Abstract WP58: Corticomotor Input Integrity To The Dorsi-plantarflexors And Motor Control In Chronic Stroke
| Autor: | Trenley Anderson, Jessica McCabe, Margaret Skelly, Ahlam Salameh, Terri Hisel, Svetlana Pundik |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Stroke. 54 |
| ISSN: | 1524-4628 0039-2499 |
| DOI: | 10.1161/str.54.suppl_1.wp58 |
| Popis: | Objective: To improve recovery of gait after stroke, we need to attain better understanding of lower extremity motor control. Transcranial magnetic stimulation (TMS) allows for evaluation of corticomotor input (CMI) integrity. Our objective was to explore the relationship between CMI to the dorsi-/plantarflexors and measures of motor impairment and gait speed. Methods: Fugl-Meyer for Lower Extremity (FM), gait speed and TMS Motor Evoked Potentials (MEP) were collected for 27 ambulatory chronic stroke survivors. Maximum MEPs (MEP max ) were collected for paretic and non-paretic tibialis anterior (TA) and lateral gastrocnemius muscles (Gastroc) using a cone-shaped TMS coil targeting primary motor cortices. We collected MEPs while seated participants activated their tested muscles to 20% of maximum effort. MEPs were normalized by the maximum compound muscle action potentials obtained by stimulation of the peripheral motor nerves. Symmetry of the corticospinal motor output was calculated as ratio of the normalized paretic and non-paretic MEP max . Analysis included descriptive statistics, paired t-test and Pearson correlation. Non-normally distributed data was log-transformed. Results: Study participants were 65.7±7.5 years old, 5.3±4.4 years after stroke and 81% male. Their mean±SD FM was 24.6±3.7 and gait speed was 0.74±0.38 m/s. For both TA and Gastroc, paretic MEP max were significantly smaller than non-paretic (p=3.8e -18 ). For Gastroc, higher ratio of paretic/non-paretic MEP max correlated with lesser impairment measured with FM (r=0.42, p=0.027). For TA, the correlation was lower and did not reach statistical significance (r=0.33, p=0.088). Gait speed did not have a significant correlation with MEP max . FM moderately correlated with gait speed (r=0.44, p=0.02). Conclusion: Gastroc MEP might be a better biomarker of motor impairment than TA. Thus, CMI to TA and Gastroc may provide different information in elucidating the mechanism of lower limb motor control. Gait speed does not correlate with CMI for dorsi-/plantarflexors which suggests that motor control of ambulation (gait speed) may differ from that of isolated joint movement (FM). |
| Databáze: | OpenAIRE |
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