Assessment of dopamine metabolism in brain of patients with dementia by means of18F-fluorodopa and PET
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By means of positron emission tomography (PET) and18F-fluorodopa (FDOPA), a study was initiated to analyze the cerebral dopamine (DA) metabolism of 32 subjects including those with AD/ SDAT and vascular dementia (VD, multi-infarct type). A semiautomated irregular ROI drawing routine to identify the striatum was developed that interactively defined the PET threshold pixels referring to the count histograms and location of the corresponding pixels. A comparative study by five examiners showed significant improvement in the area size definition and count linearity particularly for low contrast objects. The graphical plot was employed to calculate the FDOPA influx rate (Ki) for the ROI data with cerebellar radioactivity as an input function. The striatal Ki value was found to be relatively stable and did not show signs of a significant age-related change. The vascular patients had smaller Ki to the striatum than the aged control. Although the mean Ki of AD/SDAT was almost compatible with that of age-matched normals, their Ki was more scattered with higher and lower Ki cases. The multiple regression analysis revealed that the Ki could be predicted by age and the mini-mental state (MMS) performance (r2 = 0.590, p < 0.01 for AD/ SDAT, r2 = 0.401, and p < 0.05 for VD). MMS was found to be a more dominant factor than age. We conclude that dopamine metabolism became disturbed as dementia became progressively severe.
Key wordsNeurotransmission PET dementia DOPA metabolism
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- 1.Scatton B, Zivkovic B. Neuroleptics and the limbic system.In Psychopharmacology of the limbic system. Trimble MR & Zarifian E (eds.), Oxford, Oxford University Press, pp. 174–197, 1984.Google Scholar
- 2.Salamone JD. Behavioral pharmacology of dopamine system: a new synthesis.In The mesolimbic dopamine system: from motivation to action. Willner P, Scheel Krueger J (eds.), Chichester, John Wiley & Sons, pp. 599–614, 1991.Google Scholar
- 7.Adam MJ, Abeysekera B, Ruth TJ, Grierson JR, Pate BD. Synthesis of 6-(F-18)L-fluoro-dopausing F-18 labeled acetyl hypofluorite.J Nucl Med 26: P125, 1985.Google Scholar
- 8.Watanuki S, Ishii K, Orihara H, Fukuda H, Matsuzawa T. Status of multi-ring high-resolution positron emission tomography system PT931. CYRIC Annual Report 1986: 250–244, 1986.Google Scholar
- 9.Patlak CS, Blasberg RG. Graphical evaluation of blood-to-brain transfer constants from multiple-time uptake data. Generalizations.J Cereb Blood Flow Metabol 5: 584–590, 1985.Google Scholar
- 10.Patlak CS, Blasberg RG, Fenstermacher JD. Graphical evaluation of blood-to-brain transfer constants from multiple-time uptake data.J Cereb Blood Flow Metabol 3: 1–7, 1983.Google Scholar
- 11.American Psychiatric Association.Diagnostic and Statistical Manual of Mental Disorders. DSM-III-R. Washington DC, Amer Psychiat Ass, pp. 103–122, 1987.Google Scholar
- 13.Tanaka Y, Tarumizu T.Handbook on Statistics on PC, III. Tokyo, Kyoritsu Shuppan Inc., pp. 1–15, 1986.Google Scholar
- 23.Takikawa S, Dahwan V, Chaly T, Robeson W, Spetsieris P, Eidelberg D. Does striatal FDOPA uptake decrease with age?J Cereb Blood Flow Metab 13: S410, 1993.Google Scholar
- 26.Robins TW. Cognitive deficits in schizophrenia and Parkinson’s disease: Neural basis and the role of dopamine.In the mesolimbic dopamine system: From motivation to action, Willner P, Sheel-Krueger (eds.), Chichester, Jon Wiley & Sons, pp. 497–528, 1991.Google Scholar