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At least 19 recordsLinked to original sources

A study of the effectiveness of botulinum toxin type A (Dysport) in the management of muscle spasticity.

Severe muscle spasticity is common in patients with neurological disease. It is often associated with pain and distressing spasms, and frequently leads to functional motor disability. Antispasticity drugs usually result in systemic adverse effects, and peripheral nerve blocks have some disadvantages such as sensory loss and painful dysaesthesiae. In recent years botulinum toxin type A (BT/A) has been advocated for the treatment of muscle spasticity. We studied, using a functional assessment scale, the effects of BT/A on the patients' symptoms and the functional disability due to spasticity in five children and eight adults who were referred for treatment. In 10 patients the treatment goals were achieved, and children generally had a better and more sustained response than adults. There were no adverse effects reported. The present study suggests that BT/A is safe and effective in improving the motor functional disability which is often associated with severe localized muscle spasticity.

Adolescent↗

Effects of a single session of prolonged muscle stretch on spastic muscle of stroke patients.

The control of spasticity is often a significant problem in the management of patients with spasticity. The aim of this study was to evaluate the effect of a single session of prolonged muscle stretch (PMS) on the spastic muscle. Seventeen patients with spastic hemiplegia were selected to receive treatment. Subjects underwent PMS of the triceps surae (TS) by standing with the feet dorsiflexed on a tilt-table for 30 minutes. Our test battery consisted of four measurements including the modified Ashworth scale of the TS, the passive range of motion (ROM) of ankle dorsiflexion, the H/M ratio of the TS, and the F/M ratio of the tibialis anterior (TA). The results indicated that the passive ROM of ankle dorsiflexion increased significantly (p < 0.05) compared to that before PMS treatment. Additionally, PMS reduced motor neuron excitability of the TS and significantly increased that of the TA (p < 0.05). These results suggest that 30 minutes of PMS is effective in reducing motor neuron excitability of the TS in spastic hemiplegia, thus providing a safe and economical method for treating stroke patients.

Adult↗

The axonal microtubular density is higher than normal in fibres innervating spastic muscles.

In infants with spastic disorders and with congenital dysplasia of the hip (CDH), the microtubular content of nonmedullated and myelinated fibres of the anterior obturator nerves was studied with the electron microscope. In CDH infants, the microtubular content of nonmedullated and myelinated fibres was similar to values reported for experimental animals. In spastic patients, the microtubular content of nonmedullated fibres was similar to that found in CDH patients while the microtubular densities of 3- and 10-microns myelinated fibres were 37.5 and 16.7 microtubules/micron2, respectively, or 100% and 43% greater than corresponding values of CDH patients. We propose that the high firing rate determines the abnormally high microtubular content of myelinated axons supplying spastic muscles.

Axons↗

Absence of stretch reflex gain enhancement in voluntarily activated spastic muscle.

Static and dynamic stiffnesses of voluntarily activated elbow muscles were compared in spastic and contralateral arms of 15 subjects with spastic hemiparesis. Stiffnesses were estimated from the positional deflections induced by applying load perturbations to each forearm. In 11/15 subjects (73%), stiffness were comparable on the two sides. In the remaining 4/15 subjects (27%), stiffness were consistently greater on the spastic side, however, EMG recordings from these spastic muscles were of much smaller amplitude than those of the contralateral muscles, indicating that this increase was probably caused by changes in the mechanical properties of elbow muscles, rather than by stretch reflex enhancement. We conclude that for voluntarily activated muscles of spastic hemiparetic subjects, reflex stiffness (and presumably stretch reflex gain), of spastic and contralateral limbs is not significantly different. These findings impose important constraints upon theories attempting to explain spastic hypertonia, and they also provide guidelines for clinical quantification of spasticity.

Adult↗

Inferior mechanical properties of spastic muscle bundles due to hypertrophic but compromised extracellular matrix material.

