title: The effect of dopamine agonist therapy on dopamine transporter imaging in Parkinson's disease.
abstract: Single-photon emission computed tomography (SPECT) imaging with the dopamine transporter ligand, [123I] beta-CIT (2beta-carboxymethoxy-3beta-[4-iodophenyl] tropane), has been proposed as a means of measuring Parkinson's disease (PD) progression. To be useful in this role, however, [123I] beta-CIT imaging should not be influenced by the medications used to treat PD, including the dopamine agonist drugs such as pergolide. We assessed the effect of adjunctive pergolide administration on [123I] beta-CIT uptake in 12 patients with PD, who were being treated with levodopa, initiating pergolide therapy for motor fluctuations. Patients underwent [123I] beta-CIT imaging at baseline, subsequently while on pergolide therapy (6 weeks), and again 4 weeks after pergolide wash-out. Uptake in the striatum was averaged for the two sides and expressed as (striatum - occipital)/occipital, with similar calculations for putamen and caudate. Consistent with PD, the patients' mean striatal and putamen uptake ratios at baseline were significantly less (p <0.001) than the mean values from 26 normal control subjects of similar age. During pergolide treatment, the striatal and putamen [123I] beta-CIT uptake ratios were each statistically similar to baseline, although there was a slight trend toward an increased striatal value (8% higher on pergolide; p = 0.105). Caudate [123I] beta-CIT uptake was 11% higher on pergolide therapy (nominal p = 0.042, but not significant when adjusted for multiple comparisons: p = 0.126). After pergolide wash-out, the striatal, putamen, and caudate uptake ratios did not differ from baseline. Therefore, we found that pergolide therapy did not significantly affect [123I] beta-CIT SPECT imaging but we cannot exclude a small influence.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Ahlskog
authors.forename: R J
authors.initials: RJ
authors.lastname: Uitti
authors.forename: M K
authors.initials: MK
authors.lastname: O'Connor
authors.forename: D M
authors.initials: DM
authors.lastname: Maraganore
authors.forename: J Y
authors.initials: JY
authors.lastname: Matsumoto
authors.forename: K F
authors.initials: KF
authors.lastname: Stark
authors.forename: M F
authors.initials: MF
authors.lastname: Turk
authors.forename: O L
authors.initials: OL
authors.lastname: Burnett
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects*; D001931:Brain Mapping; D002230:Carbidopa / Q000008:administration & dosage / Q000009:adverse effects; D002352:Carrier Proteins / Q000187:drug effects* / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects; D018491:Dopamine Agonists / Q000008:administration & dosage* / Q000009:adverse effects; D050483:Dopamine Plasma Membrane Transport Proteins; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D007980:Levodopa / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009048:Motor Skills / Q000187:drug effects; D009419:Nerve Tissue Proteins; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000188:drug therapy*; D010479:Pergolide / Q000008:administration & dosage* / Q000009:adverse effects; D011699:Putamen / Q000000981:diagnostic imaging / Q000187:drug effects; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D002352:Carrier Proteins; D018491:Dopamine Agonists; D050483:Dopamine Plasma Membrane Transport Proteins; D004338:Drug Combinations; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C009265:carbidopa, levodopa drug combination; D010479:Pergolide; D007980:Levodopa; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine; D002230:Carbidopa