Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) present a disordered sleep pattern and frequently undergo polysomnography to exclude a primary sleep disorder. Such studies have shown reduced sleep efficiency, a reduction of deep sleep, prolonged sleep initiation, and alpha-wave intrusion during deep sleep. Deregulation of the 2-5A synthetase/RNase L antiviral pathway and a potential acquired channelopathy are also found in a subset of CFS patients and could lead to sleep disturbances. This article compiles a large sleep study database on CFS patients and correlates these data with a limited number of immune parameters as it has been thought that RNase L could be associated with these sleep disturbances.

METHODS: Forty-eight patients who fulfilled 1994 Centers for Disease Control and Prevention criteria for CFS underwent extensive medical evaluation, routine laboratory testing, and a structured psychiatric interview. Subjects then completed a complaint checklist and a two-night polysomnographic investigation. RNase L analysis was performed by gel electrophoresis using a radiolabeled 2′,5′-oligoadenylate trimer. Basic descriptive statistical parameters were calculated.

RESULTS: Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep. The present alpha-delta intrusion correlated with anxiety; no correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L.

CONCLUSIONS: The main findings are 1) validation of sleep latency problems and other sleep disturbances as already suggested by several authors; 2) alpha-delta intrusion seems associated with anxiety; and 3) elevated RNase L did not correlate with alpha-delta sleep.

 

Source: Van Hoof E, De Becker P, Lapp C, Cluydts R, De Meirleir K. Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome. Am J Med Sci. 2007 Feb;333(2):78-84. https://www.ncbi.nlm.nih.gov/pubmed/17301585

 

Nighttime sleep and daytime functioning (sleepiness and fatigue) in less well-defined chronic rheumatic diseases with particular reference to the ‘alpha-delta NREM sleep anomaly’

Abstract:

For the past 25 years, the ‘alpha-delta NREM sleep abnormality’ has been used by some as a defining or legitimizing marker for poorly defined rheumatic diseases such as fibromyalgia and chronic fatigue syndrome. Comprehensive review of the literature reveals no support for such a conclusion. Most studies involve small numbers of patients. The lack of control subjects, non-standardized recording techniques, and confusion between tonic and phasic alpha frequency activity patterns make comparison difficult.

There is much evidence that this sleep EEG pattern is not only non-specific, but may actually reflect a sleep maintaining process. The ‘sleep fragmentation’ theory of the complaint of non-restorative sleep in this patient population is invalidated by the fact that conditions characterized by severe sleep fragmentation, such as obstructive sleep apnea, are not associated with musculoskeletal symtoms. It is difficult to attribute musculoskeletal symptoms to disorders of sleep in view of the fact that the only organ of the body known to benefit from sleep, or to be adversely affected by lack of sleep, is the brain. It is concluded that fibromyalgia and chronic fatigue syndrome are associated with subjective sleep complaints, but do not represent sleep disorders.

 

Source: Mahowald ML, Mahowald MW. Nighttime sleep and daytime functioning (sleepiness and fatigue) in less well-defined chronic rheumatic diseases with particular reference to the ‘alpha-delta NREM sleep anomaly’. Sleep Med. 2000 Jul 1;1(3):195-207. http://www.ncbi.nlm.nih.gov/pubmed/10828430

 

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

Abstract:

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.

Comment in: Sleep disorders and chronic fatigue. [South Med J. 1994]

 

Source: Manu P, Lane TJ, Matthews DA, Castriotta RJ, Watson RK, Abeles M. Alpha-delta sleep in patients with a chief complaint of chronic fatigue. South Med J. 1994 Apr;87(4):465-70. http://www.ncbi.nlm.nih.gov/pubmed/8153772