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)

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

Levodopa-induced dyskinesias (LID) in Parkinson's disease (PD) may be classified into three main categories: "On" dyskinesias, diphasic dyskinesias (DD), and "off" periods. The study of 168 parkinsonian patients showed that about half (n = 84) showed one pattern of LID only. A combination of two was present in 68, and 16 had the three presentation patterns. A fairly good correlation between type of dyskinesia and presentation pattern was established. Chorea, myoclonus, and dystonic movements occurred during the "on" period. Dystonic postures, particularly affecting the feet, were mainly present in the "off" period, but a few patients had a diphasic presentation. Repetitive stereotyped movements of the lower limbs always corresponded to DD. Acute pharmacological tests using dopamine agonists (subcutaneous apomorphine 3-8 mg; intravenous lisuride 0.1-0.15 mg) and dopamine antagonists (intravenous sulpiride 200-400 mg and intravenous chlorpromazine 25 mg) were performed in 40 patients. Dopamine agonists enhanced "on" dyskinesias and markedly reduced or abolished "off" period dystonia and DD. Dopamine antagonists reduced all types of LID but usually aggravated parkinsonism. These clinical and pharmacological results indicate that LID in PD are a heterogeneous phenomenon difficult to explain on the basis of a single pathophysiological mechanism.
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PMID:Levodopa-induced dyskinesias in Parkinson's disease: clinical and pharmacological classification. 135 58

Dopamine receptor blocking drugs, commonly used in the treatment of involuntary movements, may cause potentially serious adverse effects, including tardive dyskinesia. Tardive dyskinesia has not been reported with tetrabenazine, a dopamine-depleting drug. We report a follow-up in 217 patients treated with tetrabenazine for about 18 months (range, 1 to 80). The response was rated on a scale of 0 to 5 (1 = marked improvement, 4 = no response, 5 = worsening). The mean effect from tetrabenazine was rated as follows: 2.3 in 44 patients with tardive dyskinesia, 2.6 in 15 with tardive dystonia, 2.6 in 10 with Huntington's disease, 2.7 in 17 with Gilles de la Tourette's syndrome, 2.8 in 19 with generalized dystonia, 2.8 in 57 with Meige's syndrome, and 3.4 in 25 with other focal dystonias. Twenty-two patients with a variety of unusual movement disorders had a mean effect of 2.9. Parkinsonism occurred as a side effect in 53 patients, sedation in 28, depression in 23, anxiety in 16, insomnia in 11, and akathisia in 10. The choreatic movement disorders are most amenable to tetrabenazine therapy, but tardive and idiopathic dystonia may also be responsive. Tetrabenazine is an effective and relatively safe drug for a variety of hyperkinetic movement disorders.
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PMID:Tetrabenazine therapy of dystonia, chorea, tics, and other dyskinesias. 327 37

We report a case of a 67-year-old woman who had dopa-responsive dystonia of late onset with diurnal fluctuations. She was well until the age of 65 years, when she noted the insidious onset of involuntary movements mainly involving the neck and trunk. She had no family history of movement disorders and had never received neuroleptics. Two years after her symptoms began, she visited our clinic. Neurological examination revealed slow repetitive extension and flexion movements of the neck and trunk, and irregular slow movements involving the mouth, tongue and limbs. The cranial nerves, cerebellar function, muscle strength, deep reflexes and sensory function were intact. Clinically and electromyographically, dystonia was characteristic of her involuntary movements. No parkinsonian features were present. The involuntary movements showed diurnal fluctuations that improved after sleep and the administration of L-DOPA and trihexyphenidyl. Dopamine receptor blocking agents aggravated her condition. Routine blood chemistry including copper metabolism, cerebrospinal fluid findings, and brain CT scan were all normal. Dopa-responsive dystonia is characterized by onset in childhood or adolescence and is frequently associated with parkinsonian features. Our patient had non-hereditary neck and trunk dystonia of late onset that responded to L-DOPA. Her disorder may constitute a specific form of dopa-responsive dystonia.
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PMID:[A form of dopa-responsive dystonia of late onset with diurnal fluctuations]. 833

The present studies were carried out to analyze the neurochemical and behavioral effects of peripheral sigma ligand administration in the rat. Based upon previous studies which showed an increase in turning behavior following unilateral intranigral administration of sigma ligands, we determined the effects of two sigma ligands, 1,3-di-o-tolylguanidine (DTG) and (+)-pentazocine, on extracellular dopamine levels in the rat striatum. Dopamine levels were monitored via microdialysis in awake freely moving animals following i.p. injection of the ligands. Both DTG (1 and 3 mg/kg) and (+)-pentazocine (10 mg/kg) produced a significant (30-50%) increase in extracellular dopamine. Given the relatively high concentration of sigma receptors in brain nuclei involved in facial and mouth movements, we have also determined the effects of the two sigma ligands on facial movements. Both ligands produced a significant increase in vacuous chewing movements, suggesting that studies on the consequences of sigma receptor activation may have relevance to animal models of human dystonia and/or dyskinesia.
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PMID:Increases in rat striatal extracellular dopamine and vacuous chewing produced by two sigma receptor ligands. 845 80

