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 Clostridium botulinum neurotoxins (BoNTs) A and C1 cleave specific proteins required for neuroexocytosis. We demonstrated that, in intact neurons, BoNT A cleaves 25-kDa synaptosomal-associated protein (SNAP-25), and BoNT C1 cleaves both syntaxin and SNAP-25 (Williamson et al.: Mol Biol Cell 6:61a, 1995; J Biol Chem 271:7694-7699, 1996). Here, we compare the actions of BoNT A and BoNT C1 on mature and developing mouse spinal cord neurons in cell culture and demonstrate that BoNT C1 is severely neurotoxic. In mature cultures, synaptic terminals become enlarged shortly after BoNT C1 exposure, and, subsequently, axons, dendrites, and cell bodies degenerate. Electron microscopy confirms that early degenerative changes occur in synaptic terminals when the somatic cytoplasm appears normal. In newly plated cultures, few neurons survive exposure to BoNT C1. Whereas both BoNT A and BoNT C1 cleave SNAP-25, BoNT A has no adverse effect on neurite outgrowth, synaptogenesis, or neuron survival. This cytotoxicity is unique to BoNT C1, is specific to neurons, and is initiated at the synaptic terminal, suggesting either a novel role for syntaxin or additional actions of BoNT C1. The neurodegeneration induced by BoNT C1 may be significant in terms of its efficacy for the clinical treatment of dystonia and spasticity.
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PMID:Syntaxin and 25-kDa synaptosomal-associated protein: differential effects of botulinum neurotoxins C1 and A on neuronal survival. 963 13

There are now many reports from open, uncontrolled studies which suggest that botulinum toxin A (BoNT-A) is valuable in treating spasticity. Evidence of its benefit is also gradually accumulating from randomized controlled trials (RCTs). In this presentation I will discuss the reasons why RCT evidence is being generated, and describe the findings currently available, including preliminary results from as yet unpublished trials. RCT data have been reported for leg and arm spasticity in a variety of diseases, but predominantly in stroke and multiple sclerosis patients. In most RCTs, the effects of BoNT-A are compared with placebo over a single injection cycle. The outcomes are generally positive and support the use of BoNT-A. However, data from RCTs are less convincing than those from open studies for a variety of technical reasons. These especially reflect the difficulties of finding good outcome measures for such a heterogeneous array of patients. There is good evidence that BoNT-A has clinical benefit in treating the mechanical effects of spasticity. In order to further clarify its usefulness, future research should address the strategies of short- and longer-term use of BoNT-A, and the unresolved technical issues of how to get the best out of this new treatment.
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PMID:Botulinum toxin A (BoNT-A) for spasticity in adults. What is the evidence? 1191 49

Clinical experience thus far has shown BoNT-A to be a safe and efficacious method in the short to medium term management of spasticity of the upper limb in cerebral palsy. The relaxation of hypertonic musculature allows for improvement in function and posture, reduction of pain, and in some patients, improvement in cosmesis. It is also a valuable tool in predicting response to and guiding contemplated muscle-tendon surgery. Careful patient selection, detailed clinical assessment of deformity and disability, and a clear outline of treatment goals are essential to good outcomes. Further work needs to be done to determine optimum doses of BoNT-A for individual muscles and to evaluate the long-term outcome of repeated injections.
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PMID:Botulinum toxin A in the management of upper limb spasticity in cerebral palsy. 1459 51

