Cholinesterase inhibitor use does not significantly influence the ability of 123I-FP-CIT imaging to distinguish Alzheimer's disease from dementia with Lewy bodies.
BACKGROUND
123I-labelled 2beta-carbomethoxy-3beta-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) imaging is a diagnostic tool to help differentiate dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). However, in animals, cholinesterase inhibitors (ChEi) have been reported to reduce radioligand binding to the striatal dopamine transporter. As ChEi are frequently used in people with dementia, it is important to determine whether their use affects 123I-FP-CIT uptake in the striatum.


OBJECTIVE
To clarify whether chronic ChEi therapy modulates striatal dopamine transporter binding measured by 123I-FP-CIT in patients with AD, DLB and Parkinson's disease with dementia (PDD).


METHODS
Cross sectional study in 99 patients with AD (nine on ChEi, 25 not on ChEi), DLB (nine on ChEi, 19 not on ChEi) and PDD (six on ChEi, 31 not on ChEi) comparing 123I-FP-CIT striatal binding (caudate, anterior and posterior putamen) in patients receiving compared with those not receiving ChEi, correcting for key clinical variables including diagnosis, age, sex, Mini-Mental State Examination score, severity of parkinsonism and concurrent antidepressant use.


RESULTS
As previously described, 123I-FP-CIT striatal uptake was lower in DLB and PDD subjects compared with those with AD. Median duration of ChEi use was 180 days. 123I-FP-CIT uptake was not significantly reduced in subjects receiving ChEi compared those not receiving ChEi (mean percentage reduction: AD 4.3%; DLB 0.7%; PDD 6.1%; p = 0.40). ChEi use did not differentially affect striatal 123FP-CIT uptake between patient groups (p = 0.83).


CONCLUSIONS
Use of ChEi does not significantly influence the ability of 123I-FP-CIT imaging to distinguish AD from DLB.
Taylor
John-Paul
JP
Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE, UK. john-paul.taylor@ncl.ac.uk
Colloby
Sean J
SJ
McKeith
Ian G
IG
Burn
David J
DJ
Williams
David
D
Patterson
Jim
J
O'Brien
John T
JT
D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D001665:Binding Sites; D002421:Caudate Nucleus / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism / Q000493:pharmacokinetics*; D020961:Lewy Body Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D011699:Putamen / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
D002800:Cholinesterase Inhibitors; D007457:Iodine Radioisotopes; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane