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 (PD) is a complex neurodegenerative condition involving a motor disorder that is related to reduced dopaminergic input to the striatum. Intellectual deficits are also seen in PD, but the pathophysiology of these difficulties is poorly understood. Regional cerebral blood flow (rCBF) was studied in neurologically intact subjects during the performance of attention-demanding, sentence processing tasks using positron emission tomography (PET). The results demonstrated significantly increased rCBF in a distributed set of cerebral regions during the detection of an adjective or a particular agent in a sentence, including anterior cingulate cortex, left inferior and middle frontal cortex, left inferior temporo-occipital cortex, posterolateral temporal cortex, left caudate, and left thalamus. We identified defects in this cerebral network by studying PD patients with two PET techniques. Resting PET studies revealed a significant correlation between regional cerebral glucose metabolism in anterior cingulate cortex and deficits in attending to subtle grammatical aspects of sentences. Studies of PD patients with the PET activation technique revealed little change in anterior cingulate and left frontal CBF during performance of the adjective detection or agent detection tasks. These data suggest that a defect in anterior cingulate cortex contributes to the cognitive impairments observed in PD.
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PMID:Attention and sentence processing deficits in Parkinson's disease: the role of anterior cingulate cortex. 147 27

N-isopropyl-p[123I]iodoamphetamine (123I-IMP) SPECT and regional cerebral blood flow (rCBF) studies were performed in 20 patients with Parkinson's disease (PD) and 8 normal subjects. RCBF was measured by the arterial blood sampling method which used the microsphere model. We analyzed seven factors which might be related to the rCBF in PD, i.e., age, stage, duration of the disease, cerebral atrophy, severity of dementia, laterality of symptoms and motor disability score (MDS; the degree of akinesia, rigidity, tremor, gait disturbance, freezing and pulsion sign). Compared with normal subjects, global CBF (supratentorial mean rCBF) was reduced 21.8% in PD. In particular, rCBF in the basal ganglia and that of frontal cortex were reduced 25.3%, 24.8%, respectively. Distribution patterns of rCBF in PD were almost as same as those in normals except for cerebellum. The reduction of both rCBFs in the basal ganglia and parietal cortex significantly correlated with MDS (p less than 0.05, respectively). Especially, akinesia was closely correlated to the reduction of rCBF in the parietal cortex (p less than 0.02). Moreover, we observed a significant relationship between cerebral atrophy and reduction of rCBF in each region except for cerebellum. However, there was no significant correlation between the severity of dementia and reduction of rCBF, even in the frontal cortex or parietal cortex. These data show that the severity of dementia in PD may be connected with other factors except for rCBF. 123I-IMP SPECT study is a useful method for clinical evaluation of PD.
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PMID:[Clinical evaluation of Parkinson's disease using 123I-IMP SPECT]. 261 27

Regional cerebral blood flow (rCBF) was measured by the 133Xe inhalation technique in 9 patients with Parkinson's disease and in 1 patient with pure akinesia before and during treatment with L-threo-3,4-dihydroxyphenylserine (DOPS). L-DOPS alone was administered in 4 patients, and combined with L-DOPA or bromocriptine in 6 patients. The mean, hemispheric and regional CBF was unaffected by the chronic administration of L-DOPS. In addition, no significant difference in the mean CBF was observed between the patients who showed marked or moderate improvement in parkinsonian symptoms during the treatment with L-DOPS and those who showed slight improvement or no change, or between the group treated with L-DOPS alone and the group treated in combination with L-DOPS and other drugs. These results indicate that L-DOPS does not increase the CBF in parkinsonian patients, thus the anti-parkinsonian effects of the agent are not mediated by changes in CBF.
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PMID:Effect of L-threo-3,4-dihydroxyphenylserine on regional cerebral blood flow in patients with Parkinson's disease. 312 72

Regional and mean cerebral blood flow (rCBF, CBF) were measured by tomography of inhaled 133Xe in 18 hemiparkinsonian patients before and after levodopa (L-dopa). Baseline mean CBF was 55 ml/ (100 g X min) after an L-dopa-free interval of at least 10 h (range 10-13) and remained unchanged at 56.1 ml/ (100 g X min) after optimal clinical improvement was achieved by L-dopa. However, L-dopa reduced rCBF significantly (P less than 0.05) in the striatum contralateral to the symptomatic limbs. In patients with adverse reactions such as hyperkinesias and on/off symptoms, flow tended to increase bilaterally in striatum and often markedly in midline structures anatomically related to globus pallidus and thalamus. Compared with a normal population, the subcortical rCBF distribution was asymmetrical with a reduced flow (-18%) in the striatum contralateral to the symptomatic limbs and in midline structures anatomically related to globus pallidus and thalamus (-12%). Cortical CBF was inverse related to the duration of Parkinson's disease (P less than 0.05), probably reflecting an increasing mental deterioration with time.
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PMID:Regional cerebral blood flow in hemiparkinsonian patients. Emission computerized tomography of inhaled 133Xenon before and after levodopa. 387 79

