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Query: UMLS:C0026838 (spasticity)
 6,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study was to examine gravity-induced oscillations of the lower leg in normal and spastic subjects, with a view towards evaluating a clinical test of spasticity called the "pendulum" test. Motivations for studying the pendulum test were to determine if realistic aspects of spasticity and neuromuscular control could be incorporated into a description of the motion, and to better understand the underlying neurophysiological disturbances in spasticity. For passive limb motion (in which no reflex excitation occurred), a second-order linear model did not provide an adequate description of the motion for either spastic or normal legs. Instead, system equations including nonlinear mechanical properties simulating asymmetries in the swing and amplitude dependent variations in stiffness and damping provided a more accurate description. For spastic limb motion (in which reflex excitation did occur), accurate simulation required components accounting for abnormal reflex activation, coinciding with the time course of EMG activation. These included increased stiffness and damping with their gains related to reflex EMG magnitude, and changes in the rest length of the stiffness. Comparison of numerical solutions of the equations with experimental data showed our nonlinear model simulated the motion accurately, with the variance accounted for usually exceeding 90%.
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PMID:A quantitative analysis of pendular motion of the lower leg in spastic human subjects. 174 39

The author reported a case of spastic cerebral palsy in a 4-year-old boy who underwent functional posterior rhizotomy and were followed up for more than one and a half years after surgery to evaluate the degree of spasticity. The patient's preoperative ADL was highly restricted due to severe spasticity. In the surgery, the bilateral rootlets from L2 to S1 were selectively cut if an abnormal reflex activity was demonstrated by neurophysiological methods. Spasticity markedly decreased postoperatively and alleviated the family's burden for daily care. During the period of follow up, residual spasticity has subsided and the effect in controlling spasticity was long-standing. Functional posterior rhizotomy has been recognized as an established neurosurgical treatment for spastic cerebral palsy in childhood in the North America. However, the procedure is uncommon in Japan. The author outlined here the procedure and its history. Functional posterior rhizotomy is a strong armament for treating spasticity in cerebral palsy. The procedure would greatly benefit patients with spastic cerebral palsy in combination with current treatments.
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PMID:[Functional posterior rhizotomy as a surgical treatment for spastic cerebral palsy in childhood]. 1042 87

Cutaneomuscular reflex (CMR) responses were recorded from lower-limb and trunk muscles in 27 subjects with cerebral palsy (CP) (spastic, 21; athetoid, six) and in neurologically healthy (control) subjects, aged 3 to 15 years, while standing. In the 21 subjects with spastic CP, but not in the six subjects with athetoid CP, CMR responses were more widely distributed between ipsilateral lower-limb and trunk muscles compared with age-matched control children. CMR responses in older subjects with CP were similar to younger control subjects, lacking supraspinally mediated, long-latency components. Short-latency, spinally-mediated, excitatory CMR components were seen simultaneously in pairs of distal, antagonistic lower-limb muscles in half of the subjects with spastic CP, but in none of the control children. In subjects with spastic-type CP, the abnormal reflex responses indicate disordered spinal and supraspinal inputs to motor neurones, although there was no convincing correlation between these responses and the severity of spasticity.
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PMID:Cutaneomuscular reflex responses recorded from the lower limb in children and adolescents with cerebral palsy. 1045 29

The use of splints in neurorehabilitation is common, with splints being used to meet varied clinical aims. This paper explores the use of splints after stroke and examines the rationale underpinning current use. It covers the use of splints to reduce spasticity, prevent contracture and improve activity. As well as presenting the theoretical rationale underpinning splinting as an intervention, it examines the current evidence from randomised trials testing the theories. In summary, there is strong evidence that wearing a splint all night has no additional effect in reducing spasticity over usual therapy or in preventing contracture, whether the wrist is splinted in neutral or in maximum extension. It is not surprising that splinting has not shown an effect on activity, given that there was little effect on the impairments that it was directed towards. In conclusion, it is now time to re-focus on improving muscle performance in order to enable activity rather than preparing the patient for function by affecting abnormal reflex activity.
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PMID:Neurorehabilitation splinting: theory and principles of clinical use. 2133 74

Abnormal reflexes associated with spasticity are considered a major determinant of motor impairments occurring after stroke; however, the mechanisms underlying post-stroke spasticity remain unclear. This may be because of the lack of suitable rodent models for studying spasticity after cortical injuries. Thus, the purpose of the present study was to establish an appropriate post-stroke spasticity mouse model. We induced photothrombotic injury in the rostral and caudal forelimb motor areas of mice and used the rate-dependent depression (RDD) of Hoffmann's reflex (H-reflex) as an indicator of spastic symptoms. To detect motoneuron excitability, we examined c-fos mRNA levels and c-Fos immunoreactivity in affected motoneurons using quantitative real-time reverse transcription PCR and immunohistochemical analysis, respectively. To confirm the validity of our model, we confirmed the effect of the anti-spasticity drug baclofen on H-reflex RDDs 1 week post stroke. We found that 3 days after stroke, the RDD was significantly weakened in the affected muscles of stroke mice compared with sham-operated mice, and this was observed for 8 weeks. The c-fos mRNA levels in affected motoneurons were significantly increased in stroke mice compared with sham-operated mice. Immunohistochemical analysis revealed a significant increase in the number of c-Fos-positive motoneurons in stroke mice compared with sham-operated mice at 1, 2, 4, and 8 weeks after stroke; however, the number of c-Fos-positive motoneurons on both sides of the brain gradually decreased over time. Baclofen treatment resulted in recovery of the weakened RDD at 1 week post stroke. Our findings suggest that this is a viable animal model of post-stroke spasticity.
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PMID:Weakened rate-dependent depression of Hoffmann's reflex and increased motoneuron hyperactivity after motor cortical infarction in mice. 2443 15