TY - JOUR
T1 - Chronic fatigue syndrome
T2 - Abnormally fast muscle fiber conduction in the membranes of motor units at low static force load
AU - Klaver-Krol, E. G.
AU - Hermens, H. J.
AU - Vermeulen, R. C.
AU - Klaver, M. M.
AU - Luyten, H.
AU - Henriquez, N. R.
AU - Zwarts, M. J.
N1 - Publisher Copyright:
© 2021
PY - 2021/4
Y1 - 2021/4
N2 - Objective: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of – especially muscular –fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities. Methods: Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured. Results: The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed. Conclusion: Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance. Significance: These findings help to detangle the underlying mechanisms of CFS.
AB - Objective: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of – especially muscular –fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities. Methods: Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured. Results: The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed. Conclusion: Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance. Significance: These findings help to detangle the underlying mechanisms of CFS.
KW - 2022 OA procedure
KW - Force generation
KW - Muscle fiber conduction velocity
KW - Muscle membrane dysfunction
KW - Surface electromyography
KW - Chronic fatigue syndrome
UR - http://www.scopus.com/inward/record.url?scp=85101357529&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2020.11.043
DO - 10.1016/j.clinph.2020.11.043
M3 - Article
C2 - 33639451
AN - SCOPUS:85101357529
SN - 1388-2457
VL - 132
SP - 967
EP - 974
JO - Clinical neurophysiology
JF - Clinical neurophysiology
IS - 4
ER -