Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038379 (strabismus)
 9,317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Botulinum toxins, exotoxins of Clostridium botulinum, are the most toxic naturally occurring substances known to man. For more than a century they are known to be the cause of botulism, a nowadays rare intoxication with spoiled food that leads to generalized flaccid weakness of striated muscle including pharyngeal and respiratory musculature. The toxins act primarily at peripheral cholinergic motor nerve endings by blocking the release of the neurotransmitter acetylcholine. As a consequence, action potentials in the motor nerve can no longer be transmitted to the muscle. This lack in transmission, clinically appearing as weakness, may disable or actually critically endanger affected patients. However, in certain neurological diseases characterized by an abnormal increase in muscle tone or activity, for example dystonia or spasticity, a reduction in signal transmission may actually be beneficial. Around 1980 local injections of minute amounts (in the order of 0.5 ng) of Botulinum toxin type A were first successfully used in a neurological disorder named blepharospasm which is characterized by an involuntary squinting of the eyes. Since then Botulinum toxin has developed rapidly from a frightful poison to a safe therapeutic agent with a remarkable beneficial impact on the quality of life of many thousands of patients worldwide. This review tries to outline in brief the characteristics of Botulinum toxins, their mechanism of action and the various indications for clinical use as a therapeutic agent.
 ...
PMID:Botulinum toxin: from poison to remedy. 933 23

Although botulinum toxin A was first introduced to treat strabismus and blepherospasm it is now used in an increasing number of conditions, many in the field of pediatrics. Its action results from a prevention of the release of acetylcholine from nerve terminals. A number of studies recording the effects of the toxin in the treatment of spastic cerebral palsy are reviewed, and although these can be criticized, there seems to be no doubt that it can be of benefit. It is few side effects, but it may reveal an underlying weakness. Other disadvantages are its cost and the need for repeated injections. It can be used for the relief of rigidity, although the effects in the extrapyramidal form of cerebral palsy are not so dramatic. Also it can be beneficial in some forms of dystonia, rarely if this is generalized, but certainly if it is focal, and especially if there is accompanying pain. There are several conditions seen in children, such as strabismus, blepherospasm and tremors, in which this form of treatment will rarely be indicated; but they will be mentioned. An exception may be spasmodic torticollis during adolescence if it does not respond to other therapy, as it is so disabling. Botulinum toxin can be used to block the discharges from cholinergic sympathetic and parasympathetic terminals. Focal hyperhidrosis can be very distressing among older children, and the use of the toxin should sometimes be considered in this and other autonomic disorders.
 ...
PMID:The role of botulinus toxin type A in treatment--with special reference to children. 1037 98

Paroxysmal tonic upgaze of childhood is a rare, distinctive, childhood syndrome that may be associated with ataxia and sometimes strabismus or amblyopia. Neurological examination as well as metabolic studies, electroencephalogram and neuroradiological investigations are normal in these patients. Although it has been considered as an age-related, dopa-sensitive dystonia, the exact pathogenetic mechanism is still unknown. Aggravation of attacks by fatigue, intercurrent infection or vaccination, and possible corticomesencephalic dysmaturation may underlie this abnormality. We report on a sporadic case of paroxysmal tonic upgaze with ataxia in which there was prompt aggravation of symptoms with sleep without response to levodopa treatment. This case suggests a different underlying pathogenetic mechanism from dopaminergic pathways for this syndrome.
 ...
PMID:A case of paroxysmal tonic upgaze of childhood with ataxia. 1046 69

Botulinum toxin type-A (BTX-A) is a neurotoxin which blocks presynaptic release of acetylcholine. It interferes with neuromuscular transmission, temporarily paralyzing the affected muscle. Of special interest for dermatologists is the unlabelled cosmetic applications, for conditions such as wrinkles and hyperhidrosis. Labelled indications in Europe are for cervical dystonia and cerebral palsy. In the US, it is approved for treatment of strabismus, blepharospasm and hemifacial spasm in adults. After repeated use of high doses, antibodies can develop in some individuals, making further treatment ineffective indefinitely. Even when used in high does for neurological conditions, the development of antibodies occurs in < 5&percnt of patients. In 1997, the US FDA approved a new bulk toxin source for use in the manufacture of BTX-A. It has a higher specific potency than original BTX-A formulations, reducing the amount of utilized neurotoxin protein, and thereby reducing antibody production. Another form of this neurotoxin (type B) also appears to be effective in patients who have developed antibodies to BTX-A. It is awaiting US FDA approval for treatment of cervical dystonia.
 ...
PMID:Update on Botulinum Toxin. 1075 35

Botulinum toxin is more and more frequently used as a therapeutic agent. The toxin blocks selectively and reversibly the neuromuscular junction, causing a muscle relaxation. Indications are mainly muscular hypercontraction, such as dystonia, blepharospasm, focal spasticity, strabismus or tics. The range of action extend to focal hyperhydrosis, palmar, axillary or plantar. It seems now that some painful syndrome such as migraine or tension headache may benefit from toxin injections. Esthetic indications constitute an extension to the pure medical indications.
 ...
PMID:[Current indications for the treatment with botulin toxin]. 1172 14

