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)

Parkinson's disease is essentially motor. The core symptoms comprise akinesia, rigidity and tremor. Concomitantly, signs of autonomic, cognitive and affective disturbances may be found. The disease progresses slowly and, without treatment, ultimately results in disability and loss of independence. The symptoms can be controlled for a long time by pharmacotherapy. Dopaminergic drugs such as L-DOPA, dopaminreceptor agonists, and MAO-B- and COMT-blockers can essentially improve most of the symptoms. The tremor may be alleviated by central anticholinergic drugs. With time, however, unwanted side effects such as "end of dose akinesia", "on-off phenomena", hyperkinesis and exogenous psychosis come into play. Therefore, pharmacological treatment becomes very complex in the late stages of the disease and the unwanted side effects can no longer be sufficiently controlled. It is not clear whether conservative approaches will be ever able to cope with these problems. This explains the search for novel treatment strategies, e.g. neurotransplantation, stereotaxic lesion of the subthalamic nucleus or stimulation techniques.
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PMID:[Clinical aspects and conservative therapy of Parkinson disease]. 857 92

Parkinson's disease (PD) is one of the major neurological diseases affecting elderly subjects. Presumed prevalence of PD is 80-100 per 100 thousands and it is estimated that there are approximately 100 thousands patients in Japan. From a statistic on age distribution of patients visiting doctors, it is estimated that patients with ages at 75-79(639/100,000) and 80-84(632/100,000) are highest in number. Juvenile parkinsonism is a syndrome with parkinsonian motor symptoms and dystonia developing before and after ten years of age. Reports on this syndrome have been accumulated in Japan and gene abnormality in a enzyme relating to dopamine metabolism was discovered in the hereditary progressive dystonia with marked diurnal fluctuation (Segawa). Among symptomatic parkinsonism, cerebrovascular parkinsonism is mainly due to multiple infarction in the basal ganglia or Binswanger's disease in Japan, and both conditions develops parkinsonism, pseudobulbar palsy and dementia progressively. Diffuse Lewy body disease and a unique type of progressive supranuclear palsy presenting a disorder designated "pure akinesia" were studied mainly in Japan. In drug therapies of PD, it has been argued why the maintenance dose of levodopa or dopamine agonists was generally low in Japan. In addition to constitution and drug metabolism, attitude of Japanese people to worry side effects more than merit with beneficial effects by a drug may have inevitably lead to low maintenance dose. Development of new drugs have been undertaken in parallel with US and Europe. Talipexole hydrochloride has been on market in Japan recently, but MAO-B inhibitors and COMT inhibitors are in final stages to wait evaluations by the governmental committee.
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PMID:[Clinical characteristics and trends in research of Parkinson's disease and parkinsonism in Japan]. 901 16

6-[18F]-fluorodopa (FDOPA) was developed as an analogue of L-DOPA across the blood-brain-barrier and to carry into nigrostriatal dopaminergic neurons. PET study using FDOPA revealed presynaptic dopaminergic function in the striatum of nigrostriatal system of the human brain and many studies have performed to clarify the pathogenesis of Parkinson's disease. FDOPA is also an efficient tracer to analyze pharmacokinetics of L-DOPA by measuring radioactivities of its metabolites in the peripheral blood by HPLC and to evaluate pharmacological effects on dopamine metabolism by pretreatment of dopa decarboxylase inhibitor or COMT inhibitor. PET study using FDOPA is useful not only to diagnose Parkinson's disease but also to differentiate from parkinsonism in combination with other radioactive ligands and with other neuroimaging methods such as MRI.
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PMID:[PET study using 6-[18F]-fluorodopa in Parkinson's disease]. 901 52

