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Your search keyword '"Kefalopoulou, Z"' showing total 4 results
Start Over Author "Kefalopoulou, Z" Publisher wiley
4 results on '"Kefalopoulou, Z"'

1. Increased serotonin-to-dopamine transporter ratios in Parkinson disease dyskinesias: a longitudinal study

Author

Roussakis, AA, Lao-Kaim, Martin-Bastida, A, Valle-Guzman, N, Kefalopoulou, Z, Paul, G, Widner, H, Politis, M, Foltynie, T, Barker, RA, Piccini, Michael J Fox Foundation, and Imperial College Healthcare NHS Trust- BRC Funding

Subjects
Neurology & Neurosurgery, Clinical Sciences, Neurosciences
Abstract

Background and aims Serotonergic terminals play an important role in levodopa-induced dyskinesias (LIDs) in patients with Parkinson’s disease (PD). An increased SERT-over-DAT terminal ratio in the putamen has been proposed to be a risk factor for the appearance of LIDs. We investigated the temporal relationship between serotonergic terminal changes and dopaminergic loss in the putamen and the appearance of LIDs. Methods Twelve PD patients underwent PET with 11C-DASB and 11C-PE2I; which are specific in vivo markers of serotonin (SERT) and dopamine transporters (DAT),respectively. All patients repeated 11C-DASB and 11C-PE2I PET after 17 months(±11 weeks). The simplified reference tissue model was employed using the cerebellum as a reference. 11C-DASB binding potential (BP), 11C-PE2I BP and 11C-DASB-to-11C-PE2I BP ratios were calculated. Results At baseline, all PD patients were non-dyskinetic. The mean 11C-DASB BP was 1.28(±0.14), the mean 11C-PE2I BP was 1.63(±0.41), and the median of the SERT-to-DAT ratio was 0.779(±0.19). At follow-up, the mean 11C-PE2I BP was (1.39±0.41) reduced by 14.52% from baseline (p0.10). Percentage changes in 11C-PE2I BP at follow-up were significantly greater than percentage changes in 11C-DASB BP (p

Published
2016

2. Motor associations of iron accumulation in deep grey matter nuclei in Parkinson's disease: a cross‐sectional study of iron‐related magnetic resonance imaging susceptibility

Author

Martin‐Bastida, A., primary, Lao‐Kaim, N. P., additional, Loane, C., additional, Politis, M., additional, Roussakis, A. A., additional, Valle‐Guzman, N., additional, Kefalopoulou, Z., additional, Paul‐Visse, G., additional, Widner, H., additional, Xing, Y., additional, Schwarz, S. T., additional, Auer, D. P., additional, Foltynie, T., additional, Barker, R. A., additional, and Piccini, P., additional

Published
2016
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3. Identical late motor responses in early Guillain-Barré syndrome: A-waves and repeater F-waves.

Author

Veltsista D, Kefalopoulou Z, Kintos V, and Chroni E

Subjects
Humans, Neural Conduction physiology, Retrospective Studies, Amantadine, Guillain-Barre Syndrome diagnosis
Abstract

Electrodiagnostic (EDx) studies play a key role in the investigation of suspected Guillain-Barré syndrome (GBS), providing diagnostic and prognostic information. However, initial EDx findings may not fulfill the neurophysiological criteria for the disease. The aim of this study was to estimate the occurrence and characteristics of A-waves and repeaters F-waves (Freps), both late motor responses identical in latency and configuration, in early stages of GBS. We retrospectively analyzed the initial nerve conduction study (NCS) of 26 GBS patients performed within 10 days from symptom onset. The final subtype diagnosis was acute inflammatory demyelinating polyneuropathy (AIDP) in 16 patients (six met the criteria at the initial EDx study and 10 at follow-up) and acute motor axonal neuropathy (AMAN) in 10 patients (six initially). Identical late responses were commonly found in the majority of nerves (84%). A-waves were present in 59% and an increased frequency of Freps was calculated in 61% of the 105 studied nerves. A-waves morphology (single or complex) could not distinguish between AIDP and AMAN. Nerves with normal NCS had a significantly higher frequency of A-waves, either isolated or in combination with increased index total Freps, as compared to nerves with low compound muscle action potential (CMAP) amplitudes or conduction block. Our findings suggest that both late responses can be useful as early markers of conduction changes of various pathophysiology, being frequently present even prior to abnormalities of CMAP parameters., (© 2022 Peripheral Nerve Society.)

Published
2023
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4. Motor associations of iron accumulation in deep grey matter nuclei in Parkinson's disease: a cross-sectional study of iron-related magnetic resonance imaging susceptibility.

Author

Martin-Bastida A, Lao-Kaim NP, Loane C, Politis M, Roussakis AA, Valle-Guzman N, Kefalopoulou Z, Paul-Visse G, Widner H, Xing Y, Schwarz ST, Auer DP, Foltynie T, Barker RA, and Piccini P

Subjects
Adult, Aged, Cross-Sectional Studies, Disease Susceptibility, Female, Gray Matter diagnostic imaging, Humans, Hypokinesia etiology, Hypokinesia physiopathology, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Movement Disorders etiology, Muscle Rigidity etiology, Muscle Rigidity physiopathology, Parkinson Disease complications, Parkinson Disease diagnostic imaging, Substantia Nigra diagnostic imaging, Substantia Nigra metabolism, Gray Matter metabolism, Iron metabolism, Movement Disorders physiopathology, Parkinson Disease metabolism, Parkinson Disease physiopathology
Abstract

Background and Purpose: To determine whether iron deposition in deep brain nuclei assessed using high-pass filtered phase imaging plays a role in motor disease severity in Parkinson's disease (PD)., Methods: Seventy patients with mild to moderate PD and 20 age- and gender-matched healthy volunteers (HVs) underwent susceptibility-weighted imaging on a 3 T magnetic resonance imaging scanner. Phase shifts (radians) in deep brain nuclei were derived from high-pass filtered phase images and compared between groups. Analysis of clinical laterality and correlations with motor severity (Unified Parkinson's Disease Rating Scale, Part III, UPDRS-III) were performed. Phase shifts (in radians) were compared between HVs and three PD subgroups divided according to UPDRS-III scores using analysis of covariance, adjusting for age and regional area., Results: Parkinson's disease patients had significantly (P < 0.001) higher radians than HVs bilaterally in the putamen, globus pallidus and substantia nigra (SN). The SN contralateral to the most affected side showed higher radians (P < 0.001) compared to the less affected side. SN radians positively correlated with UPDRS-III and bradykinesia-rigidity subscores, but not with tremor subscores. ancova followed by post hoc Bonferroni-adjusted pairwise comparisons revealed that SN radians were significantly greater in the PD subgroup with higher UPDRS-III scores compared to both lowest UPDRS-III PD and HV groups (P < 0.001)., Conclusions: Increased nigral iron accumulation in PD appears to be stratified according to disease motor severity and correlates with symptoms related to dopaminergic neurodegeneration. This semi-quantitative in vivo iron assessment could prove useful for objectively monitoring PD progression, especially in clinical trials concerning iron chelation therapies., (© 2016 EAN.)

Published
2017
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