Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This article reviews new medical and surgical treatments for Parkinson's disease (PD). Catechol-O-methyl-transferase (COMT) inhibitors supplement the variety of antiparkinsonian drugs interacting with the dopaminergic system. Clinical studies show that COMT inhibitors prolong the action of levodopa in patients with the "wearing off" phenomenon. The atypical antipsychotic drug clozapine is the treatment of choice for the alleviation of levodopa-induced psychosis. Clozapine also has beneficial effects on tremor and levodopa-induced dyskinesias. Thus, COMT inhibitors and clozapine provide new opportunities for the treatment of patients with longstanding PD and fluctuating responses to levodopa. Experimental evidence in animals suggests that glutamate antagonists have symptomatic and neuroprotective actions in PD. At present, however, only weak antiglutamatergic drugs that have low specificity, such as memantine, amantadine, and budipine are available for clinical studies. Neurotrophic factors, in particular ciliary neurotrophic factor and glial cell line-derived neurotrophic factor, are among the most promising new approaches for neuroprotection in PD. Problems of bioavailability, however, thus far preclude their use in patients. An improved understanding of the pathophysiology of parkinsonism has led to a renaissance of stereotaxic surgery. The subthalamic nucleus is a potential new target for surgical intervention. Ventroposterior pallidotomy has been shown to improve not only rigidity and tremor, but also akinesia. The techniques for thalamic interventions have been refined by introducing chronic thalamic stimulation. Future transplantation approaches to PD will focus on the use of genetically modified cells carrying genes for dopamine-synthesizing enzymes or neurotrophic factors. Animal studies show the feasibility of in vivo gene transfer for the treatment of PD.
 ...
PMID:New medical and surgical treatments for Parkinson's disease. 795 44

Clozapine, the only commercially available atypical neuroleptic, is approved for the treatment of schizophrenic patients who are unresponsive to or intolerant of typical neuroleptics. It has an unusual pharmacologic profile compared with standard neuroleptics, and it follows that clinical response to this drug is also different. It has shattered the notion that a drug must be capable of inducing or worsening parkinsonism to be a potent antipsychotic. Based on these findings, it is being used increasingly by neurologists for psychiatric and nonpsychiatric problems in patients with movement disorders. The most common use for clozapine among neurologists is in the management of drug-induced psychosis in Parkinson's disease (PD). This problem has been a source of increased morbidity and mortality in PD because of a lack of adequate therapeutic intervention. At this time, because of success in numerous open trials, with improvement of > 80% of patients, clozapine therapy for psychosis in PD is becoming the standard of care. It also appears to be of value in the management of some motor features of PD, including tremors and dyskinesia and possibly even sensory symptoms such as akathisia and pain. The literature also suggests that clozapine may be of potential benefit in hyperkinetic movement disorders including essential tremor, Huntington's disease, and tardive dyskinesia. We review the current data concerning the use of clozapine in patients with these movement disorders and others.
 ...
PMID:The emerging role of clozapine in the treatment of movement disorders. 925 Oct 65

A survey of the prescribing of psychotropic drugs was carried out at the Psychiatric Hospital of Bahrain. This retrospective study on 60 inpatients of the Long Stay Ward revealed a man:woman ratio of 2.7. 91% of the men and 88% of the women were over 40 years old. 44 of the 60 patients had a diagnosis of schizophrenia, the rest had dementia, depression, schizoaffective disorders, drug-induced psychosis, general paralysis or Huntington's chorea. 95% of patients received antipsychotic drugs. Thioridazine was the most common drug followed by chlorpromazine. The mean number of drugs/patient was 1.7, with 41.7% of patients receiving only 1 drug. Tardive dyskinesia was observed in 11 patients and 9 experienced varying degrees of tremor. The findings confirm that psychiatric illness treated by psychiatrists need not lead to polypharmacy. As a consequence, its treatment may be less likely to result in adverse reactions than when patients are treated by general practitioners.
 ...
PMID:Utilisation of psychotropic drugs in patients of the long stay ward. 1014 30