Clostridium botulinum, a Gram-positive, anaerobic spore-forming bacteria, is distinguished by its significant clinical applications as well as its potential to be used as bioterror agent. Growing cells secrete botulinum neurotoxin (BoNT), the most poisonous of all known poisons. While BoNT is the causative agent of deadly neuroparalytic botulism, it also serves as a remarkably effective treatment for involuntary muscle disorders such as blepharospasm, strabismus, hemifacial spasm, certain types of spasticity in children, and other ailments. BoNT is also used in cosmetology for the treatment of glabellar lines, and is well-known as the active component of the anti-aging medications Botox and Dysport. In addition, recent reports show that botulinum neurotoxin can be used as a tool for pharmaceutical drug delivery. However, BoNT remains the deadliest of all toxins, and is viewed by biodefense researchers as a possible agent of bioterrorism (BT). Among seven serotypes, C. botulinum type A is responsible for the highest mortality rate in botulism, and thus has the greatest potential to act as biological weapon. Genome sequencing of C. botulinum type A Hall strain (ATCC 3502) is now complete, and has shown the genome size to be 3.89 Mb with a G+C content of approximately 28.2%. The bacterium harbors a 16.3 kb plasmid with a 26.8% G+C content--slightly lower than that of the chromosome. Most of the virulence factors in C. botulinum are chromosomally encoded; bioinformatic analysis of the genome sequence has shown that the plasmid does not harbor toxin genes or genes for related virulence factors. Interestingly, the plasmid does harbor genes essential to replication, including dnaE, which encodes the alpha subunit of DNA polymerase III which has close similarity with its counterpart in C. perfringens strain 13. The plasmid also contains similar genes to those that encode the ABC-type multidrug transport ATPase, and permease. The presence of ABC-type multidrug transport ATPase, and permease suggests putative involvement of efflux pumps in bacteriocin production, modification, and export in C. botulinum. The C. botulinum plasmid additionally harbors genes for LambdaBa04 prophage and site-specific recombinase that are similar to those found in the Ames strain of Bacillus anthracis; these genes and their products may play a role in genomic rearrangement. Completion of genome sequencing for C. botulinum will provide an opportunity to design genomic and proteomic-based systems for detecting different serotypes of C. botulinum strains in the environment. The completed sequence may also facilitate identification of potential virulence factors and drug targets, as well as help characterize neurotoxin-complexing proteins, their polycistronic expression, and phylogenetic relationships between different serotypes.
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PMID:Clostridium botulinum: a bug with beauty and weapon. 1583 1

Botulinum toxin A (BoNT-A) is a potent biological toxin widely used for the management of skeletal muscle spasticity or dynamic joint contracture. Intramuscular injection of BoNT-A causes muscle denervation, paresis, and atrophy. This clinical effect of botulinum toxin A lasts 3 to 6 months, and injected muscle eventually regains muscle mass and recovers muscle function. The goal of the present study was to characterize the molecular and cellular mechanisms leading to neuromuscular junction (NMJ) regeneration and skeletal muscle functional recovery after BoNT-A injection. Fifty-six 1-month-old Sprague-Dawley rats were used. Botulinum toxin A was injected into the left gastrocnemius muscle at a dosage of 6 units/kg body weight. An equivalent volume of saline was injected into the right gastrocnemius muscle to serve as control. The gastrocnemius muscle samples were harvested from both hind limbs at 3 days, 7 days, 15 days, 30 days, 60 days, 90 days, 180 days, and 360 days after administration of toxin. In addition, the gastrocnemius muscles from 1-month-old rats with no injections were harvested to serve as uninjected control group. Muscle samples were processed and mRNA was extracted. Real-time polymerase chain reaction (PCR) and gene microarray technology were used to identify key molecules involved in NMJ stabilization and muscle functional recovery. More than 28,000 rat genes were analyzed and approximately 9000 genes are expressed in the rat gastrocnemius muscle. Seven days following BoNT-A injection, 105 genes were upregulated and 59 genes were downregulated. Key molecules involved in neuromuscular junction (NMJ) stabilization and muscle functional recovery were identified and their time course of gene expression following BoNT-A injection were characterized. This animal study demonstrates that following intramuscular injection of BoNT-A, there is a sequence of cellular events that eventually leads to NMJ stabilization, remodeling, and myogenesis and muscle functional recovery. This recovery process is divided into two stages (aneural and neural) and that the IGF-1 signaling pathway play a central role in the process.
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PMID:How muscles recover from paresis and atrophy after intramuscular injection of botulinum toxin A: Study in juvenile rats. 1660 9

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.
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PMID:Botulinum toxin: clinical use. 1687 Apr 87

