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Georgiopoulos, Charalampos
Publications (5 of 5) Show all publications
Georgiopoulos, C. (2019). Imaging Studies of Olfaction in Health and Parkinsonism. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Imaging Studies of Olfaction in Health and Parkinsonism
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Olfactory loss is a common non-motor symptom of Parkinson’s disease (PD), often preceding the cardinal motor symptoms of the disease. The aim of this thesis was to: (a) evaluate whether olfactory examination can increase diagnostic accuracy, and (b) study the structural and functional neural basis of olfactory dysfunction in PD with different applications of Magnetic Resonance Imaging (MRI).

Paper I was a comparison of the diagnostic accuracy between a simple smell identification test and DaTSCAN Single Photon Emission Computerized Tomography (SPECT), a nuclear medicine tomographic imaging technique that is commonly used in patients with suspected parkinsonism. The results indicate that smell test is inferior to DaTSCAN SPECT, but the combination of these two methods can lead to improved diagnostic accuracy.

Paper II showed that diffusion MRI could detect discrete microstructural changes in the white matter of brain areas that participate in higher order olfactory neurotransmission, whereas MRI with Magnetization Transfer contrast could not.

Paper III was a methodological study on how two different acquisition parameters can affect the activation pattern of olfactory brain areas, as observed with functional MRI (fMRI). The results indicate that brief olfactory stimulation and fast sampling rate should be preferred on olfactory fMRI studies.

Paper IV used olfactory fMRI and resting-state fMRI in order to elucidate potentially altered activation patterns and functional connectivity within olfactory brain areas, between PD patients and healthy controls. Olfactory fMRI showed that olfactory impairment in PD is associated with significantly lower recruitment of the olfactory network. Resting-state fMRI did not detect any significant changes in the functional connectivity within the olfactory network of PD patients.

In conclusion, the included studies provide evidence of: (a) disease-related structural and functional changes in olfactory brain areas, and (b) beneficial addition of olfactory tests in the clinical work-up of patients with parkinsonism.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2019. p. 72
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1661
National Category
Radiology, Nuclear Medicine and Medical Imaging Neurology Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-154919 (URN)10.3384/diss.diva-154919 (DOI)9789176851357 (ISBN)
Public defence
2019-04-05, Granitsalen, Campus US, Linköping, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2019-03-05 Created: 2019-03-05 Last updated: 2019-12-12Bibliographically approved
Georgiopoulos, C., Davidsson, A., Engström, M., Larsson, E.-M., Zachrisson, H. & Dizdar (Dizdar Segrell), N. (2015). The diagnostic value of dopamine transporter imaging and olfactory testing in patients with parkinsonian syndromes. Journal of Neurology, 262(9), 2154-2163
Open this publication in new window or tab >>The diagnostic value of dopamine transporter imaging and olfactory testing in patients with parkinsonian syndromes
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2015 (English)In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 262, no 9, p. 2154-2163Article in journal (Refereed) Published
Abstract [en]

The aim of the study was to compare the efficacy of olfactory testing and presynaptic dopamine imaging in diagnosing Parkinsons disease (PD) and atypical parkinsonian syndromes (APS); to evaluate if the combination of these two diagnostic tools can improve their diagnostic value. A prospective investigation of 24 PD patients, 16 APS patients and 15 patients with non-parkinsonian syndromes was performed during an 18-month period. Single photon emission computed tomography with the presynaptic radioligand I-123-FP-CIT (DaTSCAN (R)) and olfactory testing with the Brief 12-item Smell Identification Test (B-SIT) were performed in all patients. DaTSCAN was analysed semi-quantitatively, by calculating two different striatal uptake ratios, and visually according to a predefined ranking scale. B-SIT score was significantly lower for PD patients, but not significantly different between APS and non-parkinsonism. The visual assessment of DaTSCAN had higher sensitivity, specificity and diagnostic accuracy compared to olfactory testing. Most PD patients (75 %) had visually predominant dopamine depletion in putamen, while most APS patients (56 %) had visually severe dopamine depletion both in putamen and in caudate nucleus. The combination of DaTSCAN and B-SIT led to a higher rate of correctly classified patients. Olfactory testing can distinguish PD from non-parkinsonism, but not PD from APS or APS from non-parkinsonism. DaTSCAN is more efficient than olfactory testing and can be valuable in differentiating PD from APS. However, combining olfactory testing and DaTSCAN imaging has a higher predictive value than these two methods separately.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2015
Keywords
Parkinsons disease; Atypical parkinsonism; Parkinsonian syndromes; Olfaction; I-123-FP-CIT SPECT
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-122669 (URN)10.1007/s00415-015-7830-4 (DOI)000363035400018 ()26122543 (PubMedID)
Note

Funding Agencies|Ostergotland County Council (ALF); Swedish Parkinsons Foundation

