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)

We examined 50 untreated parkinsonian patients with a complaint of tremor for the presence of a resting, postural, or kinetic tremor. Tremors were recorded by an accelerometer to determine amplitude and frequency. A postural tremor was present in 92% and a resting tremor in 76%. The amplitude of postural tremor was greater than resting tremor in 50%, the same in 25%, and less in 25%. The average tremor frequency of resting and postural tremor was not significantly different. Carbidopa/levodopa reduced testing tremor in 58% and postural tremor in 46% of patients. The dopamine agonist naxoglide (PHNO) reduced resting tremor in 77% and postural tremor in 70% of patients. Postural tremor was not worsened by either drug. It is concluded that tremors in both the resting and postural positions are an integral part of the symptoms of Parkinson's disease and that both tremors have a similar frequency and pharmacological responsiveness in the early phases of the disease.
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PMID:Tremors in early Parkinson's disease. 280 93

1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) was administered via the intraperitoneal route to squirrel monkeys. Akinesia, rigidity and hypophonia were seen after repeated doses of 2 mg/kg. Postural tremor was present in one animal. Neuropathologic examination revealed cell loss restricted to the zona compacta of the substantia nigra. MPTP appears effective in producing an animal model for Parkinson's disease in the squirrel monkey, and may be one of the more selective neurotoxins described to date.
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PMID:Selective nigral toxicity after systemic administration of 1-methyl-4-phenyl-1,2,5,6-tetrahydropyrine (MPTP) in the squirrel monkey. 660 92

Postural tremor was recorded from psychiatric patients who had been treated with phenothiazine or butyrophenone neuroleptic drugs. None of the patients had previously been diagnosed as having extrapyramidal dysfunction. A significant number of these patients had abnormally low tremor frequencies. Low frequency tremors are often associated with Parkinson's disease (PD) so that some of these patients may have early signs of drug induced Parkinsonism (DIP). The results indicate that DIP is not necessarily characterised by a bilateral slow frequency tremor, but may initially be similar to idiopathic PD, even though its cause and prognosis are different.
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PMID:A study of the early signs of drug induced parkinsonism. 809 40

Clinical tremor analysis mostly is used for the measurement of tremor frequency. The analysis is based on short segments of EMG recordings and on clinical ratings of tremor intensity. Accelerometry appears to have some practical advantages. The present study was concerned with the development of a methodology for assessing tremor activity using the three parameters, frequency (Hz), amplitude (g), and occurrence of tremor (in per cent of time). These parameters were derived from joint amplitude frequency analysis of the calibrated accelerometer raw signal and from appropriate decision rules. This methodology was used in connection with 27 patients with Parkinson's disease, to investigate the aforesaid parameters of tremor activity. Postural tremor had a higher occurrence time (right-hand only) and higher frequency (left-hand only) than resting tremor, however, the average amplitudes did not differ. The correlations between right-hand and left-hand measures were higher during postural tremor test. Frequency was not correlated to amplitude or occurrence time, however, moderate correlations did exist between amplitude and occurrence time. In addition to the assessment of tremor activity, multi-channel accelerometry may be used for the detection of posture and motion. Further applications of this methodology, for example, in 24 hr ambulatory monitoring of tremor, are discussed.
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PMID:Joint amplitude and frequency analysis of tremor activity. 1007 56

The manner in which characteristics of time series in the frequency domain can enhance discrimination between physiologic and parkinsonian tremor when tremor amplitude is low was examined. Rest tremor and postural tremor with and without visual feedback were recorded twice in the two hands of a group of patients with Parkinson's disease (PD) (n = 21) and a group of healthy control subjects (n = 30) using displacement laser systems. Recordings were analyzed quantitatively using amplitude and seven frequency domain characteristics. Postural tremor with no visual feedback allowed the most efficient discrimination between the two groups of subjects especially in velocity and acceleration (derived from displacement) and allowed identification of more patients with PD as separate from the range observed in the control group. Moreover, the frequency domain characteristics that were investigated identified the majority of the patients even when amplitude did not. After eliminating redundant (correlated) characteristics, it was found that the frequency composition of tremor in PD can be described adequately with four characteristics, which are the most reliable, independent, and discriminative elements for detecting early or subtle modifications in tremor. Also, a series of finger flexions was found to enhance physiologic tremor but not tremor in PD. Discrimination of low-amplitude tremor in PD from normal physiologic tremor is enhanced by examining the median frequency of oscillations, the concentration of power in the power spectrum, and the distribution of power in particular ranges. Tremor measurement should not be limited to acceleration data as some information is more visible in velocity time series.
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PMID:Using frequency domain characteristics to discriminate physiologic and parkinsonian tremors. 1057 31