Leigh disease is a subacute neurodegenerative disorder characterized by symmetric necrotic lesions in the basal ganglia, cerebellum, thalamus, brain stem, and optical nerves and caused by altered oxidative phosphorylation. We describe the clinical, biochemical, neuroimaging, and molecular studies of a 19-year-old boy with early-onset Leigh disease manifesting as severe extrapyramidal disorder with generalized dystonia and choreoathetosis. He was born of healthy parents after an uneventful pregnancy and delivery. At the age of 2 1/2 years, after a minor respiratory infection, he developed unstable, broad-based gait and tremor of the hands. These symptoms persisted for the next several years, when ataxia became more prominent. Difficulty in swallowing, dysarthria, trunk dystonia, and marked dyskinesia of the arms and hands gradually developed. Nystagmus, transient ptosis, and strabismus also appeared. Abnormal laboratory findings included elevated plasma and cerebrospinal fluid lactate and pyruvate, with an abnormal lactate/pyruvate ratio. Cranial computed tomography and magnetic resonance imaging demonstrated signs of cerebellar atrophy, bilateral and symmetric hypodensities in the lentiform nucleus and thalamus, and transient hyperintensities of cerebral peduncles in T2-weighted sequences suggestive of Leigh disease. Muscle biopsy revealed isolated fiber atrophy, necrotic fibers undergoing phagocytosis, and no ragged-red fibers. The measured catalytic activity of cytochrome c oxidase in skeletal muscle homogenates demonstrated a partial cytochrome c oxidase deficiency No abnormalities in the mitochondrial genome and in the SURF-1 gene were found. The boy is currently receiving levodopa therapy, creatine monohydrate, and a high dosage of thiamine and lipoic acid, his condition is stabilized, and extrapyramidal symptoms are less pronounced.
 ...
PMID:Cytochrome c oxidase partial deficiency-associated Leigh disease presenting as an extrapyramidal syndrome. 1151 Sep 39

Botulinum toxin is a dreaded biological toxin elaborated by Clostridium botulinum. The action of this toxin is to cause paralysis of both voluntary and involuntary muscles. The unique property of paralysing capability of muscles has been used for the benefit of human beings. Dr Allan Scot, an ophthalmologist, first used the toxin in a patient with squint in 1981 and since then the botulinum toxin is being used in various disorders characterised by muscle overactivity such as spasticity in both children and adult, dystonic conditions such as blepharospasm, cervical dystonia, spasmodic dysphonia, writer's cramp, etc, hemifacial spasm and headache. Its main action is at the terminal nerve endings of myoneural junction and it prevents release of acetylcholine from vesicles thus causing chemical denervation. Its action persists for 3 to 4 months on an average. Its side effects such as drooping, diplopia, dysphagia, depending on the sites of injection, are few and usually transient. Generalised anaphylaxis is almost unknown. Now botulinum toxin is being used in non-neurological conditions where muscles are under spasmodic state such as achalasia cardia, anal fissure, spasm of urethral sphincter, etc. Because of wider safety range and fewer complications, botulinum toxin has been an important therapeutic armamentarium in different branches of medicine and surgery.
 ...
PMID:Botulinum toxin: a dreaded toxin for use in human being. 1245 15

Botulinum toxin has dramatically improved the treatment of a variety of neurologic disorders. Two botulinum toxin preparations are commercially available in the United States: type A (Botox) and type B (Myobloc). Current indications approved by the United States Food and Drug Administration include cervical dystonia, strabismus, blepharospasm, hemifacial spasm, and glabellar wrinkles for Botox, and cervical dystonia for Myobloc. Botulinum toxin inhibits release of acetylcholine from the neuromuscular junction, resulting in a localized paralysis when minute doses are injected. This mechanism enables botulinum toxin to alleviate symptoms of focal dystonias (which are characterized by excessive muscle contraction), and it may also, along with other theoretical mechanisms, be responsible for pain relief. Studies conducted in patients with cervical dystonia have shown that botulinum toxin effectively reduces pain associated with this disorder, suggesting that this agent may be effective in alleviating other painful syndromes.
 ...
PMID:Review of the FDA-approved uses of botulinum toxins, including data suggesting efficacy in pain reduction. 1256 61

Botulinum toxins (A and B) are neurotoxins derived from Clostridium botulinum. Clostridium are anaerobic bacteria. C. botulinum produces exotoxins (A to G) with distinct antigenicities. The neurotoxins inhibit the release of the neurotransmitter acetylcholine from the axon terminals of motor neurons. Botulinum toxin is officially used in clinic for the treatment of muscular hyperactivity (strabismus, blepharospam, cervical dystonia). Botulinum toxins are also used in non recognized clinical applications: neurogenic incontinence, palmar and axillary hyperhidrosis, chronic anal fissure. The respective formulations of Botox, Dysport and Neurobloc are described. Special considerations for administration are introduced.
 ...
PMID:[Botulism toxin in practice]. 1292 47

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.
 ...
PMID:Noncosmetic uses of botulinum toxin. 1515 50


<< Previous 1 2 3 4 5 Next >>