Item request has been placed! ×
Item request cannot be made. ×
loading  Processing Request

People with multiple sclerosis have reduced TMS-evoked motor cortical output compared with healthy individuals during fatiguing submaximal contractions

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
  • معلومة اضافية
    • بيانات النشر:
      American Physiological Society
    • الموضوع:
      2022
    • Collection:
      Griffith University: Griffith Research Online
    • نبذة مختصرة :
      People with multiple sclerosis (PwMS) typically experience greater levels of exercise-induced fatigue compared with healthy individuals. Therefore, this study examined performance fatigability in PwMS when executing a prolonged submaximal contraction. Nine PwMS (38 ±7 yr, 6 females) and nine healthy controls (35 ±6 yr, 4 females) performed an elbow flexion at 15% maximal voluntary contraction (MVC) for 26 min. MVCs were performed every 2 min during, and following, the contraction to determine if maximal force was impaired by the low-intensity contraction. Single-pulse transcranial magnetic stimulation (TMS) was delivered to the primary motor cortex with a circular coil during each MVC and during the submaximal contraction. Superimposed and resting twitches were calculated from elbow flexion torque, whereas motor-evoked potentials were calculated from biceps brachii electromyography. Ratings of perceived exertion (RPE) were obtained before each MVC. During the fatiguing contraction protocol, the MS group exhibited a reduced MVC torque compared with the healthy control group (P = 0.044), which aligned with group differences in biceps brachii EMG activity (P = 0.022) and superimposed twitch amplitude (P = 0.016). Fatigue-related decrements in MVC torque (P = 0.044) and biceps brachii EMG activity (P = 0.043) demonstrated in the MS group persisted throughout recovery. However, MS did not affect the RPE during the fatigue task. These findings suggest that PwMS may have greater levels of performance fatigability due to decreased voluntary drive from the motor cortex, which is not associated with greater ratings of perceived exertion. ; Full Text
    • ISSN:
      0022-3077
    • Relation:
      Journal of Neurophysiology; Brotherton, EJ; Sabapathy, S; Mckeown, DJ; Kavanagh, JJ, People with multiple sclerosis have reduced TMS-evoked motor cortical output compared with healthy individuals during fatiguing submaximal contractions, Journal of Neurophysiology, 2022, 128 (1), pp. 105-117; http://hdl.handle.net/10072/420552
    • الرقم المعرف:
      10.1152/jn.00514.2021
    • Rights:
      © 2022 American Physiological Society. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal website for access to the definitive, published version. ; open access
    • الرقم المعرف:
      edsbas.C5ADD8