Tremor amplitude and frequency do not always clearly differentiate subjects with particular pathologies from control subjects or from subjects with other pathologies, especially in early stages of a disease. For patients with early stages of Parkinson's disease (PD) the discriminative power of amplitude was compared with that of other time domain characteristics of tremor recordings that are probably not evident clinically. Postural tremor with and without visual feedback and rest tremor were recorded in both hands of a group of patients with Parkinson's disease (n = 21) and a group of healthy control subjects (n = 30) using displacement lasers. Velocity and acceleration data were derived from displacement data. Twelve time domain characteristics were calculated on each recording and the discriminating power of each was evaluated using the worse hand in each case. Postural tremor with no visual feedback separates the two groups of subjects most efficiently, especially in velocity and acceleration. Tremor in Parkinson's disease (in comparison to normal physiologic tremor) has a specific morphology, has a distinctive histogram, is more periodic, and contains indications of nonlinearity in the underlying dynamics. There may also be greater difference in amplitude between the two hands and time asymmetry in tremor of patients with PD. A series of finger flexions seems to enhance normal tremor but not tremor in PD and may thus aid in discrimination. Discrimination of tremor attributable to PD from normal physiologic tremor can be enhanced by measuring time domain characteristics subtler than amplitude, particularly when amplitude itself is not large. Tremor measurement should not be limited to acceleration data because some information is more visible in other variables.
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PMID:Using time domain characteristics to discriminate physiologic and parkinsonian tremors. 1070 14

The purpose of this study is to verify the features of the power spectrum of postural tremors for neuromuscular disease patients and to classify the postural tremors. The subjects were 88 neuromuscular disease patients (30 Parkinson disease (PD), 25 cerebellar disease (CER), 7 multiple sclerosis (MS), 7 neuropathy (NEU), 10 motor neuron disease (MND), 9 myopathy (MYO)). The control subjects were 12 normal young persons and 10 normal aged persons. Postural tremor was detected by accelerator sensor. Postural tremor was recorded under the two postural conditions: The subjects maintained the index finger without or with a weight load of 50 g in a horizontal position while looking at a visual target in front of the tip of the index finger. The power spectrum was calculated by an auto-regressive model (AR model). The peak frequency and the peak power were evaluated under the two conditions. Two frequency components of 8-12 Hz and 20-25 Hz appeared in the postural tremor of both normal subjects and neuromuscular disease patients. The difference of the postural tremor between the subjects mainly appeared in the 8-12 Hz component during the postural tremor with a weight load. MYO patients belonged to one group (called as group P1) due to lower peak power, CER patients belonged to one group (called as group P2) due to higher peak power, and PD and MS patients belonged to one group (called as group P3) due to lower peak frequency and higher peak power. NER and MND patients belonged to one group (called as group N which meant normal group). These results suggested that the peak frequency and the peak power of the 8-12 Hz component were changed by the conditions of both spinal reflex system and central nervous system. An oscillator within the central nervous system produced the underlying frequency of 8-12 Hz component, while the amplitude of 8-12 Hz component was governed by both spinal reflex system and central nervous system. In conclusion, the classification of postural tremor for neuromuscular disease patients was a useful index to elucidate the mechanism of tremor oscillation and to assist in clinical diagnosis of neuromuscular disease.
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PMID:Evaluation of postural tremor of finger for neuromuscular diseases and its application to the classification. 1205 36

