MacFarlane, J G, Shahal, B, Mously, C et al. · Sleep · 1996 · DOI
This study examined a specific brain wave pattern during sleep called K-alpha activity and compared it to periodic leg movements during sleep. Researchers found that patients with K-alpha activity were predominantly women, younger, and more likely to have fibromyalgia and chronic fatigue syndrome, while also experiencing unrefreshing sleep, stomach problems, and muscle pain.
This study identifies K-alpha sleep activity as a distinct polysomnographic finding associated with ME/CFS and fibromyalgia, potentially representing a physiological marker of unrefreshing sleep in these conditions. Understanding sleep architecture abnormalities may help explain the persistent fatigue and contribute to better diagnostic approaches and treatment strategies for ME/CFS patients.
This study does not establish whether K-alpha activity causes unrefreshing sleep or ME/CFS symptoms, nor does it prove that all ME/CFS patients exhibit this pattern. The cross-sectional design cannot determine whether K-alpha is a consequence of ME/CFS or a contributing factor, and the small sample size limits generalizability to the broader ME/CFS population.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
MacFarlane, J G, Shahal, B, Mously, C, & Moldofsky, H (1996). Periodic K-alpha sleep EEG activity and periodic limb movements during sleep: comparisons of clinical features and sleep parameters.. Sleep. https://doi.org/10.1093/sleep/19.3.200
BibTeX
@article{mecfsatlas-macfarlane-1996-periodic-alpha,
author = {MacFarlane, J G and Shahal, B and Mously, C and Moldofsky, H},
title = {Periodic K-alpha sleep EEG activity and periodic limb movements during sleep: comparisons of clinical features and sleep parameters.},
journal = {Sleep},
year = {1996},
doi = {10.1093/sleep/19.3.200},
note = {PubMed: 8723376},
url = {https://www.mecfsatlas.com/evidence/macfarlane-1996-periodic-alpha},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/macfarlane-1996-periodic-alpha
Contribute
Private, reviewed by a human. Not a public comment thread.