Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuous administration of haloperidol, sulpiride, or cis-flupenthixol, but not of domperidone or apomorphine, to Wistar rats for up to 3 weeks caused an increase in spontaneous purposeless chewing movements. Treatment with physostigmine and pilocarpine, but not neostigmine, for up to 3 weeks increased chewing, whilst scopolamine decreased chewing. Metergoline and cyproheptadine, but not quipazine, increased chewing after only 1 and 7 days but not thereafter. Chewing was not altered following treatment with compounds acting on GABA or noradrenaline systems or by a range of non-neuroleptic agents inducing dystonia in man. The enhancement of chewing induced by neuroleptic and cholinomimetic drugs was reduced by acute treatment with scopolamine, and reverted to control levels following drug withdrawal. Neuroleptic-induced purposeless chewing in Wistar rats appears to be primarily influenced by cerebral dopamine and acetylcholine function and may resemble acute dystonia, rather than tardive dyskinesia.
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PMID:Pharmacological characterisation of spontaneous or drug-associated purposeless chewing movements in rats. 285 1

Movement abnormalities in neuroleptic-treated, psychiatric patients are classified as (a) initial syndromes, including dystonia, parkinsonism, and hyperkinetic abnormalities such as initial dyskinesia (ID) and akathisia, all of which are related to the neuroleptic dose and can be considered as overdose phenomena; (b) tardive syndromes, mainly the classic tardive dyskinesia (TD) syndrome, more seldom tardive akathisia and tardive dystonia, which may all develop or aggravate after withdrawal of neuroleptic treatment; and (c) age-related, spontaneous dyskinesia, akathisia, and dystonia, and schizophrenia-related, hyperkinetic, often stereotyped, movements and restlessness. ID and TD can occur simultaneously, and may depend, at least partially, on identical mechanisms. The pathophysiology of TD is still not clear, and the traditional dopamine (DA) hypersensitivity model seems inadequate. Animal experiments suggest that blockade of some DA receptors in the brain (e.g., in ventromedian striatum) may counteract hyperkinesia and produce parkinsonism, while a concomitant blockade of other similar receptors in other brain regions (e.g., in anterodorsal striatum) may aggravate movements. This offers an explanation for the concomitant occurrence of parkinsonism and hyperkinetic movement abnormalities (ID and akathisia) relatively early in a neuroleptic treatment, and may also contribute to the understanding of the pathophysiology of TD. It is concluded that pathophysiologically TD is a heterogeneous syndrome depending on a subtle balance between several neurotransmitters in the brain, including DA receptor blockade and hypersensitivity of DA and GABA receptors.
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PMID:Pathophysiological mechanisms underlying tardive dyskinesia. 286 Jun 66

Tetrahydroisoxazolopyridinol (THIP), a GABA receptor agonist, gamma-acetylenic-GABA(GAG) and gamma-vinyl-GABA(GVG), two GABA transaminase inhibitors were given in single parenteral doses to three Cebus apella monkeys with persistent dyskinetic movements induced by earlier long-term administration of haloperidol. High doses of THIP temporarily abolished dyskinesias but also caused bradykinesia, ataxia, dystonia and myoclonic jerks. GAG and GVG reduced dyskinesias to a lesser extent and with fewer side effects. Whether the observed antidyskinetic effect is secondary to the concomitant general toxic effects or if these drugs have a specific antidyskinetic action remains an open question.
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PMID:GABA agonists in cebus monkeys with neuroleptic-induced persistent dyskinesias. 289 37

Tardive dyskinesia (TD) is a syndrome of involuntary movements that develops in predisposed individuals during neuroleptic drug treatment, with an average prevalence of 15%. Neuroleptic (antidopaminergic) drugs are the predominant etiological factor. Although no simple correlation can be established, both dosage and treatment duration seem to be of importance for the development of dyskinesia. It is still uncertain whether some neuroleptics carry a higher risk than others, but it appears that the atypical neuroleptic clozapine, which causes no or minimal dystonia, parkinsonism, or akathisia, also carries no or minimal risk of TD. The pathophysiological mechanisms underlying TD are unclear. The traditional dopamine hypersensitivity theory is no longer viable, whereby new hypotheses have been advanced: TD can be due to the blockade of a subset of striatal dopamine receptors, while parkinsonism is due to the blockade of another such subset, and/or can be due to a reduced GABA turnover in a subgroup of neurons connecting striatum with globus pallidus and substantia nigra. TD is best prevented by a course of neuroleptic medication involving as little antidopamine effect as possible, including minimal doses and shortest possible length of treatment. The main TD treatment principle consists of a gradual dose reduction, possibly over years. It should be added, however, that more recent investigations indicate that traditional antidopaminergic treatment in moderate doses may be safely continued over a long period without an increased risk of TD progression.
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PMID:Tardive dyskinesia. 289 70

Regional cerebral glucose metabolism was studied in 16 patients with idiopathic torticollis, using positron emission tomography. Analysis of subcortical regions revealed no consistent focal abnormality of cerebral metabolic rate for glucose, but there was a bilateral breakdown of the normal relationships between the thalamus and basal ganglia. The findings suggest disruption of the pallidothalamic projections in this focal dystonia and may imply a disturbance of GABA.
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PMID:PET studies of cerebral glucose metabolism in idiopathic torticollis. 348 80

Six patients with different forms of dystonia were treated with gamma-vinyl GABA, a specific enzyme-activated inhibitor of GABA-transaminase, in a double-blind, placebo-controlled crossover study. gamma-Vinyl GABA therapy, 2 g daily for 2 weeks, was compared with placebo by weekly assessments. There were no consistent changes in three evaluation scores. Agents that augment CNS GABA are unlikely to benefit patients with generalized dystonia.
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PMID:Double-blind study of oral gamma-vinyl GABA in the treatment of dystonia. 394 92

