Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To assess the need for a regional expertise in movement disorders, the numbers of patients, clinic visits, and medication changes for a new movement disorder clinic were recorded. During 3 1/2 years, 355 patients were seen, with 1,329 clinic visits. Idiopathic Parkinson's disease was the most common diagnosis, comprising 36% of the population, followed by dystonia (17%), tremor (12%), parkinsonism (i.e., Parkinson's plus syndromes, drug-induced parkinsonism, etc.) (10%), chorea (10%), Tourette's syndrome (6.5%), and tardive dyskinesia (3.4%). Distribution of follow-up visits was similar, with Parkinson's disease (52%) being most frequent and Tourette's syndrome (3.1%) least frequent. The relative utilization of medical care by each patient group was assessed by determining the number of medication changes and the number of clinic visits per follow-up year. No differences in these measures were found using a one-way analysis of variance. Of the Parkinson's disease patients, 67% had Hoehn and Yahr stages III-IV and 77% of the clinic visits were made by this subgroup. When considered in light of the prevalence of each of the diseases, these data show a need for an expertise in movement disorders for a population base of the size we have served.
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PMID:Profile of patients enrolled in a new movement disorder clinic. 175 52

We studied the temporal patterns of chorea and plasma levodopa profiles in 30 patients with Parkinson's disease whose motor fluctuations were difficult to characterize and treat on the basis of observation alone. We were able to determine whether chorea was associated with high levodopa concentrations or low levodopa concentrations or both. We found the following patterns of levodopa-associated chorea: chorea due to inadequate levodopa levels, chorea due to biphasic levodopa absorption, chorea associated with either rapid or slow levodopa absorption, and chorea due to long-duration levodopa absorption mimicking a sustained-release preparation. Seven patients benefited after their dosing schedules were rearranged as a result of information gained from monitoring. We conclude that any patient with levodopa-associated chorea who cannot be regulated on the basis of observation alone should be studied with simultaneous plasma levodopa measurements and clinical monitoring to detect an unusual plasma levodopa pattern that may be improved by adjustment of dosing schedule.
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PMID:Benefits of monitoring plasma levodopa in Parkinson's disease patients with drug-induced chorea. 189 65

Using [18F]dopa, [11C]raclopride, C15O2, and positron emission tomography, we have assessed striatal dopamine storage capacity, dopamine D2-receptor integrity, and regional cerebral blood flow, respectively, of 6 patients with neuroacanthocytosis. The patients with neurocanthocytosis all had chorea and variable combinations of seizures, dementia, axonal neuropathy, and orolingual self-multiation. [18F]dopa positron emmission tomographic findings were compared with 30 normal controls and 16 patients with sporadic, L-dopa-responsive, Parkinson's disease. Caudate and anterior putamen [18F]dopa uptake were normal in patients with neuroacanthocytosis, but mean posterior putamen [18F]dopa uptake was reduced to 42% of normal, similar to that in patients with Parkinson's disease. In patients with neuroacanthocytosis, mean equilibrium caudate: cerebellum and putamen: cerebellum [11C]raclopride uptake ratios were reduced to 54% and 62% of normal, compatible with a 65% and 53% loss of caudate and putamen D2-receptor-binding sites, respectively. Striatal and frontal blood flow was also depressed. The severe loss of D2-receptor-bearing striatal neuron, with concomitant loss of dopaminergic projections from the nigra to the posterior putamen, is consistent with both chorea and extrapyramidal rigidity being features of patients with neuroacanthocytosis.
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PMID:Presynaptic and postsynaptic striatal dopaminergic function in neuroacanthocytosis: a positron emission tomographic study. 189 9

Long-term treatment of human Parkinson's disease with levodopa or dopamine agonists is often complicated by the appearance of abnormal involuntary movements (dyskinesias) that are extremely difficult to control. Little is known of the cause, pathophysiological mechanisms, or possible strategies for amelioration of this manifestation of dyskinesia. A hypothesis is set forth on the neural mechanisms that mediate levodopa- or dopamine agonist-induced dyskinesia (in particular chorea) as a side effect of the treatment of parkinsonism. Evidence is drawn from both clinical observations and experimental studies in a spectrum of movement disorders ranging from ballism through chorea to parkinsonism. It is proposed that (a) All forms of chorea, whatever their origin, share a common underlying neural mechanism. (b) Disordered activity of the subthalamic nucleus is central to the generation of choreic movements. In levodopa- or dopamine agonist-induced dyskinesia, (c) The site of action of dopaminergic agents in causing chorea is the putamen. (d) The specific pathophysiological state conducive to the appearance of chorea is brought about by the long-term exposure of the dopamine-depleted (parkinsonian) putamen to exogenous dopaminergic agents. (e) Long-term exposure to dopaminergic agents causes (either directly or indirectly) preferential inhibition of the subpopulation of putaminal neurones that project specifically to the lateral segment of the globus pallidus. This causes disinhibition of lateral pallidal neurones, which become overactive and physiologically inhibit the subthalamic nucleus. (f) The hypothesis suggests a number of possible strategies that might be useful for the alleviation of levodopa-induced dyskinesia.
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PMID:A hypothesis on the pathophysiological mechanisms that underlie levodopa- or dopamine agonist-induced dyskinesia in Parkinson's disease: implications for future strategies in treatment. 197 Jan 20

Actual phenomena of various types of involuntary movements listed below were demonstrated by moving pictures, which were followed by comments on symptomatology, in particular the fundamental characteristics of an individual involuntary movement. These characteristics are the essence of each involuntary movement, and it is necessary to recognize both its phenomenon itself and its accumulated knowledge in order to realize and interpret the involuntary movement. The following involuntary movements are treated: (1) typical tremor-at-rest in paralysis agitans, (2) atypical parkinsonian tremor, (3) essential tremor, (4) chorea, (5) ballism, (6) athetosis, (7) choreoathetosis, (8) dystonia, (9) spontaneous myoclonus at rest, (10) intention or action myoclonus, (11) intention tremor and (12) hyperkinesis.
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PMID:[Symptomatology of the involuntary movement]. 201 97

