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Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cebus apella monkeys subjected to chronic haloperidol administration develop neurologic disturbances very similar to neuroleptic-induced acute dystonia human beings. After varying lengths of time, certain monkeys develop a prolonged dyskinetic syndrome resembling tardive dyskinesia (TD), as seen clinically. Two monkeys with signs of TD were given single intramuscular injections of various compounds with known effects on the catecholaminergic, cholinergic, serotoninergic and GABA-ergic neurotransmittor systems, and their effect on the TD signs were rated. Dopamine receptor blockers as well as cholinergics had an ameliorating effect on the symptoms. Some compounds known to activate the GABA system, including some benzodiazepines and the GABA-transaminase inhibitor amino-oxyacetic acid, also reduced the symptoms, as did the serotonin precursor L-5HTP. Results with serotonin antagonists were equivocal. It is concluded that dopamine receptor blockade, as well as increased activity within the GABA-ergic or cholinergic systems cause alleviation of TD. The findings are in agreement with earlier reports in man and thus seem to validate this primate model.
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PMID:Pharmacological modification of experimental tardive dyskinesia. 11 27

The autosomal recessive inherited disorder glutaryl-CoA dehydrogenase deficiency (glutaric aciduria) runs a progressive course with severe choreoathetosis and dystonia, eventually leading to total helplessness and early death. Theree patients were observed during therapeutic trials with a protein-low diet, riboflavin and GABA analogue. Diet and riboflavin had a slight-to-moderate effect on the clinical symptoms; the excretion of glutaric acid and 2-amino-adipic acid decreased considerably during treatment. Regression of neurologic symptoms was observed during treatment with GABA analogue. It is concluded that the patients should be treated as early as possible with protein-low diet, riboflavin, and GABA analogue.
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PMID:Treatment of glutaryl-CoA dehydrogenase deficiency (glutaric aciduria). Experience with diet, riboflavin, and GABA analogue. 43 Mar 18

In summary, then, without consideration of specific circuits or transmitter agents, one can conceive of a hypothetical model that involves both learning and the functional nature of the defect in torticollis and focal dystonia to describe the results obtained. The model must be further elaborated upon and tested, preferably in a quantitative manner. Naturally, the specific finding of a defective transmitter agent (e.g., GABA) such as described in parkinsonian syndrome (dopamine) or the interruption of a specific pathway that causes and improves a dyskinesia is desirable. In this chapter we have described the use of integrated EMG feedback for the treatment of focal dystonia or spasmodic torticollis. Although we have achieved significant results, it remains clear that further research in the treatment of these disorders is required. However, since this treatment does not require medication or surgery and the possibility for significant improvement is greater than 40%, it should be attempted in patients with focal dystonia or torticollis prior to other forms of therapy. SFT should be considered as a standard mode in the medical armamentarium used for the treatment of these disorders, either primarily or in conjunction with other forms of medical, surgical, and physical therapy.
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PMID:Integrated EMG feedback in the management of spasmodic torticollis and focal dystonia: a prospective study of 80 patients. 108 48

Dystonia refers to involuntary, prolonged muscle contractions leading to sustained, often twisting, postures. High dose anticholinergic therapy for childhood onset dystonia, botulinum toxin injections for focal dystonia, and levodopa for diurnal dystonia provide symptomatic relief for some patients. Despite this, treatment of both idiopathic and secondary dystonia remains inadequate for many patients. Baclofen, a pre-synaptic acting GABA agonist, has been reported to benefit dystonia in a number of retrospective studies. Dramatic improvement in symptoms, especially in gait, was found in almost 30% of 31 children and adolescents with idiopathic dystonia in one retrospective study using doses ranging from 40 to 180 mg daily. The response to baclofen of adults with focal dystonia is less dramatic. One series of 60 adults with cranial dystonia found sustained benefit in 18%. Smaller series have not consistently found significant benefit in adults. Baclofen has been used to treat several secondary dystonias: tardive dystonia has occasionally been reported to improve and there are isolated reports of improvement in dystonia occurring in Parkinson's disease and in glutaric aciduria.
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PMID:Baclofen in the treatment of dystonia. 151 73

Early case reports note marked improvements in the signs of Parkinson's disease (PD) in several patients with coexisting psychiatric disorders after treatment with electroconvulsive therapy (ECT). Studies since 1959 reveal improvement of parkinsonism in over half of PD patients receiving ECT, regardless of the presence or absence of psychiatric comorbidity. Drug-induced parkinsonism, tardive dystonia, and tardive dyskinesia have also been shown to improve with ECT administration; tic syndromes have achieved mixed results. In animals, ECT enhances dopamine-mediated effects and increases GABA concentrations in the CNS. Optimal parameters relevant to the antiparkinsonism effects of ECT require further study.
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PMID:Electroconvulsive therapy in Parkinson's disease and other movement disorders. 175 47

