Abstract
Objective
To determine if task performance and fatiguability during repeated low-level contractions of an intrinsic hand muscle differ in a group of MS subjects compared with a control group, and what central changes accompany the development of fatigue and the period of recovery, whether these measures are related to subjective ratings of fatigue or perception of effort.
Methods
Force of index finger abduction, rating of perceived effort, and motor evoked potential amplitude and silent period duration were measured during and after a 20-min. intermittent submaximal (40%) contraction of the first dorsal interosseous muscle in 23 clinically definite MS subjects with mild-moderate symptoms, and 15 controls.
Results
Rating of perceived effort increased at a greater rate in the MS group than in control subjects during exercise, and this was associated with larger increases in both MEP amplitude and silent period duration.
Conclusions
Submaximal fatiguing exercise is associated with an enhanced central motor drive and increased perception of effort in MS.
Significance
MS subjects can increase central drive during fatiguing exercise to a greater degree than controls, but this is associated with greater perceived exertion. These factors may underlie the more general complaint of fatigue experienced by people with MS.
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References
Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J (1961) An inventory for measuring depression. Arch Gen Psychiatry 4:561–571
Bigland-Ritchie B, Rice CL, Garland SJ, Walsh ML (1995) Task-dependent factors in fatigue of human voluntary contractions. Adv Expl Med Biol 384:361–380
Boniface SJ, Mills KR, Schubert M (1991) Responses of single spinal motoneurons to magnetic brain stimulation in healthy subjects and patients with multiple sclerosis. Brain 114:643–662
Borg GA (1982) Psychophysical bases of perceived exertion. Med Sci Sports Exerc 14:377–381
Bostock H, Grafe P (1985) Activity-dependent excitability changes in normal and demyelinated rat spinal root axons. J Physiol 365:239–257
Fisk JD, Pontefract A, Ritvo PG, Archibald CJ, Murray TJ (1994) The impact of fatigue on patients with multiple sclerosis. Can J Neurol Sci 21:9–14
Freal JE, Kraft GH, Coryell JK (1984) Symptomatic fatigue in multiple sclerosis. Arch Phys Med Rehab 65:135–138
Krupp LB, LaRocca NG, Muir-Nash J, Steinberg AD (1989) The fatigue severity scale. Application to patients with multiple sclerosis and systemic lupus erythematosus. Arch Neurol 46:1121–1123
McDonald WI, Sears TA (1970) The effects of experimental demyelination on conduction in the central nervous system. Brain 93:583–598
Murray TJ (1985) Amantadine therapy for fatigue in multiple sclerosis. Can J Neurol Sci 12:251–254
Ng AV, Miller RG, Gelinas D, Kent-Braun JA (2004) Functional relationships of central and peripheral muscle alterations in multiple sclerosis. Muscle Nerve 29:843–852
Nielsen JF, Norgaard P (2002) Increased post-exercise facilitation of motor evoked potentials in multiple sclerosis. Clin Neurophysiol 113:1295–1300
Perretti A, Balbi P, Orefice G, Trojano L, Marcantonio L, Brescia-Morra V, Ascione S, Manganelli F, Conte G, Santoro L (2004) Post-exercise facilitation and depression of motor evoked potentials to transcranial magnetic stimulation: a study in multiple sclerosis. Clin Neurophysiol 115:2128–2133
Piper BF (1989) Fatigue: current bases for practice. Springer New York
Ponichtera-Mulcare JA (1993) Exercise and multiple sclerosis. Med Sci Sports Exerc 25:451–465
Rice CL, Vollmer TL, Bigland-Ritchie B (1992) Neuromuscular responses of patients with multiple sclerosis. Muscle Nerve 15:1123–1132
Sacco P, Newberry R, McFadden L, Brown T, McComas AJ (1997) Depression of human electromyographic activity by fatigue of a synergistic muscle. Muscle Nerve 20:710–717
Sacco P, Thickbroom GW, Byrnes ML, Mastaglia FL (2000) Changes in corticomotor excitability after fatiguing muscle contractions. Muscle and Nerve 23:1840–1846
Sheean GL, Murray NM, Rothwell JC, Miller DH, Thompson AJ (1997) An electrophysiological study of the mechanism of fatigue in multiple sclerosis. Brain 120(Pt 2):299–315
Taylor JL, Butler JE, Allen GM, Gandevia SC (1996) Changes in motor cortical excitability during human muscle fatigue. J Physiol 490:519–528
Thickbroom GW, Byrnes ML, Archer SA, Kermode AFLM (2005) Corticomotor organisation and motor function in multiple sclerosis. J Neurol 252:765–771
Acknowledgement
This study was generously supported by the National Multiple Sclerosis Society of Australia.
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Thickbroom, G.W., Sacco, P., Kermode, A.G. et al. Central motor drive and perception of effort during fatigue in multiple sclerosis. J Neurol 253, 1048–1053 (2006). https://doi.org/10.1007/s00415-006-0159-2
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DOI: https://doi.org/10.1007/s00415-006-0159-2