Ro41-0960 is a potent, fluorine containing COMT inhibitor which has be en reported to cross the blood brain barrier and to inhibit COMT in the brain. It is structurally similar to Ro40-7592 which is currently undergoing clinical trials in Parkinson's disease. Positron emission tomographic (PET) studies in baboon using F-18 labeled Ro41-0960 demonstrated a negligible uptake in the brain both at tracer doses and with the addition of unlabeled drug (1.5 mg/kg) at all times through a 90 min experimental interval. The brain to plasma ratios of F-18 averaged about 0.025. Region of interest analysis of the brain tissue area suggests that most of F-18 in the brain was due to the blood in the brain and not the brain tissue itself. However, high uptake was observed in the kidneys and in other organs which are known to have high COMT activity. Studies in mice showed that at 30 min after injection of tracer, F-18 in kidneys was largely as unchanged [18F]Ro41-0960 and that it could be displaced with unlabeled Ro41-0960. The fact that the average brain to blood ratio for mice (n=12) was 0.04, and that similar HPLC metabolite patterns were observed for brain and blood, provides consistent evidence that nearly all the F-18 in the brain represents F-18 in the cerebral blood vessels. These studies raise the question of whether the central pharmacological effects of Ro41-0960 are due to its presence in the brain. They also provide the first example of a positron emitter labeled radiotracer for COMT, and provide initial encouraging evidence that [18F]Ro41-0960 may be used to examine COMT in peripheral organs in vivo.
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PMID:Mapping catechol-O-methyltransferase in vivo: initial studies with [18F]Ro41-0960. 949 60

We report -108Met/Val polymorphism of the COMT gene in Japanese patients with Parkinson's disease (PD). The allele frequency for -108Val was higher in PD patients compared with controls, although the differences did not reach the statistical significance. However, the frequency of -108Val homozygotes was significantly higher in PD patients (56.8%) than in control subjects (44.2%), and heterozygotes of -108Met/Val were less in PD. COMT gene polymorphism may constitute a genetic risk factor for PD among Japanese.
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PMID:Catechol-O-methyltransferase genotype and susceptibility to Parkinson's disease in Japan. Short communication. 950 77

Although there is no known cure for essential tremor or Parkinson's disease (PD), medical treatment can often significantly reduce or eliminate functional disability. Mild essential tremor does not require treatment, and early treatment does not arrest or slow the natural progression in symptoms. When essential tremor interferes with daily activities, medical treatment options include beta blockers, anticonvulsants, benzodiazepines, and carbonic anhydrase inhibitors. Because of the great variability in the presentation of PD, no single approach is appropriate for all patients. Levodopa is the mainstay of pharmacologic therapy for PD, although other agents are indicated for monotherapy or in combination with levodopa. These include traditional and newer dopamine agonists, amantadine, anticholinergics, selegiline, and an emerging class of agents called COMT inhibitors.
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PMID:Medical treatment of essential tremor and Parkinson's disease. 959 79

More than 50% of patients with Parkinson's disease (PD) develop response fluctuations following prolonged treatment with levodopa. Some are due to central pharmacodynamic mechanisms such as reduced striatal synthesis and storage of dopamine from exogenous levodopa and subsensitization of post synaptic dopaminergic receptors. Other fluctuations, especially the "delayed on" (increased time latencies from dose intake to turning "on") and "no on" (complete failure of levodopa dose to induce an "on" response) are caused by peripheral pharmacokinetic mechanisms. Patients with PD, especially those with response fluctuations, have gastric atony. The reduced motility of the stomach, combined with the poor solubility of levodopa, is the cause for the delayed and incomplete absorption of levodopa. The best strategy to overcome central pharmacodynamic mechanisms and to increase daily "on" hours can be achieved by using dopamine agonists, controlled release preparations, MAO-B and COMT inhibitors. Therapeutic strategies that improve levodopa absorption are needed to overcome response fluctuations that are caused by peripheral mechanisms. This can be achieved by crushing levodopa and drinking it as a suspension. Administration of crushed levodopa or levodopa/carbidopa/ascorbic acid solutions orally or through gastroduodenal or gastrojejunostomy tubes may also be helpful. Prokinetic drugs, such as prepulsid, improve absorption of levodopa by enhancing gastric motility. Bypassing the stomach by subcutaneous dopamine agonists (apomorphine and lisuride pumps) or by the novel prodrug of levodopa, i.e., levodopa ethylester, may produce dramatic rescue from incapacitating "off" states.
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PMID:Management of response fluctuations: practical guidelines. 971 79

