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)

Patients with idiopathic Parkinson's syndrome (IPS) show dysexecutive deficits which are not related to dementia. We investigated whether these deficits may be caused by a disturbed interaction of prefrontal cortex and selective basal ganglia loops. 5 healthy right-handed volunteers and 5 non demented IPS patients were studied with FDG PET while performing a gambling task paradigm. Control subjects and patients showed consistent bilateral activation of the dorsolateral prefrontal cortex (DLPFC) and the left caudate. Only controls activated the right cingulate, mesial prefrontal and frontoorbital cortex. Patients significantly deactivated the right thalamus. Thus missing frontoorbital and frontomesial activity may indicate an impairment of the basal ganglia loop in IPS, connecting those regions to the thalamus via the ventral striate. The connections between DLPFC and Thalamus via the left caudate remained intact. This impairment may be the neuroanatomical correlate for dysexecutive syndromes in IPS more related to misjudgement than cognitive impairment.
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PMID:Activation of basal ganglia loops in idiopathic Parkinson's disease: a PET study. 1462 93

Idiopathic Parkinson's disease (IPD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) are the most common movement disorders associated with neurodegenerative disease. A clinical differential diagnosis of IPD and atypical Parkinsonian disorders, such as MSA and PSP, is often complicated by the presence of symptoms common to both groups. Since Parkinsonism has a different pathophysiology in the cortical and subcortical brain structures, assessing the regional cerebral glucose metabolism may assist in making a differential diagnosis of Parkinsonism. The 18F-FDG PET images of IPD, MSA and PSP were assessed using statistical parametric mapping (SPM) in order to determine the useful metabolic patterns. Twenty-four patients with Parkinsonism: eight patients (mean age 67.9 +/- 10.7 years; M/F: 3/5) with IPD, nine patients (57.9 +/- 9.2 years; M/F: 4/5) with MSA and seven patients (67.6 +/- 4.8 years; M/F: 3/4) with PSP were enrolled in this study. All patients with Parkinsonism and 22 age-matched normal controls underwent 18F-FDG PET, (after 370 MBq 18F-FDG). The three groups and the individual IPD, MSA and PSP patients were compared with a normal control group using a two-sided t-test of SPM (uncorrected P < 0.01, extent threshold > 100 voxel). The IPD, MSA and PSP groups showed significant hypometabolism in the cerebral neocortex compared to the normal control group. The MSA group showed significant hypometabolism in the putamen, pons and cerebellum compared to the normal controls and IPD groups. In addition, PSP showed significant hypometabolism in the caudate nucleus, the thalamus, midbrain and the cingulate gyrus compared to the normal controls, the IPD and the MSA groups. In conclusion, an assessment of the 18F-FDG PET images using SPM may be a useful adjunct to a clinical examination when making a differential diagnosis of Parkinsonism.
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PMID:Different metabolic patterns analysis of Parkinsonism on the 18F-FDG PET. 1529 29

Mutations in the DJ-1 gene lead to autosomal recessive early-onset parkinsonism. We performed F-DOPA and FDG PET neuroimaging in two parkinsonism patients homozygous for DJ-1 mutations, three relatives heterozygous for a DJ-1 mutation and one non-carrier, all from the originally described kindred from The Netherlands. Their characteristics were compared to those of typical Parkinson's disease patients and healthy controls. Both parkinsonism patients had reduced F-DOPA uptake concordant with typical Parkinson's disease. In the, clinically unaffected, heterozygous relatives, F-DOPA metabolism was unremarkable, thus not suggesting a dosage effect of the DJ-1 gene.
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PMID:PET neuroimaging and mutations in the DJ-1 gene. 1556 91

The motor manifestations of Parkinson's disease (PD) have been linked to an abnormal spatial covariance pattern involving basal ganglia thalamocortical pathways. By contrast, little is known about the functional networks that underlie cognitive dysfunction in this disorder. To identify such patterns, we studied 15 non-demented PD patients using FDG PET and a voxel-based network modeling approach. We detected a significant covariance pattern that correlated (p<0.01) with performance on tests of memory and executive functioning. This PD-related cognitive pattern (PDCP) was characterized by metabolic reductions in frontal and parietal association areas and relative increases in the cerebellar vermis and dentate nuclei. To validate this pattern, we analyzed data from 32 subsequent PD patients of similar age, disease duration and severity. Prospective measurements of PDCP activity predicted memory performance (p<0.005), visuospatial function (p<0.01), and perceptual motor speed (p<0.005) in this validation sample. PDCP scores additionally exhibited an excellent degree of test-retest reliability (intraclass correlation coefficient, ICC=0.89) in patients undergoing repeat FDG PET at an 8-week interval. Unlike the PD-related motor pattern, PDCP expression was not significantly altered by antiparkinsonian treatment with either intravenous levodopa or deep brain stimulation (DBS). These findings substantiate the PDCP as a reproducible imaging marker of cognitive function in PD. Because PDCP expression is not altered by routine antiparkinsonian treatment, this measure of network activity may prove useful in clinical trials targeting the progression of non-motor manifestations of this disorder.
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PMID:Metabolic brain networks associated with cognitive function in Parkinson's disease. 1711 10

