Dynamic Spasticity and Its Relationship with Correlative Factors and Cortico-muscular Processing during Sit-to-stand and Stand-to-sit Tasks among Stroke Survivors
| Autor: | Yi-Ling Kuo, 郭宜怜 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Background: Spasticity is one of the features of upper motor neuron syndrome, which is characterized by a velocity-dependent response in the tonic stretch reflex. The abnormal movements of patients with stroke may result from impaired abilities associated with cortico-muscular processing and sensorimotor integration, which are related to abnormal spinal reflex conductivity. Since spasticity changes during movement, “dynamic spasticity” is a key factor that needs to be analyzed when the patients are moving. Both sit-to-stand (SitTS) and stand-to-sit (StandTS) are important tasks in our daily lives. Some evidence has revealed that several attributing factors of these two tasks, such as balance and muscle strength, are influenced by spasticity among patients with stroke. Therefore, dynamic spasticity may correlate with balance ability and muscle strength during movements. Moreover, the relationship between dynamic spasticity and task performance as well as cortico-muscular processing, remain unknown. Purposes: (1) To examine the correlation between lower extremity dynamic spasticity and muscle strength, balance as well as task performance during SitTS and StandTS tasks among stroke survivors. (2) To examine the correlation between lower extremity dynamic spasticity and cortico-muscular coherence as well as latency while the patients perform these two tasks. Methods: Twenty-five patients with first-onset stroke were recruited. When each subject performed these two tasks, the muscle activation of the affected gastrocnemius and rectus femoris was collected by electromyography (EMG) and the muscle lengthening velocity was collected by electronic goniometers. The EMG and muscle lengthening velocity were combined for calculating the composite spasticity indices of the lower extremities. The electroencephalography (EEG) collected the cortical activity signals of the motor-related cortices, which were combined with the EMG signals to analyze the cortico-muscular processing ability, namely coherence and latency. Muscle strength was assessed by the lower extremity part of Motricity index (MI-LE). Balance ability was assessed by the Berg Balance scale (BBS). The time required for performing these two tasks and the sitting impact force in the StandTS task were measured as performance outcomes. Pearson’s correlation coefficient analyses were applied to reveal the correlation between dynamic spasticity and all other outcomes. Results: Only the scores of MI-LE showed significant negative correlation with composite spasticity indices in StandTS task (r = -0.44, p = 0.03). No significant correlation was found between composite spasticity indices and all other outcomes in SitTS task. For neurophysiological outcomes, the average peak values of EEG-EMG coherence happened in the 13- to 30-Hz frequency band (β-band) mostly in both tasks. Discussion and Conclusion: The dynamic spasticity is negatively related to the muscle strength of the lower extremity, yet it does not correlate with the stroke survivors’ functional balance, performance and cortico-muscular processing abilities in SitTS and StandTS tasks. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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