title: False-positive 123I-FP-CIT scintigraphy and suggested dopamine transporter upregulation due to chronic modafinil treatment.
abstract: A 76-year-old man with movement disorder had a I-FP-CIT (DaTSCAN) SPECT exam demonstrating universally decreased striatal uptake. It was later determined that he had taken modafinil, and the scintigraphy was interpreted as false positive. Because of progressive symptoms, DaTSCAN was repeated 43 months later, with modafinil withheld for 7 days. Striatal uptake values were nearly doubled compared with the modafinil state and were now above normal upper limit. This suggests pharmacological upregulation of dopamine transport capacity by chronic modafinil treatment. In this setting, I-FP-CIT striatal uptake values should be interpreted with caution.
authors.affiliation: From the *Department of Nuclear Medicine and PET Centre, and †Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Borghammer
authors.forename: Karoline
authors.initials: K
authors.lastname: Knudsen
authors.forename: Erik
authors.initials: E
authors.lastname: Danielsen
authors.forename: Karen
authors.initials: K
authors.lastname: Østergaard
mesh_terms: D000368:Aged; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D000077408:Modafinil; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D011877:Radionuclide Imaging; D014326:Tropanes; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D001559:Benzhydryl Compounds; D050483:Dopamine Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D000077408:Modafinil