Dopaminergic imaging has been found to be normal in approximately 15% of parkinsonian patients enrolled in neuroprotective trials. We used (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) to determine the metabolic basis for this finding. We reviewed scans from 185 patients with clinical signs of Parkinson's disease (PD) who underwent (18)F-fluorodopa PET imaging for diagnostic confirmation. Of this group, 27 patients (14.6%) had quantitatively normal scans; 8 of these patients were additionally scanned with FDG PET. Pattern analysis was performed on an individual scan basis to determine whether the metabolic changes were consistent with classic PD. Computer-assisted single-case assessments of the FDG PET scans of these 8 patients did not disclose patterns of regional metabolic change compatible with classical PD or an atypical parkinsonian variant. Similarly, network quantification revealed that PD-related pattern expression was not elevated in these patients as it was in an age- and duration-matched cohort with classical PD (P < 0.0001). None of these patients developed clinical signs of classical PD or of an atypical parkinsonian syndrome at a follow-up visit conducted 3 years after imaging. The results suggest that parkinsonian subjects with normal dopaminergic imaging do not have evidence of classical PD or an atypical parkinsonian syndrome.
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PMID:Regional metabolic changes in parkinsonian patients with normal dopaminergic imaging. 1713 54

Positron emission tomography has enabled us to measure various fundamental parameters of human brain physiology and chemistry, such as cerebral blood flow, metabolism and synaptic functions. Blood flow and oxygen metabolism is important for the understanding of cerebro-vascular disease. Glucose metabolism is tightly coupled with brain function and FDG-PET is useful for the determination of epileptic foci and for the evaluation of tumor malignancy. Imaging analysis of functional neuroanatomy of these parameters is very promising for the early diagnosis of dementia, such as Alzheimer's disease. Measurement of pre- and post-synaptic function is applicable to the differential diagnosis of parkinsonism. In early stage of Parkinson's disease, only presynaptic dopaminergic function is impaired, while in multiple system atrophy with striato-nigral degeneration type, both pre-and post dopaminergic function is reduced. Development of new radiotracers is expected for detection of early specific pathological changes and more previous changes underlying the deterioration of neurochemistry, such as genetic abnormalities.
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PMID:[Positron emission tomography with FDG and newly developed tracers for the assessment of brain metabolism and synaptic function in neurological disorders]. 1753 75

Neural pathway for visual information processing involves retina, lateral geniculate body, primary visual cortex, and higher visual cortical areas, all of which have been reported to be disordered either functionally or pathologically in Parkinson disease (PD). As elementary visual disorders, there have been studies that reported reduced contrast sensitivity for middle to high spatial frequencies and impaired blue color perception. Most of those studies suggested retina as the damaged cite that is responsible for the impairments, whereas some studies pointed to the possible cortical involvement. Impairments of higher visual functions also have been reported. In the dorsal stream, impairments of object localization, depth perception, and mental rotation have been reported. In the ventral stream, object perception and visual integration of objects have been found to be impaired. A meta-analysis study, however, concluded that although there may be impairments in higher order functions like attention and problem solving capacity there is no firm evidence for the impairments of higher visual functions. Neuroimaging studies have found a relationship between reduced metabolism centered in the parietal lobe and impaired performance in higher visual functions. Impaired identification of overlapping figures has been reported in dementia with Lewy bodies a disease that is akin to PD. Capacity to discriminate textured areas has been found to be damaged in PD. We conducted a FDG-PET study to explore the relationship between brain metabolism and perception of overlapping figures, perception of shapes defined by texture differences and perception of subjective contours in PD. It revealed that there is a correlation between reduced activation in lateral occipital complex and impaired performance for these tasks, suggesting some compromised ventral rout functions.
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PMID:[Impairment in visual cognition in patients with Parkinson disease]. 1788 74

