Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026838 (spasticity)
 6,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effectiveness of radiofrequency (RF) cordotomy of segmental motoneurone pools of the lumbosacral cord in reducing spasticity of decerebrate cats is evaluated. The need for a new form of therapy for clinical spasticity is based upon the limitations of contemporary methods, including surgical and pharmacological techniques. In man, spasticity of spinal origin may be treated effectively by intrathecal administration of hyperbaric phenol solutions. The advantages and disadvantages are described. Difficulty in controlling the lesion is emphasized. Tension and EMG-length curves of the spastic triceps surae muscle in acute and chronic animals show that RF lesions (fixed amperage and duration) of the segmental motoneurone pools reduces myotatic reflex activity in accordance with the number of segments cordotomized. Clinical examination including cinematography and electromyography complement the physiological interpretation. RF lesions of the internuncial pool induce spontaneous EMG discharges. This finding is related to similar observations of EMG discharges and alterations in muscle tone after asphyxiation of the spinal cord.
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PMID:Radiofrequency cordotomy for the relief of spasticity in decerebrate cats. 528 93

In 15 patients with spastic hemiparesis the development of tension of calf muscles in relation to their electrical activation and their stretching period was studied on both sides during locomotion. Only in the spastic leg did isolated small biphasic potentials appear in the gastrocnemius E.M.G. with monosynaptic latency at the beginning of the stance phase, while the remaining gastrocnemius activation was reduced compared to the unaffected side. Perturbations of gait were followed in the spastic leg by a large monosynaptic response, while the polysynaptic reflex response was reduced. In the unaffected leg only a strong polysynaptic response appeared, which suggests a reciprocal modulation of monosynaptic and polysynaptic reflex responses. Tension development paralleled the gastrocnemius E.M.G. in the unaffected leg, while in the spastic leg tension was more closely correlated to muscle stretch. It is concluded that in spasticity the exaggerated monosynaptic reflexes represent only a small part of leg extensor activation during gait and that the tension development does not depend on these reflexes.
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PMID:Tension development and muscle activation in the leg during gait in spastic hemiparesis: independence of muscle hypertonia and exaggerated stretch reflexes. 609 May 90

Mechanical and membrane properties of smooth muscle cells and/or neuroeffector transmission in the aganglionic segment of the large intestine (Hirschsprung's disease) were compared with findings in the ganglionic segment. Tension-recording, microelectrode, and double sucrose gap methods were used. There was no difference in resting membrane potential of the longitudinal or circular muscle cell in these two segments, which were obtained at biopsy in Japanese children. In the ganglionic preparations, generations of regular prepotentials, with or without the spike, correlated well to the rhythmic contractions. However, in the aganglionic segment, irregular spike and contraction only were observed. In the circular or longitudinal muscle of the ganglionic segments, field stimulations evoked inhibitory junction potentials, excitatory junction potentials, or both and triggered initial relaxation and then a contraction of the tissue. In the aganglionic segment, however, field stimulation evoked only excitatory junction potentials followed by contraction. These results indicate that, in cases of Hirschsprung's disease, there may be a deficiency in the nonadrenergic inhibitory pathways. This is the first evidence for a lack of spasticity in muscle from the aganglionic segment of the large intestine obtained from children with Hirschsprung's disease.
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PMID:Membrane properties and innervation of smooth muscle cells in Hirschsprung's disease. 683 46

Following central motor lesions, two forms of adaptation can be observed which lead to improved mobility: (1) the development of spastic muscle tone, and (2) the activation of spinal locomotor centers induced by specific treadmill training. Tension development during spastic gait is different from that during normal gait and appears to be independent of exaggerated monosynaptic stretch reflexes. Exaggerated stretch reflexes are associated with an absence or reduction of functionally essential polysynaptic reflexes. When supraspinal control of spinal reflexes is impaired, the inhibition of monosynaptic reflexes is missing in addition to a reduced facilitation of polysynaptic reflexes. Therefore, overall leg muscle activity becomes reduced and less well modulated in patients with spasticity. Electrophysiological and histological studies have shown that a transformation of motor units takes place following central motor lesions with the consequence that regulation of muscle tone is achieved at a lower level of neuronal organization which in turn enables the patient to walk. Based on observations of the locomotor capacity of the spinal cat, recent studies have indicated that spinal locomotor centers can be activated and trained in patients with complete or incomplete paraplegia when the body is partially unloaded. However, the level of electromyographic activity in the gastrocnemius (the main antigravity muscle during gait) is considerably lower in the patients compared to healthy subjects. During the course of a daily locomotor training program, the amplitude of gastrocnemius, electromyographic activity increases significantly during the stance phase, while inappropriate tibialis anterior activation decreases. Patients with incomplete paraplegia benefit from such training programs such that their walking ability on a stationary surface improves. The pathophysiology and functional significance of spastic muscle tone and the effects of treadmill training on the locomotor pattern underlying new attempts to improve the mobility of patients with paraplegia are reviewed.
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PMID:Spinal cord lesion: effects of and perspectives for treatment. 1153 Aug 90