Available from: 2015-11-16 Created: 2015-11-13 Last updated: 2019-03-05Bibliographically approved
Davidsson, A., Georgiopoulos, C., Dizdar Segrell, N., Granerus, G. & Zachrisson, H. (2014). Comparison between visual assessment of dopaminergic degeneration pattern and semi-quantitative ratio calculations in patients with Parkinson's disease and Atypical Parkinsonian snydromes using DaTSCAN SPECT. In: : . Paper presented at Annaul Congress of the European Assocation of Nuclerar Medicine, Gothenburg, Sweden, October 18-22, 2014 (pp. P921). European Assocation of Nuclerar Medicine
Open this publication in new window or tab >>Comparison between visual assessment of dopaminergic degeneration pattern and semi-quantitative ratio calculations in patients with Parkinson's disease and Atypical Parkinsonian snydromes using DaTSCAN SPECT
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2014 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Background: Parkinson's disease (PD) is a degenerative disorder characterized by the progressive degeneration of dopamine-containing cells in substantia nigra, and it is the second most common neurodegenerative disorder worldwide. It can be difficult to differentiate between idiopathic PD and Atypical Parkinsonian syndromes (APS). In a high percentage of APS patients, the right diagnosis is not established even during late stages of the disease. Currently there is no specific test to verify PD, especially in the early stages of the disease.

The aim was to verify if 123I-FP-CIT, DaTSCAN ® can differentiate early stages of Parkinson's disease as well as patients with Atypical Parkinsonian syndromes from manifest Parkinson's disease.

Materials and methods: 121 consecutive patients were investigated with 123I-FP-CIT SPECT, during a four year period. All patients were diagnosed according to the established consensus criteria for diagnosis of Parkinson's disease (PD), (n=53), Atypical Parkinsonian syndromes (APS) (n=18). Remaining patients were grouped early PD (before onset the of L-dopa medication), (n=20), and non-PD syndromes (n=30). SPECT images were analysed visually according to a predefined ranking scale of dopaminergic degeneration, distinguishing a posterior-anterior degeneration pattern (egg shape) to a more global and severe degeneration pattern (burst striatum). Striatum ratios were quantitatively analysed with the 3D software, EXINI.

Results: In the group of APS patients the burst striatum pattern was most frequent and found in 61% (11/18 patients). In PD patients the egg shape pattern was dominating, especially in early PD where it was present in 95% (19/20 patients). The sensitivity of burst striatum degeneration pattern was 61% (95%-CI 36-83%), specificity 90% (95%-CI 81-96%). The sensitivity of egg shape pattern was 74% (95%-CI 62-84%), specificity 90% (95%-CI 47-90%). The uptake ratios were reduced in both PD and APS patients and closely related to the image pattern. The lowest putamen/caudate ratio was found in early PD.

Conclusion: In this study we found that in more than half of the patients it was possible to differentiate between PD and APS by visual interpretation only. Similar results were obtained using semi-quantitative uptake ratios, but combining visual assessment with uptake ratios did not add to the discriminating power of DATSCAN ® SPECT in this material

References: Kahraman D, Eggers C, Schicha H, Timmermann L, Schmidt M. Visual assessment of dopaminergic degeneration pattern in 123I-FP-CIT SPECT differentiates patients with atypical parkinsonian syndromes and idiopathic Parkinson's disease. J Neurol. 2012;259:251-60

Place, publisher, year, edition, pages
European Assocation of Nuclerar Medicine, 2014
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-113418 (URN)
Conference
Annaul Congress of the European Assocation of Nuclerar Medicine, Gothenburg, Sweden, October 18-22, 2014
Available from: 2015-01-19 Created: 2015-01-19 Last updated: 2018-01-12Bibliographically approved
Davidsson, A., Georgiopoulos, C., Dizdar (Dizdar Segrell), N., Granerus, G. & Zachrisson, H. (2014). Comparison between visual assessment of dopaminergic degeneration pattern and semi-quantitative ratio calculations in patients with Parkinsons disease and Atypical Parkinsonian syndromes using DaTSCAN (R) SPECT. Paper presented at The Japanese Society of Nuclear Medicine 2014. Annals of Nuclear Medicine, 28(9), 851-859
Open this publication in new window or tab >>Comparison between visual assessment of dopaminergic degeneration pattern and semi-quantitative ratio calculations in patients with Parkinsons disease and Atypical Parkinsonian syndromes using DaTSCAN (R) SPECT
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2014 (English)In: Annals of Nuclear Medicine, ISSN 0914-7187, E-ISSN 1864-6433, Vol. 28, no 9, p. 851-859Article in journal (Refereed) Published
Abstract [en]