Attacks of sustained dystonic postures of limbs and trunk can be initiated by handling or mild environmental stimuli (e.g. new cage) in an inbred line of Syrian hamsters. The severity of the dystonic syndrome in these mutant hamsters (gene symbol dtsz) is age-dependent, with a peak at about 30-40 days of age. A scoring system for grading type and severity of the dystonic attacks can be used to study the activity of drugs against dystonic movements with individual pre- and post-drug vehicle trials as control. In the present experiments, the effects of drugs which alter GABAergic functions in the brain were studied in dystonic hamsters. Anticonvulsants, i.e. valproate, diazepam and phenobarbital, which augment GABAergic neurotransmission, decreased the severity of dystonic attacks in the mutant hamsters, while administration of subconvulsive doses of pentylenetetrazol or the inverse benzodiazepine receptor agonist FG 7142 increased the severity of the syndrome. Anticonvulsants, i.e. phenytoin and carbamazepine, which are not thought to act via effects on GABAergic neurotransmission, exerted no antidystonic effects, but even worsened the attack in several animals. In contrast, the GABA-elevating drug, aminooxyacetic acid, produced a marked antidystonic effect in the hamsters. Similarly, the GABAB receptor agonist, baclofen, significant decreased the severity of the dystonic attack. The data indicate that dystonic movements in dtsz mutant hamsters can be attenuated by drugs which facilitate GABAergic functions, but worsened by drugs which impair GABAergic neurotransmission. These data thus seem to suggest that the dystonic syndrome in dtsz mutant hamsters is under GABAergic influence. The data show furthermore that dystonic hamsters are a suitable model to detect antidystonic effects of drugs.
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PMID:Effects of pharmacological manipulation of GABAergic neurotransmission in a new mutant hamster model of paroxysmal dystonia. 185 2

In order to reveal a functional difference between the two distinctly separate nuclei of the striatum, i.e. the caudate nucleus (Cd) and the putamen (Put), we studied the effects of local bicuculline (BIC) and picrotoxin (PTX) injection into these nuclei on the motor behavior in the cat. The extent of diffusion of the injected BIC could be approximated by determining the extent of spreading of the dye fast green FCF (FCF) mixed with BIC solution since the extent of diffusion of radioactive [3H]BIC mixed with BIC and FCF solution was almost the same as that of FCF.BIC and PTX are GABA antagonists and are assumed to activate efferent neurons of the Cd and Put by removing the action of GABA-ergic inhibitory synapses on them. A total of 28 BIC and 22 PTX injections was made in 20 adult cats, 22 aimed at the Cd and 28 at the Put. Injection of BIC or PTX to either the head or body of the Cd unilaterally induced locomotor hyperactivity without any postural asymmetry or circling tendency. When BIC or PTX was injected into the Put, dystonic movements (dystonia) towards the contralateral side appeared frequently in the neck and trunk. Even though the injected BIC or PTX often spread to the external segment of the globus pallidus, claustrum, or anterior sylvian gyrus, none of these areas was consistently associated with dystonia. These results demonstrate that the Cd and Put are differentially associated with locomotor and postural functions.
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PMID:Differential roles of the caudate nucleus and putamen in motor behavior of the cat as investigated by local injection of GABA antagonists. 185 76

Meige's disease is a form of focal dystonia characterized by symmetric dystonic spasms of facial muscles, sometimes associated with dystonic movements of other midline muscle groups. The etiology and pathophysiology of the disease have not been established. There is evidence that Meige's disease may result from striatal dopaminergic preponderance coupled with cholinergic overactivity. Several authors have noted a high prevalence of depression in patients with Meige's disease, suggesting a common neurochemical abnormality. Depression, in turn, is associated with decreased pineal melatonin secretion. We propose, based on studies demonstrating that melatonin regulates dopaminergic, cholinergic and GABA-ergic functions, that alterations in melatonin functions may enhance the development of the disease. This hypothesis may open new avenues toward understanding the pathophysiology of the disease and developing newer therapeutic strategies.
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PMID:Melatonin secretion and the pathophysiology of Meige's disease (idiopathic orofacial dystonia): a hypothesis. 197 65

A 13-year-old boy was the victim of a strangulation attempt. His behavior was normal by the 6th day after the assault. However, from the 7th day, he developed choreoathetosis, dystonia and marked pseudobulbar palsy. CT and T2-weighted MRI at this time revealed a low density and high signal intensity in the region of the bilateral putamen and caudate respectively for the first time. Thereafter, these symptoms and changes in CTs and MRIs subsided gradually over two months. Sequential analysis of CSF for GABA and dopamine during illness revealed reciprocal changes each other with normal recovery. Because of delayed onset of neurological changes, and findings of CSF with reversible symptoms the delayed encephalopathy after strangulation is probably related to biochemical alteration secondary to anoxia in vulnerable basal ganglia.
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PMID:[Delayed postanoxic encephalopathy after strangulation--the serial neuroradiological and neurochemical studies]. 210 26

Interneurons in the Red Nucleus (RN) are known to be under cortical control and to exert an inhibitory action, mediated by GABAergic mechanisms, on the main output towards the spinal cord. The effects of discrete injections of a GABA receptor agonist (muscimol) or an antagonist (bicuculline) in the Red Nucleus were tested on a motor task performed by seven cats. The subjects were trained to release a lever with a flexion movement of the forelimb controlled by a reaction time (RT) paradigm. Muscimol as well as bicuculline increased RTs in a dose-dependent manner at doses below 100 ng. However the parameters of the force exerted on the lever were differentially altered by the two drugs. Muscimol increased RTs by slowing down the force change preceding movement as well as slightly delaying its latency. While bicuculline increased drastically the force change latency. It could also speed up the force change velocity for low doses. At higher doses (up to 500 ng) both drugs produced an arrest of the performance either associated with anxiety signs (bicuculline) or dystonic movements of the head followed by body rotations (muscimol). The strong motor impairments as well as the disruption of the conditioned performances following muscimol or bicuculline microinjection in the RN suggest an important functional role for GABAergic interneurons. Under the control of cortical afferences they can modulate rubrospinal activity and participate in the triggering of a conditioned movement.
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PMID:GABAergic mechanisms in the cat red nucleus: effects of intracerebral microinjections of muscimol or bicuculline on a conditioned motor task. 222 85


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