The passive mechanical properties of small muscle fiber bundles obtained from surgical patients with spasticity (n = 9) and patients without neuromuscular disorders (n = 21) were measured in order to determine the relative influence of intracellular and extracellular components. For both types of patient, tangent modulus was significantly greater in bundles compared to identical tests performed on isolated single cells (P < 0.05). However, the relative difference between bundles and single cells was much greater in normal tissue than spastic tissue. The tangent modulus of normal bundles (462.5 +/- 99.6 MPa) was 16 times greater than normal single cells (28.2 +/- 3.3 MPa), whereas the tangent modulus of spastic bundles (111.2 +/- 35.5 MPa) was only twice that of spastic muscle cells (55.0 +/- 6.6 MPa). This relatively small influence of the extracellular matrix (ECM) in spastic muscle was even more surprising because spastic muscle cells occupied a significantly smaller fraction of the total specimen area (38.5 +/- 13.6%) compared to normal muscle (95.0 +/- 8.8%). Based on these data, normal muscle ECM is calculated to have a modulus of 8.7 GPa, and the ECM from spastic muscle of only 0.20 GPa. These data indicate that spastic muscle, although composed of cells that are stiffer compared to normal muscle, contains an ECM of inferior mechanical strength. The present findings illustrate some of the profound changes that occur in skeletal muscle secondary to spasticity. The surgical implications of these results are discussed.

Adult↗

[Pathology of spastic muscles. Study of 26 patients].

Spastic hypertonia is observed in various central neurological diseases. Pathology of spastic muscle is not well known. Tibial selective microsurgical neurotomy is used for the spastic foot treatment. Twenty-six hemiplegic patients, spastic since more than one year, underwent selective tibial microsurgical neurotomy. Biopsies of soleus, lateral and medial gastrocnemius muscles were performed during surgical treatment, after free patient consent and ethical committee approval. The aim of this study was to describe histopathological lesions of spastic muscles, with histological and histoenzymatic techniques. Histological studies revealed myogenic atrophy, concerning both types of fibers or only type II fibers. They also showed type I (slow fibers) to type II (fast fibers) transformation, in the three studied muscles. These results are similar to those described in the literature.

Adolescent↗

The effects of reflex path length on clonus frequency in spastic muscles.

Clinical evaluation of clonus in spastic muscles was performed by comparing reflex path length with clonus frequency for different muscles in the same patient. It was found that clonus frequency varied inversely with reflex path length (r = 0.84, p less than 0.001). The findings confirm that clonus is generated by a peripheral mechanism of self re-excitation rather than a central spinal pacemaker.

Adult↗

Involuntary single motor unit discharges in spastic muscles during EMG biofeedback training.

The apparent involuntary single motor unit discharges observed in many extremity muscles of spastic patients necessitate monitoring raw electromyography during training sessions. The clinician should note that electronic components of some biofeedback instruments may amplify and distort these units so that the feedback, whether by meter or by variable pitch tone, may erroneously be perceived by the patient as a high level of muscle tension.

Action Potentials↗

Dantrolene. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic use in malignant hyperthermia, the neuroleptic malignant syndrome and an update of its use in muscle spasticity.

Dantrolene sodium acts primarily by affecting calcium flux across the sarcoplasmic reticulum of skeletal muscle. Recently, dantrolene has been used very successfully in the treatment of several rare hypercatabolic syndromes which have previously been associated with high mortality rates. In malignant hyperthermia, where early diagnosis and treatment usually with intravenous dantrolene in association with other supportive measures (and often subsequent dantrolene therapy) is performed, recovery is seen in virtually 100% of patients. There is a rapid resolution of hyperthermia, dysrhythmias, muscle rigidity, tachycardia, hypercapnia, mottled or cyanotic skin, and metabolic acidosis, and a slower normalisation of myoglobinuria and elevated serum creatine phosphokinase levels. In patients with family history or previous episodes of malignant hyperthermia, prophylactic treatment with dantrolene prior to anaesthesia prevents the syndrome occurring in most cases. Where malignant hyperthermia has developed patients have been successfully treated with further dantrolene therapy. Dantrolene has also been used successfully in the treatment of a few cases of heat stroke and the neuroleptic malignant syndrome--both of which have many similarities to malignant hyperthermia. Dantrolene is well established in the treatment of patients with muscle spasticity where it generally improves at least some of the components of spasticity (i.e. hyper/hypotonia, clonus, muscle cramps and spasms, resistance to stretch and flexor reflexes, articular movement, neurological and motor functions and urinary control). However, in some patients, particularly those with multiple sclerosis, dantrolene may not be effective, and in many cases muscular strength may diminish. Long term dantrolene therapy has been associated with hepatic toxicity and may cause problems in patients treated for disorders of muscle spasticity. Thus, dantrolene offers a unique advance in the therapy available for the treatment of hypercatabolic disorders and is also useful in the treatment of muscle spasticity of various aetiology.