Between 1986 and 1988 a door-to-door survey was conducted on a stable rural population of 60,820 in central Ethiopia. Trained lay health workers made a complete census and identified cases with symptoms and signs of neurological disorders, using specially designed questionnaires which, in a previous pilot study, were found to have a sensitivity of 91% and specificity of 85%. Neurological disorders in the rural population were epilepsy, postpoliomyelitis paralysis, mental retardation, peripheral neuropathy (mainly due to leprosy), and deaf-mutism with prevalence rates (cases/100,000 population) of 520, 240, 170, 150 and 130, respectively. The prevalence rates of the other less common neurological disorders were 62 for hemiparesis (15 of which were for cerebrovascular accidents), 20 for cerebral palsy, 16 for optic atrophy, 12 for perceptive deafness, 10 for tropical spastic paraparesis, 7 for Parkinson's disease and 5 for motor neuron disease, ataxia and chorea/athetosis. Among related non-neurological conditions, blindness, locomotor disability and deafness were predominant. The significance and role of such a neuroepidemiological study in laying the strategies for the prevention of neurological disorders and rehabilitation of patients are discussed in the context of a developing country.
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PMID:Community-based study of neurological disorders in rural central Ethiopia. 208 51

Videotapes of patients with Huntington's chorea, tardive dyskinesia (TD), and L-DOPA-induced chorea in Parkinson's disease were taken while the patients were seated with their legs dangling. The videotapes were scored in a blinded fashion for suppressibility of dyskinesias. Most patients with TD or L-DOPA-induced chorea substantially suppressed their involuntary movements, whereas most patients with Huntington's chorea did not. There was a small overlap between the TD and Huntington's chorea groups and suppressibility therefore could not absolutely distinguish between them. Suppressibility testing may nonetheless be a valuable clinical tool since a good, excellent, or complete suppressibility rating was highly suggestive of TD but not Huntington's chorea. TD and L-DOPA-induced chorea may be more pathophysiologically similar to each other than either is to Huntington's chorea.
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PMID:A blinded study of the suppressibility of involuntary movements in Huntington's chorea, tardive dyskinesia, and L-dopa-induced chorea. 214 44

We present a review on recent neuroimaging techniques, like x-ray computed tomography (XCT), magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission tomography (SPECT) in dementia and related diseases. Significant new findings have been obtained using techniques reflecting proton density, regional brain perfusion and brain metabolism. In dementia of the Alzheimer type, for example, temporoparietal and sometimes also frontal reductions in cerebral blood flow and metabolism are characteristic. The infarctions found in multi-infarct dementia are especially well visualized on T2-weighted MRI images. Pick's disease is characterized by brain atrophy and decrease of radiotracer activity in the frontal lobes. In huntington's chorea the metabolic rate on PET scan in the area of the caudate nuclei may be reduced even before signs and symptoms become apparent. Furthermore, neuroimaging provides us with fairly typical finding in Creutzfeld-Jakob's disease, alcoholic dementia, Wilson's disease, hydrocephalus, Parkinson's disease, progressive supranuclear ophthalmoplegia, Fahr's disease, and the olivopontocerebellar ataxias. Neuroimaging techniques, however, have always to be interpreted in conjunction with clinical findings, thus disclosing their full range of information.
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PMID:[Diagnostic differentiation of dementia diseases by modern imaging procedures]. 227 95

Intermittent treatment with L-dopa over a 2-year period induced abnormal involuntary movements in MPTP-treated squirrel monkeys. Dyskinesias included a choreic and dystonic component. Dose-response curves for chorea and dystonia revealed that the same dose of L-dopa (30 mg/kg) induced the highest score for both dyskinesias: however, the severity was much greater for chorea. Choreic movements were always most prevalent at the time of peak effect, whereas dystonia was apparent at the time of peak effect and at "end-of-dose", and was occasionally observed spontaneously. Our findings indicate that squirrel monkeys treated with MPTP develop L-dopa-induced dyskinesias which closely resemble those observed in Parkinson's disease. This species provides a valuable animal model to develop improved therapeutic agents.
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PMID:Characterisation of dyskinesias induced by L-dopa in MPTP-treated squirrel monkeys. 239 4

1. Experimental models of ballism, chorea and Parkinson's disease have been developed in the primate, and the underlying neural mechanisms which mediate these disorders of movement have been investigated using the 2-deoxyglucose uptake technique. 2. In ballism, the subthalamic nucleus is either lesioned or underactive. Because of the excitatory nature of subthalamic efferent fibres, this leads to abnormal underactivity of neurons in the medical segment of the globus pallidus which project to the ventral anterior and ventral lateral nuclei of the thalamus, and to the pedunculopontine nucleus of the caudal midbrain. 3. In chorea, there is underactivity of GABAergic striatal (putaminal) neurons which project to the lateral segment of the globus pallidus. This leads to overacting of lateral pallidal neurons and, thus, physiological inhibition of the subthalamic nucleus. Common neural mechanisms, therefore, underlie the appearance of dyskinesia in ballism and chorea. 4. In parkinsonism, there is overactivity of putaminal neurons projecting to the lateral pallidal segment. This results in excessive inhibition of lateral pallidal neurons and, as a consequence, disinhibition of the subthalamic nucleus. Overactivity of the subthalamic nucleus provides excessive drive upon medial pallidal neurons projecting to thalamic and pedunculopontine nuclei.
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PMID:Neural mechanisms in disorders of movement. 256 16


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