Alpha-delta Sleep Research Articles

Le sommeil du fibromyalgique : revue des données cliniques et polygraphiques

Fibromyalgia syndrome is a common chronic pain syndrome that is often associated with sleep disturbances characterized by subjective experience of non-restorative sleep. The complaints of sleep disturbances are correlated with polysomnographic features showing clear abnormalities in the continuity of sleep as well as in the sleep architecture. Sleep-recording abnormalities are characterized by a reduced sleep efficiency with increased number of awakenings, a reduced amount of slow wave sleep and an abnormal alpha wave intrusion in non rapid eye movement, termed alpha-delta sleep. These data were confirmed by spectral analysis of sleep showing an increased EEG power density in the higher frequency band and a reduced EEG power density in the lower frequency bands. Moreover, other microstructural aspects of sleep were modified with high frequency of arousals and alpha-K complex reported, both indicators of fragmented sleep. The fibromyalgia symptoms may relate to a non-restorative sleep disorder associated with the alpha-EEG sleep anomalies. However, alpha-EEG sleep anomaly is non-specific for fibrositis, also seen in normal controls during stage 4 sleep deprivation. Moreover, fibromyalgia patients may also experience primary sleep disorder such as sleep apnea or periodic leg movements. The etiology of this common condition is incompletely understood and the existence of a specific entity of fibromyalgia is still a matter of debate. However, several studies have found abnormal brain metabolism of substances such as serotonin implicated in sleep arousal and pain mechanisms and administration of tricyclic antidepressants and selective serotonin reuptake inhibitors may be useful in fibromyalgia. Pain, poor sleep quality and anxiety may contribute to the clinical picture. Several factors such as psychological, environmental, genetic factor, altered serotonin metabolism and altered sleep physiology are involved in the pathogenesis of fibromyalgia.

Sleep in Fibromyalgia Patients: Subjective and Objective Findings

Fibromyalgia (FM) patients report early morning awakenings, awakening feeling tired or unrefreshed, insomnia, as well as mood and cognitive disturbances; they may also experience primary sleep disorders including sleep apnea. Longitudinal studies have demonstrated the chronic nature of these disturbances in patients with FM. A distinct relationship exists between poor sleep quality and pain intensity. Polysomnographic findings during sleep in these patients include an alpha frequency rhythm, termed alpha-delta sleep anomaly, which is also seen in normal controls during stage 4 sleep deprivation; deep pain induced during sleep in normal controls also causes this anomaly. Sleep architecture is altered in FM patients showing an increase in stage 1, a reduction in delta sleep, and an increased number of arousals. Before prescribing pharmacologic compounds aimed at modifying sleep, adequate pain control and sleep habits should be achieved; tricyclic antidepressants, trazadone, zopiclone, and selective serotonin reuptake inhibitors, however, may be required. More research is needed to elucidate the cellular and molecular mechanisms involved in the sleep disturbances occurring in patients with FM.

Sleep in fibromyalgia patients: subjective and objective findings.

Fibromyalgia (FM) patients report early morning awakenings, awakening feeling tired or unrefreshed, insomnia, as well as mood and cognitive disturbances; they may also experience primary sleep disorders including sleep apnea. Longitudinal studies have demonstrated the chronic nature of these disturbances in patients with FM. A distinct relationship exists between poor sleep quality and pain intensity. Polysomnographic findings during sleep in these patients include an alpha frequency rhythm, termed alpha-delta sleep anomaly, which is also seen in normal controls during stage 4 sleep deprivation; deep pain induced during sleep in normal controls also causes this anomaly. Sleep architecture is altered in FM patients showing an increase in stage 1, a reduction in delta sleep, and an increased number of arousals. Before prescribing pharmacologic compounds aimed at modifying sleep, adequate pain control and sleep habits should be achieved; tricyclic antidepressants, trazadone, zopiclone, and selective serotonin reuptake inhibitors, however, may be required. More research is needed to elucidate the cellular and molecular mechanisms involved in the sleep disturbances occurring in patients with FM.

