Browsing by Subject "Motor control"

Now showing 1 - 4 of 4
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    Correction to: Test-Retest Reliability and Interpretation of Common Concussion Assessment Tools: Findings from the NCAA-DoD CARE Consortium
    (Springer, 2018-07) Broglio, Steven P.; Katz, Barry P.; Zhao, Shi; McCrea, Michael; McAllister, Thomas; CARE Consortium Investigators; Biostatistics, School of Public Health
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    Nociceptive Influence on Cortical Output within Proximal-Distal Muscles in the Upper-Limb
    (Elsevier, 2021) Eckert, Nathanial R.; Greenwell, Davin; Poston, Brach; Riley, Zachary A.; Exercise & Kinesiology, School of Health and Human Sciences
    A single pulse of high intensity electrical current delivered to the digits of the hand during voluntary contractions produces a period of decreased electromyographic (EMG) activity, known as a cutaneous silent period (CSP) (Caccia G and Violini A, 1973; Inghilleri M et al., 1997). Pairing transcranial magnetic stimulation (TMS) with digit stimulation results in motor evoked potentials (MEPs) with reduced amplitudes in thenar muscle (Kofler, 2008). It is not known if similar behavior can be observed in more proximal upper-limb muscles. The current study investigated the CSP on several muscles throughout the upper-limb. 14 subjects performed isometric contractions with the following muscles: abductor pollicis brevis (APB), flexor carpi radialis (FCR), extensor carpi radialis (ECR), biceps brachii (BIC), triceps brachii (TRI), anterior deltoid (AD), and posterior deltoid (PD). During the isometric contractions, subjects experienced three different stimulation conditions: electrical stimulation (10x perceptual threshold) of digit II only (CSP), transcranial magnetic stimulation only (TMS), and digit II stimulation plus TMS (TMS+). The TMS evoked MEP was significantly greater than TMS+ MEP for APB ( p <0.001), FCR ( p =0.006), and BIC ( p <0.049) muscles. The opposite relationship was seen within the PD ( p <0.047) muscle. An ANOVA test of normalized MEP values (TMS+/TMS) showed significant differences in APB vs TRI ( p = 0.004) and PD ( p = 0.003), and in FCR vs TRI ( p = 0.046) and PD ( p = 0.037) muscles. The results suggest that the CSP modulates descending drive differentially across upper-limb muscles.
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    Test-Retest Reliability and Interpretation of Common Concussion Assessment Tools: Findings from the NCAA-DoD CARE Consortium
    (Springer, 2018-05) Broglio, Steven P.; Katz, Barry P.; Zhao, Shi; McCrea, Michael; McAllister, Thomas; CARE Consortium Investigators; Biostatistics, School of Public Health
    BACKGROUND: Concussion diagnosis is typically made through clinical examination and supported by performance on clinical assessment tools. Performance on commonly implemented and emerging assessment tools is known to vary between administrations, in the absence of concussion. OBJECTIVE: To evaluate the test-retest reliability of commonly implemented and emerging concussion assessment tools across a large nationally representative sample of student-athletes. METHODS: Participants (n = 4874) from the Concussion Assessment, Research, and Education Consortium completed annual baseline assessments on two or three occasions. Each assessment included measures of self-reported concussion symptoms, motor control, brief and extended neurocognitive function, reaction time, oculomotor/oculovestibular function, and quality of life. Consistency between years 1 and 2 and 1 and 3 were estimated using intraclass correlation coefficients or Kappa and effect sizes (Cohen's d). Clinical interpretation guidelines were also generated using confidence intervals to account for non-normally distributed data. RESULTS: Reliability for the self-reported concussion symptoms, motor control, and brief and extended neurocognitive assessments from year 1 to 2 ranged from 0.30 to 0.72 while effect sizes ranged from 0.01 to 0.28 (i.e., small). The reliability for these same measures ranged from 0.34 to 0.66 for the year 1-3 interval with effect sizes ranging from 0.05 to 0.42 (i.e., small to less than medium). The year 1-2 reliability for the reaction time, oculomotor/oculovestibular function, and quality-of-life measures ranged from 0.28 to 0.74 with effect sizes from 0.01 to 0.38 (i.e., small to less than medium effects). CONCLUSIONS: This investigation noted less than optimal reliability for most common and emerging concussion assessment tools. Despite this finding, their use is still necessitated by the absence of a gold standard diagnostic measure, with the ultimate goal of developing more refined and sound tools for clinical use. Clinical interpretation guidelines are provided for the clinician to apply with a degree of certainty in application.
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    White matter microstructure relates to motor outcomes in myotonic dystrophy type 1 independently of disease duration and genetic burden
    (Springer Nature, 2021-03-01) Koscik, Timothy R.; van der Plas, Ellen; Gutmann, Laurie; Cumming, Sarah A.; Monckton, Darren G.; Magnotta, Vincent; Shields, Richard K.; Nopoulos, Peggy C.; Neurology, School of Medicine
    Deficits in white matter (WM) integrity and motor symptoms are among the most robust and reproducible features of myotonic dystrophy type 1 (DM1). In the present study, we investigate whether WM integrity, obtained from diffusion-weighted MRI, corresponds to quantifiable motor outcomes (e.g., fine motor skills and grip strength) and patient-reported, subjective motor deficits. Critically, we explore these relationships in the context of other potentially causative variables, including: disease duration, elapsed time since motor symptom onset; and genetic burden, the number of excessive CTG repeats causing DM1. We found that fractional anisotropy (a measure of WM integrity) throughout the cerebrum was the strongest predictor of grip strength independently of disease duration and genetic burden, while radial diffusivity predicted fine motor skill (peg board performance). Axial diffusivity did not predict motor outcomes. Our results are consistent with the notion that systemic degradation of WM in DM1 mediates the relationship between DM1 progression and genetic burden with motor outcomes of the disease. Our results suggest that tracking changes in WM integrity over time may be a valuable biomarker for tracking therapeutic interventions, such as future gene therapies, for DM1.