Dopamine (DA) deficiency has been implicated in Lesch-Nyhan disease (LND), a genetic disorder that is characterized by hyperuricemia, choreoathetosis, dystonia, and compulsive self-injury. To establish that DA deficiency is present in LND, the ligand WIN-35,428, which binds to DA transporters, was used to estimate the density of DA-containing neurons in the caudate and putamen of six patients with classic LND. Comparisons were made with 10 control subjects and 3 patients with Rett syndrome. Three methods were used to quantify the binding of the DA transporter so that its density could be estimated by a single dynamic positron emission tomography study. These approaches included the caudate- or putamen-to-cerebellum ratio of ligand at 80-90 min postinjection, kinetic analysis of the binding potential [Bmax/(Kd x Vd)] using the assumption of equal partition coefficients in the striatum and the cerebellum, and graphical analysis of the binding potential. Depending on the method of analysis, a 50-63% reduction of the binding to DA transporters in the caudate, and a 64-75% reduction in the putamen of the LND patients was observed compared to the normal control group. When LND patients were compared to Rett syndrome patients, similar reductions were found in the caudate (53-61%) and putamen (67-72%) in LND patients. Transporter binding in Rett syndrome patients was not significantly different from the normal controls. Finally, volumetric magnetic resonance imaging studies detected a 30% reduction in the caudate volume of LND patients. To ensure that a reduction in the caudate volume would not confound the results, a rigorous partial volume correction of the caudate time activity curve was performed. This correction resulted in an even greater decrease in the caudate-cerebellar ratio in LND patients when contrasted to controls. To our knowledge, these findings provide the first in vivo documentation of a dopaminergic reduction in LND and illustrate the role of positron emission tomography imaging in investigating neurodevelopmental disorders.
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PMID:Dopamine transporters are markedly reduced in Lesch-Nyhan disease in vivo. 864 11

Levodopa-induced dyskinesias result in considerable functional impairment for patients and formidable therapeutic challenges for physicians. A practical method of treating such dyskinesias is first to classify the levodopa dyskinesias according to their temporal profile after drug administration, namely, into predictable (interdose, biphasic and 'off-period') and unpredictable ('on-off') dyskinesias. Treatment of each type of dyskinesia requires a different and relatively specific therapeutic strategy. With progression of Parkinson's disease, the threshold for interdose dyskinesia lowers, while the threshold for antiparkinsonian efficacy is unchanged; therefore, the strategy is to maintain levodopa concentrations between these 2 thresholds and avoid high concentrations. Frequent small doses of liquid levodopa preparations may be indicated. Clozapine appears to increase the threshold for dyskinesia. However, its usefulness is limited primarily by dose-related sedation and by dose-unrelated agranulocytosis. Buspirone and fluoxetine may have specific antidyskinetic benefit. Surgical treatment may aid selected patients, although criteria for selection are not fully established. The biphasic dyskinesias occur just before and just after an oral dose of levodopa. They result when levodopa concentrations fall below or rise above the threshold for therapeutic efficacy; therefore, the strategy is to maintain concentrations as nearly constant as possible above that threshold. Dopamine agonists such as subcutaneous apomorphine combined with domperidone may be particularly helpful. Thalamic stimulation can also benefit selected patients. 'Off-period' dyskinesias occur at times of predicted low concentrations of levodopa. The treatment strategy is to provide sufficient levodopa or dopaminergic stimulation during those intervals. Dopamine agonists (e.g. bromocriptine at night) may help the characteristic early foot dystonia. Anticholinergic agents may also help. The unpredictable ('on-off') dyskinesias are first analysed to establish a pattern of response. Then, on the basis of that pattern, they are treated by maintaining levodopa concentrations or dopaminergic tone during the periods that would ordinarily be 'off.' Administration of liquid levodopa preparations, addition of dopaminergic agents, restriction of treatment during the morning hours as well as restriction of the majority of dietary protein in the evening meal may provide a period of predictable good function early in the day. Clozapine, even early in treatment, appears to reduce the incidence of these dyskinesias. Rescue with apomorphine during a malignant prolonged 'off' phase is particularly valuable.
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PMID:Methods of managing levodopa-induced dyskinesias. 882 14

