Objectives: In healthy subjects, fatiguing exercises induce a period of post-exercise corticomotor depression (PECD) that is absent in Parkinson's disease (PD). Our objective is to determine the time-course of corticomotor excitability changes following a 10-s repetitive index finger flexion-extension task performed at maximal voluntary rate (MVR) and a slower sustainable rate (MSR) in PD patients OFF and ON levodopa.
Methods: In 11 PD patients and 10 healthy age-matched controls, motor evoked potentials (MEPs) were recorded from the extensor indicis proprius (EIP) and first dorsal interosseous (FDI) muscles of the dominant arm immediately after the two tasks and at 2-min intervals for 10 min.
Results: In the OFF condition the PECD was absent in the two test muscles after both the MVR and MSR tasks. In the ON condition finger movement kinematics improved and a period of PECD comparable to that in controls was present after both tasks.
Conclusion: The absence of PECD in PD subjects off medication indicates a persisting increase in corticomotor excitability after non-fatiguing repetitive finger movement that is reversed by levodopa.
Significance: Dopamine depletion is associated with impaired modulation of corticomotor excitability after non-fatiguing repetitive finger movement.
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http://dx.doi.org/10.1016/j.clinph.2013.09.004 | DOI Listing |
Mov Disord
December 2024
School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.
Background: Reduced step length is a hallmark of gait disturbance in people with Parkinson's disease (PD). Although treadmill training is effective for improving step length, the associated neural mechanisms have not been fully investigated. Moreover, exploring the baseline neurophysiological predictors for step length improvement after training could facilitate personalized gait rehabilitation for PD.
View Article and Find Full Text PDFbioRxiv
November 2024
Department of Psychiatry and Behavioral Sciences, Stanford University Medical Center, 401 Quarry Road, Stanford, CA, 94305, USA.
Transcranial magnetic stimulation (TMS) applied to the motor cortex has revolutionized the study of motor physiology in humans. Despite this, TMS-evoked electrophysiological responses show significant variability, due in part to inconsistencies between TMS pulse timing and ongoing brain oscillations. Variable responses to TMS limit mechanistic insights and clinical efficacy, necessitating the development of methods to precisely coordinate the timing of TMS pulses to the phase of relevant oscillatory activity.
View Article and Find Full Text PDFPain
December 2024
The Gray Centre for Mobility and Activity, Parkwood Institute, St. Joseph's Healthcare, London, Canada.
Repetitive transcranial magnetic stimulation (rTMS) has shown promise as an intervention for pain. An unexplored research question is whether the delivery of rTMS prior to pain onset might protect against a future episode of prolonged pain. The present study aimed to determine whether (1) 5 consecutive days of rTMS delivered prior to experimentally induced prolonged jaw pain has a prophylactic effect on future pain intensity and (2) whether these effects were accompanied by increases in corticomotor excitability (CME) and/or sensorimotor peak alpha frequency (PAF).
View Article and Find Full Text PDFInt J Yoga
September 2024
Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
Fibromyalgia is an idiopathic chronic widespread pain syndrome marked with specified tender points. There is no permanent cure of the disease. A 50-year-old man and his 49-year-old wife suffered from widespread pain, morning stiffness, sleep problems, and fatigue with complaints of brain fogging and forgetfulness from the past 13 and 26 years, respectively.
View Article and Find Full Text PDFmedRxiv
November 2024
Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, USA.
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