Quetiapine is an atypical antipsychotic with clozapine-like pharmacology but without associated agranulocytosis. We report our complete experience with quetiapine for the treatment of drug-induced psychosis (DIP) in Parkinson's disease (PD). Thirty-five patients with PD and DIP aged 75 years (range, 58-89) with a mean PD duration of 8.4 years on an average of 427 mg levodopa per day received a mean dose of 40.6 mg quetiapine daily. Twenty of 24 neuroleptic-naive patients reported marked improvement of psychosis without a decline in motor function as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS-motor). Ten patients had a baseline and 4-week follow-up assessment using the Mini-Mental Status Examination (MMSE) and Brief Psychiatric Rating Scale (BPRS). The improvement in BPRS score (32.6 versus 22.8) was clinically and statistically significant (p = 0.024). Three of 24 were unable to tolerate quetiapine because of orthostatic hypotension, headache, nausea, and persistence of hallucinations. One patient died of an unrelated cause. We also tried to switch 11 psychiatrically stable patients on clozapine (eight) and olanzapine (three). Five patients made this transition without a loss of effect as measured on BPRS and MMSE. Six did not (five on clozapine, one on olanzapine) because of confusion, erratic behavior, and increased hallucinations. No crossover failure had worsened PD except for increased tremor in one. Quetiapine is useful and well-tolerated as a first drug to treat DIP in PD but must be used cautiously to replace other atypical antipsychotic drugs.
 ...
PMID:Quetiapine for the treatment of drug-induced psychosis in Parkinson's disease. 1034 74

This paper gives an overview of the clinical importance of SPECT and PET imaging of the dopaminergic system in the differential diagnosis and for the determination of the progression rate of Parkinson's disease (PD). D2 receptor imaging can help to differentiate multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) from PD. In patients treated with neuroleptics it is possible to determine the rate of striatal D2 receptor blockade using this technique. This occupancy rate parallels the occurrence of parkinsonian side effects. Its measurement helps in the selection of newer atypical neuroleptics, which can be used to treat drug-induced psychosis in PD because they do not aggravate parkinsonian symptoms. Imaging of dopaminergic neurons with [123I]beta-CIT SPECT or [18F]DOPA PET is a way to visualize and quantify the nigrostriatal dopaminergic lesion in PD. Findings correlate with clinical rating scales and demonstrate the feasibility of detecting the preclinical lesion in patients with hemiparkinson or familial PD. [123I]beta-CIT SPECT can easily distinguish patients with essential tremor and patients with "lower body parkinsonism" due to a subcortical vascular encephalopathy. MSA and PSP cannot be separated from PD with this method alone. Longitudinal studies with [123I]beta-CIT SPECT and [18F]DOPA PET can quantify the progression rate in PD. SPECT results from our own group show a low rate of progression in patients with a long duration of disease and a more marked progression rate in patients with shorter disease duration. In the former group regions in the striatum with higher beta-CIT binding at the time of the first SPECT scan decline faster than regions with lower binding. These findings suggest a curvilinear course of progression which starts at different time points in different striatal regions and which levels off after several years of disease duration. These findings are in line with data from PET studies and underline the importance of an early start of neuroprotective strategies. Preliminary data from PET and SPECT studies in early PD suggest that dopamine agonists might have a slight neuroprotective effect and might slow down the rate of progression of the disease.
 ...
PMID:SPECT and PET imaging of the dopaminergic system in Parkinson's disease. 1119 11