Regional cerebral blood flow (rCBF) was measured using the stable xenon enhanced CT method in previously untreated 13 patients with Parkinson's disease to evaluate CBF abnormality related to dysfunction of the nigrostriatal dopaminergic neurons. The patients comprised 5 men, 8 women with Hoehn-Yahr stage II-III. Age at onset ranged from 51 to 73 years (mean +/- SD, 61.8 +/- 8.9) and the duration of illness ranged from 1 to 96 months (15.1 +/- 24.1 months). In this series, there was no clinical evidence of hypertension, diabetes mellitus and cognitive impairment. rCBF was measured during 4-5-minutes inhalation of 33% stable xenon gas-67% oxygen. The first measurement of rCBF was performed in all of the patients before L-dopa treatment. After initiation of L-dopa treatment (333.3 +/- 47.1 mg/day), the second measurement was carried out in 6 patients (1 man and 5 women) who had shown symptomatic improvement. The interval between both measurements was 57.7 +/- 16.9 days. The following results were obtained. 1) No significant CBF asymmetry was noted in any of the striatum, pallidum, thalamus, cerebrum, cerebellum and frontal lobe in untreated patients with Parkinson's disease. 2) After L-dopa treatment, rCBF was significantly increased only in the striatum as compared with the pretreatment level (51.9 +/- 9.3-->63.1 +/- 9.9 ml/100 g/min, p < 0.01). 3) This increase was significantly greater on the more severely affected side (contralateral to the predominantly symptomatic limb) (p < 0.05). These results suggest that the increase of rCBF in the striatum is closely related to functional improvement of the nigrostriatal dopaminergic neurons.
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PMID:[The effects of dopamine on regional cerebral blood flow in patients with Parkinson's disease before and after L-dopa--measurement by Xe-enhanced CT]. 772 88

N-isopropyl-p[123I]iodoamphetamine (123I-IMP) SPECT and quantitative regional cerebral blood flow (rCBF) studies were performed in 111 patients with cerebral disorders. Continuous arterial blood sampling method based on the microsphere model was used as a quantitative rCBF measurement. We evaluated rCBF in patients with dementia and also in patients with poor activities of daily living (ADL). Patients with dementia showed significant reduction of mean CBF in contrast to patients without dementia. Significant decrease of rCBF in the bilateral frontal cortex, parietal cortex and basal ganglia and the right temporal cortex were found in demented patients. Although patients with vascular dementia showed decreased rCBF in bilateral basal ganglia, demented patients with Parkinson's disease showed no significant reduction of rCBF in any regions. Patients with poor ADL showed decreased rCBF in all brain regions. And particularly frontal and basal ganglionic defects were most pronounced. Patients with poor ADL resulted from cerebral infarction showed significant decrease of rCBF in bilateral basal ganglia. However, there was no significant correlation in Parkinson's disease between ADL and rCBF. The rCBF measurement with 123I-IMP is useful for clinical evaluation of demented patients and patients with poor ADL.
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PMID:[Quantitative regional cerebral blood flow study with 123I-IMP in patients with dementia and in patients with poor activities of daily living]. 827 96

Most positron emission tomography (PET) studies of regional cerebral function in idiopathic torsion dystonia (ITD) have failed to show abnormalities, but there have been few studies of the changes in regional cerebral blood flow (rCBF) that occur during movement in dystonia. Using PET, we have studied six patients with familial generalized ITD both at rest and while moving a joystick with the right hand. The patterns of CBF change obtained were compared with those in six age-matched control subjects. In the dystonia group, free selection of movement was associated with relative increases in rCBF above that observed in control subjects in the left premotor area, the supplementary motor area (SMA), the anterior cingulate cortex, and the left dorsolateral prefrontal area. Subcortical increases were observed within the cerebellum and the putamen. There was a relative decrease in flow through the contralateral primary sensorimotor cortex. These findings contrast with those reported in patients with Parkinson's disease undertaking the same task in which the activity in the SMA and putamen was decreased. We suggest that arm dystonia in ITD is associated with overactivity of the premotor areas, including the SMA, and that this results from release of the thalamus from the normal inhibitory influence of the globus pallidus internal segment. Other abnormalities of basal ganglia control of brain stem centers may be involved in axial dystonia.
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PMID:Increased activation of frontal areas during arm movement in idiopathic torsion dystonia. 953 46

