TY  - JOUR
A1  - Brumberg, Joachim
A1  - Küsters, Sebastian
A1  - Al-Momani, Ehab
A1  - Marotta, Giorgio
A1  - Cosgrove, Kelly P.
A1  - van Dyck, Christopher H.
A1  - Herrmann, Ken
A1  - Homola, György A.
A1  - Pezzoli, Gianni
A1  - Buck, Andreas K.
A1  - Volkmann, Jens
A1  - Samnick, Samuel
A1  - Isaias, Ioannis U.
T1  - Cholinergic activity and levodopa-induced dyskinesia: a multitracer molecular imaging study
JF  - Annals of Clinical and Translational Neurology
N2  - Objective: To investigate the association between levodopa‐induced dyskinesias and striatal cholinergic activity in patients with Parkinson's disease.
Methods: This study included 13 Parkinson's disease patients with peak‐of‐dose levodopa‐induced dyskinesias, 12 nondyskinetic patients, and 12 healthy controls. Participants underwent 5‐[\(^{123}\)I]iodo‐3‐[2(S)‐2‐azetidinylmethoxy]pyridine single‐photon emission computed tomography, a marker of nicotinic acetylcholine receptors, [\(^{123}\)I]N‐ω‐fluoropropyl‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)nortropane single‐photon emission computed tomography, to measure dopamine reuptake transporter density and 2‐[\(^{18}\)F]fluoro‐2‐deoxyglucose positron emission tomography to assess regional cerebral metabolic activity. Striatal binding potentials, uptake values at basal ganglia structures, and correlations with clinical variables were analyzed.
Results: Density of nicotinic acetylcholine receptors in the caudate nucleus of dyskinetic subjects was similar to that of healthy controls and significantly higher to that of nondyskinetic patients, in particular, contralaterally to the clinically most affected side.
Interpretation: Our findings support the hypothesis that the expression of dyskinesia may be related to cholinergic neuronal excitability in a dopaminergic‐depleted striatum. Cholinergic signaling would play a role in maintaining striatal dopaminergic responsiveness, possibly defining disease phenotype and progression.
KW  - levodopa-induced dyskinesia
KW  - cholinergic activity
KW  - Parkinson’s disease
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170406
VL  - 4
IS  - 9
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Solnes, Lilja B.
A1  - Leal, Jeffrey P.
A1  - Du, Yong
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - Visual and Semiquantitative Accuracy in Clinical Baseline 123I-Ioflupane SPECT/CT Imaging
JF  - Clinical Nuclear Medicine
N2  - PURPOSE:
We aimed to (a) elucidate the concordance of visual assessment of an initial I-ioflupane scan by a human interpreter with comparison to results using a fully automatic semiquantitative method and (b) to assess the accuracy compared to follow-up (f/u) diagnosis established by movement disorder specialists.

METHODS:
An initial I-ioflupane scan was performed in 382 patients with clinically uncertain Parkinsonian syndrome. An experienced reader performed a visual evaluation of all scans independently. The findings of the visual read were compared with semiquantitative evaluation. In addition, available f/u clinical diagnosis (serving as a reference standard) was compared with results of the human read and the software.

RESULTS:
When comparing the semiquantitative method with the visual assessment, discordance could be found in 25 (6.5%) of 382 of the cases for the experienced reader (ĸ = 0.868). The human observer indicated region of interest misalignment as the main reason for discordance. With neurology f/u serving as reference, the results of the reader revealed a slightly higher accuracy rate (87.7%, ĸ = 0.75) compared to semiquantification (86.2%, ĸ = 0.719, P < 0.001, respectively). No significant difference in the diagnostic performance of the visual read versus software-based assessment was found.

CONCLUSIONS:
In comparison with a fully automatic semiquantitative method in I-ioflupane interpretation, human assessment obtained an almost perfect agreement rate. However, compared to clinical established diagnosis serving as a reference, visual read seemed to be slightly more accurate as a solely software-based quantitative assessment.
KW  - Single-Photon-Emissions-Computertomographie
KW  - SPECT
KW  - Parkinson’s disease
KW  - Parkinsonism
KW  - DaTscan
KW  - 123I-Ioflupane
KW  - SPECT
KW  - SPECT/CT
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168181
SN  - 1536-0229
VL  - 44
IS  - 1
ER  -