Botulinum toxin type-A (BoNT-A) prevents the release of acetylcholine at cholinergic junctions, thereby causing temporary muscle weakness lasting 3-4 months. It is now widely used to treat a broad range of clinical disorders characterized by muscle hyperactivity. BoNT-A has proved effective in the management of several neurological conditions and, in particular, in the management of movement disorders (e.g. blepharospasm, cervical dystonia, laryngeal dystonia, limb dystonia, hemifacial spasm, focal tics, tremor and other hyperkinetic disorders). As a treatment of spasticity, BoNT-A can improve mobility and dexterity as well as preventing the development of distressing and costly secondary complications. In cerebral palsy, BoNT-A is of value, being able to delay or even avoid surgery until motion patterns have become established.
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PMID:Clinical value of botulinum toxin in neurological indications. 1711 46

Spasticity is a widespread, disabling form of muscle overactivity affecting patients with central nervous system damage resulting in upper motor neurone syndrome. There is a range of effective therapies for the treatment of spasticity (e.g. physical, anaesthetic, chemodenervation and neurolytic injections, systemic medication and surgery), but all therapies must be based on an individualized, multidisciplinary programme targeted to achieve patient goals. Appropriate therapy should be based on the extent and severity of spasticity, but spasticity and its consequences, regardless of presentation or cause, are commonly treated with systemic agents. This may be ill-advised as systemic treatment is associated with many undesirable effects. In particular, elderly patients with post-stroke spasticity are at risk from the central adverse effects of systemic medication (e.g. sedation and gait disturbance), which make them more susceptible to falling, with an associated increased risk of fracture. The rising costs of fracture care and its sequelae are fast becoming an international problem contributing to high healthcare expenditure. Botulinum toxin type-A (BoNT-A) treatment is highly effective for some of the more common forms of spasticity and muscle overactivity, and has a favourable profile when compared with systemic agents and other focal treatments. Therefore, the clinical benefits of BoNT-A treatment outweigh the apparent high costs of this intervention, showing it to be a cost-effective treatment.
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PMID:Improvements in healthcare and cost benefits associated with botulinum toxin treatment of spasticity and muscle overactivity. 1711 47

Hereditary spastic paraplegia (HSP) is characterized by lower extremity spasticity. Symptomatic therapy generally includes physical therapy and oral antispastic agents, in selected cases intrathecal baclofen. Because of the positive results in other treatments of spasticity, the use of botulinum neurotoxin type A (BoNT-A) might also be considered for patients with HSP. We report the effect of BoNT-A injections in 19 unselected patients with HSP treated by the members of the German Spasticity Education Group. In 17 patients, the modified Ashworth scale had improved by one point. In one patient, it improved by three points. Most of the patients reported reduction of spasticity. BoNT-A injections were continued in 11 of 19 patients (57.9%). All of the patients with continued injections had a good or very good global subjective improvement. Patients with less pronounced spasticity and patients with accompanying physical therapy tended to exhibit a better effect. Only four patients reported adverse effects which were increased weakness in three patients and pain in one patient. BoNT-A injections appear to reduce spasticity effectively and safely, especially in patients with mild to moderate spasticity. The preliminary results of our case series should encourage larger studies of BoNT-A injections in HSP.
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PMID:Botulinum neurotoxin type A injections reduce spasticity in mild to moderate hereditary spastic paraplegia--report of 19 cases. 1799 30

A previous study in subjects with focal dystonia suggested that the greater and longer-lasting effect induced by botulinum toxin type A (BoNT-A) on the tonic vibration reflex (TVR) than on the maximal M-wave (M-max) might be the physiological marker of the toxin's action at the level of intrafusal muscle fibres. With this approach, we investigated the possible effect of BoNT-A on fusimotor synapses in eight patients with post-stroke spasticity (four with no residual motor capacity before treatment and four with partially spared muscle strength and residual motor capacity). TVR and M-max were recorded from the wrist and finger flexor muscles before treatment and at 1, 4 and 7 months afterwards. The TVR reduction was greater than the M-max reduction and remained fairly constant over time only in the subjects with a residual motor capacity before the treatment. This pilot study suggests that some degree of strength and active movement is necessary for the action of BoNT-A on intrafusal fibres.
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PMID:Intrafusal effects of botulinum toxin in post-stroke upper limb spasticity. 1826 70


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