To investigate the diagnostic value of brain magnetic resonance image (MRI) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) in the differentiation of multiple system atrophy (MSA) from Parkinson's disease (PD). Thirty-five patients with MSA (23 MSA-P and 12 MSA-C) and 17 patients with PD were included in this study. Overall correct diagnosis rates between clinical and imaging diagnosis among MSA-P, MSA-C, and PD patients were 80% for visual MRI analysis, 88.5% for visual (18)F-FDG PET analysis, and 84.3% for SPM-supported analysis of (18)F-FDG PET. The sensitivity of brain MRI, and visual and SPM analysis of (18)F-FDG PET in differentiating MSA from PD was 72.7%, 90.9%, and 95.5%, respectively, the specificity was 100% for each imaging analysis, the positive predictive value was 100% for each imaging analysis, and the negative predictive value was 60%, 81.8%, and 90%, respectively. Our results suggest that brain MRI and (18)F-FDG PET are diagnostically useful in differentiating MSA (MSA-P and MSA-C) from PD, and indicate that (18)F-FDG PET has a tendency toward higher sensitivity compared to brain MRI, but a larger longitudinal study including pathological data will be required to confirm our findings.
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PMID:Comparison of brain MRI and 18F-FDG PET in the differential diagnosis of multiple system atrophy from Parkinson's disease. 1789 42

Deep brain stimulation (DBS) of the bilateral subthalamic nucleus (STN) in Parkinson's disease is thought to produce adverse events such as emotional disorders, and in a recent study, we found fear recognition to be impaired as a result. These changes have been attributed to disturbance of the STN's limbic territory and would appear to confirm that the negative emotion recognition network passes through the STN. In addition, it is now widely acknowledged that damage to the orbitofrontal cortex (OFC), especially the right side, can result in impaired recognition of facial emotions (RFE). In this context, we hypothesized that this reduced recognition of fear is correlated with modifications in the cerebral glucose metabolism of the right OFC. The objective of the present study was first, to reinforce our previous results by demonstrating reduced fear recognition in our Parkinson's disease patient group following STN DBS and, second, to correlate these emotional performances with glucose metabolism using (18)FDG-PET. The (18)FDG-PET and RFE tasks were both performed by a cohort of 13 Parkinson's disease patients 3 months before and 3 months after surgery for STN DBS. As predicted, we observed a significant reduction in fear recognition following surgery and obtained a positive correlation between these neuropsychological results and changes in glucose metabolism, especially in the right OFC. These results confirm the role of the STN as a key basal ganglia structure in limbic circuits.
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PMID:Subthalamic nucleus stimulation affects orbitofrontal cortex in facial emotion recognition: a PET study. 1849 Mar 59

Bilateral symptoms and signs of Parkinson's disease (PD) are often improved by unilateral subthalamic nucleus deep brain stimulation (STN-DBS). However, the mechanism for such bilateral effects is unknown. This study was intended to examine effects of unilateral STN-DBS using positron emission computed tomography (PET) and to elucidate mechanisms for bilateral improvement achieved by unilateral stimulation.We conducted (18)F-fluorodeoxyglucose ((18)FDG) and (18)F-fluorodopa ((18)F-DOPA ) PET scans in PD patients whose bilateral limb symptoms and axial symptoms were improved by unilateral DBS. Two scans were performed in each PET study: when DBS was on and off. We compared those images using statistic parametric mapping (SPM) 99.The significant clinical improvement obtained by unilateral DBS was shown as improvements in bilateral motor limb, axial, and gait subscores of the Unified PD Rating Scale (UPDRS). Moreover, (18)FDG PET revealed significant metabolic increases in the ipsilateral ventrolateral thalamic areas and metabolic decrease at the contralateral globus pallidus interna (GPi). In contrast, (18)F-DOPA PET showed no significant differences between DBS on and off.Ipsilateral thalamic activation might induce ipsilateral motor cortical activation, which explains the improvement of contralateral limb symptoms. Furthermore, deactivation of the contralateral GPi might disinhibit the thalamus and contralateral motor cortex, which explains reduction of ipsilateral limb symptoms. These results suggest the mechanisms for bilateral improvement achieved by unilateral DBS.
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PMID:Mechanisms of unilateral STN-DBS in patients with Parkinson's disease : a PET study. 1856 67


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