scholarly journals Blood Flow as a Route for Bidirectional Propagation of Synucleinopathy in Parkinson's Disease?

2020 ◽  
Vol 35 (10) ◽  
pp. 1751-1751
Author(s):  
Véronique Sgambato
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
Bidirectional Propagation

Lower vascular tone and larger plasma volume in Parkinson's disease with orthostatic hypotension

2011 ◽  
Vol 111 (2) ◽  
pp. 443-448 ◽  
Author(s):  
J. T. Groothuis ◽  
R. A. J. Esselink ◽  
J. P. H. Seeger ◽  
M. J. H. van Aalst ◽  
M. T. E. Hopman ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
Orthostatic Hypotension ◽  
Vascular Resistance ◽  
Plasma Volume ◽  
Venous Pressure ◽  
Dilution Method ◽  
Significant Difference ◽  
Head Up Tilt

The pathophysiology of orthostatic hypotension in Parkinson's disease (PD) is incompletely understood. The primary focus has thus far been on failure of the baroreflex, a central mediated vasoconstrictor mechanism. Here, we test the role of two other possible factors: 1) a reduced peripheral vasoconstriction (which may contribute because PD includes a generalized sympathetic denervation); and 2) an inadequate plasma volume (which may explain why plasma volume expansion can manage orthostatic hypotension in PD). We included 11 PD patients with orthostatic hypotension (PD + OH), 14 PD patients without orthostatic hypotension (PD − OH), and 15 age-matched healthy controls. Leg blood flow was examined using duplex ultrasound during 60° head-up tilt. Leg vascular resistance was calculated as the arterial-venous pressure gradient divided by blood flow. In a subset of 9 PD + OH, 9 PD − OH, and 8 controls, plasma volume was determined by indicator dilution method with radiolabeled albumin (125I-HSA). The basal leg vascular resistance was significantly lower in PD + OH (0.7 ± 0.3 mmHg·ml−1·min) compared with PD − OH (1.3 ± 0.6 mmHg·ml−1·min, P < 0.01) and controls (1.3 ± 0.5 mmHg·ml−1·min, P < 0.01). Leg vascular resistance increased significantly during 60° head-up tilt with no significant difference between the groups. Plasma volume was significantly larger in PD + OH (3,869 ± 265 ml) compared with PD − OH (3,123 ± 377 ml, P < 0.01) and controls (3,204 ± 537 ml, P < 0.01). These results indicate that PD + OH have a lower basal leg vascular resistance in combination with a larger plasma volume compared with PD − OH and controls. Despite the increase in leg vascular resistance during 60° head-up tilt, PD + OH are unable to maintain their blood pressure.

scholarly journals Correlation between regional cerebral blood flow and dementia in Parkinson's disease.

1986 ◽  
Vol 53 (1) ◽  
pp. 112-114
Author(s):  
Tokuzo Miyazaki ◽  
Akiro Terashi ◽  
Hiroyuki Tezuka ◽  
Noboru Kasahara ◽  
Isamu Koizumi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood

scholarly journals Positron Emission Tomography in Parkinson’s Disease

1992 ◽  
Vol 19 (S1) ◽  
pp. 138-141 ◽  
Author(s):  
Barry J. Snow
Keyword(s):  
Parkinson’S Disease ◽  
Positron Emission Tomography ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
D2 Receptor ◽  
The Body ◽  
Emission Tomography ◽  
Motor Tasks ◽  
Positron Emission ◽  
Ligand Interactions

ABSTRACT:Positron emission tomography (PET) allows the study of physiological and neurochemical processes which would otherwise be inaccessible, using radioactive labels on biological compounds to follow their fate in the body. By analysing changes of concentration with time we can measure blood flow, neuronal metabolism and receptor ligand interactions. In Parkinson’s disease (PD), PET has been used to examine the dopaminergic deficit and its relationship to motor performance. It has also been shown to detect asymptomatic dopaminergic lesions that have implications for the etiology of PD. In untreated PD there is increased density of D2 binding sites, while in chronically treated PD with motor fluctuations, D2 receptor density is reduced. [18F]-fluorodeoxyglucose studies of demented PD patients show a pattern of cortical metabolism similar to Alzheimer’s disease. Activation studies, which measure changes in blood flow during the performance of motor tasks, show reduced activation of medial frontal areas in PD.

scholarly journals Motor Improvement-Related Regional Cerebral Blood Flow Changes in Parkinson’s Disease in Response to Antiparkinsonian Drugs

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Soutarou Taguchi ◽  
Nachi Tanabe ◽  
Jun-ichi Niwa ◽  
Manabu Doyu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Structures ◽  
Regional Cerebral Blood ◽  
Motor Improvement ◽  
Antiparkinsonian Drugs ◽  
Deep Brain

Little is known about the relationship between regional cerebral blood flow (rCBF) change and clinical improvement in patients with Parkinson’s disease (PD). Single-photon emission computed tomography (SPECT) measurement of cerebral blood flow allows evaluation of temporal changes in brain function, and using SPECT, we aimed to identify motor improvement-related rCBF changes in response to the administration of antiparkinsonian drugs. Thirty PD patients (16 without dementia; 14 with dementia) were scanned with technetium-99m labeled ethyl cysteinate dimer SPECT and were rated with the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale part III, both before and after a single administration of antiparkinsonian drugs. The SPECT data were processed using Statistical Parametric Mapping 2, the easy Z-score Imaging System, and voxel-based Stereotactic Extraction Estimation. The rCBF responses in the deep brain structures after administration of antiparkinsonian drugs tended to be larger than those in cortical areas. Among these deep brain structures, the rCBF increases in the substantia nigra (SN), lateral geniculate (LG) body, and medial geniculate (MG) body correlated with drug efficacy (p<0.05, respectively). A subgroup analysis revealed that the motor improvement-related rCBF change in the MG was statistically significant, irrespective of cognitive function, but the significant changes in the LG and SN were not found in subjects with dementia. In conclusion, our SPECT study clearly exhibited drug-driven rCBF changes in PD patients, and we newly identified motor improvement-related rCBF changes in the LG and MG. These results suggest that rCBF changes in these regions could be considered as candidates for clinical indicators for objective evaluation of disease progression. Furthermore, functional studies focusing on the LG and MG, especially in relation to therapies using audio-visual stimuli, may bring some new clues to explain the pathophysiology of PD.

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