The aim of this study was: (1) To determine the minimum number of characteristics necessary to discriminate between postural tremor recorded in control subjects (CO), in subjects exposed to manganese (MN), and in patients with Parkinson's disease (PD), and (2) to examine the continuum of changes between the three groups examined. Workers previously exposed to Mn (n = 10), patients with PD (n = 10), and control subjects (CO) (n = 11) underwent a clinical examination. Blood Mn was measured at the end of exposure time for the MN group and 12 months later at the beginning of the experiment for all groups. Postural tremor with visual feedback was recorded in the index finger with a laser system. Statistical criteria were used to reduce computed tremor characteristics to a minimal set of reliable discriminating variables. Two variables were retained namely corrected wobble (CW), describing the morphology of the tremor oscillations, and variability ratio (VR), describing proportional power of tremor. Both variables had an overall correct classification rate of 77.4%. Blood Mn levels at the time of the experiment were similar for all groups and had insignificant correlation with tremor variables. However, blood Mn levels in workers which were also measured at the end of exposure time (i.e., 12 months before) showed significant correlation (Spearman's rank coefficient) with both harmonic index (rho = 0.70, P = 0.03) and first maximum of the autocorrelation function (rho = 0.89, P = 0.001). We conclude that (1) the tremor of workers exposed to Mn could be adequately described with only two variables; (2) a continuum of changes between tremor recorded in control subjects, in subjects exposed to Mn and in patients with PD was observed, with the MN group always found in between the control (CO) and the PD groups; (3) while blood Mn levels in workers were back at control levels at the time of the experiment, the effect of Mn on postural tremor was still detected. Thus our method has the potential to detect the effect of Mn on tremor with only two variables even after Mn level in the blood is back to normal values.
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PMID:Quantifying postural tremor in workers exposed to low levels of manganese. 1548 38

We report a 73-year-old woman who had depression, dementia, and parkinsonism. She had postural tremor since her fortics. She was losing her weight since age 66 years. She noted difficulty in walk at age 72 (2001). She could not stand without assistance on July 2001, and she became hypobulic. On admission to our hospital on November 2001, she had dementia and revised Hasegawa dementia scale (HDS-R) was 8/30. She had mild limitation of the upward gaze, and rigidity in the neck, but not in the limbs. Postural tremor was seen. No muscle weakness was noted and tendon reflexes were normal. She was treated with levodopa/carvidopa, but she did not improve. She did not eat much. She was transferred to another hospital and she suddenly died on January 2002. The patient was discussed in a neurological CPC, and a chief discussant arrived at a conclusion that the patient had Parkinson disease with dementia. Some participants thought the diagnosis was progressive supranuclear palsy or diffuse Lewy body disease. The examination at autopsy revealed mild neuronal loss and Lewy bodies in the substantia nigra. Many Lewy bodies were observed in the cerebral cortex which corresponded to the neocortical type of DLB, and Lewy neurites were seen in the CA2 of the hippocampus by immunohistochemistry for alpha-synuclein. Spongy change was seen in the parahippocampus. Pathological diagnosis was diffuse Lewy body disease.
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PMID:[A 73-year-old woman with depression, dementia, and parkinsonism]. 1627 38

The overlap among tremor disorders is wide and complex because essential tremor patients may present resting tremor coexisting with postural tremor, while postural may coexist with resting tremor in Parkinson's disease. We investigated dopamine transporter binding in 61 subjects presenting with isolated atypical tremors defined as unilateral either postural, resting, or mixed (i.e. resting and postural) tremor, without rigidity or bradykinesia, by means of 123I-FPCIT SPECT imaging at baseline. Patients were followed-up clinically for 28.4 +/- 7.2 months. Twenty-five patients with baseline normal SPECT continued to present only tremor at follow-up. Among 36 patients with abnormal SPECT, 23 (64%) developed PD, while the remaining 13 continued to present only tremor at follow-up. The value of 123I-FPCIT SPECT in predicting the evolution to PD was very high in a way independent from the first clinical presentation of tremor (Rest tremor, P = 0.015; Mixed tremor, P = 0.015; Postural tremor, P = 0.039; chi-square test). Our data suggest that the clinical presentation of isolated tremors is insufficient to allow a precise early-stage diagnosis, whereas the detection of presynaptic nigrostriatal dopaminergic dysfunction could lead to diagnosis of atypical tremor disorders at a very early stage. We suggest this disorder to be labeled as "isolated tremor with dopaminergic presynaptic dysfunction".
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PMID:Predictive value of nigrostriatal dysfunction in isolated tremor: a clinical and SPECT study. 1875 37


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