with a presumed inhibitory effect of leptin on hypocretin-containing cells, CSF leptin levels tended to correlate positively with CSF hypocretin-1 levels. C-reactive protein was higher (4.2 +/- 0.9 mg/L) in narcoleptic subjects with hypocretin deficiency than in controls (1.4 +/- 0.3 mg/L, p = .0055), a difference still significant after adjustment on confounding factors. DISCUSSION Our data do not support a role for leptin in mediating increased body mass index in narcolepsy. A moderate but selective increase in C-reactive protein in hypocretin-1 deficient subjects should prompt research on inflammation in narcolepsy.
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Affiliation(s)
- Isabelle Arnulf
- Center for Narcolepsy, Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, CA, USA.
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147
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Huang YS, Tafti M, Guilleminault C. Daytime sleepiness with and without cataplexy in Chinese–Taiwanese patients. Sleep Med 2006; 7:454-7. [PMID: 16815745 DOI: 10.1016/j.sleep.2006.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 05/08/2006] [Accepted: 05/16/2006] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Investigation of Chinese-Taiwanese patients with excessive sleepiness, but no association with other sleep disorders, and with the presence or absence of cataplexy. PATIENTS AND METHODS Thirty-five patients, successively referred between 2002 and 2004, underwent polysomnography (PSG), repeat multiple sleep latency test (MSLT), and human leukocyte antigen (HLA) typing. Three patients without cataplexy also had cerebrospinal fluid (CSF) hypocretin measurements. RESULTS DQB1*0602 was associated with cataplexy in over 90% of Chinese-Taiwanese cases. Absence of cataplexy and <2 sleep-onset REM periods (SOREMPs) was seen in only two subjects, but presence of two SOREMPs did not dissociate DQB1*0602 positive and negative or cataplexy positive and negative subjects. As a group, narcoleptics with cataplexy had a higher number of SOREMPs, and the mean sleep latency was much shorter in narcoleptics with cataplexy than in the non-cataplectic patients, independent of the number of SOREMPs. CONCLUSIONS Chinese-Taiwanese patients with cataplexy present with similar HLA findings as Black and Caucasian patients, but the presence of two or more SOREMPs in Chinese-Taiwanese patients is not a sufficient diagnostic tool to identify narcolepsy. When cataplexy is not present, description of PSG nd HLA findings may be a better approach than using a label with little scientific significance, allowing for better collection of patients' phenotype.
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Affiliation(s)
- Yu-shu Huang
- Sleep Disorders Clinic, Chang-Gung University Hospital, Taipei, Taiwan, ROC
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148
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Affiliation(s)
- Hangwi Tang
- Respiratory and Sleep Services, Auckland City Hospital, Auckland, New Zealand.
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149
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Abstract
A significant proportion of patients with primary biliary cirrhosis (PBC) suffer from severe fatigue. The aim of this study was to characterize patterns of daytime sleep in patients with PBC (using both objective and subjective assessment approaches) and to study the association between sleep abnormality and fatigue severity. Fatigue severity was assessed in 48 female subjects with PBC (using a disease-specific quality of life instrument (the PBC-40) and a generic fatigue measure (Fatigue Impact Scale [FIS]) as well as 48 case-matched normal controls. All participants also completed the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS, which assesses daytime hypersomnolence). Objective sleep assessment was performed using accelerometry over 7 days. Global sleep quality assessed by the PSQI was significantly lower in the PBC group compared to controls (P < .0001). ESS scores were significantly higher in patients with PBC than controls (P = .0001), suggesting significantly greater daytime somnolence in the patients with PBC. Objective sleep assessment confirmed that subjects with PBC were sleeping on average almost twice as long as controls during the daytime. Both degree of daytime somnolence (ESS) and actual daytime sleep activity (accelerometry) correlated strongly with fatigue severity in the patient group (r2 = 0.5, P < .0001 and r2 = 0.2, P < .01, respectively). In conclusion, Sleep abnormality, in the form of excessive daytime somnolence, is present in a significant proportion of patients with PBC, with the degree of daytime somnolence correlating strongly with the degree of fatigue. Existing agents effective at reducing daytime somnolence (such as modafinil) hold potential for the treatment of fatigue in PBC.
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Affiliation(s)
- Julia L Newton
- Liver Research Group, School of Clinical Medical Sciences, University of Newcastle, Newcastle-upon-Tyne, UK
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150
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Abstract
To localize cerebral perfusion differences during cataplexy, brain SPECT subtraction was performed between cataplexy and baseline awake period or REM sleep in patients with narcolepsy. During cataplexy, subtracted SPECT showed hyperperfusion in right amygdala, bilateral cingulate gyri, basal ganglia, thalami, premotor cortices, sensorimotor cortices, right insula, and brainstem, and hypoperfusion in prefrontal cortex and occipital lobe. This result suggests that cataplexy is produced by the activation of amygdalo-cortico-basal ganglia-brainstem circuit.
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Affiliation(s)
- Seung Bong Hong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea.
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