Objective To verify if I-123-FP-CIT, DaTSCAN (R) can differentiate early stages of Parkinsons disease (PD) as well as patients with Atypical Parkinsonian syndromes (APS) from manifest Parkinsons disease. Methods 128 consecutive patients were investigated with I-123-FP-CIT SPECT during a 4-year period. All patients were diagnosed according to the established consensus criteria for diagnosis of PD (n = 53) and APS (n = 19). Remaining patients were grouped early PD (before onset of L-DOPA medication), (n = 20), vascular PD (n = 6), and non-PD syndromes (n = 30) and SWEDD (n = 1). SPECT images were analyzed visually according to a predefined ranking scale of dopaminergic nerve cell degeneration, distinguishing a posterior-anterior degeneration pattern (egg shape) from a more global and severe degeneration pattern (burst striatum). Striatum uptake ratios were quantitatively analyzed with the 3D software, EXINI. Results In the group of APS patients, the burst striatum pattern was most frequent and found in 61 % (11/18 patients). In PD patients, the egg shape pattern was dominating, especially in early PD where it was present in 95 % (19/20 patients). The positive predictive value for the egg shape pattern to diagnose PD was 92 % in this material (APS and all PD patients) and the specificity 90 % for the burst striatum pattern to exclude APS. The uptake ratios were reduced in both PD and APS patients and closely related to the image ranking. Conclusion In this study, we found that in more than half of the patients it was possible to differentiate between PD and APS by visual interpretation only. Similar results were obtained using semi-quantitative uptake ratios. Combining visual assessment with uptake ratios did not add to the discriminating power of DaTSCAN (R) SPECT in this material.

Place, publisher, year, edition, pages
Springer Verlag (Germany), 2014
Keywords
I-123-FP-CIT SPECT; Parkinsons disease (PD); Early stage of PD; Atypical Parkinsonian syndromes; Semi-quantitative evaluation; Visual pattern assessment
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-113060 (URN)10.1007/s12149-014-0878-x (DOI)000345400100003 ()24997753 (PubMedID)
Conference
The Japanese Society of Nuclear Medicine 2014
Available from: 2015-01-09 Created: 2015-01-08 Last updated: 2018-01-12
Georgiopoulos, C., Davidsson, A., Granerus, G., Dizdar (Dizdar Segrell), N. & Zachrisson, H. (2011). DaTSCAN SPECT EVALUATION OF PATIENTS WITH MOVEMENT DISORDERS. In: EUROPEAN JOURNAL OF NEUROLOGY: . Paper presented at 15th Congress of the European-Federation-of-Neurological-Societies (EFNS), Budapest, Hungary, September 10-13, 2011 (pp. 567-567). Wiley-Blackwell, 18 (Suppl. 2)(SI), Article ID P2617.
Open this publication in new window or tab >>DaTSCAN SPECT EVALUATION OF PATIENTS WITH MOVEMENT DISORDERS
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2011 (English)In: EUROPEAN JOURNAL OF NEUROLOGY, Wiley-Blackwell, 2011, Vol. 18 (Suppl. 2), no SI, p. 567-567, article id P2617Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Introduction: Molecular imaging with DaTSCAN SPECTis widely used as a diagnostic tool in patients with movementdisorders in the form of Parkinson's Disease (PD),Parkinson-plus syndromes and Tremor. In the present studythe potency of DATScan SPECT to detect degeneration inthe basal ganglia in early stages of PD, before the onset ofmedication, is evaluated. In addition the efficacy ofDaTSCAN for differential diagnosis between patients withidiopathic PD and patients with Parkinson-plus syndromesis examined.

Methodology: Participants: 21 patients with PD in earlystages, before the onset of medication, 20 patients withidiopathic PD and 6 patients with Parkinson-plussyndromes. 15 participants with normal results ofDaTSCAN SPECT and a clinical diagnosis different fromPD or Parkinson-plus were used as control.

DaTSCAN SPECT: In the present study the quantificationof Striatum Occipital/Occipital and the Xeleris workstation(GE) were used.

Results: The quantification for patients with idiopathic PD(1.185±0.05687) was significantly lower (p<0.0001) fromthe control (2.369±0.1258) and significantly lower (p<0.05)from that of patients in early stages of PD, before the onsetof medication (1.359±0.05324). There was no significantdifference between the idiopathic PD and Parkinson-plussyndromes (1.103±0.2442).

Conclusion: DaTSCAN SPECT can detect efficiently earlydegeneration in the basal ganglia before the onset ofmedication is needed. Its efficacy for the differentialdiagnosis between idiopathic PD and Parkinson-plussyndromes is questioned. The combination of imaging andclinical examination is mandatory for a certain diagnosis.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2011
Series
European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-71081 (URN)10.1111/j.1468-1331.2011.03552.x (DOI)000294806601394 ()
Conference
15th Congress of the European-Federation-of-Neurological-Societies (EFNS), Budapest, Hungary, September 10-13, 2011
Available from: 2011-09-30 Created: 2011-09-30 Last updated: 2018-01-12Bibliographically approved
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