| Autor: |
Chloe, Clark-Papasavas, Joel T, Dunn, Suki, Greaves, Andrew, Mogg, Rosemary, Gomes, Stuart, Brownings, Kathy, Liu, Bonnita, Nwosu, Paul, Marsden, John, Joemon, Marcel, Cleij, Robert, Kessler, Robert, Howard, Suzanne, Reeves |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
International journal of geriatric psychiatry. 29(10) |
| ISSN: |
1099-1166 |
| Popis: |
Dopamine D2/3 receptor positron emission tomography tracers have guided antipsychotic prescribing in young people with schizophrenia by establishing a 'therapeutic window' of striatal D2/3 receptor occupancy. Older people, particularly those with dementia, are highly susceptible to motor side effects and may benefit from the appropriate application of imaging techniques. The study aimed to adapt [18F]fallypride imaging for use in occupancy studies in Alzheimer's disease (AD) and to investigate whether data acquisition could be made more tolerable by piloting the protocol in a small sample.Six participants with AD (three men; 85.0 ± 5.6 years old; MMSE = 16.0 ± 2.4) were recruited prior to commencing amisulpride for the treatment of psychosis and associated agitation. [18F]fallypride binding potential (BPND ) was determined using an interrupted scanning protocol at baseline (n = 6) and after 27.0 ± 6.1 days of amisulpride (25-50 mg) treatment (n = 4). D2/3 occupancy was calculated by percentage reduction in BPND between scanning sessions. Image data were re-analysed after reducing individual sampling times to 20 min.The protocol was tolerated well, apart from the final (40 min) session of the post-treatment scan in one participant. Higher occupancies were achieved in the striatum (caudate 47-70%, putamen 31-58%) and thalamus (54-76%) than in the inferior temporal gyrus (27-43%). There was high agreement between occupancy values derived using longer and shorter sampling times (mean absolute difference 6.1% in the inferior temporal gyrus;2% all other regions).The protocol is feasible for use in AD and represents the first step towards establishing dose-occupancy relationships across older clinical populations. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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