The spontaneous occurrnce of blepharospasm and dystonic movements in face muscles, particularly those of the perioral and mandibular regions, has been named Meige's disease. Other dystonic features as spasmodic torticollis, dysphagia, spasmodic dysphonia and segmental dystonia of the limbs may, eventually, be present in the same patient. There is very little knowledge about the pathology of this disease. Many hypotheses concerning the pathophysiology of this entity have been put forward, most of them correlating the clinical response to several drugs with known action on the neurotransmitter system of the brain. There are some evidences that it may exist a dopaminergic preponderance in the disease. In the nigro-striatal pathway, one of the retrograde loops in the feed-back control of dopamine synthesis by nigral neurons is dependent on GABA. Increasing GABA activity through GABA agonists that cross the blood-brain barrier could result in a decreased dopaminergic action in the nigro-striatal pathway and, thus, ameliorate the dystonic symptoms which might have been produced by its increased function. We have used baclofen, a GABA-agonist drug, to treat five patients with Meige's disease, in a single-blinded trial. These were four females and one male, with age ranging from 50 to 63 years. The drug was started at 20mg/day, being increased by 10mg each three days reaching a maximum dose of 70mg/day. One of the patients showed marked improvement of blepharospasm and orofacial dystonia and a second patient had a moderate improvement in the same symptoms. Another patient showed moderate improvement of limb dystonia, but had no benefit in the facial movements.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Treatment of Meige disease with a GABA receptor agonist]. 409 37

In eight monkeys (Cercopithecus aethiops), previously treated with haloperidol for 4-14 months, we have examined the behavioral effect of: (1) methylphenidate vs apomorphine; (2) 4,5,6,7-tetrahydroisoxazolo-(5,4-c)-pyridin-3-ol(THIP, a GABA agonist) vs diazepam; and (3) THIP and diazepam in methylphenidate-induced behavior. Methylphenidate (0.5-5.0 mg/kg) and apomorphine (0.1-0.5 mg/kg) both increased locomotion, but otherwise exhibited different behavioral profiles. Methylphenidate induced repetitive movements of head, limbs, and trunk, and hallucinatory-like behavior, but not oral hyperkinesia (licking and gnawing), whereas apomorphine preferentially caused oral hyperkinesia. THIP produced a syndrome of bradykinesia, dystonia, ataxia, myoclonus, sedation, and decreased responsiveness, whereas diazepam produced only bradykinesia, ataxia, sedation, and decreased responsiveness, but not dystonia and myoclonus. Methylphenidate-induced locomotion and repetitive movements were reduced by THIP and diazepam, whereas hallucinatory-like behavior was markedly aggravated by THIP, but not by diazepam.
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PMID:Methylphenidate, apomorphine, THIP, and diazepam in monkeys: dopamine-GABA behavior related to psychoses and tardive dyskinesia. 642 Aug 23

Neurological side effects associated with neuroleptic drugs result from a complex interaction of multiple neurotransmitters. To clarify the etiology of neuroleptic-induced acute dystonic reactions, monkeys (Cercopithecus aethiops) were treated with haloperidol at doses sufficient to evoke dystonia, and the effects of agents that influenced dopaminergic, cholinergic, or GABAergic neurotransmitters were evaluated. Apomorphine, a dopamine (DA) agonist, and biperiden, an acetylcholine (ACh) antagonist, decreased acute dystonia, whereas alpha-methyl-p-tyrosine (AMPT), an inhibitor of DA synthesis, and physostigmine, an ACh agonist, agonist, increased the symptoms. Muscimol, a GABA agonist, increased the dystonias in a dose-dependent way, and GABA inhibition with picrotoxin also aggravated dystonia, complicated by systemic intoxication and seizures. The reciprocal interaction between DA and ACh influences is consistent with clinical findings and animal models of dyskinesias. Dystonia may also be modulated by GABAergic substrates, but the results suggest complex interactions among DA, ACh, and GABA neurotransmission. Symptoms involving the orofacial, limb, and trunk regions, and purposeless overactivity are discussed in comparison with acute and tardive neuroleptic-induced movement disorders.
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PMID:Dopamine, acetylcholine, and GABA effects in acute dystonia in primates. 677 41

The 'Wriggle Mouse Sagami (WMS)' is a new neurological mutant with severe dystonic movements of the trunk and extremities whose pathological characters are transmitted by an autosomal recessive gene (wri). Manifestations first appear at 10 days to 2 weeks after birth and progress until 12 weeks of age. In spite of the severe dystonic movements, no marked abnormalities had been found in the cyto- or myeloarchitecture of the central nervous system or that of the peripheral nerves, except for the impaired development of the dendritic trees of the Purkinje cells. In this study we quantitatively demonstrated decreased synaptic connections of parallel fibers on the dendritic spines of the Purkinje cells as early as 2 weeks after birth. On the other hand, synaptic boutons on the dendritic shafts and somata of the Purkinje cells and synaptic bouton-like structures which contained synaptic vesicles but without synaptic membrane specialization, were significantly increased in the molecular layer at 9 weeks of age. Glutamic acid decarboxylase immunohistochemistry suggested that some of these increased synaptic boutons and other bouton-like structures may have originated in GABA interneurons, such as stellate cells, basket cells and Golgi cells, and in the cerebellar nuclei. Because of the severity of the manifestations, it appears that synaptic alteration in interneurons also occurs in the other parts of the CNS.
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PMID:Abnormal synaptic architecture in the cerebellar cortex of a new dystonic mutant mouse, Wriggle Mouse Sagami. 768 93


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