Alpha-delta sleep in patients with a chief complaint of chronic fatigue.

Our prospective, standardized cohort study was designed to assess the presence of alpha wave intrusions during non-rapid eye movement sleep (alpha-delta sleep) and its relationship to fibromyalgia, major depression, and chronic fatigue syndrome (CFS) in patients with a chief complaint of chronic fatigue. The study group comprised 30 consecutive patients seen at a university hospital referral clinic for evaluation of chronic fatigue. All patients had nocturnal polysomnography, dolorimetric tender point assessment for fibromyalgia, a comprehensive history, physical, and laboratory evaluation, and a structured psychiatric interview. Alpha-delta sleep was identified in 8 of the 30 patients (26%), major depression in 20 (67%), CFS in 15 (50%), and fibromyalgia in 4 (13%). Ten of the 30 patients (33%) had a primary sleep disorder (sleep apnea, periodic limb movements, or narcolepsy). Alpha-delta sleep was not significantly correlated with fibromyalgia, CFS, major depression, or primary sleep disorders, but was significantly more common among patients who had chronic fatigue without major depression. We conclude that primary sleep disorders are relatively common among patients with chronic fatigue and must be diligently sought and treated. Alpha-delta sleep is not a marker of fibromyalgia or CFS, but may contribute to the illness of nondepressed patients with these conditions.

Polysomnography in idiopathic muscle pain syndrome (fibrositis)

Muscle pain occurs in various neuromuscular disorders with characteristic physiological or biochemical abnormalities. There is, however, a group of patients in whom there is no clear physiological or structural basis for their pains. This syndrome has been called fibrositis or fibromyalgia. Sleep abnormalities have been reported in some of these patients, but have not been confirmed by others. We studied 8 patients with this disorder and found sleep abnormalities that were characterized by nocturnal myoclonus, alpha-delta sleep, and abnormalities compatible with depression. Polysomnography was, therefore, instrumental in helping direct the treatment of these patients. Therapeutic approaches aimed to correct the specific disorders were effective in improving the pain symptoms.

Sleeping with and Without Norepinephrine: Effects of Metoclopramide and D,L-Threo-3,4-Dihydroxyphenylserine on Sleep in Dopamine Beta-Hydroxylase Deficiency

Sleep characteristics are presented for two female patients (aged 21 and 31 years) with central and peripheral dopamine beta-hydroxylase (DBH) deficiency. This deficiency results in the absence of norepinephrine, epinephrine, and their metabolites in plasma, urine, and cerebrospinal fluid, while concentrations of dopamine are increased. The sleep pattern of these patients was studied when they were untreated, after blockade of central dopamine receptors with metoclopramide, and after restoring norepinephrine production with D,L-threo-3,4-dihydroxyphenylserine (DOPS). When the patients were untreated sleep duration was normal, with tendencies of a decreased amount of rapid eye movement (REM) sleep, presence of alpha-delta sleep, and an increased amount of slow-wave sleep. The amount of REM sleep varied between 18 and 21% of sleep period time. Administration of metoclopramide resulted in a slight reduction of REM sleep to 16-17%, whereas wakefulness after sleep onset increased. During treatment with DOPS, an increase in the amount of REM sleep was observed in both patients to an average amount of 27%. These data indicate that in patients with DBH deficiency norepinephrine is not essential for the development of a normal sleep/wake pattern but may have a facilitatory role in the generation of REM sleep.

Unusual EEG Patterns

Some of the unusual patterns that can be encountered on the EEG are described briefly. The patterns are grouped according to the predominant frequencies involved and/or by distinctive morphology or distribution. Those involving predominantly the alpha frequency range are alpha squeak, retained alpha, alpha-delta sleep, unilateral decrease in reactivity of alpha activity, and extreme spindles. The patterns involving the beta frequency range are the fast alpha variant, posterior temporal fast activity in children, the fast spiky spindle variant, central fast activity, and diffuse paroxysmal or continuous fast activity. The patterns of predominant theta frequencies are the slow alpha variant, frontal arousal rhythm, rhythmic temporal theta activity of drowsiness, midline theta rhythms, and focal parietal theta activity. Activity in the delta range includes the transient rhythmic slowing occurring after eye closure and the more continuous posterior rhythmic slowing. Patterns with a distinct morphology or distribution include the breach rhythm, wicket spikes, zeta waves, periodic frontal sharp complexes, subclinical rhythmic electrographic discharge of adults, and the EEG pattern of holoprosencephaly.

