In a message dated 10/8/04 7:01:13 PM, DSNurse@... writes:

<< Altered central nervous system signal during motor performance in chronic
fatigue syndrome.

Journal: Clin Neurophysiol. 2004 Oct;115(10):2372-81.

Authors: Siemionow V, Fang Y, Calabrese L, Sahgal V, Yue GH.

Affiliation: Department of Biomedical Engineering, The Lerner Research
Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue,
Cleveland, OH 44195, USA.

NLM Citation: PMID: 15351380


Objective: The purpose of this study was to determine whether brain
activity of chronic fatigue syndrome (CFS) patients during voluntary
motor actions differs from that of healthy individuals.

Methods: Eight CFS patients and 8 age- and gender-matched healthy
volunteers performed isometric handgrip contractions at 50% maximal
voluntary contraction level. They first performed 50 contractions with a
10 s rest between adjacent trials-'Non-Fatigue' (NFT) task. Subsequently,
the same number of contractions was performed with only a 5 s rest
between trials-'Fatigue' (FT) task. Fifty-eight channels of surface EEG
were recorded simultaneously from the scalp. Spectrum analysis was
performed to estimate power of EEG frequency in different tasks. Motor
activity-related cortical potential (MRCP) was derived by triggered
averaging of EEG signals associated with the muscle contractions.

Results: Major findings include: (i) Motor performance of the CFS
patients was poorer than the controls. (ii) Relative power of EEG theta
frequency band (4-8 Hz) during performing the NFT and FT tasks was
significantly greater in the CFS than control group [Formula: see text]
(iii) The amplitude of MRCP negative potential (NP) for the combined NFT
and FT tasks was higher in the CFS than control group [Formula: see text]
(iv) Within the CFS group, the NP was greater for the FT than NFT task
[Formula: see text] whereas no such difference between the two tasks was
found in the control group.

Conclusions: These results clearly show that CFS involves altered central
nervous system signals in controlling voluntary muscle activities,
especially when the activities induce fatigue.

Significance: Physical activity-induced EEG signal changes may serve as
physiological markers for more objective diagnosis of CFS. >>