The frequency, phenomenology, and risk factors of hallucinations and delusions were investigated in 64 consecutive inpatients with Parkinson's disease. Fifty patients were admitted to our hospital with symptoms related to Parkinson's disease: psychiatric problems 27 (psychosis 22; anxiety 2; depression 2; mania 1): motor symptoms, 20 (wearing-off 5; akinesia 4; freezing 4; postural instability 4; dyskinesia 2; tremor 2; dystonia 1), and sensory symptoms, 3. Fourteen patients were admitted with other medical problems (pneumonia 4; cerebral infarction 3; bone fracture 3; lumbago 2; seizure 1; cat bite 1). Totally 49 patients had psychiatric problems. Psychosis was present in 43 patients, dementia in 10, depression in 8, mania in 1, anxiety in 10, agitation in 6, stereotypy in 2, and hypersexuality in 2. Of the 43 patients with psychoses, 40 presented with visual hallucinations, 18 with auditory hallucinations, and 23 with delusions. To determine what the clinical correlates with the severity of psychosis were, we divided the patients into 3 groups: the severe group, 22 patients admitted because of psychotic symptoms; the mild group, 21 patients admitted because of problems other than psychosis but presenting psychotic symptoms; and the control group, 21 patients who had no psychotic symptoms. Incidences of auditory hallucinations and delusions were higher in the severe group as compared to the mild group. Patients in the severe group had higher Hoehn-Yahr stages, lower Mini-Mental State Examination scores, decreased H/M ratios of cardiac 123I-MIBG uptake, and lower frequencies of background activity on electroencephalograms. There were no differences in age at admission, age at onset of Parkinson's disease, duration of illness, amounts of levodopa and dopamine agonists received, Hamilton's depression rating scores, and brain MR findings, including atrophy and ischemic changes. Emergence of psychotic symptoms in parkinsonian patients appears to be clearly associated with impaired cognitive function. Therefore, it may be associated with the disease process itself. Terms such as dopaminomimetic or levodopa-induced psychosis may not be appropriate when describing psychosis in Parkinson's disease.
 ...
PMID:[Psychoses in patients with Parkinson's disease; their frequency, phenomenology, and clinical correlates]. 1571 92

To investigate whether transcranial brain sonography (TCS) discriminates different courses of idiopathic Parkinson's disease (PD), 101 patients with clinically definite PD were studied. In four patients, TCS was not possible due to insufficient acoustic temporal bone windows. Substantia nigra (SN) hyperechogenicity was found in 96% of assessable patients. Larger SN echogenic size correlated with younger age at PD onset (Spearman correlation, r = -0.383; P < 0.001), but not with age, PD duration, or severity. Marked bilateral SN hyperechogenicity indicated early-onset rather than late-onset PD, and akinetic-rigid (AR) or mixed-type (MX) PD rather than tremor-dominant PD. SN echogenic sizes were larger contralateral to the clinically more affected side in AR PD and MX PD patients. Reduced echogenicity of brainstem raphe was associated with depression (RR = 1.61; 95% CI = 1.05-2.46; P = 0.044) but not with other clinical features. Caudate nucleus hyperechogenicity was, independently from PD duration, related to drug-induced psychosis (RR = 2.40; CI = 1.36-4.22; P = 0.001), but not to motor fluctuations. Lenticular nucleus hyperechogenicity indicated AR PD rather than tremor-dominant PD (RR = 1.44; CI = 1.11-1.86; P = 0.040). Frontal horn dilatation > 15.4 mm (mean of bilateral measurements) indicated increased risk of dementia (RR = 4.11; CI = 1.51-11.2; P = 0.001). We conclude that TCS displays characteristic changes of deep brain structures in different clinical manifestations of PD.
 ...
PMID:Transcranial brain sonography findings in clinical subgroups of idiopathic Parkinson's disease. 1708 96

Deep brain stimulation of subthalamic nucleus (STN-DBS) is currently the most common therapeutic surgical treatment for patients with Parkinson's disease (PD) who have failed medical management. The percentage improvement in Unified Parkinson's disease Rating Scale (UPDRS) part II (activities of daily living) and III (motor) scores was more than 50%. Furthermore, levodopa-induced dyskinesias are dramatically improved because STN stimulation permits an approximately 50% reduction in antiparkinsonian treatment. How should we decide an appropriate candidate for DBS? It seems that there is a little difference about indication of DBS between neurosurgeons and neurologists. Since the efficacy of DBS is the improvement in dopaminergic drug-sensitive motor symptoms, we offer surgery to patients only when medical therapy has failed; (1) severe motor fluctuations, (2) severe dyskinesia, (3) tremor uncontrollable by medications, (4) painful dystonia, (5) side-effect for medication (drug-induced psychosis, nausea, vomitting). Taking account of contraindications is important to get successful outcome of the surgery. Dementia, cognitive deficits and psychosis (not drug-induced) are not improved by DBS. When patients are not able to see experienced doctors who manage in programming and dealing with postoperative problems, they are not appropriate candidates. Though benefit to mobility is evident, a risk-benefit assessment should to be made for each patient.
 ...
PMID:[The indication of DBS in Parkinson' disease (from a neurological standpoint)]. 2319 28