Animals↗

Adaptation of the properties of spastic muscle with wrist extension deformity.

To show that human muscle may adapt to tendon transfer, adaptation of flexor carpi ulnaris (FCU) function was studied by measuring active and passive length-force characteristics at initial operation and at reoperation in a case of extension deformity secondary to FCU tendon transfer. At reoperation, FCU was 20 mm shorter; active force decreased approximately 10%, indicating atrophy; and passive force increased, reflecting increased stiffness. FCU fiber length was unchanged. The presented case shows that human forearm muscle may adapt to a transferred function.

Adaptation, Physiological↗

Pathology of spastic muscle in cerebral palsy.

The histopathology of muscle in cerebral palsy has not been elucidated because correlated morphologic and biochemical data on normal pediatric muscles are insufficient to allow adequate correlation of pathologic findings. One hundred and eight muscle biopsies were taken during reconstructive operations on 85 patients. Normal values for pediatric muscles were obtained from a literature review and supplemented with our data on normal patients. Fiber sizes are normally different for children of different ages. Histochemical staining of enzyme systems demonstrate that adenosine triphosphatase staining, pre-incubated at pH 9.4, 4.6, AND 4.3 WAS USED FOR FIBer typing and fiber size. Depending on the muscle biopsied and the clinical status of the patient, there is a variety of patterns of type I and type II fiber atrophy, hypertrophy, and myopathy. In some cases, denervation changes are present to suggest nerve entrapment. Correlated clinical observations suggest type I fiber predominant muscles do not re-educate well when surgically transferred to perform a specified function.

Adenosine Triphosphatases↗

Dantrolene sodium: long-term effects in patients with muscle spasticity.

Seventy-seven patients with muscle spasticity secondary to central nervous system pathology were treated with dantrolene sodium for periods of up to two years. The drug was effective in reducing muscle spasms, clonus, muscle tone, and the force of muscle contraction elicited by Achilles tendon tap and tibial nerve stimulation, but improvement of function was seen less often. The incidence of side-effects was considerable, and poses a problem regarding patient acceptance of drug treatment.

Adolescent↗

Ashworth Scales are unreliable for the assessment of muscle spasticity.

Ashworth Scales are the most widely used tests to assess the severity of muscle spasticity. These scales offer qualitative and subjective information; consequently, there are issues concerning validity and reliability. This article presents the results of a study comparing interrater reliability of the original and of the modified Ashworth Scales for measuring muscle spasticity in elbow flexors. Fifteen patients with hemiplegia (nine men and six women) with a median age of 52 years (interquartile range, 28-64) participated in this study. Two physiotherapists rated the muscle tone of elbow flexors according to ratings criteria of the Ashworth and the modified Ashworth Scales. Kappa values for the original Ashworth and the modified Ashworth Scales were 0.17 (SE 0.21; p = 0.41) and 0.21 (SE = 0.12; p = 0.08), respectively. The scales showed similar levels of reliability (chi2= 0.0285, df=1, p = 0.7). The Ashworth Scales are not reliable for the assessment of muscle spasticity. In the absence of interrater reliability, the validity of the measurements may also be questioned.

Adult↗