Parkinson's disease is characterised by a variable combination of tremor, rigidity, bradykinesia and impaired righting reflexes. The cumulative life-time risk is one in 40. Levodopa remains the single most effective treatment in older patients, and the minimum dose to achieve maximum functional benefit should be employed. When fluctuations occur, controlled release preparations and selegiline can improve function. Oral dopamine agonists have a role but the combined side effect profile with levodopa should be monitored. COMT inhibitors have recently become available. Subcutaneous apomorphine can be helpful when "on-off" phenomena are marked. The concept of neuroprotection continues to be debated. Surgery is an option for fitter older people but neurotransplantation remains essentially a research tool.
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PMID:The treatment of Parkinson's disease in older people. 983 45

The recent advances in the treatment of Parkinson's disease have made for significant improvements in the quality of life and mortality rate of those who suffer from this neurodegenerative disease. At the same time, the number of options and the complexity of multi-drug regimens have posed a great challenge for the clinician caring for the patient with Parkinson's disease. Though there are still many questions to be answered in regard to the potential neuroprotective effects of several medications, a few general rational treatment plans can be outlined. In patients requiring treatment in the early stages of the disease, especially with a predominance of tremor, anticholinergics or amantadine should be considered initially. At this point, it would be reasonable to add selegiline for both therapeutic and possible neuroprotective effects. As a patient becomes more affected by the disease and additional therapy is necessary, starting either a dopamine agonist or levodopa would be a rational choice. Continuation of selegiline and, possibly, amantadine for neuroprotective reasons should be contemplated. Titration in levodopa therapy (with controlled-release or standard levodopa) to higher levels should prompt addition of a dopamine receptor agonist if one has not been started previously. Conversely, if a patient is receiving only a dopamine receptor agonist and is becoming progressively disabled, levodopa should be added to the regimen. Fluctuations in motor abilities may be improved further by the use of a COMT inhibitor. Patients with uncontrollable motor fluctuations should be considered for surgery. Undoubtedly, the coming years will bring more treatment options and more evidence on which sequences and combinations of therapies are the most beneficial. Differences in efficacy and adverse effects for each patient must be taken into consideration when outlining and carrying out a treatment plan. By using a rational approach to the treatment of Parkinson's disease, with the above guidelines in mind, the patient should be able to enjoy a good quality of life and level of function for many years.
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PMID:The treatment of Parkinson's disease: current concepts and rationale. 984 72

The management of Parkinson's disease has undergone recent changes with the advent of new therapies, both pharmacotherapy and surgery. Available interventions are discussed. Levodopa remains the mainstay of therapy. New drugs include the dopamine agonists and COMT inhibitors. New dopamine agonists which may have a levodopa "sparing effect;" it has been suggested that some of the drugs should be considered as first line treatments for newly diagnosed Parkinson's disease patients. We review roles of these drugs. The concept of neuroprotection in neurodegenerative disorders such as Parkinson's disease became popular in the mid 1980s and it is hoped that eventually therapy will be directed at slowing progression of the disease. A great deal more work needs to be done before a suitable agent is identified as being neuroprotective. Potential neuroprotective agents are reviewed. Surgical therapies for Parkinson's disease consisting of various forms of lesion surgery as well as stimulation procedures are reviewed. Complications of drug therapy include motor problems such as motor response fluctuations, as well as psychiatric complications including levodopa-induced psychosis. Atypical neuroleptic agents and ECT for psychiatric syndromes associated with Parkinson's disease are discussed. Algorithms for the management of early disease as well as the management of psychosis in Parkinson's disease are included. Treatment options for advanced disease are tabulated.
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PMID:Management of Parkinson's disease a review of current and new therapies. 1097 42


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