Alzheimer's disease is the most common cause of dementia, but Parkinson's disease also shows dementia in the later stages. Donepezil is a cholinesterase inhibitor used for the treatment of Alzheimer's disease. Variable responses to this drug suggest that Alzheimer's disease is clinically heterogeneous. In the clinical trial of tacrine, a first developed cholinesterase inhibitor, three cases markedly improved and, several years later, they were pathologically confirmed as dementia with Lewy bodies (DLB). In recent years, another cholinesterase inhibitor, rivastigmine, has also been reported to be effective for patients with DLB by a placebo-controlled, double-blind, multicenter study. Parkinson's disease with dementia, which is known to fulfill the pathological criteria of DLB, also shows a favorable response to donepezil. In some cases, not only does cognitive function improve, but also parkinsonism. Both DLB and Parkinson's disease with dementia show characteristic CBF patterns: While the parietal and temporal lobes are involved in Alzheimer's disease, the occipital lobe is additionally affected in these diseases. Alzheimer's disease and Parkinson's disease have been considered discrete disease entities. However, viewed from the aspects of response to donepezil treatment and CBF patterns, both diseases overlapped. A brain SPECT may be a useful tool to detect such treatable conditions.
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PMID:Responses to donepezil in Alzheimer's disease and Parkinson's disease. 1248 Jul 91

In the last years there has been a wide consensus on the importance of brain imaging in assessing neurodegenerative and psychiatric disorders. Different techniques for functional and anatomical examination are currently clinically implemented in neurology and psychiatry to improve sensitivity, specificity and accuracy of the diagnosis of various diseases. In addition, the increasing life expectancy in the Western world raises the social importance and the economical impact of age-related neurodegenerative disorders since the incidence of Alzheimer disease and Parkinson disease is higher in the elderly. An early diagnosis of neuro-psychiatric diseases and the assessment of "natural" changes of regional cerebral blood flow (rCBF) distribution during normal aging are hence of utmost importance. In the recent past brain disorders have extensively been investigated by means of optimised nuclear medicine techniques, instruments and algorithms. Diagnosis can be better achieved by identifying those structures in which CBF or metabolism deviate from normality resulting in significant changes as compared to a reference database. In the present paper we present some studies investigating, by means of recently implemented diagnostic tools, patients bearer of various neuro-psychiatric disorders. The improved nuclear medicine techniques and instrumentation, the state-of-the-art software for brain imaging standardisation and the use of sophisticated multivariate data analysis are extensively reviewed.
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PMID:Optimisation of statistical methodologies for a better diagnosis of neurological and psychiatric disorders by means of SPECT. 1643 3

To evaluate functional neuronal compensation after partial damage to the nigrostriatal system, we lesioned rats unilaterally in the striatum with 6-hydroxydopamine. Five weeks later, cerebral perfusion was mapped at rest or during treadmill walking using [(14)C]-iodoantipyrine. Regional CBF-related tissue radioactivity (CBF-TR) was quantified by autoradiography and analyzed by statistical parametric mapping and region-of- interest analysis. Lesions were confirmed by tyrosine hydroxylase immunohistochemistry and changes in rotational locomotor activity. Functional compensations were bilateral and differed at rest and during treadmill walking. Consistent with the classic view of striatopallidal connections, CBF-TR of lesioned compared to sham-lesioned rats increased in the ipsilateral subthalamic nucleus (STN) and internal globus pallidus, and decreased in the striatum and external globus pallidus. Contrary to the classic view, CBF-TR increased in the ipsilateral ventral lateral, ventral anterior thalamus and motor cortex, as well as in the central medial thalamus, midline cerebellum, and contralateral STN. During walking, perfusion decreased in lesioned compared to sham-lesioned rats across the ipsilateral striato-pallidal-thalamic-cortical motor circuit. Compensatory increases were seen bilaterally in the ventromedial thalamus and red nucleus, in the contralateral STN, anterior substantia nigra, subiculum, motor cortex, and in midline cerebellum. Enhanced recruitment of associative sensory areas was noted cortically and subcortically. Future models of compensatory changes after nigrostriatal damage need to address the effects of increased neural activity by residual dopaminergic neurons, interhemispheric interactions and differences between resting and locomotor states. Identification of sites at which functional compensation occurs may define useful future targets for neurorehabilitative or neurorestorative interventions in Parkinson's disease.
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PMID:Changes in brain functional activation during resting and locomotor states after unilateral nigrostriatal damage in rats. 1748 21


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