Dopamine (DA) uptake sites, or transporters, were examined with [125I]RTI-121 in mutant mice that exhibit motor control deficits, namely weaver, lurcher and dystonia musculorum. In lurcher mice, the distribution of [125I]RTI-121 binding was similar to controls, except for a decrease in the subthalamic nucleus. For dystonia musculorum mice, the labelling presented no differences between controls and mutants, except for decreases in the dorsal half of caudal neostriatum and in the ventral tegmental area. Moreover, in this mutant the left rostral neostriatum DA transporters were reduced, when compared to the right counterpart. In weaver heterozygote (wv/+) mice, the distribution and density gradients of [125I]RTI-121 labelling were similar as in their controls, except in caudal neostriatum, where binding was slightly higher. In contrast, the weaver homozygote (wv/wv) showed important decreases in labelling of the dorsal quadrant of rostral neostriatum as well as of the dorsal half of caudal neostriatum, where the reductions of binding densities were of 65% to 70%, respectively. There were also slight decreases in [125I]RTI-121 binding in olfactory tubercles as well as in subthalamic nucleus, but only in wv/wv mice. In substantia nigra pars compacta and ventral tegmental area of wv/wv mice the labelling was lower; however, while the 60% decrease in labelling in substantia nigra was highly significant, the 30% reduction in ventral tegmental area did not attain statistical significance. In summary, in the ataxic neurological mutant mice studied, important reductions of DA transporters were documented only for the weaver mice, the cerebellar mutant presenting, besides its cerebellar pathology, a known degeneration of mesencephalic dopaminergic neurons. The results rule out major alterations of the central DA systems in lurcher and dystonia musculorum, and are compatible with the hypothesis that the dopaminergic abnormalities of weaver mutants are not secondary to cerebellar atrophy, but may be a direct consequence of the abnormal weaver gene expressed by DA neurons leading to their apoptotic death.
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PMID:Distribution of dopamine transporters in basal ganglia of cerebellar ataxic mice by [125I]RTI-121 quantitative autoradiography. 946 Jul 3

Movement disorders following midbrain haemorrhage are infrequently encountered in rehabilitation, and are uncommonly corrected by pharmacologic means. This report describes a 20 year-old male with a prior history of cocaine abuse who presented with a 4 day history of dysarthria and blurred vision following methamphetamine abuse. Physical examination demonstrated hypertension, left facial hemispasm, bilateral upward gaze paresis and ataxic gait. Magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) showed multifocal parenchymal haematomas in the mesencephalic tegmentum, subcortical left front region and right anterior thalamus consistent with cavernous angiomas. The patient was transferred to rehabilitation on hospital day 5. The following day, he developed choreoathetoid movements, dystonia, and aphasia, secondary to an extension of the midbrain haemorrhage. Cogentin was initiated with slight improvement in choreoathetoid movements. The patient began intensive multidisciplinary rehabilitation therapy but after 18 days of therapy, the patient remained totally dependent in activities of daily living (ADLs), transfers, mobility and was unable to communicate in any manner. A trial of Sinemet was initiated, with resultant steady improvement in functional ability over the next month. By discharge, the patient was independent in ADLs and ambulation. By 9 months post discharge follow-up, the patient was fully independent with normal cognition, and had self tapered all medications without ill effect. Dopamine agonist trials of appropriate duration appear indicated in cases of movement disorder (paucity or excess) following midbrain lesions.
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PMID:Pharmacologic management of movement disorder after midbrain haemorrhage. 965 26

Parkinson's disease is a progressive degenerative disorder of the central nervous system. The hallmark physical signs are tremor, rigidity and bradykinesia. Idiopathic Parkinson's disease is caused by the progressive loss of dopaminergic neurons in the substantia nigra and nigrostriatal pathway of the midbrain. Secondary parkinsonism may be caused by certain drugs (e.g., metoclopramide and haloperidol) or by cerebrovascular disease (e.g., multiple lacunar strokes). The disease can usually be diagnosed based on the history and physical findings. Dopamine replacement is still considered the most efficacious treatment for Parkinson's disease, but dopamine agonists, formerly prescribed only as adjunctive therapy, are emerging as useful initial therapy. Other pharmacologic treatments include drugs that inhibit dopamine-metabolizing enzymes (monoamine oxidase-B and catechol O-methyltransferase). Injections of botulinum toxin can be helpful in patients with associated dystonia or blepharospasm. Surgery may be indicated for certain patients or when symptoms do not respond to medical therapy. Additional adjunctive therapies include physical therapy, nutritional counseling and techniques to help patients manage emotional and cognitive changes related to the disease.
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PMID:Update on Parkinson's disease. 1022 2


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