Sleep patterns in congenital dopamine beta-hydroxylase deficiency

Sleep patterns of two young female patients with congenital dopamine beta-hydroxylase deficiency are described. In this orthostatic syndrome central and peripheral noradrenergic failure occurs as a result of impaired beta-hydroxylation of dopamine. Consequently, the levels of dopamine and its metabolites are elevated. The relative importance of noradrenaline deficit in the face of dopamine excess for sleep-regulatory mechanisms can be inferred from the sleep pattern of these patients. No subjective sleep complaints were reported. The sleep patterns showed a high percentage of slow-wave sleep in both patients (29% and 34% of sleep period time) and a relatively low to normal percentage of REM sleep (18% and 21%). A normal cyclic REM sleep pattern was observed. Alpha-delta sleep occurred during light sleep (15% and 8%); consequently, the amount of stage 2 sleep was reduced. These results indicate that functional insufficiency of the noradrenergic system in two patients with dopamine beta-hydroxylase deficiency is not associated with profound changes in the (REM) sleep pattern. This supports a modulatory or permissive role for noradrenaline in REM sleep mechanisms.

Sleep fragmentation in rheumatoid arthritis

Fatigue is commonly reported by patients with rheumatoid arthritis (RA), and it is frequently used to evaluate disease activity and response to therapy. We theorized that the feeling of fatigue in patients with RA may be a manifestation of disturbance of sleep. Sixteen patients with chronic, active RA, who were selected for early onset of fatigue (less than 6 hours after morning awakening), were extensively evaluated by formal all-night polysomnographic recording and multiple sleep latency testing (MSLT). Although no sleep deprivation was found, all patients had some type of marked disturbances of sleep, including unanticipated sleep apnea (2 patients), frequent movement of extremities (all 16 patients), and frequent arousal (all 16 patients). The alpha-delta sleep pattern was present in 13 patients, and 7 were found by MSLT to be hypersomnolent. None of the patients accurately recognized the degree of their sleep disruption. Our findings from the MSLT indicate that fatigue in patients with RA may be a manifestation of sleep fragmentation, rather than a nonspecific constitutional symptom.

Musculosketal Symptoms and Non-REM Sleep Disturbance in Patients with “Fibrositis Syndrome” and Healthy Subjects

In sleep studies of (a) patients with the "fibrositis syndrome" and (b) healthy subjects undergoing stage 4 sleep deprivation, we observed in both groups the anomalous presence of alpha-rhythms in the non-rapid-eye-movement (NREM) sleep EEG. This phenomenon has been termed alpha-delta sleep. In the healthy subjects stage 4 deprivation was accompanied by the temporary appearance of muscoloskeletal and mood symptoms comparable to the symptoms seen chronically in the patients. It is suggested that the external arousing stimulus, which induced alpha-delta sleep in the subjects, is paralleled in the patients by an internal arousing mechanism. Such a mechanism, acting in competition with the NREM sleep system, would impair the presumed restorative function of NREM sleep and lead to the development of symptoms. It is proposed that the "fibrositis" symptom complex be considered a "non-restorative sleep syndrome". Evidence froms presented in support of the hypothesis that a disorder of serotonin metabolism serves as a basis for both the EEG sleep disturbance and the symptoms.

Alpha-delta sleep

Alpha-delta sleep is an EEG defined sleep stage which consists of 5–20% delta waves mixed with large amplitude alpha waves. It appears to replace delta sleep in some patients with chronic, somatic malaise and fatigue. Etiology is currently unknown, but it appears that alpha-delta sleep involves some (metabolic?) brain dysfunction.